383 dyno #'s? Having issues
383 dyno #'s? Having issues I'm trying to figure out what my car should be putting out. This isnt jay2002ss. this is his roommate. i am also registered on here as 1Bad68Camaro but i cant get his account to log off so i can use mine. I have a 68 camaro. 383 stroker, flat tops with 10.5 to 1 comp. Brodix track 1 heads, comp cams hydraulic roller with .540 lift and 242 deg duration, edelbrock performer rpm airgap intake, holley 750 with vacuum secondaries, k&n pro-flo filter kit, doug thorley tri-y headers. I put it on the dyno yesterday and thought it would do well. The car normally pulls to 7k pretty well. However, on the dyno the hp actually peaked at 4400 rpm and held that same peak number all the way to 6k where he shut it down. Also the a/f was pretty strang. He took it from 11 to 1 up to 12.4 to 1 and it actually lost 2hp. I uncapped my dumps right after the headers and only picked up 2 hp but the a/f went nuts and was fluctuating alot. Also the peak numbers from 4400 and up where fluctuating alot. There is alot of spikes up and down on the chart. I was told this cam should pull up to at least 6500. I believe i have at least one fouled plug and i know the power valve on the carb is acting up. Going to put a new valve in it today and try it. Any idea what peak numbers should be around if it hit 330 rwhp at 4400 rpm? Thanks for any info.
That sounds like a combo that Cory had on his 1500 series truck...
383, Lightly ported Track 1 heads, 10.5 to 1, Air gap intake, 750 holley, shortie headers into good dual exhaust. The only change was we used a 222/230 ish cam(dont remember exact spects GM/crane 846 cam I believe). After tuning it made 345Crwhp (through unlocked verter). That cam pulled all the way up to he let off, I think he was shifting at 6k rpm...I would expect sense you'll have less loss through drive train that 360ish sounds like a good number to shoot for, maybe 380 with that cam....
Also, don't worry about your final AFR...Some engines don't respond well to leaner numbers...I believe this really is cause by cyl to cyl variance which a single wide band can't account for..Example my engine liked 12.5 AFR over 13 to 1. I gained 7rwhp running it richer. We had done a lot of drivabilty tuning first and noted some big temp changes at the headers while parked...We adjusted best we could but I knew that this would most likely affect the over all AFR the engine wanted to run at...
383, Lightly ported Track 1 heads, 10.5 to 1, Air gap intake, 750 holley, shortie headers into good dual exhaust. The only change was we used a 222/230 ish cam(dont remember exact spects GM/crane 846 cam I believe). After tuning it made 345Crwhp (through unlocked verter). That cam pulled all the way up to he let off, I think he was shifting at 6k rpm...I would expect sense you'll have less loss through drive train that 360ish sounds like a good number to shoot for, maybe 380 with that cam....
Also, don't worry about your final AFR...Some engines don't respond well to leaner numbers...I believe this really is cause by cyl to cyl variance which a single wide band can't account for..Example my engine liked 12.5 AFR over 13 to 1. I gained 7rwhp running it richer. We had done a lot of drivabilty tuning first and noted some big temp changes at the headers while parked...We adjusted best we could but I knew that this would most likely affect the over all AFR the engine wanted to run at...
Last edited by jimbob; Dec 12, 2005 at 05:26 AM.
Looks like my hei was giving up on me when i get past 4400 rpm. Does anybody know how well the kit works that puts the msd setup on the hei distributer with an external coil? I've heard different opinions here locally.
I believe you would be just as well off using the msd module with their in-cap coil, if you have a blaster 2 coil or something just laying around it may be a pretty good idea.
QUOTE=Jay2002ss]Looks like my hei was giving up on me when i get past 4400 rpm. Does anybody know how well the kit works that puts the msd setup on the hei distributer with an external coil? I've heard different opinions here locally.[/QUOTE]
QUOTE=Jay2002ss]Looks like my hei was giving up on me when i get past 4400 rpm. Does anybody know how well the kit works that puts the msd setup on the hei distributer with an external coil? I've heard different opinions here locally.[/QUOTE]
I already have a msd 6al and blaster 2 coil that i've had a little while, just never got around to installing it. Dont really want to put another couple hundred into a new distributer if i dont have to, especially if mine will work like it with the msd setup.
Ditch the VS Holley and HEI and get a 650 DP Holley #4777 and the Proform centersection #67100C and grab the MSD #8361. Jet the carb 82/82, set timing at 15/34(probably will have to put the lightest springs in the distributer that comes with it) and redyno. Also, what springs are ya runnin on those track 1s? You need Comp Cams #987-16s or equivalent. The HEI system is not good for higher rpm operation(5k and up), 5.5k is about it on a good one. Youn want A/F to be 12.2-12.5 on a carbed set up like this and power should be 380ish if its built properly, whats the full specs on the cam? Cam specs if it was mine and those lifts you posted would be around 108 lsa on a 106 icl.
Trending Topics
Just put on the msd 6al and damn, it made a hell of a difference in how it revs and sounds. Its just running so much smoother now. It still has quite a bit of lag from the carb tho, will be trying another carb tomorrow or friday to see if that cures it. I also have new plugs and a bit roll of wire insulator to put my wires in to make sure they are not arcing anywhere since it gets so hot near those headers. If all goes well i will take her back to the dyno really soon to see what kind of a difference it made.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
