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Can turbo upgrade throw off air fuel settings?

Discussion pertaining to positive pressure E28s.
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ecartoys
Posts: 211
Joined: Jan 22, 2007 10:19 PM
Location: So Cal

Can turbo upgrade throw off air fuel settings?

Post by ecartoys »

Just upgraded my K27 turbo to one with slightly bigger cold side compressor outlet and now my car is running lean - from 13.8 to 15.2 on idle.

Could this be caused by the changing in the turbo or I now have a vacuum leak somewhere?

I have checked twice for vacuum leaks in the dark and are not finding anything. Will try again tomorrow morning but just wondering if the change in the turbo can cause this?
Kyle in NO
Posts: 17638
Joined: Feb 12, 2006 12:00 PM
Location: Nasty Orleans------> Batten-Rooehjch------>More Souther LA

Post by Kyle in NO »

Sounds like a leak to me. Going bigger on the housing shouldnt affect the AFRs at idle.
RDAvena
Posts: 514
Joined: Feb 12, 2006 12:00 PM
Location: Falcon, CO

Post by RDAvena »

Did you replace the orange O-ring that goes between the cartridge and the compressor housing?
ecartoys
Posts: 211
Joined: Jan 22, 2007 10:19 PM
Location: So Cal

Post by ecartoys »

Kyle in NO wrote:Sounds like a leak to me. Going bigger on the housing shouldnt affect the AFRs at idle.
Kyle,

The compressor housing is the same, the shop had removed and thin out the inner wall of the compressor inlet and uses a larger turbine. The air outlet is still the same size. I will check for leaks today.
Thanks.


RDAvena,

The turbo was completely rebuilt by a shop so I am not sure which orange o-ring you are referring to.
The only things I did were to teflon the pressure hose to the compressor and bolt the turbo to the car.
Thanks.
turbodan
Posts: 9246
Joined: Jan 09, 2007 10:19 PM

Post by turbodan »

That has to be ain air leak. The turbo doesnt do anything at idle. Its just part of the plumbing.

Easy way to fix the problem: install megasquirt. Manifold pressure based fueling means it only accounts for the air that makes it into the engine. No such thing as an unmetered air leak...
ecartoys
Posts: 211
Joined: Jan 22, 2007 10:19 PM
Location: So Cal

Post by ecartoys »

Silly me. I disconnected two plug wires to make it easier to remove the wastegate and so the car is firing on 4 cylinders. To make it worst I also forgot to tighten the intake elbow hose. :oops: That is what happens when you ran of time and daylight on an upgrade.

Problem solved and are very happy with the results. Now I am hitting 4PSI at 2K RPM and 12PSI at 3K RPM with the upgraded K27 turbo on my 85 745i. Stock K27 was getting 2PSI at 2K RPM and 12 PSI at 4K RPM.

Here's a pic of the turbos. Image
T_C_D
Posts: 7733
Joined: May 27, 2009 11:42 AM
Location: Twin Cities
Contact:

Post by T_C_D »

ecartoys wrote: Problem solved and are very happy with the results. Now I am hitting 4PSI at 2K RPM and 12PSI at 3K RPM with the upgraded K27 turbo on my 85 745i. Stock K27 was getting 2PSI at 2K RPM and 12 PSI at 4K RPM.

Here's a pic of the turbos.

Awesome results!
Jimmie G
Posts: 452
Joined: Feb 12, 2006 12:00 PM

Post by Jimmie G »

I was wanting to post a question about the kkk27 60 upgrade I got one of these from todd but still have not got my head back from a friend that is porting and installing 39mm exhaust valves. And have not installed the new motor yet.

Jimmie
ecartoys
Posts: 211
Joined: Jan 22, 2007 10:19 PM
Location: So Cal

Post by ecartoys »

Jimmie G wrote:I was wanting to post a question about the kkk27 60 upgrade I got one of these from todd but still have not got my head back from a friend that is porting and installing 39mm exhaust valves. And have not installed the new motor yet.

Jimmie
Please post your findings when available - a comparison would be good since my K27 upgrade did not come from Todd. In fact I don't even have the specs from it as I just leave it up to my shop guy. All I told him was to get me boost faster and earlier while maintaining boost at top end.
ecartoys
Posts: 211
Joined: Jan 22, 2007 10:19 PM
Location: So Cal

Post by ecartoys »

T_C_D wrote:

Awesome results!

Thanks Todd. So far so good on the turbo. Now I just need to find a better wastegate since yours is not available.

On another note. I have not hear back from you on the chip. I need to know which ECU chip configuration you have before I am able to send it to you. Also I sent you an email and a PayPal invoice and did not hear back from either.

Please let me know.

Thanks.
T_C_D
Posts: 7733
Joined: May 27, 2009 11:42 AM
Location: Twin Cities
Contact:

Post by T_C_D »

$$ sent. Thanks.
ecartoys
Posts: 211
Joined: Jan 22, 2007 10:19 PM
Location: So Cal

Post by ecartoys »

T_C_D wrote:$$ sent. Thanks.
.

Got it. Thanks.

Just let me know if it is a 4 chip, 2 chip or 1 chip configuration that you need and I will get it right out to you.

I am also working on a smog chip that is specifically for CA smog which could also be used for other states since California's standard is so strict.

Let me know.

Thanks.
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