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shay2nak
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better check your AFR
 

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I've tried 3" on my S240 with stock tune dynoed at 260hp and found the AFR too lean, about 13-14. This is too lean for an FI car.

After added a Unichip and tune it richer, 12+ AFR, I've got 270hp. Still a very conservative tune, should be able to get 280hp.
 

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Discussion Starter #5
Interesting, I have a lot of reasearch to do.
  1. is the fuel mixture not controlled by a Mass air flow sensor
  2. what is the ideal AF number
  3. Is there a manifold air pressure sensor
  4. does this motor have a knock sensing system
 

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Discussion Starter #6
I've tried 3" on my S240 with stock tune dynoed at 260hp and found the AFR too lean, about 13-14. This is too lean for an FI car.

After added a Unichip and tune it richer, 12+ AFR, I've got 270hp. Still a very conservative tune, should be able to get 280hp.
Those are large numbers for RWH. Did you or has anyone ran a stock S240 on a dyno before making these changes?

Thanks, Will
 

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Interesting, I have a lot of reasearch to do.
  1. is the fuel mixture not controlled by a Mass air flow sensor
  2. what is the ideal AF number
  1. Technically that is supposed the be the ONE advantage that MAF is supposed to have over MAP. The ability to draw in more air and everything stay in check. In reality I, personally, have never seen a car where MAF provided any advatage over MAP. MAP is awsomeness in every way as long as you have the ability to tune the ECU.
  2. Peronally, on forced induction, I would want at most ~12.5:1. 11.x:1 would make me more comfortable with long term reliabilty.
 

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  1. Technically that is supposed the be the ONE advantage that MAF is supposed to have over MAP. The ability to draw in more air and everything stay in check. In reality I, personally, have never seen a car where MAF provided any advatage over MAP. MAP is awsomeness in every way as long as you have the ability to tune the ECU.
  2. Peronally, on forced induction, I would want at most ~12.5:1. 11.x:1 would make me more comfortable with long term reliabilty.
Thanks for the info.
 

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No. But did a AFR check with stock S240. It was way too lean.


Interesting, I wonder if anyone else has checked AF ratio on stock units. So you had the same AF results with stock as you did with a smaller pulley? Was this tested on the same equip.
I'm wondering if we should use AF numbers as a baseline before and after rather than absolute like we do HP and torque?
Has anyone checked the same car for AF using different equipment?
 

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No. But did a AFR check with stock S240. It was way too lean.


Interesting, I wonder if anyone else has checked AF ratio on stock units. So you had the same AF results with stock as you did with a smaller pulley? Was this tested on the same equip.
I'm wondering if we should use AF numbers as a baseline before and after rather than absolute like we do HP and torque?
Has anyone checked the same car for AF using different equipment?
I've done the job on my S240 to snapshot before upgrade. i've used an innovate LM2 to log AFR vs RPM/MAF&MAP.

The MAF Bosch captor can measure MAP too but it's not used by the stock ECU. I've added it as an analog entry of my LM2 to check supercharger pressure!

Here are the screenshots:

The MAF avearage:
The MAP values:
The MAF min values:
 

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Discussion Starter #15
I've done the job on my S240 to snapshot before upgrade. i've used an innovate LM2 to log AFR vs RPM/MAF&MAP.

The MAF Bosch captor can measure MAP too but it's not used by the stock ECU. I've added it as an analog entry of my LM2 to check supercharger pressure!

Here are the screenshots:

The MAF avearage:
The MAP values:
The MAF min values:
Those numbers seem really lean from what I thought might be normal. Can you give your opinion on what these numbers mean to you? (was I slow responding or what? It's been a busy year.)
 

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hey guys I am new here but really enjoy reading the threads.
I'm planning to change a smaller pulley with my Cup260(stock 2011), here is my options:

1. 3.0" with nothing elses change
2. 2.9" with intercooler cooling improvements (cool air / water spray), tighter belt
3. 2.6" with ECU tune/fuel pump/IC cooling/belt/water injection

what would be your suggests and what HP would it be?

thanks!
 

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hey guys I am new here but really enjoy reading the threads.
I'm planning to change a smaller pulley with my Cup260(stock 2011), here is my options:

1. 3.0" with nothing elses change
2. 2.9" with intercooler cooling improvements (cool air / water spray), tighter belt
3. 2.6" with ECU tune/fuel pump/IC cooling/belt/water injection

what would be your suggests and what HP would it be?

thanks!
For all those pulley sizes you will need a new ECU tune, larger injectors, and a larger fuel pump (Your car might have a 190 fuel pump being a 260, so you may not need a new fuel pump... maybe others can chime in about that).
 

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For all those pulley sizes you will need a new ECU tune, larger injectors, and a larger fuel pump (Your car might have a 190 fuel pump being a 260, so you may not need a new fuel pump... maybe others can chime in about that).
thanks!

how about the CUP260 injector? I thought it is 440c.c., not enough for 3.0" or 2.9" ?
 

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Thats the response I expect from todays tech. How long have you run it that way? Any downside?
I've also got a RLS inter cooler...I've run it with TRD air box/filter and then got a KF tune...it ran like $h!t with the KF tune. Since I didn't get any help from Lukas (of KF), I've replaced the intake with a SSC CAI...it didn't make the KF tune work any better. I posted my problems here on LT and then Lukas started to help me and sent like 10 different tune chasing this problem...never got it right and returned it to stock tune. Runs OK, but still dies at every stoplight...kind of annoying. With the TRD intake, it didn't do this as much. I'll have to replace the SSC intake and put back the TRD.
 
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