Why is this such a slug without the spray?
Why is this such a slug without the spray? Heres what I have:
Small Block Chevy (not an LS1)
Accel DFI, Novi2000 producing 11psi. Intercooled, TPIS Miniram(which I'm not too fond of), Dart II Iron Heads 2.02/160 valves, headers, into 2.5" duals. 8:1 compression, oringed block, splayed caps, good crank and rods
Cam specs: roller hydraulic 236/248 @.050 113LSA, .586"/.562" lift
Went to the dyno yesterday, and this set-up only put down 365rwhp? The a/f was right around 12:1 the entire pull. I only run pump gas, and total timing at max boost was set at 22deg.
Why is this so slow?
Am I being too conservative on my timing map?
Then I spray it with a 300 shot which brought it up to 663rwhp, which is good, but I expected bigger numbers from the blower.
Small Block Chevy (not an LS1)
Accel DFI, Novi2000 producing 11psi. Intercooled, TPIS Miniram(which I'm not too fond of), Dart II Iron Heads 2.02/160 valves, headers, into 2.5" duals. 8:1 compression, oringed block, splayed caps, good crank and rods
Cam specs: roller hydraulic 236/248 @.050 113LSA, .586"/.562" lift
Went to the dyno yesterday, and this set-up only put down 365rwhp? The a/f was right around 12:1 the entire pull. I only run pump gas, and total timing at max boost was set at 22deg.
Why is this so slow?
Am I being too conservative on my timing map?
Then I spray it with a 300 shot which brought it up to 663rwhp, which is good, but I expected bigger numbers from the blower.
Trending Topics
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
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
You've got to remember there's a 700R4 behind it which isn't helping much. Also what is the overlap between the valves on the cam. Is it in the negatives? If not you could be blowing the boost right out the exaust valve. Get rid of the miniram quick. Another thing. Were is the peak power? Are your valve springs weak? Also check your mechanical aspect of your timing. If somthing is off, the DFI could read 22* of timing but the motor could see none or even negatives. If it's none of that then all i can say is jump on the roof.
Well since you're running 16 degrees of overlap i would say that could be a huge problem right there. Check all charge piping and make sure you're actually seeing 11 lbs. Then do a compression check.
Nate
Nate
Wow, thanks for everyones help so far!
The compression is good, its a fresh motor.
The actuall timing is matched to the DFI.
Valve springs are stong as hell because of the wet shot.
The cam is really a nitrous cam.
I guess that it cam+ miniram is the biggest problem.
I'll do some more tuning, and probably leave it for this season, since i just got it together. It still hauls on the spray, so when I need to put it down I can.
Slowhawk, I've been looking for a reason to get down there, this might be a good time.
The compression is good, its a fresh motor.
The actuall timing is matched to the DFI.
Valve springs are stong as hell because of the wet shot.
The cam is really a nitrous cam.
I guess that it cam+ miniram is the biggest problem.
I'll do some more tuning, and probably leave it for this season, since i just got it together. It still hauls on the spray, so when I need to put it down I can.
Slowhawk, I've been looking for a reason to get down there, this might be a good time.
theres nothing wrong with the miniram....welll as long as you get one of the ones thats not porus... and it machined right so it seals properly... lol.
biggest problem i see is a bit of a mismatch.
CR is setup for big boost... but you arnt running big boost so its hurting you.
the cam is NOT forced induction friendly... jumping to a smaller cam in this case would give you a power increase.. valve overlap is BAD in forced induction motors.
biggest problem i see is a bit of a mismatch.
CR is setup for big boost... but you arnt running big boost so its hurting you.
the cam is NOT forced induction friendly... jumping to a smaller cam in this case would give you a power increase.. valve overlap is BAD in forced induction motors.
TECH Enthusiast
Joined: Jul 2004
Posts: 546
Likes: 1
From: Washington
I bet if you calculated your dynamic compression ratio with that cam, you'd be somewhere around 6.5:1. Your dynamic boost compression ratio, then, might be as high as 11:1. Long story short, as most everyone has pointed out, it's just your cam that's killing your power.
I ruin the end of films...
iTrader: (2)
Joined: Nov 2002
Posts: 1,545
Likes: 0
From: Taking back some video tapes
More lift. My old blower cam was 236/242, .600/.612 @ 114 and that was a small Procharger w/ a 100-hit.
I don't see a problem w/ 8:1 compression on iron heads. Aluminum heads, yes, that's a bit low, but not too bad w/ irons.
I don't see a problem w/ 8:1 compression on iron heads. Aluminum heads, yes, that's a bit low, but not too bad w/ irons.
I disagree with most of you, except for the boost part.
I run 236/246//114//590/600 cam, makes 754rwhp at 6600 thru unlocked T400, with 21 psi. I make over 700rwhp by 5000 rpms and my average hp is over 700rwhp. My cam was originally going to be 236/242 from Terry but I asked for more exhaust duration.
Sure you are not getting crazy belt slippage or something?
I'd be running 15psi at least with that compression.
I run 236/246//114//590/600 cam, makes 754rwhp at 6600 thru unlocked T400, with 21 psi. I make over 700rwhp by 5000 rpms and my average hp is over 700rwhp. My cam was originally going to be 236/242 from Terry but I asked for more exhaust duration.
Sure you are not getting crazy belt slippage or something?
I'd be running 15psi at least with that compression.
Wow, thoes are some serious numbers with a kinda-similar cam....huh
Well, its easy enough to increase boost. I'm not getting belt slip, but it has a monster pulley on the blower, so thats why its only producing 11 psi. I had called paxton directly before about getting a smaller pulley, but they couldn't help me because its a custom set-up.
Anybody reccomened a place who could set me up with a pulley for the Novi?
Well, its easy enough to increase boost. I'm not getting belt slip, but it has a monster pulley on the blower, so thats why its only producing 11 psi. I had called paxton directly before about getting a smaller pulley, but they couldn't help me because its a custom set-up.
Anybody reccomened a place who could set me up with a pulley for the Novi?
Originally Posted by Pro Stock John
I disagree with most of you, except for the boost part.
I run 236/246//114//590/600 cam, makes 754rwhp at 6600 thru unlocked T400, with 21 psi. I make over 700rwhp by 5000 rpms and my average hp is over 700rwhp. My cam was originally going to be 236/242 from Terry but I asked for more exhaust duration.
Sure you are not getting crazy belt slippage or something?
I'd be running 15psi at least with that compression.
I run 236/246//114//590/600 cam, makes 754rwhp at 6600 thru unlocked T400, with 21 psi. I make over 700rwhp by 5000 rpms and my average hp is over 700rwhp. My cam was originally going to be 236/242 from Terry but I asked for more exhaust duration.
Sure you are not getting crazy belt slippage or something?
I'd be running 15psi at least with that compression.
Can you use Mustang blower pulleys? if so try the Mustang sites.
If not, perhaps talk to Lee @ ASP.
Something does not make sense with your combo, I'd expect you to be over 550rwhp.
Is your converter really loose or your trans messed up?
If not, perhaps talk to Lee @ ASP.
Something does not make sense with your combo, I'd expect you to be over 550rwhp.
Is your converter really loose or your trans messed up?
