haha good point

 

i've got far more into my time attack car then i'd like to admit. its a dedicated track car, i'd like to think no expense spared (although we all know there is a limit for everyone).

i run the stock ecu for one simple reason. not any tune by any shop i have seen has had as smooth a running car on a standalone as what i can do on the stock ecu. instant startup, idle, cruising and consistant WOT with temp compensation etc... so thats why i run a MAF and stock ecu on an otherwise complete race car.

i don't run speed density because from my experience its very buggy. you can have it tuned perfect, then the next startup it does something odd you didn't expect. making power with SD is easy. WOT tuning works great. but its the transient conditions that drive me crazy. its very inconsistant, limited tuning due to the two 1D array method. the smoothest method i've found is running open loop 100% of the time, but then it gets bad gas mileage. keep in mind i am far more picky with the tranients then just about anyone so what i consider annoying, most might not notice.

i have considered giving SD a try due to the fact that the BOV selection is limited. i'm fed up with the forge RS because it flutters so hard at part throttle. the APS twin vent is the perfect BOV for MAF cars but its sooooo impossible to find.

 

wow good info.. So you have actually played with it and experienced the issues with it and prefer the MAF. Ive been in a stock ecu SD and AEM evo and my MAF evo ran smoother then both as well. I was going to play with it in the summer just to see what i could get out of it, but i trust your word big time.

Ive recently tuned a guy you tuned, he upgraded his turbo and your tune was very nice, you make great maps man. I thought I was the only one that cared about having smooth maps, but yours were very nice and done right. So kudos to you.

I know you're fixing Acree's car also right now.

I also have the Forge type RS BOV on my personal evo and experience the flutter also. I have maybe 20k in my car in mods, it adds up so quick its sickening. I can only imagine how much you have in a time attack car, im willing to bet its double whats in mine.

So you recommend the APS twin vent BOV?

 

the english racing guys(aaron) seem to have sd locked in and have no complaints from the guys ive talked to in washington that run it everyday going through the mountains and suck...im not sure if he knows a secret to it or what but he definitely knows his **** when it comes to sd

 

I have tuned quite a few guys that were converted by SD back to MAF for what its worth. more then I can count on 1 hand. It just requires alot of maintenance i guess to get right.

 

Hmmm, my experience with SD is the AFRs are rock solid independent of IAT. 16* 12.0 under boost and 647whp, 77* and 647whp, 106* and I am at the lake so it doesnt matter.

Oh wait thats because I dont use a normal one IAT sensor LOL

 

What sensor?!?!

 

I will pull up all the dyno sheets and then just have them compare AFR between these pulls or for that matter one. There is no maintainence to the tune that I have had to do in my personal car (now almost 2 years on SD) or customer cars once it has been tuned.

 

is ivey a confermed shop that does speed density ? good info in this thread

 

I am interested in hearing you elaborate on this...

 

he uses the fuel temp instead of ait

 

The one thing that has been systematically ignored from my advice on SD is using fuel temp instead of the IAT.

One HUGE reason, post turbo heat soak at low boost. Small turbos blow hot air at idle (think hair dryer), the intercooler is doing nothing, the intake temps go up to 140+ and the car pulls timing and dumps fuel and it drives/idles like crap until it gets cooled back down.

Mitsu NEVER intended the programming to be used this way. Its only concerned with engine bay air temp at or near the MAF. Back to back tests on 3 cars yielded the same results, MAF temp is the same as fuel temp. The fuel gets warmed up in a heatsoaked manifold and cools enough by the time it gets to the tank (fuel temp sensor) that they match. I saw 96* at the MAF and 96* fuel temp.

I hate to be "that guy" but I am right and everyone else is wrong, use fuel temp instead of IAT. We dont use it in these, V3 DSMlink, AEM to a point, Autronic, etc. The car is very drivable at all temps since the ECU is doing what it was meant to. If you take the time to completely alter the IAT to timing trim tables to work correctly to match all of these changes then its good. For the most part you end up telling it to ignore it though so it comes back to leaving it on the fuel temp.

Exception is the 2G with Evo swap, then you need an IAT but I use the stock MAF for that and hide it (but use it as engine bay temp).

aaron

 

So its just a rom mod then? no hardwiring required with your method? I tried to say you used the fuel temp sensor to razorlab and he basically told me i was nuts. I could have sworn you did it on acrees car and acree told me that he didnt have to edit or install nothing and i was thinking .. wow i wanna try LOL.

Its to cold here now to tinker with that stuff, but id like to to once it gets nicer out.

 

correct, no hard wiring

 

All code, no hardware other than the MAP sensor.