C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

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Old Apr 4, 2009 | 12:55 PM
  #41  
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The motor I built was supposed to make top power at 5800 rpm. If you think that's a winder O.K.,I don't.If you want to know how to make the SLP,s work you need to go to Third Gen. org.What they do is cut the SLP's open and fully Siamese the runners except for the very bottom that bolts to the base.Then weld them back up.They have been working on long tube runners for a long time. Just look for the sticky in search of a better TPI.
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Old Apr 4, 2009 | 04:29 PM
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Originally Posted by GREGGPENN
Siamesed SLPs or a FIRST would have raised the ceiling. You didn't say anything about the rest of your build and/or if you'd disagree with the results I described above.
Gotta agree with Gregg on this one. Not much said about the build, auto or 6speed? Rear gears? Stall convertor if auto...
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Old Apr 4, 2009 | 05:08 PM
  #43  
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Originally Posted by steven mack
The motor I built was supposed to make top power at 5800 rpm. If you think that's a winder O.K.,I don't.If you want to know how to make the SLP,s work you need to go to Third Gen. org.What they do is cut the SLP's open and fully Siamese the runners except for the very bottom that bolts to the base.Then weld them back up.They have been working on long tube runners for a long time. Just look for the sticky in search of a better TPI.
I agree -

There is a great bunch of posts over there. The interesting one is about one guy who modified a first intake to use the slp runners. He opened them up all the way, and is now a hair over 400hp at the rear wheels on a 355 motor.
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Old Apr 4, 2009 | 07:42 PM
  #44  
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Originally Posted by tmichaud
I agree -

There is a great bunch of posts over there. The interesting one is about one guy who modified a first intake to use the slp runners. He opened them up all the way, and is now a hair over 400hp at the rear wheels on a 355 motor.
Now that's cool !
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Old Apr 5, 2009 | 09:47 AM
  #45  
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Originally Posted by HlhnEast
How many of you fellers have SLP runners on your car? Can about the same benefit in air flow be accomplished with porting/polishing the OEM runners? At around $350, the SLP's are kinda pricey if I can see similar gains with a little elbow grease.

The reason I ask is I am about to put a set of headers on so I would like to improve the flow of the intake side as well


You started right. spend $350 on the runners and then port and Siamese them. Don't sweat the intake. great way to get in large trouble and the bang is small.

With headers and low restriction mufflers you will be impressed with what the L98 will do.

Take a looki .. if a backyard bumpkin like me can do anyone can.

http://s289.photobucket.com/albums/ll226/tjm4809/

TJM
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Old Apr 5, 2009 | 09:57 AM
  #46  
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Hi TJM
are the stock SLP runners (without porting) worth for me ?
i have a .30 engine with ZZ4 Cam,1.5 Full roller rockers,1 5/8 headers (soon),and im planning to add a set of this runners,will they create more torque ?
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Old Apr 5, 2009 | 01:18 PM
  #47  
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Originally Posted by Calderone
Now that's cool !
Here is a link to that thread (good read).

The guy is 1989GTATransAm

http://www.thirdgen.org/techboard/tp...lp-runner.html

His particular build was this (it may have been slightly tweaked for the 400 breaking run):
355ci
Dart Pro One 200cc heads,
10.72:1 compression, 8.5:1 dynamic compression ratio
TPI with highly modified 1st style SLP runners, moded GM plenum and First Injection TPI intake manifold,
Mike Jones 228/228 cam,
Yank SS3600 converter, Dyno Don 1 3/4" shorty headers with excellent Dyno Don custom exhaust,
custom cold air intake
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Old Apr 5, 2009 | 01:51 PM
  #48  
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thanks for the link TMI
i will save that !
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Old Apr 5, 2009 | 01:53 PM
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are the stock SLP runners (without porting) worth for me ?
i have a .30 engine with ZZ4 Cam,1.5 Full roller rockers,1 5/8 headers (soon),and im planning to add a set of this runners,will they create more torque ?
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Old Apr 5, 2009 | 03:25 PM
  #50  
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Originally Posted by Calderone
are the stock SLP runners (without porting) worth for me ?
i have a .30 engine with ZZ4 Cam,1.5 Full roller rockers,1 5/8 headers (soon),and im planning to add a set of this runners,will they create more torque ?
Gregg Penn will go bonkers if he reads this, but a good set of Tri-Y headers instead of 4 into 1] and the ported SLP , allowing for what you have should get you about 10% more torque, but it should make the torque a lot closer to 4,000rpm or so, than the truck like peak you have now at 3200 rpm.

Horsepower follows torque and my guess is 300Hp?

My experience is the curve went up in total torque, feels about the same on the low end, and extends higher into the RPM range.

Bassini makes a pretty good set. The try-i is designed as a torque exhaust and mates well with the Siamese ports .

They almost seem made for each other?

TJM
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Old Apr 5, 2009 | 09:03 PM
  #51  
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Originally Posted by TJM
Gregg Penn will go bonkers if he reads this, but a good set of Tri-Y headers instead of 4 into 1] and the ported SLP , allowing for what you have should get you about 10% more torque, but it should make the torque a lot closer to 4,000rpm or so, than the truck like peak you have now at 3200 rpm.


I agree the stock SLPs peak will be 4k ish. I wouldn't expect it to be a slug above that. At least another 1000 rpms would be "fun". 5k-6k rpms not so much though.

Originally Posted by TJM
The tri-Y is designed as a torque exhaust and mates well with the Siamese ports .

They almost seem made for each other?

TJM
Abso-friggin-lutely!

BTW Tom: I have a set of Tri-Y's -- for that very reason.

Last edited by GREGGPENN; Apr 5, 2009 at 11:43 PM. Reason: Added STOCK SLPs to qualify the statment
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Old Apr 5, 2009 | 11:40 PM
  #52  
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Originally Posted by steven mack
The motor I built was supposed to make top power at 5800 rpm. If you think that's a winder O.K.,I don't.
5800 peak is more of a "winder" than (reasonably) modified TPI's will ever hit. I agree 5800 is no F1 race car too! Again, I think they are good for 4700-5300 -- depending on how they are setup. I would have never used or recommended a TPI to someone hoping for a 5800 rpm peak.

Originally Posted by steven mack
If you want to know how to make the SLP,s work you need to go to Third Gen. org. What they do is cut the SLP's open and fully Siamese the runners except for the very bottom that bolts to the base. Then weld them back up. They have been working on long tube runners for a long time. Just look for the sticky in search of a better TPI.
Been there, seen that. Again, that's where shorter runner intakes are the better choice -- unless someone is FORCED to stay TPI.
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Old Apr 5, 2009 | 11:48 PM
  #53  
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i refuse !
i want to stay tpi
who says ?
economy and looks oh ...and torque
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Old Apr 6, 2009 | 07:40 AM
  #54  
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Originally Posted by GREGGPENN


I agree the stock SLPs peak will be 4k ish. I wouldn't expect it to be a slug above that. At least another 1000 rpms would be "fun". 5k-6k rpms not so much though.



Abso-friggin-lutely!

BTW Tom: I have a set of Tri-Y's -- for that very reason.
Did you get the Bassini?

TJM
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Old Apr 6, 2009 | 08:31 PM
  #55  
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Originally Posted by TJM
Did you get the Bassini?

TJM
No. I, like you, have a set of VTech 1.75" Tri-Ys. However, the secondaries are shortened 4" for clearance. I also had the #2 reangled. Won't be installed until the weather warms up though.
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Old Apr 7, 2009 | 06:42 AM
  #56  
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I found a Mini Ram, TPiS fuel rails and regulator, brand new for $750. The guy sold his car before installing them. Definately a big savings over the website. Used setups are a couple hundred less. I have to buy the rails and reg anywayand I am thinking seriously about it. Waddaya think of that deal?
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Old Apr 7, 2009 | 02:17 PM
  #57  
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The price is definitely right.

There are different sizes of MR's though. Make sure you know which port size it has -- and how that relates to what you may/may not do to your heads.

They can be different (ports) and still work, just an FYI. I believe the MR comes in 1204, 1205, and 1206 port sizes.
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Old Apr 7, 2009 | 03:00 PM
  #58  
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Originally Posted by GREGGPENN
The price is definitely right.

There are different sizes of MR's though. Make sure you know which port size it has -- and how that relates to what you may/may not do to your heads.

They can be different (ports) and still work, just an FYI. I believe the MR comes in 1204, 1205, and 1206 port sizes.
there are also different versions, I believe #2 they started correcting some flow issues with certiain cylinders.
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Old Apr 7, 2009 | 04:30 PM
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Originally Posted by pologreen1
there are also different versions, I believe #2 they started correcting some flow issues with certiain cylinders.
Interesting... However, ANY front-loading plenumed intake provides uneven flow to the cylinders (usually gets more air to the rear cylinders). Are the early versions THAT bad? IOW, bad enough not to buy/install...
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