kwik_ls1

iTrader: (60)

Hey all, I was just wondering if anybody has any advice for me. Let em start out by saying I have a 99 Z28 and it has all bolt-ons such as LT's, offroad Y, catback exhaust, ATI underdrive superdamper, etc. I put a D1SC Procharger on it with 42lb injectors and a Racetronix 255 pump. I took it to Hardcore Motorsports and it is showing only making 400 rwhp on a Dynojet dyno. I know my car is running super rich so I am wondering if the actual tune is the problem. The motor has 60k on it with no internal work done to it. I talked to a couple of guys saying they were pushing 500rwhp at the rear with the exact same mods. So could it be the tune or something else? I have the Procharger kit from SDCE and it has the good tensioner so there is no belt slippage, pushing a full 9 lbs of boost. Let me know guys.

Thanks.

Ed Blown Vert

iTrader: (2)

Did you tune it? You have to adjust for the larger injectors. You will run real rich if you don't.

What is your AFR?

kwik_ls1

iTrader: (60)

I had my car tuned at Hardcore Motorsports and they tuned it but it ran very rich. They tuned it for all of the variables and it still ran like crap. It was good at WOT but at cruising speeds it had big time hesitations that I don't think should be there. Plus at idle, it was spitting out carbon or raw gas. Plus it fouled out 2 sets of HGK TR6's. It got really crappy gas mileage too. It should not be like that at all. What do you think?

kwik_ls1

iTrader: (60)

By the way, they said my A/F ratio was 12.5:1. I am not sure if that is good or no. I haven't messed with the tuning part ever so I am unsure until I get a wideband. I think the lower the number the richer the car is running and higher is leaner.

LSs1Power

iTrader: (5)

12.5 AF is not rich at all... In fact its on the lean side giving that it will run leaner on the streets. Do a compression test and see if u have any problems there. How much timing are u running? You have a problem somewhere in the tune or engine.

Blackbird

find a new tuner

Ed Blown Vert

iTrader: (2)

White_Hawk

iTrader: (3)

I think I dynoed my car before you guys up there right before memorial day. When I pulled my car out, Dave pulled your's in. He couldn't even get it into the dyno room because it was running so bad. I know you had some bigger injectors in there, but it should have still idled (unless the plugs were already gone). It sounded like there was something wrong with it when you brought it there - like a head gasket or a ringland. I suggested to Dave that he run a compression/leakdown test on the car before tuning it. I don't know if he did or not, you might want to call him and ask.

I'd check the plugs, do a compression/leakdown, and if those are all OK, get the car back up there and have him fix it. Dave is a pretty good tuner, he just moved back to Flint from SanDiego. You have any scans of it you could post?

-Geoff

Ferocity02

iTrader: (60)

I have the same problem, mods and dyno numbers in sig.

Got Me SOM

iTrader: (2)

yea something isn't right, at minimum that car should be making 450 to the tire.

ferocity your car should be making close to 500.

Ferocity02

iTrader: (60)

I figured that out myself. The question is where the hell is my 100+ rwhp?!?!?

Ed Blown Vert

iTrader: (2)

Whats your timing and AFR? Any KR?

DarkblueTA

AGREED! and fast....stay off the 'WOT go-pedal' untill you do

NoGo

iTrader: (2)

Stock valve springs??

kwik_ls1

iTrader: (60)

Thanks for the responses all. It has stock springs, cam , heads etc. It has all stock internals. I talked with Procharger and they said that it should make 60% more hp than stock. It should at least make an extra 150 hp. It has every single bolt-on that you can do. It only made 400 rwhp. It should've made at least 450 hp. Anyways, I am not totally sure what the timing is set at or the actual AFR. I know he said 12.5:1. I am not sure if that is at WOT or just during cruise or idle. The car is back at Hardcore now and am waiting to go get it tonight. He tuned it kind of lean but it is still puffing black smoke at WOT and at idle, running hella rich, plus it's just eating gas. The plugs got fouled out in 1 week after I had it back and that is why I took it back to them, plus an O2 went out on it.

Geoff, they did a leak down test on it and it came back normal. The car idles and drives fine at WOT but when it is cruising, there is big time hesitation like it is dumping too much gas in the cylinders and it can't keep up with all of the fuel. Let me know what you guys think.

Ed Blown Vert

iTrader: (2)

Sound like he didn't tune correctly for the injectors. Any idea what your LTFT's are?

Got Me SOM

iTrader: (2)

right that tells you she's too rich. I'd take it to a different shop that KNOWS how to tune ls1's that is a sponsor on this board. You must have a loss of compression or something.

NoGo

iTrader: (2)

Post the dyno graph. A picture is worth a thousand words.

FWIW, on good portion of LS1 cars, the stock springs can't hack it under boost and have trouble closing against the boost pressure.
This type of problem can clearly be seen on a dyno graph as an irregular flatened portion of the curve in the upper RPM.

Although it sounds like the tuning is not spot-on, in my opinion, even if the car had the absolute worst possible tune in it you should still be making in the ballpark of 450+. Tuning is the icing on top, not the meat of the power production. I doubt that you are going to find 100+ ponies in the tuning.

Phoenix 2001

Some told me that some adjustments would need to be made to lower the comp ratio on a LS1 to accommodate a super charger. This is what I heard but not sure.

NoGo

iTrader: (2)

Lowering the static compression is a good idea in terms of reducing the odds of detonation on pump gas (ie increasing setup reliability), but is not a necessity at lower boost conditions (up to ~10 psi stock bottom end).