Hey Chad,

Yes I have tuned a lot of 2007 Sti's and I do get the same thing. On those cars I see a high IDC as well, but only to a point. I don't run that much boost in them only to around 17-18 psi again due to the bad gas and heat.

I think that the calculation that is used for the STI is actually pretty close. I have seen some that get a high IDC but dont lean out, BUT between shifts does cause a very lean misfire. ( Which is really really bad for them with the weak pistons)

I would think that the overall calculation should not be that hard to figure out based on an injector duty vs ms maybe versus latency. I would like to see the injector sheet at different voltages and different fuel pressures. It is strange for sure because the BSFC should be pretty low considering the pretty high VE of the motor but it seems to be otherwise. Or some component in the fuel system is just lacking. Hard to say at this point but I do know that the fuel pump made a big difference for sure.


Also Chad I would KILL for 94 let alone 93 lol. I guess you dont know what you got until its gone lol.

The tune would be mild but very safe. You will pick up power as well as a more consistant state of running. These ECU's are starting get pretty adaptive but the ignition control is pretty cool.


Dan the car picked up a bit of knock but early in the throttle. Really from about 2500-4500 it knocked to the tune of 1-2 counts. The problem is the way the ignition control works even a little bit of knock it starts to trim out timing off of the low octane map, thus decreasing the ignition advance even with a bit of knock.

The other thing I forgot to talk about is the MIVEC in this car. I did some playing around with it and it really helped spool. As soon as I get back to the shop I will post spool comparison. I need more time with it but I think there is a good amount to be gained with the MIVEC timing.

Thanks for the feedback everyone,

Mitch M

 

I always suggest a walbro 342 pump on STI's - that may help with IDC

 

dan l.....nice posts

 

Al,

yeah we do pumps on almost everything... anytime we tune... but see some weird stuff with 07's....

i hate to admit it, but i dont care for the subies... but, we still work on them... evo's spoil you

cb

 

As you probably know cylinder heads by themself don't usually make a lot of power. Its what the cylinder head allows you do to when tuning that makes the power. It really chaps my *** when people quote cylinder head peak flow numbers at maximum lift when a cylinder head is dynamic flow device. While we are at it I guess we can all get comfortable quoting static compression ratios!

 

great info as always mitch.