What are all the big nitrous guys using for their tune? Is everyone going SD? Looking to go 8.xx and have most everything mapped out just need to decide on my tuning. Its a solid roller. Any advice input will help. Thanks.


I have HP tuners BTW

 

You can do it either way. I have a buddy's car tuned in Open Loop MAF mode that has been 8.8 @ 152 on spray. I have my car tuned in OLSD and have been 9.4 @ 144. I prefer open loop tuning. Specially for cars that will see race gas.

Ofcourse these are wet shots that I am talking about here. A dry shot needs to go thru the MAF unless you want to get into more tricky stuff.

 

I wont be using a dry shot, Why do you prefer open loop for race gas?

 

Leaded fuel eats O2 sensors and I hate them anyways.

 

OLSD
definately.

 

so can anyone go into depth more on this if you dont mind i wont be running near those times but am wanting to have a very good tune on the car

 

what part of it are you looking for more info on?

 

If you could, I'd tune it to run OLMAF (with OLSD as a backup incase of MAF failure). Any adjustment for a wet shot of nitrous as far as fuel is concerned is outside of the PCM's view and control. Since one of the reasons MAFs are used is because they accomodate day-to-day changes in conditions better, one could assume you'd have a more consistent foundation with a MAF tune over a SD tune. Then for the most part, all you'd have to worry about is your jetting and timing.

 

my main concern is this car will see more street racing time then track and with the people ive been talking with so far speed density is looking more for me... but there are so many questions i have about it being that ive never delt with it and dont know the best way to go about my tune... i am buying hp tuners so making adjustments wont be a problem with sd like when weather changes and things but just wanted to hear some ls1 guys outlook

 

Well Im boosted, But SD I will say is godly IMHO. Weather changes have little affect on my car. I just drove from texas to GA, the car runs a little harder here because of that ethonal 10% **** I. On cold days of course boost loves that **** I see small changes in the afr like.5 in the commanded afr. Hot humid days she is alittle sluggish, But what car is not? I was afraid of the temp, att, and climate change befor I went sd but now im sd and wont look back. Oh on the down side for me I carry a extra map because I spray meth sometimes. VIC JR

 

ill be nitrous but my buddys have talons that are boosted and they are leaning me twards sd just didnt know if there was a huge benifet from the ma or sd.. they say there tunes change with weather nothing drastic but they make minor chanes here and there

 

OLMAF isn't gonna fine tune much better than OLSD. He could just run CLSD and if he wanted to run some race gas at the track, just pull the O2s out.

I'm running OLSD right now in my bolt on car, for tuning purposes, and haven't notice more than a .2-.3 AFR difference in 30 degree weather changes with varying humidity. Retuning ever so often wouldn't be any problem even if I just left it in OLSD.

Even still, with a wet shot, all you have to worry about is jetting and timing. Regardless of the method you use for airflow modeling.

 

what would be the benieft of olmaf i thought the whole pourpuse was to do away with the maf so its not fighting with the oxygen senors and ill be doing a wideband also for tuning pourpesese

 

At WOT if it's right, it's right. And if it's not right, well then it's not right.

For part throttle SD has the advantage if the VE is dialed in. With a MAF tune it's still gonna reference the VE tables during transitions. Because by the time it took a reading of Hz as registered by the MAF, deciphered that into air flow by way of the MAF tables, and then calculated fuel for that amount of airflow, the actual amount of airflow would have already changed and the fueling would be off.

So why not just eliminate the middle man and run SD.

 

I don't know. I would never have even considered it. I mean if you're going through the trouble of OL then you obviously don't really care that much about day to day changes anyway. I mean if you just want to run race gas they make unleaded stuff.

If there is a benefit would someone please share it.

 

prolly pissing you off but am new to this tuning myself my car has already been tuned but when going speed density im going to have it retuned and walked through how to do it by someone exp. what does the ve stand for exactly?

 

VE is volumetric efficiency or the efficiency that air moves through the engine. In the PCM it is referenced manifold pressure and rpm. At any given cell in that table there will be a percentage of calculated total engine volume.

MAF calculations are made from the MAF tables and SD calculations come from the VE tables.

 

ok thanks for explaining that to me... and this car will probably run c16 85% of the time anyway so i should be able to turn it up a little more what kind of timing are nitrous guys running with rods and pistons stock heads better cam?

 

How much nitrous? I believe the guys running 8s, like the OP is after, are running around 10 degrees WOT. You can probably search that.

 

prolly 150 to 200 deff wont be going 8s but that faster the better