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michel lane · 05-15-2014, 02:07 AM

Hi all , I have been reading the various articles about different providers who can supply a tune for the car .Does anyone know if any of the providers have actually access the ecu , to change the fuelling and ignition table for there tunes ?.

I am a little concerned on some of the tunes after looking at the AFR tables on the dyno runs . I know the BMW ecu are pretty good , so they will pull the ignition if it detects knock, but this also means pulling the power .

I have seen a stock dyno run and in 4th , the AFR drop to around 12-12.6 on boost all the way to the red line between 4k to 8k rpm.

On other dyno charts with various mods , I have seen the AFR hover between 13-14 on a wideband . Now this tells me that the tune does not apply any additional fuel when the boost is turned up . On other dyno'd runs I have seen the AFR between 14-16 , which is crazy!

From a a tuning point of view , I find this a little uncomfortable , as the EGT (exhaust gas temperatures)will be getting pretty hot, which means cats will be heating up and pistons will be reaching there limits.

Does anyone know if these engines have forged pistons and rods ? As they have a heat range to around 1200 degrees C .

The ecu will pull power , but the whole point of a tune is to increase power , so in a way you are adding more boost to increase power , but the ecu has to pull timing to reduce knock which means reduction in power.

When I was building single Supra's that ran around 600 to 800hp, we always looked at producing the biggest gains in hp and torque with the fuel and ignition tables , but reducing the amount of boost. More boost means more heat , which results to things going bang ! .

I am taking the car to a Dastek dyno on Saturday to get a reading , these are 4 wheel drive dyno and are pretty accurate, they give a good flywheel HP reading. I tend to use Dastek and dyno dynamics units as they provide a pretty accurate figure when compared to each other .In the Uk most decent dyno'd provide a flywheel reading and not whp unless you use a hub dyno, which will give you a Hub reading . The whole point of this exercise is to clarify the AFR readings and not the HP gains .

I have also recently purchased a BMS piggy back tune , so I can get some runs with and without the tune . This will give me an idea if the fuelling is modified from the AFR readings . If the AFR increases then I am tempted to put an after market Fuel pressure regulator to increase the fuelling on boost , unfortunately this will increase fuelling across the rev band , so my mpg will decrease but boost fuelling will stay within the 12 range .But on the other hand wait until someone can give me positive feedback on a tune that address the AFR readings and shows some accurate results on a dyno .

I will be monitoring , AFR , boost , hp and torque , to see if they are consistent with each other .

What are people's thoughts on this ?

05-15-2014, 02:07 AM	#1
michel lane Private First Class 3 Rep 135 Posts Drives: BMW M6 F13 Join Date: May 2014 Location: UK, CLEVELAND. Sedgefield iTrader: (0)	Tune questions Hi all , I have been reading the various articles about different providers who can supply a tune for the car .Does anyone know if any of the providers have actually access the ecu , to change the fuelling and ignition table for there tunes ?. I am a little concerned on some of the tunes after looking at the AFR tables on the dyno runs . I know the BMW ecu are pretty good , so they will pull the ignition if it detects knock, but this also means pulling the power . I have seen a stock dyno run and in 4th , the AFR drop to around 12-12.6 on boost all the way to the red line between 4k to 8k rpm. On other dyno charts with various mods , I have seen the AFR hover between 13-14 on a wideband . Now this tells me that the tune does not apply any additional fuel when the boost is turned up . On other dyno'd runs I have seen the AFR between 14-16 , which is crazy! From a a tuning point of view , I find this a little uncomfortable , as the EGT (exhaust gas temperatures)will be getting pretty hot, which means cats will be heating up and pistons will be reaching there limits. Does anyone know if these engines have forged pistons and rods ? As they have a heat range to around 1200 degrees C . The ecu will pull power , but the whole point of a tune is to increase power , so in a way you are adding more boost to increase power , but the ecu has to pull timing to reduce knock which means reduction in power. When I was building single Supra's that ran around 600 to 800hp, we always looked at producing the biggest gains in hp and torque with the fuel and ignition tables , but reducing the amount of boost. More boost means more heat , which results to things going bang ! . I am taking the car to a Dastek dyno on Saturday to get a reading , these are 4 wheel drive dyno and are pretty accurate, they give a good flywheel HP reading. I tend to use Dastek and dyno dynamics units as they provide a pretty accurate figure when compared to each other .In the Uk most decent dyno'd provide a flywheel reading and not whp unless you use a hub dyno, which will give you a Hub reading . The whole point of this exercise is to clarify the AFR readings and not the HP gains . I have also recently purchased a BMS piggy back tune , so I can get some runs with and without the tune . This will give me an idea if the fuelling is modified from the AFR readings . If the AFR increases then I am tempted to put an after market Fuel pressure regulator to increase the fuelling on boost , unfortunately this will increase fuelling across the rev band , so my mpg will decrease but boost fuelling will stay within the 12 range .But on the other hand wait until someone can give me positive feedback on a tune that address the AFR readings and shows some accurate results on a dyno . I will be monitoring , AFR , boost , hp and torque , to see if they are consistent with each other . What are people's thoughts on this ?
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