AFR Install
Thread Starter
TECH Fanatic
Joined: Jan 2002
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From: harrisburg, pa
Well Tony..I have to say you were right on the button and know your product..
SAE 423.3rwhp and 383rwtq but it would have made 430-440rwhp with some lifter bleed corrected...the peak was flat. Im not sure if the owner is going to swap back the stock rockers or change lifters/preload. There was zero KR on Sunoco 94 and A/F was 12.8. I dont have the dyno graph. Torque was FLAT!
Weather was interesting... .95 correction factor on the dyno..so the actuals were alot higher. We rechecked the dyno using:
http://wahiduddin.net/calc/calc_hp_dp.htm
64F, 30.31, 21F, 160
http://weather.noaa.gov/weather/current/KPTW.html
and it works out.
Hope you guys use this info to help you select the right parts for your combination. This owner is happy and this is what we expected. Camshaft selection is very important with these heads.
SAE 423.3rwhp and 383rwtq but it would have made 430-440rwhp with some lifter bleed corrected...the peak was flat. Im not sure if the owner is going to swap back the stock rockers or change lifters/preload. There was zero KR on Sunoco 94 and A/F was 12.8. I dont have the dyno graph. Torque was FLAT!
Weather was interesting... .95 correction factor on the dyno..so the actuals were alot higher. We rechecked the dyno using:
http://wahiduddin.net/calc/calc_hp_dp.htm
64F, 30.31, 21F, 160
http://weather.noaa.gov/weather/current/KPTW.html
and it works out.
Hope you guys use this info to help you select the right parts for your combination. This owner is happy and this is what we expected. Camshaft selection is very important with these heads.
Last edited by SAM98WS6; Feb 3, 2005 at 03:27 PM.
The combo turned out well although some things I would recommend on others. 1) Notch the pistons, use a higher lift cam and a smaller chamber. This customer would not agree to notching and P-V was a concern. 2) Use stock rockers or use Morel lifter with aftermarket rockers. I've personally seen the Morels solve the flat spot at higher rpms.
This customer has the FLP headers and Y pipe. That Y pipe is a bottle neck at the merge and we've seen 12 rwhp gains from swaps to Kooks.
There is a solid 25 rwhp left in this with some more bolt ons like a FAST 90 and a set of Kooks. I have no doubt. Swap the aftermarket rockers or add the Morels and another 5 or so could be had up top.
The torque curve was awesome. Very round and symetrical. Power was good for what we had. Driveabilty was like stock. Just a slight lope at idle. The customer was very happy with the combo and is exactly what he wanted and thats what matters.
This customer has the FLP headers and Y pipe. That Y pipe is a bottle neck at the merge and we've seen 12 rwhp gains from swaps to Kooks.
There is a solid 25 rwhp left in this with some more bolt ons like a FAST 90 and a set of Kooks. I have no doubt. Swap the aftermarket rockers or add the Morels and another 5 or so could be had up top.
The torque curve was awesome. Very round and symetrical. Power was good for what we had. Driveabilty was like stock. Just a slight lope at idle. The customer was very happy with the combo and is exactly what he wanted and thats what matters.
Thread Starter
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From: harrisburg, pa
Oh yeah...and we dynoed in a garage full of stripped 2005 CTS-V's and C6 getting cages...new car parts laying everwhere
Nothing like seeing a CTS-V trunklid with rags and tools laying on it beside a workbench.
Nothing like seeing a CTS-V trunklid with rags and tools laying on it beside a workbench. Thread Starter
TECH Fanatic
Joined: Jan 2002
Posts: 1,205
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From: harrisburg, pa
I dont think we can get a graph yet..the dyno PC had issues...hold your horsies.
The owner said he is completely satisfied...drives just like stock...didnt want his wife to notice he did anything to the car...you know how that goes...
The owner said he is completely satisfied...drives just like stock...didnt want his wife to notice he did anything to the car...you know how that goes...
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so, does this end the AFR head debate over whether or not they work? and do you think it helps to support the test that VHP did by putting the heads on a stock c5? after all, you raised compression as well as VHP/AFR did. just comparing the before and after peak results: a gain of 79 rwhp and 33 rwtq. great hp gain. lacking in the tq gain. but this is only peak. waiting on the actual graphs to see the entire curve like everyone else. 
good job though.
good job though. Last edited by mrr23; Feb 3, 2005 at 09:00 PM.
Hey Guys...
I'm glad things seemed to work out well and I also look forward to seeing the graghs etc.
To be perfectly honest, I don't think this combination was "optimized" to its full potential in the sense that it could have used more CR, tighter quench, and an exhaust system that wasn't as restrictive to help the high RPM charge where that cam choice would have shined a bit more. I actually question whether THIS exact combination with a slighlty smaller cam would have made more torque everywhere and similar peak numbers because they seem to be hampered by the exhaust anyway. Certainly the larger cam leaves more HP to be tapped into as the owner continues to get bitten by the "speed bug" and start addressing a few of the other areas that might be holding him back currently.
Considering the combination as a whole, I think the gains were impressive, especially if there was more to be tapped into with a different lifter or rocker set up as was previously mentioned.
Thanks,
Tony
I'm glad things seemed to work out well and I also look forward to seeing the graghs etc.
To be perfectly honest, I don't think this combination was "optimized" to its full potential in the sense that it could have used more CR, tighter quench, and an exhaust system that wasn't as restrictive to help the high RPM charge where that cam choice would have shined a bit more. I actually question whether THIS exact combination with a slighlty smaller cam would have made more torque everywhere and similar peak numbers because they seem to be hampered by the exhaust anyway. Certainly the larger cam leaves more HP to be tapped into as the owner continues to get bitten by the "speed bug" and start addressing a few of the other areas that might be holding him back currently.
Considering the combination as a whole, I think the gains were impressive, especially if there was more to be tapped into with a different lifter or rocker set up as was previously mentioned.
Thanks,
Tony
Sam sent the graph. This is the best I could do with it. Definite valvetrain harmonics up top. Stock rockers would cure this. I've also seen the Morel lifters cure this but only if it was collapsing stock lifters. Beautiful flat torque curve.
Thread Starter
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From: harrisburg, pa
yeah..he sent me a fax...and our old scanners dont work with our new PCs...so i went beggin for a scan job...best i could get
I asked him if he was up for trying the stock rockers and 3" flowmaster Y welded in...didnt hear back.
I asked him if he was up for trying the stock rockers and 3" flowmaster Y welded in...didnt hear back.
Originally Posted by mikey
Ask him if he wants to try a set of Kooks headers and ORYP. I'll make him a deal he can't refuse. Then we'll see some power 
Guys...
Looking at that gragh it seems pretty obvious there is a slight loss of valve control due to the heavier rocker arms past 6000 RPM's....I bet stock rockers pick this engine up 5-10 without a problem.
I've hit on this in a few other threads but just to reiterate, anytime you run an aftermarket heavier rocker set-up, you must opt for our 8019 spring upgrade. It handles the heavier valve gear much better at RPM due to the additional seat pressure and spring rate. Also, at that point in time an aftermarket lifter (Comp, Crane, Morrel) is not a bad idea either.
Tony M.
Looking at that gragh it seems pretty obvious there is a slight loss of valve control due to the heavier rocker arms past 6000 RPM's....I bet stock rockers pick this engine up 5-10 without a problem.
I've hit on this in a few other threads but just to reiterate, anytime you run an aftermarket heavier rocker set-up, you must opt for our 8019 spring upgrade. It handles the heavier valve gear much better at RPM due to the additional seat pressure and spring rate. Also, at that point in time an aftermarket lifter (Comp, Crane, Morrel) is not a bad idea either.
Tony M.
