Big difference in hacking the tune for a 07pcm which is a 900 truck
And later yr 900 pcms there is no hacking

Then talking about a 800 pcm

For those with a 900pcm it's not even close to same pcm as the older 800pcm.....for a 800 SD is way to go

 

I learn something new everyday! I can wrench on anything, but I only know a little bit about tuning... Thanks for the info! Now as for the SD tuning in the 800 trucks, would it be easier for a novice tuner compared to trying to keep the MAF and tuning it?

 

Every tuner has a different opinion on what works better. My coworker (tuner for our shop) does not like tuning speed density nor do I, hense the reason I did the ls3 maf on my twin turbo truck and it worked out great. I have had the truck tuned speed density before and it ran like crap if there was a change in altitude or weather changed. Now I dont know if that was just because the tuner didn't do a good job or what it was but I will not have another vehicle of mine tuned SD.

 

Just out of curiosity, what size piping do you have the ls3 MAF in, how much boost are you running, and how close are you to maxing out the MAF?

 

If the tune ran like crap with weather changes then it wasn't tuned properly sorry to point that out but I've rocked same tune all yr around and it goes negative up here to high 90s

A correct SD has every single factor you need when comes to boost...look at this way every single aftermarket pcm tunes speed density....now everyone sit back and think about that and what some read on the net


Properly tuned SD reacts faster on a 800 trucks pcm then that thing called a MAF


Also once tuned for SD you never have to make adjustments for different boost settings and only timing for different levels

My 02 truck has been SD since 2007 and has been on different fuels including e85 where it was driven in snow

 

Running a 4" tube. Right now it's at 13 psi and making 650 rwhp with a long ways to go before the maf is maxed out. I will have to look back at the logs to see exactly where it was at

 

Cool thanks! That's what I figured. Im gonna run a 4" intake tube in the future and I'm sure around 15-16psi the ls3 MAF will be just fine.

 

The stock MAF isn't the limitation, the PCM is. So I don't see what adding the LS3 MAF did for you, because you still have to hack the tune up to get it to work semi-properly even if the MAF has an extended range.

My opinion is that SD+MAF is the best. More data points for fueling calculations. But given the limitations of the 800 pcm, SD is the best way to go with boost IMO. Quik is still under the impression that whatever works for him, must mean anyone doing it differently is wrong. Stock48 went 10s, maybe even 9s on a MAF tune.

 

I agree, SD+MAF is the best! I've learned a few things about gmt800 trucks today! Thanks

 

As for the stock48 comment ....he even stated he had to hack the pcm a lot to make it work

As for the other comment, having shop experience and tuned countless vehicles in the last 9 yrs from 8s vehicles and 1100rwhp setups to stock vehicles ...I've been around and done a lot of variations to pcms

It comes from experience