2000 AP1, Im running a SOS kit novi 1200 blower on a griptec 3.2 pulley with the green belt and making 12 psi and 395 WHP. Previously I was on the 3.6 SOS pulley making 9 psi at 365 WHP. This was done on a street tune and not a dyno. From the charts and reading other members power levels my 12 psi on the 3.2 pulley seems really low. Is this a tuning problem or can it be attributed to something else? My engine is healthy and I had the same tuner install the SOS kit and he really took his time and made sure there are no leaks. Do I just have a really conservative tune and should I try a new tuner or maybe one of my mods are bottlenecking my power, maybe my exhaust?

My setup is:
novi 1200
Upgraded racing heat exchanger
ID 1000s injectors
3 bar omni map sensor
AEM V2
WAlboro 255
AEM AFR wideband
Fujitsubo single exit power getter 63'
Berk HFC 63'
Buddyclub headers
ACT clutch

 

If you are getting 12psi at 9k rpm. Then I'd assume you have belt slippage. I get 16psi on a novi1200 at 8300rpm on a 2006.

 

Whats the elevation where you live? Ambient temperature also matters.

I see 13psi at 1900' elevation in 60-70deg weather. I see 15psi in 35 degree weather at 400' above sea level.

Do you have a datalog of boost in a WOT pull?

 

I'm going to max out the tensioner and see what happens today

 

Are you running a 3.2 also? My elevation isn't that high I'm in NJ, I think 250'
I'll do a run after maxing out the tensioner then post the datalog, my previous pull was 75 degree and maxed at 12 psi

 

Datalog a WOT run and post a graph on the MAP sensor signal and RPM, any potential slipping should be easy to spot.

 

No one directly answered your question. No, the tune doesn't affect psi.

Its strictly a mechanical function. This size pump, pumping this fast, into this big an air tank = this psi.

Now realize something important. You might have the same size pump as others (same head unit blower), at same speed (same pulley sizes, same rpm), but you don't have the same size tank.

In the analogy, air tank is your motor. While its same displacement as others, same engine rpm, a bunch of other variables are there.

Exhaust system, engine health, etc. The size of the air rank is also always changing. With rpm, woth throttle position.

Actually, its more like pumping air into a tank with a small hole in it. So it never fills up.

Also understand psi is NOT a direct correlation to power.

So for example, today someone gets 15 psi. They only change exhaust, to something freer flowing. Now they make more power, but now they are at 12 psi.

They didn't change anything with sc setup. Yet they make more power, but less boost.

Basically, same pump, at same speed, but now the air tank has a larger hole in it. So it reaches less psi.

Also realize your car in different places will make different psi. So you can't directly compare someone at a different elevation psi with your psi. Their car in same place as you might make same psi as you. But since they're somewhere else, they make different psi.

The blower is locked in to spin at a set blower rpm for a given engine rpm. Its mechanically driven. So the air its able to compress will be more dense, or less dense, depending on elevation.

14.5psi of atmospheric barometric pressure at sea level means a magic one inch square tube, the length to reach up from sea into outer space, when you collect all air in tube and weigh it, its 14.5 pounds. Go higher, mountains, etc, tube shorter, less air, less weight, less starting psi. Less dense air (because less air on top squeezing it), means blower can't boost it as much.

So same car, same sc setup, less psi in mountains (turbo doesn't suffer as much, since less dense air means less wind resistance, so same engine rpm, turbo will spin faster, partially making up for less barometric pressure. Turbo isn't mechanically linked to engine rpm.)

 

Your power doesn’t seem too low. If you go with a true full 3 inch cat less exhaust I’m sure you will pick up 20+whp.

 

Sorry - should've included this in the other post. I'm on a 3.4" pulley, Novi1200, AP2 8400rpm redline

 

On a 3.2 griptec I usually see people making 14+ at like 430 wheel, maybe it's because I was street tuned and I should put it on a dyno. But I think it might be my exhaust b/c it a left side single exit and it has 2 resonators which is probably restricting the flow. It sucks b/c I really like the exhaust, I'm thinking of switching to the mxp exhaust it's a 70' dual with no drone and not overly obnoxious