Switching and porting plenums
Le Mans Master
Joined: Aug 2000
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From: Australia
Team Owner
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From: altered state
St. Jude Donor '05
Plenum work looks good there, nothing wrong with a strong TPI car.
It wont be a superram but personally Ill take the hit on upper hp over having to mess with that lid. Lots of low end torque on the street can be fun without breaking speed limits or winding it up to the moon to get your jollies.
Ditto on laying on your back under a C4. I wont miss is a bit.
It wont be a superram but personally Ill take the hit on upper hp over having to mess with that lid. Lots of low end torque on the street can be fun without breaking speed limits or winding it up to the moon to get your jollies.
Ditto on laying on your back under a C4. I wont miss is a bit.
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Safety Car
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From: Made In America
St. Jude Donor '10-'11
I never said the plenum was cast iron. The E86 HEADS are cast iron. I was asking if that made a difference. 89 is different so I did not know if the E styles were different.
Safety Car
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From: Vero Beach Florida
[QUOTE=Harley Davidson;1569700131]What year plenums for the L98 are interchangable. Say would a cast iron 86 plenum fit a 1990?
In your first post you kind of did ask that but you might of been thinking heads
You can buy blockoff plates for any year cold start injector
Last edited by floridamale; Apr 16, 2009 at 11:07 AM.
Thread Starter
Safety Car
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St. Jude Donor '10-'11
If I put these on a stock TPI, will I see any gain? They are SLP runners. Look alot different than the stock oens.
http://www.mamotorworks.com/corvette?frame=3.8395
http://www.mamotorworks.com/corvette?frame=3.8395
Last edited by M.J.L.; Apr 16, 2009 at 01:03 PM.
Le Mans Master
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From: Tampa Florida
Yes those are the same runners I'm slapping on the new build. The SLPs are good for a few hundred extra RPM (even on a stocker) since they have the area cut down between the tubes from the manufacturer....basically the idea is this gap produces a "shorter" runner effect... typically the shorter the runner the higher the RPM band is effectively moved....which is why you hear about people cutting the back out of the runners and grinding the guts out only to leave a small extension before the intake. Below is a pic of the SLP runner (on the right) I finished porting the other day....still needs some work though. The one on the left has had some light porting which is how I purchased it from another CF member.
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Le Mans Master
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From: Tampa Florida
Le Mans Master
Joined: Jul 2007
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From: Tampa Florida
Take a look at this link and you'll get a better idea of what will result. The motor in the link is a 383 so your # won't even come close to those but notice how the torque/Hp curves shift between the setups....expect a similar but less dramatic curve shifts to occur if you go this route.
http://www.superchevy.com/technical/...t_results.html
http://www.superchevy.com/technical/...t_results.html
Le Mans Master
Joined: Aug 2000
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From: Australia
Improved my 60 ft times and lowered ET at the track.
The dyno will "show" a change but in real terms starting with 330ft/ lb you won't know it
Le Mans Master
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From: Tampa Florida
Tough to say...if you read their ad it says "up to 20 hp" so it depends on your application.....with all the porting maybe the full 20 hp. As mentioned before if you remove a restriction there will be another down the path so in a perfect world you'd want swap all three components (plenum, intake & runners) to hi-flow stuff....of course a good set of heads would help too. If you get a "SLP" sticker kit expect to gain ~ 20+ hp once you stick'em to the car
I'll PM you one other option which may work for you.
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From: Made In America
St. Jude Donor '10-'11
I've owned a set of the SLP runners before and you can notice the SOTP difference.
Tough to say...if you read their ad it says "up to 20 hp" so it depends on your application.....with all the porting maybe the full 20 hp. As mentioned before if you remove a restriction there will be another down the path so in a perfect world you'd want swap all three components (plenum, intake & runners) to hi-flow stuff....of course a good set of heads would help too. If you get a "SLP" sticker kit expect to gain ~ 20+ hp once you stick'em to the car
I'll PM you one other option which may work for you.
Tough to say...if you read their ad it says "up to 20 hp" so it depends on your application.....with all the porting maybe the full 20 hp. As mentioned before if you remove a restriction there will be another down the path so in a perfect world you'd want swap all three components (plenum, intake & runners) to hi-flow stuff....of course a good set of heads would help too. If you get a "SLP" sticker kit expect to gain ~ 20+ hp once you stick'em to the car
I'll PM you one other option which may work for you.
