compression ratio with a supercharger?
Thread Starter
Melting Slicks
Joined: Apr 2002
Posts: 2,308
Likes: 1
From: Portsmouth VA
compression ratio with a supercharger?
i am building a forged 409ci LT4 to be a really hot street motor that will also be a weekend racer.
if i put a vortech blower on there, what kind of compression ratio should i shoot for??
if a vortech makes around 150hp on a stock motor, about how much hp should i expect from putting it on a built motor??
thanks for your input!!
Sonny
if i put a vortech blower on there, what kind of compression ratio should i shoot for??
if a vortech makes around 150hp on a stock motor, about how much hp should i expect from putting it on a built motor??
thanks for your input!!
Sonny
Thread Starter
Melting Slicks
Joined: Apr 2002
Posts: 2,308
Likes: 1
From: Portsmouth VA
Re: compression ratio with a supercharger? (krivera)
probably 6-8psi??
i'm not really sure yet...
i'm considering buying a used vortech kit that was posted here on the forum last night. i sent him an e-mail for more info, but haven't heard back from the guy yet.
i would consider buying a intercooler for it if need be.
thanks
sonny
[Modified by SonnyinVA, 4:24 PM 1/29/2003]
i'm not really sure yet...
i'm considering buying a used vortech kit that was posted here on the forum last night. i sent him an e-mail for more info, but haven't heard back from the guy yet.
i would consider buying a intercooler for it if need be.
thanks
sonny
[Modified by SonnyinVA, 4:24 PM 1/29/2003]
Melting Slicks
Joined: Jan 2002
Posts: 3,293
Likes: 79
From: Jackson MI
Re: compression ratio with a supercharger? (SonnyinVA)
i would consider buying a intercooler for it if need be.
Thread Starter
Melting Slicks
Joined: Apr 2002
Posts: 2,308
Likes: 1
From: Portsmouth VA
Re: compression ratio with a supercharger? (mn_vette)
i hope to have over 500 hp on just motor...
so where do you get a custom intercooler?
what kind of compression could i run without one?
so where do you get a custom intercooler?
what kind of compression could i run without one?
Melting Slicks
Joined: Jan 2002
Posts: 3,293
Likes: 79
From: Jackson MI
Re: compression ratio with a supercharger? (SonnyinVA)
for a compression ratio I believe what you want to shoot for running 6-8psi a 10 - 9.5:1 should work especially with an intercooler. You could even get away with more if you like. But if you are planning on going with higher boost I would say 9 - 8.5:1 Don't take my opionon only though, talk to some people that have actually done it.
As for a custom intercooler I'm not sure, but if you find someone to get one for you that fits in the vette please let me know.
As for a custom intercooler I'm not sure, but if you find someone to get one for you that fits in the vette please let me know.
Racer
Joined: Oct 2000
Posts: 315
Likes: 0
From: Johnstown PA
Re: compression ratio with a supercharger? (mn_vette)
Just my .02!! I had my SC on for under 1000 miles and blew the head gasket between 3 and 5 cylinders. I will now sell the SC and possibly explore with nitrous. My comp. was 10.75 on my 383 and i was boosting appr. 4-6#'s so i was told by the company. I didn't get a boost gauge for the 5G i spent. I did finally buy one but didn't get to put it in.!! Once again, just my experience! I didn't enjoy my car at all this summer! :cry
[img]temp.corvetteforum.net/c4/snakecharmer/vette_engine.jpg[/img]
[img]temp.corvetteforum.net/c4/snakecharmer/vette_engine.jpg[/img]
Melting Slicks
Joined: Sep 2002
Posts: 2,631
Likes: 0
From: Union City CA
Re: compression ratio with a supercharger? (SnakeCharmer)
CanI run 10psi Boost( INtercooled) with some timming taken out on 9.5 to 1 compression? ;) Montys running like 20psi Boost on 8.5compression and to make 1200HP, :yesnod:
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Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Re: compression ratio with a supercharger? (SonnyinVA)
If you are seriously plan for forced induction, I suggest you to lower your c/r 9.1. you will need a Vortech T trim or ATI D1 blower for your 409ci. S trim/ PB600-ATI are not big enough for your motor.
I don't know what HP ATI IC rating, but Shalin ex-blown 1993 355ci LT1 12psi pushing 575rwhp without having any problem
Bruce
93LT1 Conv w/ZF6
Blown D1-SC/N2O
ARE built 383ci/Stage II heads
[Modified by Bruce, 9:37 AM 2/1/2003]
I don't know what HP ATI IC rating, but Shalin ex-blown 1993 355ci LT1 12psi pushing 575rwhp without having any problem
Bruce
93LT1 Conv w/ZF6
Blown D1-SC/N2O
ARE built 383ci/Stage II heads
[Modified by Bruce, 9:37 AM 2/1/2003]
Melting Slicks
Joined: Sep 2002
Posts: 2,631
Likes: 0
From: Union City CA
Re: compression ratio with a supercharger? (Bruce)
If you are seriously plan for forced induction, I suggest you to lower your c/r 9.1. you will need a Vortech T trim or ATI D1 blower for your 409ci. S trim/ PB600-ATI are not big enough for your motor.
I don't know what HP ATI IC rating, but Shalin ex-blown 1993 355ci LT1 12psi pushing 575rwhp without having any problem
Bruce
93LT1 Conv w/ZF6
Blown D1-SC/N2O
ARE built 383ci/Stage II heads
[Modified by Bruce, 9:37 AM 2/1/2003]
I don't know what HP ATI IC rating, but Shalin ex-blown 1993 355ci LT1 12psi pushing 575rwhp without having any problem
Bruce
93LT1 Conv w/ZF6
Blown D1-SC/N2O
ARE built 383ci/Stage II heads
[Modified by Bruce, 9:37 AM 2/1/2003]
Melting Slicks
Joined: Sep 2002
Posts: 2,631
Likes: 0
From: Union City CA
Re: compression ratio with a supercharger? (Bruce)
If you get the air intake temp down, and back off with some timming, how much more boost do you think you can run? I hear people running 20psi to 28psi boost on a 8.5 to 1 compression, does it really affect how much tou can shove into it when you step up to 9.1? I know that if your running like 10 or 10.5 your only limmited to 6-8 when intercooled, but the difference between 9.1 and 8.5 is only .6 and difference of 8psi that adds to the Combustion camber pressure.
LIke a 8.5 should put out 125PSI and then you add up to 28( Thats the highest I've ever heard of) which comes out to 152PSI. Then if you run NA with 11 to 1 your combustion camber should be 161PSI. But these numbers are never true, because you always loose some, you could be at 9 to 1 compression, but if you put on a pressure checker in the sparkplug hole and the reading only comes to 125.
Or is it that your combustion chamber pressure should never exceed 165 or 170PSI for pump Gas and some more for race gas? So that way you could figure out how much boost you could run on different compression ratios. To all add up to a number under 160-170? OR do they use a different method? :confused:
LIke a 8.5 should put out 125PSI and then you add up to 28( Thats the highest I've ever heard of) which comes out to 152PSI. Then if you run NA with 11 to 1 your combustion camber should be 161PSI. But these numbers are never true, because you always loose some, you could be at 9 to 1 compression, but if you put on a pressure checker in the sparkplug hole and the reading only comes to 125.
Or is it that your combustion chamber pressure should never exceed 165 or 170PSI for pump Gas and some more for race gas? So that way you could figure out how much boost you could run on different compression ratios. To all add up to a number under 160-170? OR do they use a different method? :confused:
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Re: compression ratio with a supercharger? (Light84vette)
I don't know where you get your figure from. BEFORE you came on this board. Shalin used to post here. I and many other have met Shalin. His 9:1 with 12psi 575rwhp. In fact I have seen the damn car. His dynoed # are on pump gas. In fact he was well known by most forum menbers.
Bruce
Bruce
Melting Slicks
Joined: Sep 2002
Posts: 2,631
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From: Union City CA
Re: compression ratio with a supercharger? (Bruce)
Take a chill pill FOO. I just wanted to know what would be the max boost you could run on a Engine using 9.1 to 1 compression? WHy do you have to get all ANgry about it? :confused:
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Re: compression ratio with a supercharger? (Light84vette)
angry? what ya talking about heh? One, you don't have a supercharged car. therefore you don't know what you are talking about. You only get your figure from left and right. We are talking about real world forced induction on hand experienced here.
Another note. If you are running very high boost 17+ psi, yes 8:5 is better . But most street supercharged car are running under 14psi and the 9:1 c/r is perfect for that application.
Bruce
[Modified by Bruce, 7:26 PM 2/2/2003]
Another note. If you are running very high boost 17+ psi, yes 8:5 is better . But most street supercharged car are running under 14psi and the 9:1 c/r is perfect for that application.
Bruce
[Modified by Bruce, 7:26 PM 2/2/2003]
Melting Slicks
Joined: Sep 2002
Posts: 2,631
Likes: 0
From: Union City CA
Re: compression ratio with a supercharger? (Bruce)
Thats a lot of boost for 9.1, I first thought that you could not go more than 8 psi on anything more than 8.5 to 1 compression, thanks for clearing that up.
WHat kind of Forced induction cars do you own? :chevy
WHat kind of Forced induction cars do you own? :chevy
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Re: compression ratio with a supercharger? (Light84vette)
Thats a lot of boost for 9.1, I first thought that you could not go more than 8 psi on anything more than 8.5 to 1 compression, thanks for clearing that up.
WHat kind of Forced induction cars do you own?
_______
NO problem :)
see my sig
Bruce
93LT1 Conv w/ZF6
Blown D1-SC/N2O
ARE built 383ci/Stage II heads
WHat kind of Forced induction cars do you own?
_______
NO problem :)
see my sig
Bruce
93LT1 Conv w/ZF6
Blown D1-SC/N2O
ARE built 383ci/Stage II heads
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
Re: compression ratio with a supercharger? (Light84vette)
my car motor built up late last Summer. No track time or dyno # yet. But will find out in the Spring when I get Shalin help me doing the tunning. Why Shalin? because NO one out there can do perfect tune on the speed density car with blower. Shalin is the only one can do the tune perfect. In the pass many has called Shalin is the super tuner in supercharged LT1.
Bruce
Bruce
Melting Slicks
Joined: Sep 2002
Posts: 2,631
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From: Union City CA
Re: compression ratio with a supercharger? (Bruce)
Did you do anything to prepare the Transmission for that kind of power? I though the manuals like ZF and T56 could only take no more that 500Ftlbs of torque? :confused: