forged Ls2 402 dyno
Thread Starter
Instructor
Joined: Sep 2006
Posts: 165
Likes: 0
From: laguna niguel ca
forged Ls2 402 dyno
What do you guys think about the hp curve past 5300 rpms, i still have the stock intake manifold, and shorty headers, would a fast 90/90 and a set of long tubes fix the plateau at 5300 rpms? I love the numbers it just seems to run out of steam a little early.
im running a 12:1 compression ratio, w/ 224/228 cam. 205cc afr heads.
http://i5.photobucket.com/albums/y15...eatherDyno.jpg
im running a 12:1 compression ratio, w/ 224/228 cam. 205cc afr heads.
http://i5.photobucket.com/albums/y15...eatherDyno.jpg
Pro
Joined: Jun 2005
Posts: 734
Likes: 0
From: Austin TX
That cam is very tiny for those cubes. Me thinks it may be why the curve is limited. I'd suggest moving to something near the high 230s and near .600 lift to let those afrs shine.
Edit: didn't see you had shorty headers on there. I'd definately get some long tubes as well. LS6 intake manifold should work well for you if you don't want to spring for the fast.
Edit: didn't see you had shorty headers on there. I'd definately get some long tubes as well. LS6 intake manifold should work well for you if you don't want to spring for the fast.
Last edited by Boob; May 8, 2008 at 11:21 AM.
Thread Starter
Instructor
Joined: Sep 2006
Posts: 165
Likes: 0
From: laguna niguel ca
I had a smaller 220/224 cam in my old ls6 w/ the 205cc afr's, otherwise it was a stock block w/ the same external set up and dyno'd 435 @ 6600 rpms w/ 390 ftlbs.
I did upgrade the cam slightly when the 402 went in to a 224/228 because i liked the drivability of the smaller cam. I would think that all else being equal the ls2 402 w/ bigger cam should make more hp than the ls6 stock block. This leads me to thinking the intake/exhaust set up might be choking the curve down a bit. kinda looking to see if my logic is right enough to go out and nab a new intake/exhaust. The cam is in and im not wanting to spend the money on diff one to scoop another 10 hp and lose drivability when if im thinking straight i should pull another 40+ w/ a fast 90 and some better headers. Looking around im not seing too many people w/ 402's that arent running a better intake/ headers. i guess what im saying is that i know a better intake/headers will yeild me power, but my question is will it pull the hp up at higher rpms, or is that all the cam's fault?
I did upgrade the cam slightly when the 402 went in to a 224/228 because i liked the drivability of the smaller cam. I would think that all else being equal the ls2 402 w/ bigger cam should make more hp than the ls6 stock block. This leads me to thinking the intake/exhaust set up might be choking the curve down a bit. kinda looking to see if my logic is right enough to go out and nab a new intake/exhaust. The cam is in and im not wanting to spend the money on diff one to scoop another 10 hp and lose drivability when if im thinking straight i should pull another 40+ w/ a fast 90 and some better headers. Looking around im not seing too many people w/ 402's that arent running a better intake/ headers. i guess what im saying is that i know a better intake/headers will yeild me power, but my question is will it pull the hp up at higher rpms, or is that all the cam's fault?
Last edited by nvygw171; May 8, 2008 at 11:56 AM.
Pro
Joined: Jun 2005
Posts: 734
Likes: 0
From: Austin TX
That's a hard question to answer. What intake is on it now?
I don't see a double hump tq curve, so I'm assuming you have an ls6 intake on there. For a cam that size it should flow up to about 6100 rpm. My graph gets to it's highest hp around 5700 and stays there untill 6600 when we let off. Didn't drop like yours does. Of course I have a significantly bigger cam likely on a tighter LSA.
This makes me think a limitation, if any, can be found in your exhaust setup. Other than that I'd say it would likely be the cam. Those heads give you a lot of options. A good tuner should be able to make a bigger cam equally driveable for you.
On a stock unported throttlebody and ls6 intake (383 ci) I'm putting out over 480 rwhp on an LS6 intake manifold.
I don't see a double hump tq curve, so I'm assuming you have an ls6 intake on there. For a cam that size it should flow up to about 6100 rpm. My graph gets to it's highest hp around 5700 and stays there untill 6600 when we let off. Didn't drop like yours does. Of course I have a significantly bigger cam likely on a tighter LSA.
This makes me think a limitation, if any, can be found in your exhaust setup. Other than that I'd say it would likely be the cam. Those heads give you a lot of options. A good tuner should be able to make a bigger cam equally driveable for you.
On a stock unported throttlebody and ls6 intake (383 ci) I'm putting out over 480 rwhp on an LS6 intake manifold.
Thread Starter
Instructor
Joined: Sep 2006
Posts: 165
Likes: 0
From: laguna niguel ca
Correct it is an ls6 manifold. Is making my peak hp @ 5200 rpms on a 402 stoker abnormal or am i just used to seing a diifferent kind of curve on my ls6. Ill try 1 7/8" long tube header and and see what that does. are you running headers on your ls6? what do you think about the 1.8 -1.85 roller rockers? would the give enough lift to pull the curve up or am i seriously lacking in the cam dept?
Last edited by nvygw171; May 8, 2008 at 12:27 PM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Instructor
Joined: Sep 2006
Posts: 165
Likes: 0
From: laguna niguel ca
I had the 205's on the previous ls6, im going to swap the shorty's for some lt's and see if it doesnt bump up the curve a little. I would like to get close to the 480 numbers that seem to be fairly common for mild 402's, my lack of LT's seems to be the biggest choke point i have right now. These heads should see me to that number right?
Last edited by nvygw171; May 9, 2008 at 02:47 PM.
Melting Slicks
Joined: Sep 2003
Posts: 2,062
Likes: 117
What do you guys think about the hp curve past 5300 rpms, i still have the stock intake manifold, and shorty headers, would a fast 90/90 and a set of long tubes fix the plateau at 5300 rpms? I love the numbers it just seems to run out of steam a little early.
im running a 12:1 compression ratio, w/ 224/228 cam. 205cc afr heads.
http://i5.photobucket.com/albums/y15...eatherDyno.jpg
im running a 12:1 compression ratio, w/ 224/228 cam. 205cc afr heads.
http://i5.photobucket.com/albums/y15...eatherDyno.jpg
Long tubes and 90/90 will give you a lot more than only at 5300rpm...
You will gain everywhere from 3000rpm to 6500rpm.
Christian
