SwampWS6

iTrader: (7)

Does anyone actually know the limits of the PCM on a boosted LT1? And or stock MAP sensor?

I was told by some that it was 12#s and some said it was 15#s. Just wondering if any of you had experience with it.

Thanks!

96capricemgr

iTrader: (1)

Stock MAP is single BAR as in can't read boost.

Far as limits, depends on the tuner's skill at tuning speed density once the MAF is maxed out.
Many will tell you 700hp is hard but then you get someone like Jeff Green making 4400lbs run high 150s in the quarter on a soft launch with OBD2 pcm opti, 4l60e and a bunch of other parts that can't work.
That car makes a lot more than 700rwhp, but since the dyno loading is so much different than what the chassis does at the track it won't dyno, pcm gets all confused and he got a 400rwhp chart.....

SwampWS6

iTrader: (7)

Thanks for the input. Now the only conflict I have with what you said is that 2 tuners from different states told me that I would be fine with the stock MAP. Because my concern was that I was told by a few also that you cant tune on the MAP. I was under the assumption I needed a 2 bar MAP

96capricemgr

iTrader: (1)

You can use a 2 BAR MAP but lose resolution. Pick a tuner and do what he wants you to, different guys have different preferences on how to get to the end goal.

SwampWS6

iTrader: (7)

Can you explain what it means to lose resolution? How detrimental is it to my cars performance?

Thanks

Shownomercy

iTrader: (1)

People still like carbs and think EFI is the devil. Same logic applies to optis and 24x...

That being said, if you scale a MAP sensor to make it work given the parameters you tell it that say 1psi is actually read as .5psi, so you trick the sensor into doubling its range but sacrificing the quality of the readings you get.

Either way, as my tuner pointed out, you pay once for a SD tune, or twice for a MAF... once for the first MAF tune and the second time for the SD tune once MAF is maxed out.

You will def max out the MAF and odds are end up with some hobbled together tune combining stuff.

SwampWS6

iTrader: (7)

So is it worth the risk of upgrading to a 2 bar MAP?

Shownomercy

iTrader: (1)

I am clueless with LT1 PCM shens, but I do not see how you can run boost with a stock MAP.

Talk to the guy tuning it, not us.

96capricemgr

iTrader: (1)

To tune effectively on a stock MAP you would likely need a good boost controller so boost for rpm is dead steady predictable, then ramp fuel up on rpm.
Really for a turbo, 24x is probably the easier solution with a good 2BAR MAP.

nitrous2fast

iTrader: (2)

Quality of readings is the same and not lesser quality. The resolution lost is the pcms ability to apply different variations of spark angle and fueling at close intervals. Running the 2 bar in place of the 1 bar makes the interval double in size. ie the 90kpa column is now not just 10 kpa in size but now 20. That is the lost resolution. The pcms ability to provide different sets of functions per interval are limited. So adding more range makes each set larger and thus less tailored to a specific rpm/map reading.

SwampWS6

iTrader: (7)

Thanks for explaining that

SwampWS6

iTrader: (7)

Thanks. The 24x will be my next upgrade. Funds look a little funny now to do so. Just trying to get the most outta what I got right now