What to adjust?

[rextheracer]

Ive been on a street tune in my Turbo 06 gto for a while now. One thing ive noticed is the feel of the car in cold temperatures.

I know a car operates better when its cold, but the change in the way the car runs is pretty huge.

The car has always kind of fallen over itself in boost...not smooth at all choppy almost. It just feels like it has so much more in it. Then winter rolls around and going into boost the car is smooth as butter and fast as heck (only with temps below 40 degrees)

My question is, what do I have set wrong? obviously something isnt on point if the car runs perfectly in cold weather and feels totally off in anything above 40 degrees... so should I be looking at timing? fuel?

[gn2beatu]

Your goona see a huge differance when its cold. What boost you running and what fuel? E85 would make a HUGE differance if your not running it. You can put a ton more timing in it with E85.

Post the tune so we can look at it.

[rextheracer]

Your goona see a huge differance when its cold. What boost you running and what fuel? E85 would make a HUGE differance if your not running it. You can put a ton more timing in it with E85.

Post the tune so we can look at it.

Im running 7 pounds on 93 octane I would do e85 but there is literally 1 station that carries it within an hour of my house..... heres the tune we have so far:

[gn2beatu]

One thing you may want to look into is propane injection. It is very high octain 119ish. But even better is the outlet temps at -40ish. It has its own intercooling effect on the intake air temp charge. A tank can last over a year, and is super cheap to refill. It is gaining popularity over meth due to the intercooling effect it has. Nothing jumps out at me as terribly wrong with the tune, but I do have two other suggestions.

Here is something that may help in the temp department. Your cylinder charge temp filter (not bias) but filter, change all values to 1.00 What this will do is allow IAT temp changes get recognized faster by the ecm. Especialy important in heat soaked IAT's when idling at stop lights, and then getting on it.

LS motors like to have a minimum 5ms of dwell time. Change all values less than 6ms in your table up to 6ms up to 5000rpm. At 5500rpm change to 5.5ms and at 6000+ change to 5.0ms May help ignition a tad, as it will let you run a bit larger spark plug gap too.

If you havent done it already, make sure your getting your intake air from a true cold air source and not from the engine compartment. IAT is everything. Not sure what intercooler your running, but if you dont have an air/water one, you may want to pick one up. They are cheap at $220.00 I just bought the one you can see below. I will use it with a standard water cooler for now. But if you google super chiller, they make a unit that ties into your cars A/C that holds a fixed amount of water, and keeps the temp at 30 degress. Your IAT temps will always be aroudn 30 degrees over ambient. Kinda like having a rear A/C core, but its used for your air to water intercooler. It kicks out at WOT, but the residual cool water will keep it cool throughout the run. Just some things to think about.

http://www.ebay.com/itm/CXRacing-Uni...item2a16395b36

Maybe someone else can help you with a few little things. Its when you do all the little changes, that combined make for one big change. Especialy in drive-ability.

[DSteck]

Propane is old head stuff. Meth has a cooling effect as well.

The bias value is for MANIFOLD AIR TEMP... Not IAT. IAT is recognized as fast as the sensor can report a new temperature. That's what impacts timing.

Turbos making 7psi on a 6.0L don't need a liquid intercooler. A standard air to air has plenty of capacity.




OP, I will look at your file later. A log would help out.

[edcmat-l1]

Without a data log it's awfully hard to tell anything. Just by the description though, I would imagine it's overly rich, and when the weather's cooler, and the air is denser, it leans out some, and runs better. That's just going by description. Another thought is it's pulling timing via IAT when warm, and knocking some steam out of it.

[gn2beatu]

@ Dsteck - yep - shoulda said manifold air temp. Although with no coolant in the intake, intake air temps is what changes the manifold temp...... just sayin ;-)

@ OP - edcmat has a valid point too, most people run thier turbo tunes waaaay too rich. what is your actual WOT A/F? Looks like your commanding 12.0ish with the PE enrichment.

[DSteck]

I really think there's a lot you don't fully understand. MAT isn't going to cause him these issues.

[gn2beatu]

I didnt say it was goona cure all his issues, I just told him to change the setting so the computer recognizes temp changes faster.

You guys are so nitpicky on wording. Both of my suggestions are valid and helpful.....sigh. I dont know why everyone has to be so critical. I wonder how many good people there USED to be helping here, that quit due to all the people who are so fast to criticize others suggestions. Your not so bad personaly, there are worse here. If a suggestions helpful, great, go with it, but dont be so anal on exact wording. You know both of those suggestions will have a positive impact, even if minimal. Like I said earlier, its the little things that add up to one big thing.

[rextheracer]

We are running low 11's at wot...but since boost enrich isnt enabled the afrs vary with engine load and boost pressure and rpm. Im just trying to get an idea is all. We are commanding 12ish, but I dont think it ever gets to that point (unless I look at the wideband at the wrong times..haha) It does run a lot better lean though.

[gn2beatu]

What is your extensive intake work? You cut the manifold top off and port it? Im in the process of doing that now on my truck intake. Kinda like LS2 portworks used to do, except Im also shortening the runners to 5" instead of the stock 12" range. Im also removing the tube in the center. Have allot of plastic work to do yet, but heres a pic just to give you an idea. Hoping to kill 30 ft lbs torque down low and gain at least that back or more in the high RPM HP.

I would agree with you though that it would run allot better if the A/F where a bit leaner. Maybe try to get it to 12.2 range and see if it likes that better. In fact thats probably why it runs so much better when its cold. G/L with the tuning & give those two ideas a shot. Let me know how it works out.

[rextheracer]

sorry for the late reply guys....car got wrecked the next day and just now got it back. heres a log with the random misfires:

[rextheracer]

with the random knock*