5 more psi=20hp? Tuners help

[lostsoul]

I have a built 9.2:1 @15psi and only getting 530rwhp =-/ ... it just aint right


why my procharger goes limp at higher rpm.. why am I not in the high 500s.. I also have meth inj but they didnt change the tune for it.. ahhhhhhh.. now I'm brok and unemployed and ahhhhhhhh

 

[Speed+Clinic]

Looks like you willneed a bigger s/c unit to put in more boost or change pistons. low comp works great with turbos because no belt problems if you keep upping the boost.

 

[michael.konor]

I have a built 9.2:1 @15psi and only getting 530rwhp =-/ ... it just aint right


why my procharger goes limp at higher rpm.. why am I not in the high 500s.. I also have meth inj but they didnt change the tune for it.. ahhhhhhh.. now I'm brok and unemployed and ahhhhhhhh

What was the outside temperature? What was your intake temps? Is your meth injection before or after the IAT sensor?

I learned a valuable lesson about 5 years ago when I was running superchargers, going with a smaller pulley = more boost + more heat. Sure I got more PSI, but the corresponding heat caused my engine to pull timing.

My tuner at the time threw a bigger pulley and belt on my car that he had laying around. I had lower boost, but my power levels went up noticeably.

 

[NUTCASE]

one possibility as stated is your lower cr. how much boost do you plan on pushing through that motor? if not much more than 15 you would of been better served by the stock cr.

also are your heads/cam/intake/exaust manifolds stock? if so it is easy to get to a point of diminishing returns where when you up the boost you are just adding heat because the stock parts are just not flowing the air.

but as stated above, I think a lot of it is your lower cr. add more boost. if you are still seeing limited gains you may want to look into some supporting mods.

 

[Marc s]

Well I finally got enough miles on my new forged engine to add some more boost and try and improve on my 440 hp.
So I put a reichard racing 2.89 pulley on with a heavy duty tensioner and a gator back belt to bring my boost to 15 psi from the 10 that I had.

I just got back form the dyno. the first pull showed it was way rich in the top end, and my power was down to 395hp. so we started taking away fuel until we got it right and still had only had only 415 hp.
so We started adding timing ( remember we started with the same tune that made 440 hp adn 395 tq a month earlier)

We ended up at 21 deg total timing and 458 hp 427tq.

The only other thing I can add is that I did drop the compression to 8.6 to1 so I can run more boost and shoot some nitrous.

Question? how high can I go with the timing on pump Gas? 93 oct.

It just seems like a lot of work for such little gain.
and seat of the pants says its no faster. ( track day thursday will tell)

Going back a few years, on my stock 3V, I made 569whp on 14-15lbs of boost. I decided to build a forged motor and lowered my compression to 8.25:1. On the same tune, I lost 90whp. I had to raise the boost to 23lbs to get back to 575whp. I unstrapped the car, tore the engine apart and raised the compression to 9.73:1. Low compression and centri's never work. The car will be a dog under the curve and will only have enough cylinder volume towards the peak. However, you will never be able to spin the 2200 fast enough to compensate for the low compression. The 2200 moves 1450CFM of air. you will need a much larger centri to make the power that you could have made with more compression and the 2200. With the compression that you have, nitrous is a good way to add cylinder pressure.

On my engine with 9.73:1 compression, I make 20lbs of boost on pump gas and 18.5 degrees of timing. Keep in mind that my block is zero decked. Zero decking improves quench and helps resist detonation. I also have very large cams that bleed off some cylinder pressure. To keep it simple, cylinder pressure + timing + heat is what creates detonation. Boost is just a measure of restriction. Assuming everything is built right in your engine, you really do have 8.6:1 compression, and your ring end gap is correct, I would not hesitate to throw 20lbs of boost at it. I would back the timing down to 15 degrees and work your way up 1 degree at a time and keep the A/F around 11.2. I would set it up so it pulls timing once the IAT's reach 115-120.

The good Terminator tuners believe that with stock compression, 20lbs of boost and 20 degrees of timing is safe with 92 octane. Their IAT's are much higher than yours will ever be.

 

[fhlh]

I have a built 9.2:1 @15psi and only getting 530rwhp =-/ ... it just aint right


why my procharger goes limp at higher rpm.. why am I not in the high 500s.. I also have meth inj but they didnt change the tune for it.. ahhhhhhh.. now I'm brok and unemployed and ahhhhhhhh

LostSOLE

brotha needs a new pair of shoes!

 

[lostsoul]

nooo sole..hahah

I have the stock heads except stiffer valve springs. New blower will have to wait till I find a job or some forum homies sets up a donation thing