Lt4 dyno pull today....
Thread Starter
Race Director
Joined: Oct 2000
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From: N. Alabama
Lt4 dyno pull today....
This was my first pull with the vette. I have LT4 hot cam in the LT4, corsa's and SLP K & N filter setup.
The best of four pulls is 316 HP/ 303 torque.
A friend predicted these numbers. He has a normally aspirated 382 RWHP LT4 that he dynoed with each upgrade.
Cam alone is not going to get me there. Long tube headers are probably the next best addition with 52 MM TB. :cheers:
The best of four pulls is 316 HP/ 303 torque.
A friend predicted these numbers. He has a normally aspirated 382 RWHP LT4 that he dynoed with each upgrade.
Cam alone is not going to get me there. Long tube headers are probably the next best addition with 52 MM TB. :cheers:
Le Mans Master
Joined: Aug 2002
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From: Clearwater FL
St. Jude Donor '06
Re: Lt4 dyno pull today.... (southern_son)
Did you get the computer tuned for the cam? I thought the hotcam with your setup is good for ~ 30 horses over a 300 baseline; seems you are 15 short unless it was a hot day and your #'s weren't corrected. Or your friend may be right in needing the long tubes (no cats) to take full advantage. Iv'e heard this setup and one word : LOUD...
Le Mans Master
Joined: Aug 2000
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From: Lost in the mountains of TN
Re: Lt4 dyno pull today.... (C4DC)
Did you get the computer tuned for the cam? I thought the hotcam with your setup is good for ~ 30 horses over a 300 baseline; seems you are 15 short unless it was a hot day and your #'s weren't corrected. Or your friend may be right in needing the long tubes (no cats) to take full advantage. Iv'e heard this setup and one word : LOUD...
Le Mans Master
Joined: Aug 2000
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From: Corona CA
Re: Lt4 dyno pull today.... (southern_son)
What kind of dyno did you use, Dynojet or Mustang?
My LT4 stock dynoed at 299. Redynoed on the same Dynojet after Corsas I got the 313 you see in my sig. I am looking at the hot cam and hoping for 340 to the rear wheels.
My LT4 stock dynoed at 299. Redynoed on the same Dynojet after Corsas I got the 313 you see in my sig. I am looking at the hot cam and hoping for 340 to the rear wheels.
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Thread Starter
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Joined: Oct 2000
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From: N. Alabama
Re: Lt4 dyno pull today.... (southern_son)
Yes, this was on a Dyno model. I have new opti, plugs and 8.5 wires. This is stock LT4 program on vette. There was a curious 'spike' of increase in HP from 4.5 K to 5.5 K on the graph. Car was run at 205 degrees head temp. Several vette autocrossers here have said that the exhaust is the problem. One, with a C5, changed intake and exhaust but left original cam in the LS1 and got 380 RWHP. I guess it really does boil down to breathing.
Race Director
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Re: Lt4 dyno pull today.... (southern_son)
One, with a C5, changed intake and exhaust but left original cam in the LS1 and got 380 RWHP. I guess it really does boil down to breathing.
I've seen 320-330 on an intake / exhaust LS1. I might even buy 350 if he had headers on there but 380 is just absurd.
Race Director
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From: Texas
Re: Lt4 dyno pull today.... (southern_son)
Sounds like you're leaving a little hp on the table somewhere. I'm at 342. I was 300 bone stock down to the paper air filter element and at 310 with the mods in my sig *except for* the HOT Cam and Meziere and tuning.
What rpm is your peak hp at? My peak is just under 6400rpm (I've bumped my fuel cutoff to 6800). If you're stopping the dyno run before the stock fuel cutoff of 6400rpm, that may be the answer.
As for the C5 guy turning 380 with only intake and exhaust changes....:bs I think he's neglecting to tell you something. It'd have to be an '02 or '03 Z06 to even get close with only those mods. The LSx is a great engine design, but not that great!
[Modified by 96GS#007, 7:48 AM 8/29/2003]
What rpm is your peak hp at? My peak is just under 6400rpm (I've bumped my fuel cutoff to 6800). If you're stopping the dyno run before the stock fuel cutoff of 6400rpm, that may be the answer.
As for the C5 guy turning 380 with only intake and exhaust changes....:bs I think he's neglecting to tell you something. It'd have to be an '02 or '03 Z06 to even get close with only those mods. The LSx is a great engine design, but not that great!
[Modified by 96GS#007, 7:48 AM 8/29/2003]
Le Mans Master
Joined: Jul 2000
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From: OKC OK
Re: Lt4 dyno pull today.... (Nathan Plemons)
LT4POWR,
BTW what cam are you running?
BTW what cam are you running?
Drifting
Joined: Jun 2001
Posts: 1,997
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From: Lake Ozark MO
Re: Lt4 dyno pull today.... (southern_son)
My last run (concurrent with 96GS#007's) was 316rwhp. This with an A4 (unlocked), no electric water pump and stock exhaust manifolds (muffler elims... just for effect :) ) on an LT4/Hotcam conversion.
Check your fuel curves. I've found that you can be quite a bit off on spark and not make much of a difference. My 316 run was with 3 degrees retarded on the top end to compensate for later nitrous use (ended up about 36 max).
Be sure to run the rpm over 6400. The Hotcam seems to peak around there with LT4 (or equivalent) heads and stock/shorty headers.
One thing to keep an eye on is your overall hp/torque averages for the run. A leaned out run may produce a high peak HP number but you could suffer down low. Better to be a bit rich. You'll find better overall averages that way.
[Modified by Dan Parker '96, 8:19 PM 8/29/2003]
Check your fuel curves. I've found that you can be quite a bit off on spark and not make much of a difference. My 316 run was with 3 degrees retarded on the top end to compensate for later nitrous use (ended up about 36 max).
Be sure to run the rpm over 6400. The Hotcam seems to peak around there with LT4 (or equivalent) heads and stock/shorty headers.
One thing to keep an eye on is your overall hp/torque averages for the run. A leaned out run may produce a high peak HP number but you could suffer down low. Better to be a bit rich. You'll find better overall averages that way.
[Modified by Dan Parker '96, 8:19 PM 8/29/2003]
Thread Starter
Race Director
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From: N. Alabama
Re: Lt4 dyno pull today.... (southern_son)
OK, MY BAD!!! I never really looked at the graph until tonight! I never hit the fuel cut off as I backed off at what appears to be 6250 on the strongest run. The graph is at the highest peak at that point. Of course I should have more in there! duh! (well spank my butt and send me to bed without any supper) :)
I still should get some headers, though. :smash: :smash:
I still should get some headers, though. :smash: :smash:
