WikiLEC - User contributions [en]

Boost Creep

2013-12-03T20:27:14Z

Ccb056:

'''Boost Creep'''

Boost creep occurs when the wastegate/turbocharger combination is improperly sized and cannot dump enough exhaust gasses. The symptom is rising boost as RPMs rise, sometimes in an uncontrolled fashion. To reduce this effect, either install a larger capacity wastegate, or an exhaust turbine with a higher A/R ratio.

'''Overboost'''

Overboost occurs after boost creep, when the boost pressure reaches a level to signal fuel cutoff.

'''A/R Ratio'''

The ratio of the exhaust inducer nozzle area (A) over the exhaust inducer radius (R; measured from the center of the turbine shaft to the center of the inducer nozzle). This number (usually from about 0.4 to 1.0) gives you an indication as to the tradeoff between lag and high volume efficiency for a given configuration. When the A/R ratio is low, then the small inducer area creates high velocity flow at low volumes, thus improving spin up. A high A/R allows high volumes of gas to flow through the exhaust turbine, making the turbine more efficient at those high volumes, but it will then be sluggish to spin up.

Since A/R ratio is a significant factor in turbo lag, some manufacturers have devised means for varying the A/R ratio to reduce lag while still maintaining high-volume efficiency. Such a scheme properly carried out would eliminate the need for a wastegate, which is indeed the case with the Garrett VNT (Variable Nozzle Turbocharger). The VNT uses adjustable vanes inside the exhaust scroll to change the angle of attack of the incoming gasses as they strike the exhaust turbine.

'''Experimental Data'''

The data shown below is collected via [[ElanScan]] under the following conditions:
# 3rd Gear acceleration (allows for more datapoints than 2nd gear, and safer speeds than 4th gear)
# WOT (Wide Open Throttle)

[http://forum.lotuselancentral.com/viewtopic.php?p=275396#p275396 GeoffSmith's recomendations]

{| class="wikitable"
|-
!  Wastegate  ||  Downpipe  !!  Pre Cat  !!  Main Cat  !!  Diameter  !!  ECU  !!  Ambient Temp  !!  Humidity  !!  Boost Creep  !!  Overboost  !!  WG Duty Cycle  !!  User  !!  Link
|-
| 21 mm || OEM || PCE || NO || 2.50 in || OEM || 0 degC || 56% || 4000 RPM || NO || 0% ||ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=276742#p276742 OEM ECU]
|-
| 21 mm || OEM || PCE || NO || 2.50 in || Everest || 5 degC || 91% || NO || NO || 0% || ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=277183#p277183 Everest]
|-
| OEM || Piper || N/A || Piper Sports || 2.25 in || Mountain || ... || ... || YES || YES || ... || paulsmithmk || [http://forum.lotuselancentral.com/viewtopic.php?f=36&t=19191&start=200 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=270471#p270471 overboost]
|-
| 20 mm || Piper || N/A || ... || 2.00 in || OEM || ... || ... || YES || YES || ... || Steve A || [http://forum.lotuselancentral.com/viewtopic.php?p=275311#p275311 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=275298#p275298 overboost]
|-
| OEM || Piper || N/A || NO || 2.25 in || OEM || ... || ... || YES || YES || ... || cliff || [http://forum.lotuselancentral.com/viewtopic.php?p=275329#p275329 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=275333#p275333 no cat]
|-
| 21.5 mm || Piper || N/A || NO || 2.25 in || Everest || ... || ... || YES || 6500 RPM || ... || HJ2 || [http://forum.lotuselancentral.com/viewtopic.php?p=275570#p275570 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=286695#p286695 port];[http://forum.lotuselancentral.com/viewtopic.php?p=275398#p275398 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=277460#p277460 cured with mods]
|-
| 21 mm || Knox || N/A || NO || 2.25 || Everest || ... || ... || NO || NO || ... || steve matthews || [http://forum.lotuselancentral.com/viewtopic.php?p=286488#p286488 specs]
|-
| Ported || OEM || PCE || ... || 2.25 || Everest || ... || ... || NO || NO || ... || dapinky || [http://forum.lotuselancentral.com/viewtopic.php?p=286495#p286495 specs]
|-
| 22 mm || OEM || PCE || NO || 2.50 || ... || ... || ... || NO || NO || ... || Peter_W || [http://forum.lotuselancentral.com/viewtopic.php?p=286712#p286712 specs]
|-
| 21.5 mm || Piper || N/A || OEM || OEM || OEM || ... || ... || NO || NO || 70% || BDC Peter || [http://forum.lotuselancentral.com/viewtopic.php?p=287363#p287363 specs] [http://forum.lotuselancentral.com/viewtopic.php?p=287432#p287432 elanscan]
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|}

Boost Creep

2013-12-02T03:03:07Z

Ccb056:

'''Boost Creep'''

Boost creep occurs when the wastegate/turbocharger combination is improperly sized and cannot dump enough exhaust gasses. The symptom is rising boost as RPMs rise, sometimes in an uncontrolled fashion. To reduce this effect, either install a larger capacity wastegate, or an exhaust turbine with a higher A/R ratio.

'''Overboost'''

Overboost occurs after boost creep, when the boost pressure reaches a level to signal fuel cutoff.

'''A/R Ratio'''

The ratio of the exhaust inducer nozzle area (A) over the exhaust inducer radius (R; measured from the center of the turbine shaft to the center of the inducer nozzle). This number (usually from about 0.4 to 1.0) gives you an indication as to the tradeoff between lag and high volume efficiency for a given configuration. When the A/R ratio is low, then the small inducer area creates high velocity flow at low volumes, thus improving spin up. A high A/R allows high volumes of gas to flow through the exhaust turbine, making the turbine more efficient at those high volumes, but it will then be sluggish to spin up.

Since A/R ratio is a significant factor in turbo lag, some manufacturers have devised means for varying the A/R ratio to reduce lag while still maintaining high-volume efficiency. Such a scheme properly carried out would eliminate the need for a wastegate, which is indeed the case with the Garrett VNT (Variable Nozzle Turbocharger). The VNT uses adjustable vanes inside the exhaust scroll to change the angle of attack of the incoming gasses as they strike the exhaust turbine.

'''Experimental Data'''

The data shown below is collected via [[ElanScan]] under the following conditions:
# 3rd Gear acceleration (allows for more datapoints than 2nd gear, and safer speeds than 4th gear)
# WOT (Wide Open Throttle)

[http://forum.lotuselancentral.com/viewtopic.php?p=275396#p275396 GeoffSmith's recomendations]

{| class="wikitable"
|-
!  Wastegate  ||  Downpipe  !!  Pre Cat  !!  Main Cat  !!  Diameter  !!  ECU  !!  Ambient Temp  !!  Humidity  !!  Boost Creep  !!  Overboost  !!  WG Duty Cycle  !!  User  !!  Link
|-
| 21 mm || OEM || PCE || NO || 2.50 in || OEM || 0 degC || 56% || 4000 RPM || NO || 0% ||ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=276742#p276742 OEM ECU]
|-
| 21 mm || OEM || PCE || NO || 2.50 in || Everest || 5 degC || 91% || NO || NO || 0% || ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=277183#p277183 Everest]
|-
| OEM || Piper || N/A || Piper Sports || 2.25 in || Mountain || ... || ... || YES || YES || ... || paulsmithmk || [http://forum.lotuselancentral.com/viewtopic.php?f=36&t=19191&start=200 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=270471#p270471 overboost]
|-
| 20 mm || Piper || N/A || ... || 2.00 in || OEM || ... || ... || YES || YES || ... || Steve A || [http://forum.lotuselancentral.com/viewtopic.php?p=275311#p275311 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=275298#p275298 overboost]
|-
| OEM || Piper || N/A || NO || 2.25 in || OEM || ... || ... || YES || YES || ... || cliff || [http://forum.lotuselancentral.com/viewtopic.php?p=275329#p275329 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=275333#p275333 no cat]
|-
| 21.5 mm || Piper || N/A || NO || 2.25 in || Everest || ... || ... || YES || 6500 RPM || ... || HJ2 || [http://forum.lotuselancentral.com/viewtopic.php?p=275570#p275570 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=286695#p286695 port];[http://forum.lotuselancentral.com/viewtopic.php?p=275398#p275398 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=277460#p277460 cured with mods]
|-
| 21 mm || Knox || N/A || NO || 2.25 || Everest || ... || ... || NO || NO || ... || steve matthews || [http://forum.lotuselancentral.com/viewtopic.php?p=286488#p286488 specs]
|-
| Ported || OEM || PCE || ... || 2.25 || Everest || ... || ... || NO || NO || ... || dapinky || [http://forum.lotuselancentral.com/viewtopic.php?p=286495#p286495 specs]
|-
| 22 mm || OEM || PCE || NO || 2.50 || ... || ... || ... || NO || NO || ... || Peter_W || [http://forum.lotuselancentral.com/viewtopic.php?p=286712#p286712 specs]
|-
| 21.5 mm || Piper || N/A || OEM || OEM || OEM || ... || ... || NO || NO || 70% || peter || [http://forum.lotuselancentral.com/viewtopic.php?p=287363#p287363 specs]
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|}

Boost Creep

2013-11-25T21:00:28Z

Ccb056:

'''Boost Creep'''

Boost creep occurs when the wastegate/turbocharger combination is improperly sized and cannot dump enough exhaust gasses. The symptom is rising boost as RPMs rise, sometimes in an uncontrolled fashion. To reduce this effect, either install a larger capacity wastegate, or an exhaust turbine with a higher A/R ratio.

'''Overboost'''

Overboost occurs after boost creep, when the boost pressure reaches a level to signal fuel cutoff.

'''A/R Ratio'''

The ratio of the exhaust inducer nozzle area (A) over the exhaust inducer radius (R; measured from the center of the turbine shaft to the center of the inducer nozzle). This number (usually from about 0.4 to 1.0) gives you an indication as to the tradeoff between lag and high volume efficiency for a given configuration. When the A/R ratio is low, then the small inducer area creates high velocity flow at low volumes, thus improving spin up. A high A/R allows high volumes of gas to flow through the exhaust turbine, making the turbine more efficient at those high volumes, but it will then be sluggish to spin up.

Since A/R ratio is a significant factor in turbo lag, some manufacturers have devised means for varying the A/R ratio to reduce lag while still maintaining high-volume efficiency. Such a scheme properly carried out would eliminate the need for a wastegate, which is indeed the case with the Garrett VNT (Variable Nozzle Turbocharger). The VNT uses adjustable vanes inside the exhaust scroll to change the angle of attack of the incoming gasses as they strike the exhaust turbine.

'''Experimental Data'''

The data shown below is collected via [[ElanScan]] under the following conditions:
# 3rd Gear acceleration (allows for more datapoints than 2nd gear, and safer speeds than 4th gear)
# WOT (Wide Open Throttle)

[http://forum.lotuselancentral.com/viewtopic.php?p=275396#p275396 GeoffSmith's recomendations]

{| class="wikitable"
|-
!  Wastegate  ||  Downpipe  !!  Pre Cat  !!  Main Cat  !!  Diameter  !!  ECU  !!  Ambient Temp  !!  Humidity  !!  Boost Creep  !!  Overboost  !!  WG Duty Cycle  !!  User  !!  Link
|-
| 21 mm || OEM || PCE || NO || 2.50 in || OEM || 0 degC || 56% || 4000 RPM || NO || 0% ||ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=276742#p276742 OEM ECU]
|-
| 21 mm || OEM || PCE || NO || 2.50 in || Everest || 5 degC || 91% || NO || NO || 0% || ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=277183#p277183 Everest]
|-
| OEM || Piper || N/A || Piper Sports || 2.25 in || Mountain || ... || ... || YES || YES || ... || paulsmithmk || [http://forum.lotuselancentral.com/viewtopic.php?f=36&t=19191&start=200 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=270471#p270471 overboost]
|-
| 20 mm || Piper || N/A || ... || 2.00 in || OEM || ... || ... || YES || YES || ... || Steve A || [http://forum.lotuselancentral.com/viewtopic.php?p=275311#p275311 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=275298#p275298 overboost]
|-
| OEM || Piper || N/A || NO || 2.25 in || OEM || ... || ... || YES || YES || ... || cliff || [http://forum.lotuselancentral.com/viewtopic.php?p=275329#p275329 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=275333#p275333 no cat]
|-
| 21.5 mm || Piper || N/A || NO || 2.25 in || Everest || ... || ... || YES || 6500 RPM || ... || HJ2 || [http://forum.lotuselancentral.com/viewtopic.php?p=275570#p275570 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=286695#p286695 port];[http://forum.lotuselancentral.com/viewtopic.php?p=275398#p275398 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=277460#p277460 cured with mods]
|-
| 21 mm || Knox || N/A || NO || 2.25 || Everest || ... || ... || NO || NO || ... || steve matthews || [http://forum.lotuselancentral.com/viewtopic.php?p=286488#p286488 specs]
|-
| Ported || OEM || PCE || ... || 2.25 || Everest || ... || ... || NO || NO || ... || dapinky || [http://forum.lotuselancentral.com/viewtopic.php?p=286495#p286495 specs]
|-
| 22 mm || OEM || PCE || NO || 2.50 || ... || ... || ... || NO || NO || ... || Peter_W || [http://forum.lotuselancentral.com/viewtopic.php?p=286712#p286712 specs]
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|}

Boost Creep

2013-11-03T18:37:49Z

Ccb056:

'''Boost Creep'''

Boost creep occurs when the wastegate/turbocharger combination is improperly sized and cannot dump enough exhaust gasses. The symptom is rising boost as RPMs rise, sometimes in an uncontrolled fashion. To reduce this effect, either install a larger capacity wastegate, or an exhaust turbine with a higher A/R ratio.

'''Overboost'''

Overboost occurs after boost creep, when the boost pressure reaches a level to signal fuel cutoff.

'''A/R Ratio'''

The ratio of the exhaust inducer nozzle area (A) over the exhaust inducer radius (R; measured from the center of the turbine shaft to the center of the inducer nozzle). This number (usually from about 0.4 to 1.0) gives you an indication as to the tradeoff between lag and high volume efficiency for a given configuration. When the A/R ratio is low, then the small inducer area creates high velocity flow at low volumes, thus improving spin up. A high A/R allows high volumes of gas to flow through the exhaust turbine, making the turbine more efficient at those high volumes, but it will then be sluggish to spin up.

Since A/R ratio is a significant factor in turbo lag, some manufacturers have devised means for varying the A/R ratio to reduce lag while still maintaining high-volume efficiency. Such a scheme properly carried out would eliminate the need for a wastegate, which is indeed the case with the Garrett VNT (Variable Nozzle Turbocharger). The VNT uses adjustable vanes inside the exhaust scroll to change the angle of attack of the incoming gasses as they strike the exhaust turbine.

'''Experimental Data'''

The data shown below is collected via [[ElanScan]] under the following conditions:
# 3rd Gear acceleration (allows for more datapoints than 2nd gear, and safer speeds than 4th gear)
# WOT (Wide Open Throttle)

[http://forum.lotuselancentral.com/viewtopic.php?p=275396#p275396 GeoffSmith's recomendations]

{| class="wikitable"
|-
!  Wastegate  ||  Downpipe  !!  Pre Cat  !!  Main Cat  !!  Diameter  !!  ECU  !!  Ambient Temp  !!  Humidity  !!  Boost Creep  !!  Overboost  !!  WG Duty Cycle  !!  User  !!  Link
|-
| 21 mm || OEM || PCE || NO || 2.50 in || OEM || 0 degC || 56% || 4000 RPM || NO || 0% ||ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=276742#p276742 OEM ECU]
|-
| 21 mm || OEM || PCE || NO || 2.50 in || Everest || 5 degC || 91% || NO || NO || 0% || ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=277183#p277183 Everest]
|-
| OEM || Piper || N/A || Piper Sports || 2.25 in || Mountain || ... || ... || YES || YES || ... || paulsmithmk || [http://forum.lotuselancentral.com/viewtopic.php?f=36&t=19191&start=200 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=270471#p270471 overboost]
|-
| 20 mm || Piper || N/A || ... || 2.00 in || OEM || ... || ... || YES || YES || ... || Steve A || [http://forum.lotuselancentral.com/viewtopic.php?p=275311#p275311 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=275298#p275298 overboost]
|-
| OEM || Piper || N/A || NO || 2.25 in || OEM || ... || ... || YES || YES || ... || cliff || [http://forum.lotuselancentral.com/viewtopic.php?p=275329#p275329 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=275333#p275333 no cat]
|-
| 20.5 mm || Piper || N/A || NO || 2.25 in || Everest || ... || ... || YES || 6500 RPM || ... || HJ2 || [http://forum.lotuselancentral.com/viewtopic.php?p=275570#p275570 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=276086#p276086 port];[http://forum.lotuselancentral.com/viewtopic.php?p=275398#p275398 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=277460#p277460 cured with mods]
|-
| 21 mm || Knox || N/A || NO || 2.25 || Everest || ... || ... || NO || NO || ... || steve matthews || [http://forum.lotuselancentral.com/viewtopic.php?p=286488#p286488 specs]
|-
| Ported || OEM || PCE || ... || 2.25 || Everest || ... || ... || NO || NO || ... || dapinky || [http://forum.lotuselancentral.com/viewtopic.php?p=286495#p286495 specs]
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|}

Boost Creep

2013-11-03T18:35:31Z

Ccb056:

'''Boost Creep'''

Boost creep occurs when the wastegate/turbocharger combination is improperly sized and cannot dump enough exhaust gasses. The symptom is rising boost as RPMs rise, sometimes in an uncontrolled fashion. To reduce this effect, either install a larger capacity wastegate, or an exhaust turbine with a higher A/R ratio.

'''Overboost'''

Overboost occurs after boost creep, when the boost pressure reaches a level to signal fuel cutoff.

'''A/R Ratio'''

The ratio of the exhaust inducer nozzle area (A) over the exhaust inducer radius (R; measured from the center of the turbine shaft to the center of the inducer nozzle). This number (usually from about 0.4 to 1.0) gives you an indication as to the tradeoff between lag and high volume efficiency for a given configuration. When the A/R ratio is low, then the small inducer area creates high velocity flow at low volumes, thus improving spin up. A high A/R allows high volumes of gas to flow through the exhaust turbine, making the turbine more efficient at those high volumes, but it will then be sluggish to spin up.

Since A/R ratio is a significant factor in turbo lag, some manufacturers have devised means for varying the A/R ratio to reduce lag while still maintaining high-volume efficiency. Such a scheme properly carried out would eliminate the need for a wastegate, which is indeed the case with the Garrett VNT (Variable Nozzle Turbocharger). The VNT uses adjustable vanes inside the exhaust scroll to change the angle of attack of the incoming gasses as they strike the exhaust turbine.

'''Experimental Data'''

The data shown below is collected via [[ElanScan]] under the following conditions:
# 3rd Gear acceleration (allows for more datapoints than 2nd gear, and safer speeds than 4th gear)
# WOT (Wide Open Throttle)

[http://forum.lotuselancentral.com/viewtopic.php?p=275396#p275396 GeoffSmith's recomendations]

{| class="wikitable"
|-
!  Wastegate  ||  Downpipe  !!  Pre Cat  !!  Main Cat  !!  Diameter  !!  ECU  !!  Ambient Temp  !!  Humidity  !!  Boost Creep  !!  Overboost  !!  WG Duty Cycle  !!  User  !!  Link
|-
| 21 mm || OEM || PCE || NO || 2.50 in || OEM || 0 degC || 56% || 4000 RPM || NO || 0% ||ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=276742#p276742 OEM ECU]
|-
| 21 mm || OEM || PCE || NO || 2.50 in || Everest || 5 degC || 91% || NO || NO || 0% || ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=277183#p277183 Everest]
|-
| OEM || Piper || N/A || Piper Sports || 2.25 in || Mountain || ... || ... || YES || YES || ... || paulsmithmk || [http://forum.lotuselancentral.com/viewtopic.php?f=36&t=19191&start=200 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=270471#p270471 overboost]
|-
| 20 mm || Piper || N/A || ... || 2.00 in || OEM || ... || ... || YES || YES || ... || Steve A || [http://forum.lotuselancentral.com/viewtopic.php?p=275311#p275311 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=275298#p275298 overboost]
|-
| OEM || Piper || N/A || NO || 2.25 in || OEM || ... || ... || YES || YES || ... || cliff || [http://forum.lotuselancentral.com/viewtopic.php?p=275329#p275329 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=275333#p275333 no cat]
|-
| 20.5 mm || Piper || N/A || NO || 2.25 in || Everest || ... || ... || YES || 6500 RPM || ... || HJ2 || [http://forum.lotuselancentral.com/viewtopic.php?p=275570#p275570 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=276086#p276086 port];[http://forum.lotuselancentral.com/viewtopic.php?p=275398#p275398 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=277460#p277460 cured with mods]
|-
| 21 mm || Knox || N/A || NO || 2.25 || Everest || ... || ... || NO || NO || ... || steve matthews || [http://forum.lotuselancentral.com/viewtopic.php?p=286488#p286488 specs]
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|}

Boost Creep

2013-11-03T18:35:15Z

Ccb056:

'''Boost Creep'''

Boost creep occurs when the wastegate/turbocharger combination is improperly sized and cannot dump enough exhaust gasses. The symptom is rising boost as RPMs rise, sometimes in an uncontrolled fashion. To reduce this effect, either install a larger capacity wastegate, or an exhaust turbine with a higher A/R ratio.

'''Overboost'''

Overboost occurs after boost creep, when the boost pressure reaches a level to signal fuel cutoff.

'''A/R Ratio'''

The ratio of the exhaust inducer nozzle area (A) over the exhaust inducer radius (R; measured from the center of the turbine shaft to the center of the inducer nozzle). This number (usually from about 0.4 to 1.0) gives you an indication as to the tradeoff between lag and high volume efficiency for a given configuration. When the A/R ratio is low, then the small inducer area creates high velocity flow at low volumes, thus improving spin up. A high A/R allows high volumes of gas to flow through the exhaust turbine, making the turbine more efficient at those high volumes, but it will then be sluggish to spin up.

Since A/R ratio is a significant factor in turbo lag, some manufacturers have devised means for varying the A/R ratio to reduce lag while still maintaining high-volume efficiency. Such a scheme properly carried out would eliminate the need for a wastegate, which is indeed the case with the Garrett VNT (Variable Nozzle Turbocharger). The VNT uses adjustable vanes inside the exhaust scroll to change the angle of attack of the incoming gasses as they strike the exhaust turbine.

'''Experimental Data'''

The data shown below is collected via [[ElanScan]] under the following conditions:
# 3rd Gear acceleration (allows for more datapoints than 2nd gear, and safer speeds than 4th gear)
# WOT (Wide Open Throttle)

[http://forum.lotuselancentral.com/viewtopic.php?p=275396#p275396 GeoffSmith's recomendations]

{| class="wikitable"
|-
!  Wastegate  ||  Downpipe  !!  Pre Cat  !!  Main Cat  !!  Diameter  !!  ECU  !!  Ambient Temp  !!  Humidity  !!  Boost Creep  !!  Overboost  !!  WG Duty Cycle  !!  User  !!  Link
|-
| 21 mm || OEM || PCE || NO || 2.50 in || OEM || 0 degC || 56% || 4000 RPM || NO || 0% ||ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=276742#p276742 OEM ECU]
|-
| 21 mm || OEM || PCE || NO || 2.50 in || Everest || 5 degC || 91% || NO || NO || 0% || ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=277183#p277183 Everest]
|-
| OEM || Piper || N/A || Piper Sports || 2.25 in || Mountain || ... || ... || YES || YES || ... || paulsmithmk || [http://forum.lotuselancentral.com/viewtopic.php?f=36&t=19191&start=200 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=270471#p270471 overboost]
|-
| 20 mm || Piper || N/A || ... || 2.00 in || OEM || ... || ... || YES || YES || ... || Steve A || [http://forum.lotuselancentral.com/viewtopic.php?p=275311#p275311 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=275298#p275298 overboost]
|-
| OEM || Piper || N/A || NO || 2.25 in || OEM || ... || ... || YES || YES || ... || cliff || [http://forum.lotuselancentral.com/viewtopic.php?p=275329#p275329 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=275333#p275333 no cat]
|-
| 20.5 mm || Piper || N/A || NO || 2.25 in || Everest || ... || ... || YES || 6500 RPM || ... || HJ2 || [http://forum.lotuselancentral.com/viewtopic.php?p=275570#p275570 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=276086#p276086 port];[http://forum.lotuselancentral.com/viewtopic.php?p=275398#p275398 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=277460#p277460 cured with mods]
|-
| 21 mm || Knox || N/A || NO || 2.25 || Everest || ... || ... || NO || NO || ... || steve matthews || [http://forum.lotuselancentral.com/viewtopic.php?p=286488#p286488 stats]
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|-
| ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ... || ...
|}

Boost Creep

2013-11-03T18:27:11Z

Ccb056:

'''Boost Creep'''

Boost creep occurs when the wastegate/turbocharger combination is improperly sized and cannot dump enough exhaust gasses. The symptom is rising boost as RPMs rise, sometimes in an uncontrolled fashion. To reduce this effect, either install a larger capacity wastegate, or an exhaust turbine with a higher A/R ratio.

'''Overboost'''

Overboost occurs after boost creep, when the boost pressure reaches a level to signal fuel cutoff.

'''A/R Ratio'''

The ratio of the exhaust inducer nozzle area (A) over the exhaust inducer radius (R; measured from the center of the turbine shaft to the center of the inducer nozzle). This number (usually from about 0.4 to 1.0) gives you an indication as to the tradeoff between lag and high volume efficiency for a given configuration. When the A/R ratio is low, then the small inducer area creates high velocity flow at low volumes, thus improving spin up. A high A/R allows high volumes of gas to flow through the exhaust turbine, making the turbine more efficient at those high volumes, but it will then be sluggish to spin up.

Since A/R ratio is a significant factor in turbo lag, some manufacturers have devised means for varying the A/R ratio to reduce lag while still maintaining high-volume efficiency. Such a scheme properly carried out would eliminate the need for a wastegate, which is indeed the case with the Garrett VNT (Variable Nozzle Turbocharger). The VNT uses adjustable vanes inside the exhaust scroll to change the angle of attack of the incoming gasses as they strike the exhaust turbine.

'''Experimental Data'''

The data shown below is collected via [[ElanScan]] under the following conditions:
# 3rd Gear acceleration (allows for more datapoints than 2nd gear, and safer speeds than 4th gear)
# WOT (Wide Open Throttle)

[http://forum.lotuselancentral.com/viewtopic.php?p=275396#p275396 GeoffSmith's recomendations]

{| class="wikitable"
|-
!  Wastegate  ||  Downpipe  !!  Pre Cat  !!  Main Cat  !!  Diameter  !!  ECU  !!  Ambient Temp  !!  Humidity  !!  Boost Creep  !!  Overboost  !!  WG Duty Cycle  !!  User  !!  Link
|-
| 21 mm || OEM || PCE || NO || 2.50 in || OEM || 0 degC || 56% || 4000 RPM || NO || 0% ||ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=276742#p276742 OEM ECU]
|-
| 21 mm || OEM || PCE || NO || 2.50 in || Everest || 5 degC || 91% || NO || NO || 0% || ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=277183#p277183 Everest]
|-
| OEM || Piper || N/A || Piper Sports || 2.25 in || Mountain || ... || ... || YES || YES || ... || paulsmithmk || [http://forum.lotuselancentral.com/viewtopic.php?f=36&t=19191&start=200 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=270471#p270471 overboost]
|-
| 20 mm || Piper || N/A || ... || 2.00 in || OEM || ... || ... || YES || YES || ... || Steve A || [http://forum.lotuselancentral.com/viewtopic.php?p=275311#p275311 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=275298#p275298 overboost]
|-
| OEM || Piper || N/A || NO || 2.25 in || OEM || ... || ... || YES || YES || ... || cliff || [http://forum.lotuselancentral.com/viewtopic.php?p=275329#p275329 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=275333#p275333 no cat]
|-
| 20.5 mm || Piper || N/A || NO || 2.25 in || Everest || ... || ... || YES || 6500 RPM || ... || HJ2 || [http://forum.lotuselancentral.com/viewtopic.php?p=275570#p275570 specs];[http://forum.lotuselancentral.com/viewtopic.php?p=276086#p276086 port];[http://forum.lotuselancentral.com/viewtopic.php?p=275398#p275398 overboost];[http://forum.lotuselancentral.com/viewtopic.php?p=277460#p277460 cured with mods]
|}

Boost Creep

2013-11-03T18:25:07Z

Ccb056:

'''Boost Creep'''

Boost creep occurs when the wastegate/turbocharger combination is improperly sized and cannot dump enough exhaust gasses. The symptom is rising boost as RPMs rise, sometimes in an uncontrolled fashion. To reduce this effect, either install a larger capacity wastegate, or an exhaust turbine with a higher A/R ratio.

'''Overboost'''

Overboost occurs after boost creep, when the boost pressure reaches a level to signal fuel cutoff.

'''A/R Ratio'''

The ratio of the exhaust inducer nozzle area (A) over the exhaust inducer radius (R; measured from the center of the turbine shaft to the center of the inducer nozzle). This number (usually from about 0.4 to 1.0) gives you an indication as to the tradeoff between lag and high volume efficiency for a given configuration. When the A/R ratio is low, then the small inducer area creates high velocity flow at low volumes, thus improving spin up. A high A/R allows high volumes of gas to flow through the exhaust turbine, making the turbine more efficient at those high volumes, but it will then be sluggish to spin up.

Since A/R ratio is a significant factor in turbo lag, some manufacturers have devised means for varying the A/R ratio to reduce lag while still maintaining high-volume efficiency. Such a scheme properly carried out would eliminate the need for a wastegate, which is indeed the case with the Garrett VNT (Variable Nozzle Turbocharger). The VNT uses adjustable vanes inside the exhaust scroll to change the angle of attack of the incoming gasses as they strike the exhaust turbine.

'''Experimental Data'''

The data shown below is collected via [[ElanScan]] under the following conditions:
# 3rd Gear acceleration (allows for more datapoints than 2nd gear, and safer speeds than 4th gear)
# WOT (Wide Open Throttle)

[http://forum.lotuselancentral.com/viewtopic.php?p=275396#p275396 GeoffSmith's recomendations]

{| class="wikitable"
|-
!  Wastegate  ||  Downpipe  !!  Pre Cat  !!  Main Cat  !!  Diameter  !!  ECU  !!  Ambient Temp  !!  Humidity  !!  Boost Creep  !!  Overboost  !!  WG Duty Cycle  !!  User  !!  Link
|-
| 21 mm || OEM || PCE || NO || 2.50 in || OEM || 0 degC || 56% || 4000 RPM || NO || 0% ||ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=276742#p276742 OEM ECU]
|-
| 21 mm || OEM || PCE || NO || 2.50 in || Everest || 5 degC || 91% || NO || NO || 0% || ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=277183#p277183 Everest]
|-
| OEM || Piper || N/A || Piper Sports || 2.25 in || Mountain || ... || ... || YES || YES || ... || paulsmithmk || [http://forum.lotuselancentral.com/viewtopic.php?f=36&t=19191&start=200 specs] [http://forum.lotuselancentral.com/viewtopic.php?p=270471#p270471 overboost]
|-
| 20 mm || Piper || N/A || ... || 2.00 in || OEM || ... || ... || YES || YES || ... || Steve A || [http://forum.lotuselancentral.com/viewtopic.php?p=275311#p275311 specs] [http://forum.lotuselancentral.com/viewtopic.php?p=275298#p275298 overboost]
|-
| OEM || Piper || N/A || NO || 2.25 in || OEM || ... || ... || YES || YES || ... || cliff || [http://forum.lotuselancentral.com/viewtopic.php?p=275329#p275329 overboost] [http://forum.lotuselancentral.com/viewtopic.php?p=275333#p275333 no cat]
|-
| 20.5 mm || Piper || N/A || NO || 2.25 in || Everest || ... || ... || YES || 6500 RPM || ... || HJ2 || [http://forum.lotuselancentral.com/viewtopic.php?p=275570#p275570 specs] [http://forum.lotuselancentral.com/viewtopic.php?p=276086#p276086 port] [http://forum.lotuselancentral.com/viewtopic.php?p=275398#p275398 overboost]
|}

Boost Creep

2013-11-03T18:24:56Z

Ccb056:

'''Boost Creep'''

Boost creep occurs when the wastegate/turbocharger combination is improperly sized and cannot dump enough exhaust gasses. The symptom is rising boost as RPMs rise, sometimes in an uncontrolled fashion. To reduce this effect, either install a larger capacity wastegate, or an exhaust turbine with a higher A/R ratio.

'''Overboost'''

Overboost occurs after boost creep, when the boost pressure reaches a level to signal fuel cutoff.

'''A/R Ratio'''

The ratio of the exhaust inducer nozzle area (A) over the exhaust inducer radius (R; measured from the center of the turbine shaft to the center of the inducer nozzle). This number (usually from about 0.4 to 1.0) gives you an indication as to the tradeoff between lag and high volume efficiency for a given configuration. When the A/R ratio is low, then the small inducer area creates high velocity flow at low volumes, thus improving spin up. A high A/R allows high volumes of gas to flow through the exhaust turbine, making the turbine more efficient at those high volumes, but it will then be sluggish to spin up.

Since A/R ratio is a significant factor in turbo lag, some manufacturers have devised means for varying the A/R ratio to reduce lag while still maintaining high-volume efficiency. Such a scheme properly carried out would eliminate the need for a wastegate, which is indeed the case with the Garrett VNT (Variable Nozzle Turbocharger). The VNT uses adjustable vanes inside the exhaust scroll to change the angle of attack of the incoming gasses as they strike the exhaust turbine.

'''Experimental Data'''

The data shown below is collected via [[ElanScan]] under the following conditions:
# 3rd Gear acceleration (allows for more datapoints than 2nd gear, and safer speeds than 4th gear)
# WOT (Wide Open Throttle)

[http://forum.lotuselancentral.com/viewtopic.php?p=275396#p275396 GeoffSmith's recomendations]

{| class="wikitable"
|-
!  Wastegate  ||  Downpipe  !!  Pre Cat  !!  Main Cat  !!  Diameter  !!  ECU  !!  Ambient Temp  !!  Humidity  !!  Boost Creep  !!  Overboost  !!  WG Duty Cycle  !!  User  !!  Link
|-
| 21 mm || OEM || PCE || NO || 2.50 in || OEM || 0 degC || 56% || 4000 RPM || NO || 0% ||ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=276742#p276742 OEM ECU]
|-
| 21 mm || OEM || PCE || NO || 2.50 in || Everest || 5 degC || 91% || NO || NO || 0% || ccb056 || [http://forum.lotuselancentral.com/viewtopic.php?p=277183#p277183 Everest]
|-
| OEM || Piper || N/A || Piper Sports || 2.25 in || Mountain || ... || ... || YES || YES || ... || paulsmithmk || [http://forum.lotuselancentral.com/viewtopic.php?f=36&t=19191&start=200 specs] [http://forum.lotuselancentral.com/viewtopic.php?p=270471#p270471 overboost]
|-
| 20 mm || Piper || N/A || ... || 2.00 in || OEM || ... || ... || YES || YES || ... || Steve A || [http://forum.lotuselancentral.com/viewtopic.php?p=275311#p275311 specs] [http://forum.lotuselancentral.com/viewtopic.php?p=275298#p275298 overboost]
|-
| OEM || Piper || N/A || NO || 2.25 in || OEM || ... || ... || YES || YES || ... || cliff || [http://forum.lotuselancentral.com/viewtopic.php?p=275329#p275329 overboost] [http://forum.lotuselancentral.com/viewtopic.php?p=275333#p275333 no cat]
|-
| 20.5 || Piper || N/A || NO || 2.25 in || Everest || ... || ... || YES || 6500 RPM || ... || HJ2 || [http://forum.lotuselancentral.com/viewtopic.php?p=275570#p275570 specs] [http://forum.lotuselancentral.com/viewtopic.php?p=276086#p276086 port] [http://forum.lotuselancentral.com/viewtopic.php?p=275398#p275398 overboost]
|}

Boost Creep

2013-11-03T18:22:53Z

Ccb056:

Boost Creep

2013-11-03T18:18:14Z

Ccb056:

Boost Creep

2013-11-03T18:16:25Z

Ccb056:

Boost Creep

2013-11-03T18:13:49Z

Ccb056:

Boost Creep

2013-11-03T18:13:02Z

Ccb056:

Boost Creep

2013-11-03T18:12:02Z

Ccb056:

Boost Creep

2013-11-03T18:08:53Z

Ccb056:

Boost Creep

2013-11-03T18:08:31Z

Ccb056:

Boost Creep

2013-11-03T18:06:15Z

Ccb056:

Boost Creep

2013-11-03T18:00:33Z

Ccb056:

Boost Creep

2013-11-03T18:00:00Z

Ccb056:

Gearbox removal

2013-11-03T00:36:30Z

Ccb056: added a link to the forum thread

1. Start by jacking up car, removing front wheels, pop out wheel centres, put wheels back on and loosen drive shaft nuts.

[[Image:Loosendriveshaftnuts.jpg|150px]]

2. Jack up car, remove front wheel, place another jack at the inner jacking point at the rear of the prongeron and raise the car.

[[Image:Removewheel-1-.jpg|150px]]

3. Now put car on axle stands at normal front jacking points. I have also placed a block of wood under the sills just in case!

[[Image:Supportonaxlestands-1.jpg|150px]]

4. Now open the bonnet and remove the air filter and associated pipe work

[[Image:Removeairfilter-1-.jpg|150px]]

5. Remove the clutch cable from the clutch lever. At this point it is also worth removing the bolt that holds on the expansion bottle.

[[Image:Removeclutchcablefrombracket-1-.jpg|150px]]

6.Remove the clutch cable from the guide bracket.

[[Image:Removegearsmallselectorpinandcable-1-.jpg|150px]]

7. Remove the spring clip from the smaller of the two gear selector cables and pop off the cable.

[[Image:Removelargegearselectorcablepin-1-.jpg|150px]]

8. Remove the spring clip from the larger gear selector cable.

[[Image:Removelargegearselectorcable-1-.jpg|150px]]

9. Pop off the larger gear selector cable from its pin.

[[Image:Removespeedocable-1-.jpg|150px]]

10. Remove the speedo cable by removing the 10mm nut and clamp plate.

[[Image:Removegearselectorcablebracket-1-.jpg|150px]]

11. Remove the three bolts that hold on the gear selector cable mounting bracket. This avoids accidently adjusting the cable lengths.

[[Image:Disconnectreversinglightswitch-1-.jpg|150px]]

12. Disconnect the wiring from the reversing light switch.

Its now time to work under the car.

[[Image:Draingearboxoil-1-.jpg|150px]]

13. Drain the gearbox oil by removing the drain plug.

[[Image:Removecaliperandtopballjoint-1-.jpg|150px]]

14. Unbolt the top wishbone ball joint. Take note of how many shims are placed in front of and behind the balljoint. there should be 8 shims in total for each ball joint. In my car there are also inserts to set the camber. Remove the brake caliper and tie it up out of the way.

The drive shaft nuts can now be removed.

The nearside drive shaft should be pushed through the hub and then popped or levered out of the gearbox. This can be a fiddle as it is held in place by a snap ring. Do not pull the driveshaft out as this might damage the inner plunge joint.

The off side drive shaft should be removed by removing the jackshaft bracket bolts then pushing the driveshaft through the hub. The offside driveshaft has no circlip at the gearbox and will slip out easily.

The drive shafts can be left supported by the suspension yolks but make sure they are not in the way of the gearbox.

[[Image:Prongeronfront-1-.jpg|150px]]

[[Image:Prongerondamperandbellhousingbolts-1-.jpg|150px]]

[[Image:Prongeronviewonramp-1-.jpg|150px]]

At this point support the gearbox and engine from above or below using a trolley jack.

I used a bracket to support the engine from above and I placed a trolley jack under the sump. I also put a strap around the gearbox and over the support frame up above.

15. Remove the progeron and the front damper along with two of the bellhousing bolts. Start at the front of the car and work your way back.

[[Image:Removeexhaustdownpipe-1-.jpg|150px]]

16. Now remove the exhaust downpipe

[[Image:Remove4boltsfromflywheelcoverplate-1-.jpg|150px]]

17. Remove the four bolts securing the flywheel cover plate.

[[Image:Removerearenginemountbracket-1-.jpg|150px]]

18. Its time to remove the rear engine mount bracket.

[[Image:Frontgearboxmount-1-.jpg|150px]]

19. Now remove the gearbox mount. This has several parts, a damper and a couple of L shaped spacer plates.

[[Image:Finaltopbellhousingbolt-1-.jpg|150px]]

[[Image:Thirdtopbellhousingboltviewedthroughwheelarch-1-.jpg|150px]]

[[Image:Anothertopbellhousingbolt-1-.jpg|150px]]

[[Image:Gearboxinitialalignmentfrombelow-1-.jpg|150px]]

20. the only thing holding the gearbox on now is three bell housing bolts at the top. These are a bit awkward to get to.

[[Image:|150px]]

21. The gearbox can now be pulled free from the engine and lowered to the floor.

A few things worth considering before putting it all back together.

It is worth trial fitting the mounts onto the gearbox as you will find you have an awful lot of bits lying around.

[[Image:Gearboxnearsidemounttempfitted-1-.jpg|150px]]

[[Image:Gearboxnearsidemounttempfitted2-1-.jpg|150px]]

[[Image:Gearboxnearsidemounttempfitted3-1-.jpg|150px]]

Start with the gearbox mount

[[Image:Gearboxrearenginemounttempfitted-1-.jpg|150px]]

Then the rear engine mount

[[Image:Gearboxinitialalignment-1-.jpg|150px]]

Aligning the box is quite tricky but perseverence will pay off.

I hope this post will help anyone considering removing their gearbox or changing a clutch on their Elan.

[http://forum.lotuselancentral.com/viewtopic.php?f=48&t=22395 Link to forum thread]

Boost Creep

2013-11-01T07:15:43Z

Ccb056:

Boost Creep

2013-11-01T07:15:01Z

Ccb056:

Boost Creep

2013-11-01T07:04:20Z

Ccb056:

Boost Creep

2013-11-01T07:03:48Z

Ccb056:

Boost Creep

2013-11-01T07:01:11Z

Ccb056:

Boost Creep

2013-11-01T07:00:04Z

Ccb056:

Boost Creep

2013-11-01T06:54:21Z

Ccb056:

Boost Creep

2013-11-01T06:52:06Z

Ccb056:

Boost Creep

2013-11-01T06:47:11Z

Ccb056:

Boost Creep

2013-11-01T06:46:32Z

Ccb056: New page: '''Boost Creep''' Boost creep occurs when the wastegate/turbocharger combination is improperly sized and cannot dump enough exhaust gasses. The symptom is rising boost as RPMs rise, somet...

Wheel bearings

2013-06-19T23:46:08Z

Ccb056: /* Rear wheel bearing - SKF kit: VKBA 529 */

{{stub}}

SKF are generally recognised as a manufacturer of best quality bearings: SKF kit references provided by Bob Brown.

==Front wheel bearing - SKF kit: VKBA 736==

'''Information from the [http://ret0027h.eresmas.net/lotuselancentral/archives/march03mb.htm Old LEC bulletin board]:'''

Mar 2, 2003 - 12:37 - From: keith g

Title: Bearing

Message: Lotus number A100C6009F on bearing SKF BAHB 311396B

'''Information from [http://www.ourbearings.com/wheel_bearings.htm Chinese wheel bearing cross reference] and [http://www.kml-bearing.com/upload/news/180/double-row-angula-contact-ball-bearing-two-inner-rings-1.html KML] '''

[[Image:FrontWheelBearing.gif|250px]]

Inside diameter (d)=39mm

Outside diameter (D)=72mm

Outer race width (B)=37mm

Outer race width (C)=37mm

Weight (W)=0.56kg

Seal type: B

''Notes:

Double row angular contact ball bearings with ladder

The inner ring is locked & the outer ring have a lead ladder''

[http://forum.lotuselancentral.com/viewtopic.php?f=45&t=10517&p=128423&hilit=skf#p128423 LEC discussion!]

FRONT WHEEL BEARING ''FBK067''

Also Fitted to:-

DAEWOO Espero JF/JA19 1.5i 04/95-08/97

DAEWOO Espero JF/JA8 1.8i 04/95-08/97

DAEWOO Espero JF/JAW 2.0i 04/95-08/97

DAEWOO Lanos TA/TF6 1.6i 08/97-01/02

DAEWOO Lanos TFC 1.4i 08/97-01/02

DAEWOO Nexia TF/TA19Y 1.5i 04/95-08/97

DAEWOO Nubira JF/JA35/69 2.0i 09/97-01/02

DAEWOO Nubira JF356/696 1.6i 07/99-01/02

DAEWOO Nubira JF356/696 1.6i 09/97-01/02

LOTUS Elan 1.6i 1/90-12/95

ROVER/MG ROVER City Rover 1.4i 1/03-

VAUXHALL Astra Belmont 1.7D 01/89-10/91

VAUXHALL Astra Belmont 1.8i 01/89-10/91

VAUXHALL Astra Convertible II 2.0i 1/87-12/93

VAUXHALL Astra Convertible III 1.8i 1/91-12/99

VAUXHALL Astra Convertible III 2.0i 1/91-12/99

VAUXHALL Astra I 1.6 1/79-12/84

VAUXHALL Astra I 1.6D 1/79-12/84

VAUXHALL Astra I 1.8i 1/79-12/84

VAUXHALL Astra II 1.6 1/84-12/91

VAUXHALL Astra II 1.6D 1/84-12/91

VAUXHALL Astra II 1.7D 1/84-12/91

VAUXHALL Astra II 1.8i 1/84-12/91

VAUXHALL Astra II 2.0i 1/84-12/91

VAUXHALL Astra III 1.4i 1/91-12/98

VAUXHALL Astra III 1.6i 1/91-12/98

VAUXHALL Astra III 1.7TD 1/91-12/98

VAUXHALL Astra III 1.8i 1/91-12/98

VAUXHALL Astra III 2.0i 1/91-12/98

VAUXHALL Astra Van I 1.6 1/82-12/84

VAUXHALL Astra Van I 1.6D 1/82-12/84

VAUXHALL Astra Van II 1.6 1/84-12/91

VAUXHALL Astra Van II 1.6D 1/84-12/91

VAUXHALL Astra Van II 1.7D 1/84-12/91

VAUXHALL Astra Van III 1.7TD 1/91-12/98

VAUXHALL Astramax 1.6 01/89-09/91

VAUXHALL Astramax 1.6D 09/85-01/89

VAUXHALL Astramax 1.7D 01/89-09/91

VAUXHALL Astramax 1.7D 10/91-01/94

VAUXHALL Belmont 1.6 01/86-08/86

VAUXHALL Belmont 1.6D 01/86-01/89

VAUXHALL Belmont 1.8i 01/86-01/89

VAUXHALL Calibra 2.0i 02/94-12/95

VAUXHALL Calibra 2.0i 06/90-02/94

VAUXHALL Calibra 2.0i 06/90-12/95

VAUXHALL Calibra 2.0i 09/90-04/92

VAUXHALL Calibra 2.0i turbo 04/92-12/92

VAUXHALL Cavalier II 1.6 1/81-12/88

VAUXHALL Cavalier II 1.6D 1/81-12/88

VAUXHALL Cavalier II 1.8i 1/81-12/88

VAUXHALL Cavalier II 2.0i 1/81-12/88

VAUXHALL Cavalier III 1.6 1/88-12/95

VAUXHALL Cavalier III 1.7TD 1/88-12/95

VAUXHALL Cavalier III 1.8 1/88-12/95

VAUXHALL Cavalier III 2.0i 1/88-12/95

http://www.trupart.co.uk/trupart/buyguide/html/tbk351.htm

==Rear wheel bearing - SKF kit: VKBA 529==

The following rear wheel bearing kit will fit the Elan and is available from most motor factors, priced £7.50 each (19/1/2008):

VW Jetta GL 1985-1998

VW Golf 1984-1992 (MK1), 1992-1998 (MK3)

However, the oil seal that comes with this kit is not the correct one.

The following oil seal is required:

GM part number 90217059 priced £9.52 each from Vauxhall dealer (19/1/2008)

or

Vauxhall Corsa 1983-1993 rear wheel bearing kit priced £7 each from local motor factors (19/1/2008)

I changed mine last week (07/05/2008) and found the seal in the VW kit to be a good fit in the hub. It appears to seal adequately, but I will keep an eye on it to make sure it keeps the grease in!
Dave Pink

Timken SET1 and SET8 for inner and outer bearings respectively also work.

[[Category:Components]]