383ci making 340whp - advices needed
04-03-2008, 06:02 PM
#1
383ci making 340whp - advices needed So, I have bought 383ci with compression ratio 9.2:1. It's only making 330-340whp. Previous owner built it for turbo, but now I can't do this (money), so want to get a little bit more power out of it NA or nitrous.
Here are spec:
383ci
Patriot stage 2 LS1 heads , 67cc, CR 9.2:1
Thunder Racing 214/220 .600/.523 115 LSA cam
LS6 intake manifold
BBK 80mm TB
stock MAF with Fast Toys ported ends
Volant cold air
Pacesetter LTs
Pacesetter ORY
Flowmaster 3" catback
M6 with 12 bolt
It's only making 340whp, 110mph in 1/4
It seems I will not put turbo this year, but I really want more power for now.
What could I do? I mean, not major $2000+ changes.
Cam maybe? Or just 200hp doze of NOS?
Car has nitrous installed but not set up yet
So, please help me make this car faster
it's very rare in my country, and I want it to fly
Here are spec:
383ci
Patriot stage 2 LS1 heads , 67cc, CR 9.2:1
Thunder Racing 214/220 .600/.523 115 LSA cam
LS6 intake manifold
BBK 80mm TB
stock MAF with Fast Toys ported ends
Volant cold air
Pacesetter LTs
Pacesetter ORY
Flowmaster 3" catback
M6 with 12 bolt
It's only making 340whp, 110mph in 1/4
It seems I will not put turbo this year, but I really want more power for now.
What could I do? I mean, not major $2000+ changes.
Cam maybe? Or just 200hp doze of NOS?
Car has nitrous installed but not set up yet
So, please help me make this car faster
it's very rare in my country, and I want it to fly 
04-03-2008, 06:13 PM
#2
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dude you need to bring the compression up and the only way i can thionk of to do that is to either replace the turbo pistons or mil the heads down or buy a differnt set of heads that will bring the compression up and make alot more power plus you need to change that turbo cam out since your not running a turbo. if you want a NA motor you need a cam with a 112 seperation to get the heads milled and a new cam its only goin to cost you about $500
04-03-2008, 06:18 PM
#3
As I already said I won't rebuild whole motor It will get turbo eventually.
I need to extract more power now without very expensive changes, ruining the whole concept of low-compression engine
Although, if heads (not top-end of them) are not more than say $400, I think I could afford them...
It will get turbo eventually.I need to extract more power now without very expensive changes, ruining the whole concept of low-compression engine
Although, if heads (not top-end of them) are not more than say $400, I think I could afford them...
04-03-2008, 08:17 PM
#4
Cam is hurting you, especially for a 383. Also, you need comression. If you can cut the chambers down to 60cc, you'd be in better shape. But that won't run well with a turbo.
Here's the problem: the motor was built for a turbo. Without it, expect much lower performance. No way around the parts needed for a turbo compared to a naturally aspirated motor. Two totally different requirements.
But, you knew this already......
Here's the problem: the motor was built for a turbo. Without it, expect much lower performance. No way around the parts needed for a turbo compared to a naturally aspirated motor. Two totally different requirements.
But, you knew this already......
04-03-2008, 08:47 PM
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04-03-2008, 09:21 PM
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Just get a different cam for now and even that won't make a huge difference. Yet if you are looking not to spend a lot that is the only thing I can think of that isn't expensive. Not sure it will really work but it shouldn't hurt. You might just have to suck it up until you can spring for the turbo.
04-04-2008, 03:03 AM
#11
Do you think cam won't give me some 25whp for this engine?
You see something is still wrong even when we account for low compression. When CR was discussed here on forum I remember seeing 3-4% increase of power/torque for one point of CR.
So if I'd have 11.2:1 instead of 9.2:1, I'd have only 6-8% more, that would make 360-370whp. Is that really what 383ci should produce?
I'm totally new to LSx scene, but from reading around I thought at least 450whp should be no problem on manual 383ci car?
You see something is still wrong even when we account for low compression. When CR was discussed here on forum I remember seeing 3-4% increase of power/torque for one point of CR.
So if I'd have 11.2:1 instead of 9.2:1, I'd have only 6-8% more, that would make 360-370whp. Is that really what 383ci should produce?
I'm totally new to LSx scene, but from reading around I thought at least 450whp should be no problem on manual 383ci car?
04-04-2008, 03:12 AM
#12
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I think the right cam could pick it up a fair amount, but if you do that, you should save your old one for when you get a turbo. A well thought out and built 383 should make at least 450whp, if not more, depending on heads and some other stuff.
04-04-2008, 03:41 AM
#13
Yes, surely I'd keep this cam until turbo is installed thinking of new cam like a temp fix, while it is NA or nitroused...
I just want to know how much whp could I gain from another cam... If it's only 10-15whp, than it's not worth the hassle
thinking of new cam like a temp fix, while it is NA or nitroused...I just want to know how much whp could I gain from another cam... If it's only 10-15whp, than it's not worth the hassle
04-04-2008, 06:26 AM
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Nick--
04-04-2008, 07:17 AM
#15
Didn't quite get you...
I'm ready to change cam, because i think cam can be had for under $300-400??, and that is affordable as a temporary solution (I could try to sell it later anyway).
But to change compression ratio it is either change heads, or change rotating assembly - both are expensive and would cost half of the turbo install
I'm ready to change cam, because i think cam can be had for under $300-400??, and that is affordable as a temporary solution (I could try to sell it later anyway).
But to change compression ratio it is either change heads, or change rotating assembly - both are expensive and would cost half of the turbo install
04-04-2008, 07:33 AM
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I think compression and cam are your best bet. If you are mechanically inclined you can yank the heads and have them milled for less then 200 dollars. Add about another 400 for a new cam and with 600 dollar or so you should be well into the 400+ rwhp numbers.
04-04-2008, 07:39 AM
#17
The 383 is a big engine to have such a small (214/220) cam to start with.
When my 383 was first built, I had the TR224 cam installed at the time.
It ran great, and smooth, but since I decided to stay NA, i went even bigger the following year.
My 383 w/TR224 put down 425rwhp. That made for a very smooth running car with great power! IMO, it was a sleeper.
My setup now has a 234/238 cam profile, making over 475rwhp (updated dyno tune coming up next week for exact numbers). The car is a monster now, very fast, and certainly NOT a sleeper anymore.
Food for thought, good luck with your setup and choices.
04-04-2008, 07:55 AM
#19
Michael: in my country, TransAm is certainly not a sleeper, whatever cam it has
So if it is still drivable around city with big cam, I'd go for it
You certainly have done smth. else that gained you 50whp, not only changed to larger cam?
So if it is still drivable around city with big cam, I'd go for it
You certainly have done smth. else that gained you 50whp, not only changed to larger cam?
04-04-2008, 08:16 AM
#20
The only other changes from the one dyno-tune to the next, besides the larger cam is:
- Racetronix Fuel Pump
- Electric Water Pump
- FAST 90 Intake, Unported (replacing the stock LS6)
Fuel pump gained nothing, EWP maybe a few ponies, and the FAST90 probably added some decent hp along with the 234/238 cam.
Trouble is your compression (like already stated). It should be raised for NA, than lowered again for Turbo. How to do that and do it cheaply, I'm not sure.
Ideally your cam choice should match your heads. So if you could afford to do a cam/head swap for NA, then re-install these heads & cam when ready to go Turbo.
Just a suggestion, no one said going fast is cheap.
