Originally Posted by Sm5654
I have decided to buy myself a piece of mind and upgrade the LS7 due to this valve guide debacle. Patrick at Quality Motorsports in Lewisville, TX and I discussed what is best for my needs/wants and here is what we came up with:
WCCH-GM Stage 2 CNC LS7 Heads
Cam package; dual valve springs, 160 thermostat
Ported intake manifold and throttle body
LG carbon cold air intake
My question to the group is what advantages do I gain by also installing headers? I am at my budget limit for this upgrade so if they are installed it will be at a later time. I know the car will sound throatier (is that a word?) and gain some HP, but it seems like $2k for an exhaust note is kinda steep. Will it be worth it to install them by themself at a later date?
Question 2: the cam spec he gave me is 237/252? What does that mean and how much HP can I expect to put down? I'm hoping to hit around 550.
Thanks for the info gentlemen...
First off, congrats on your choice in modifications, and for being proactive in managing the valve issues of the LS7. You have chosen some of the best parts available.
The following is a comparison dynograph in my car with the listed modification before and after the installation of KOOKS Headers and catted X pipe.
The car was tuned with the listed modifications and while still running the stock exhaust manifolds, run for a few weeks, and then the headers were added in place of the stock manifolds, and the car retuned for the headers.
The graph and the Run Files are enclosed for both. Bottom line is if you're doing a cam, then I'd strongly recommend the headers if you can swing them. The bottleneck in my original setup, was the stock exhaust manifolds and cats.
This is actually a continuation of my prior thread.
In that thread I ultimately made the decision to add headers.
With the headers and the tuning now taken over by Ed Hutchings, the car is at 527.34 RWHP/492.75 RWTQ over the prior 508.02/482.81 with the stock manifolds.
Peak gains are impressive, but the real benefit of the headers, and what has made them well worth the money, is demonstrated at around 3500 -3700 RPM where there is a gain of 26.81 RWHP/ 38.05 lb/ft RWTQ
over the stock manifolds. At 3750 RPM there is about a 40 RWTQ difference.
....and yes, you can feel it.
There is a gain throughout the entire RPM range, as indicated in the comparison dyno chart.
So if anyone is wondering how much power I was leaving on the table by running the stock manifolds, the answers are below.
Look at what happens, with the horsepower and torque readings comparing the pulls with the stock manifolds vs with the headers, at any given RPM, but especially from about 3500RPM on in to 6800 RPM which is where we shut it down.
This is the "before", ie the setup without headers and using the stock manifolds with the best tune that we could get.
This is the "after", ie the setup with headers and using the stock manifolds, and following final tuning for the headers.
DRM Bilstein shocks
2008 axle shafts
Katech LS9X clutch
Tick remote clutch bleeder
Callaway Honker CAI
Ported stock Throttle body
Ported stock intake manifold
Katech Torquer 110 Cam
Katech C5R Timing Chain
WCCH Stage 2 Cylinder Heads
KOOKS 1 7/8 headers X Pipe with Cats
NGK TR6 Spark plugs
Tuning by Ed Hutchings
Forum member RIchieRichZ06 got even more impressive gains after going with headers from the stock manifolds.
With regard to your second question, this is a good article if you are interested in what the numbers mean.