We finished the build of a customer's 2000 Camaro SS this last week. The car has our LS7 ased 400 shrot block, PRC CNC'd L92 heads and the stock L76 intake, 60# injectors (for a dry shot later on), 240/252 114LSA camshaft, Kooks 1 7/8" LT's, true duals with some funky mufflers. The car is a 6 speed with a 3.73 equipped 9" rear-end. It has the stock MAF on it.

After the tune (Thanks Jason @ Texas Speed!!), the car made 515rwhp and right about 485ftlbs of torque. I'll post the graph Monday, but the torque curve is nice! The torque is already close to 450ftlbs by 2000rpm!! Peak horsepower was around 6400rpm if I recall correctly.

 

what might be holding that back? i would think it would make more whp. the 500 ftlbs is great, only reason iam asking is my 416 made all most that with livernoise cnc l92 and i thought it was being held back.

 

nice torque!

 

Great seeing more L92 headed motors over 500 rwhp.

 

Nice numbers fellas!

 

I think the L76 intake, stock MAF, restrictive mufflers, and the 3.73's 9 bolt are all keeping it from being a dyno queen. We will be addressing those issues with the customer in the future and working on this some more, but for now I think the numbers are in line where they should be!

Yall will like the torque curve! I should have remembered to bring the dyno sheet home to scan it so that I could get it uploaded sooner

 

Very good numbers Matt and congrats on your efforts...... Not knowing the flow data on the PRC ported L-92's it would appear that the camshaft selection would be designed to crutch a poor flowing exhaust port/system compared to the intake port/manifold flow numbers. The stock LS-7 uses a short intake duration while the exhaust duration is quite different, (read large). It's something like 211/230 ballpark figures. I thought GM did this to offset a restricted exhaust system given the stock exhaust manifolds/mufflers on the Z06. The Kooks 1 7/8" headers should flow very well however with suspect mufflers down stream in your application. Just sitting here looking at camshaft duration numbers that some builders use, there appears to be at least two different schools of thought. One being extremely wide split between the intake and exhaust duration while others have what I would call a more conventional duration split, (say 4 degrees or so). The other thing that is of note here is the use of the L-92/L-76 head/intake conbination on large displacement engines. The L-92's would need to be modiflied/CNCed for use in this application at some dollar cost which is unknown to me for optimum results. After the heads are CNCed for better flow you have to install a somewhat restricted intake manifold. Unless I'm missing something here you have a head/intake manifold selection, (LS-7) on the shelf that may show somewhat better numbers than the modified L-92/L-76 combination at around the same cost or within a few hundred dollars of each other. The modification to the LS-7 heads would be to change out the springs and retainers if I am correct. Have you, (SDPC) tried the LS-7 combination on your 440 short block? It's too early in the morning for this.

D.J.

 

split is to address I/E ratio rather than anything past the port IIRC.

A log showing MAP pressure at WOT would indicate if there was an intake restriction. If it differs from Barro, then there is the answer at least on the intake side anyway.

 

Thanks ringram, I understand the I/E ratio at the head. But I believe the system should be looked at as a whole as well. Most of us can't run open headers. I also understand that a restricted intake would pull a vacuum at WOT. Patrick G. has addressed the down stream aspect of his exhaust system by using a merge collector at the junction where both header/exhaust pipes meet on a F-body. I am assuming he is using it for that effect......................I brought up the L-92 head issue in the past and someone brought up the point of the L-92 being not respected due to it's low cost. I don't know how much cheaper a CNCed L-92 is over a box stock LS-7 head. I'm sure some of the guys here will chime in later on today and set me straight. To me that LS-7 head is a great value given the Ti valves and light weight exhaust valve and it's flow data. I know guys have brought up the lash caps coming off using high lift cams, etc. but Katech says that hasn't been a problem on their builds, (Spintron & real world data).

D.J.

 

There's the graph! It actually made power a little higher up than I had remembered, as you can see! We'll get a bigger MAF and some mufflers that flow (or straight pipes) on the car and she should see 525rwhp or so.

And yes, to answer the questions about the camshaft....the camshaft was designed to aid the exhaust performance a bit. Because of the weaker exhaust side of the L92 heads (same goes for the LS7 heads actually) and these weak/restrictive mufflers we decided to give it some extra split to help the situation.

 

Crazy torque right from go!

 

UPDATE: The car had some throttle control issues with the bracket that was fabricated for the L76 intake (cable driven TB car)....now it's is going 100% TPS and it made 530rw with 502tq

 

Holy bat poop. Can I swap a kidney for a LS7 topped version of this?

 

WOW-that torque is sick right out of the gate

 

That's a lot of tq! Now try to get that to hook!!! Congrats!

 

I also liked where the power curve laid up top....not the L76 intake issues you see alot of falling on its face around 6400rpm or so

 

Most of that gain was actually from the retune that was done at Real Performance Motorsports in Lewisville......

 

Nice pickup from where ever it came from.

D.J.

 

awesome! can you post the new 530/502 graph?