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Looking for a bit more power

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Old Jun 30, 2016 | 06:54 PM
  #1  
EDGE's Avatar
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From: Mississauga, Ontario Canada
Car: 1987 GTA
Engine: 5.7
Transmission: T5WC
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Looking for a bit more power

As the title says, I want a bit more out of my motor but nothing crazy. I'll never race it and I want to stay with the TPI. I'd like to go with different heads, cam and intake but stay with my .020 over 5.7 block. Years ago I did the 2.02/1.60 valve combo on the factory head and left the intake, plenum and runners alone, but I don't know if that really made much of a difference. Back then I let my naivety fall for big numbers. I don't know if I should port out my stock intake, plenum and runners or go with AS&M runners and an edelbrock intake or hog out the stock base. Would I be better reworking my heads or go with something new that's already assembled? Again I'm not looking for crazy. Just something that gets up and goes. Is in the neighborhood of 300hp something TPI will accommodate? I'd like to stay with my stock plenum but have it reworked.
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Old Jun 30, 2016 | 09:22 PM
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Re: Looking for a bit more power

I'd say cam it, stealth ram for now. thats gonna be the best use of money for now. plus i can vouch, once you get bit by the horsepower bug, youre gonna keep going. check out my sig, i'm planning on port/polish intake manifold, siamese SLP runners and plenum. might be the most i can do with my TPI setup without stealth ram.

I'd say do new heads, but that such a PITA w/o pulling motor
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Old Jun 30, 2016 | 09:53 PM
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From: 53.0907° N, 113.4695° W
Re: Looking for a bit more power

Do you have headers and a decent exhaust system?
That would be number one on my list.
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Old Jun 30, 2016 | 10:40 PM
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From: Chicago, Il
Car: 1986 Iroc Z28
Engine: 305 TPI
Transmission: 700R4
Re: Looking for a bit more power

+1 for Headers for sure...nice difference when I had the tpi set up
+ 1 for cam/stealth ram if you insist on staying tpi!
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Old Jul 1, 2016 | 04:51 AM
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From: Mississauga, Ontario Canada
Car: 1987 GTA
Engine: 5.7
Transmission: T5WC
Axle/Gears: 3:27
Re: Looking for a bit more power

Originally Posted by skinny z
Do you have headers and a decent exhaust system?
That would be number one on my list.
I have the Edelbrock TES headers, and Flowmaster 80 series muffler. I know the headers aren't a site favourite but I can't really go long tube given the height off the ground. Like I said, not looking for anything too crazy. As for heads, would I be best to rework mine given they already have valve work or would something like a Vortec or maybe AFR be a better route?
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Old Jul 1, 2016 | 09:33 PM
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Re: Looking for a bit more power

The next logical step is heads and a cam.
The Vortec has always been a favourite of mine but given that you want to keep the TPI, the Vortecs are out unless you want to go for the specific intake manifold too. I'd go the aftermarket route. Nothing too big in the intake runner department. AFR is never a bad choice.
The cam falls in line with the heads. Work out your compression ratio, taking into consideration the heads you might go with and select a cam that designed to work in that CR range and compliments the TPI. There are plenty of very strong TPI builds here at 3rd gen with bolt on parts.
If you went with a 180-190cc intake runner AFR head and selected a short(ish) cam along the lines of 220 @ .050" duration and .500" lift, you'd end up with a strong runner that could be easily tuned to work with your TPI.
Check out the TPI forum.
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Old Jul 3, 2016 | 07:11 PM
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From: MA
Car: 1989 IrocZ
Engine: 421 Dart Stroker
Transmission: 4L60E Cahall Performance Built
Axle/Gears: Midwest Chassis Fab 9/ 3.55 gears
Re: Looking for a bit more power

Tpis makes a l98 cam that works well with the tpi setup. I think a cam a mild heads like the afr 180s or 190s wpukd make a great street engine. Small stall convertor would be a good boost too.
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Old Jul 3, 2016 | 07:28 PM
  #8  
EDGE's Avatar
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From: Mississauga, Ontario Canada
Car: 1987 GTA
Engine: 5.7
Transmission: T5WC
Axle/Gears: 3:27
Re: Looking for a bit more power

Originally Posted by skinny z
The next logical step is heads and a cam.
The Vortec has always been a favourite of mine but given that you want to keep the TPI, the Vortecs are out unless you want to go for the specific intake manifold too. I'd go the aftermarket route. Nothing too big in the intake runner department. AFR is never a bad choice.
The cam falls in line with the heads. Work out your compression ratio, taking into consideration the heads you might go with and select a cam that designed to work in that CR range and compliments the TPI. There are plenty of very strong TPI builds here at 3rd gen with bolt on parts.
If you went with a 180-190cc intake runner AFR head and selected a short(ish) cam along the lines of 220 @ .050" duration and .500" lift, you'd end up with a strong runner that could be easily tuned to work with your TPI.
Check out the TPI forum.
Figuring on a fully ported Edelbrock lower and runners in addition to a set of AFR heads. Cars a 5 speed (I'm aware of the limitations but I don't race) so a stall is not even in the equation. Just need to settle on a cam that's fairly aggressive but not stupid. I ultimately want a nice balanced setup that will give me some goodetails midrange jam. Car always felt good coming through that 3000 rpm range.
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Old Jul 4, 2016 | 07:15 PM
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From: 53.0907° N, 113.4695° W
Re: Looking for a bit more power

Check the Southern California forum. Those guys have gone a long way with TPI and it's derivatives. Making good power with the OEM parts or the aftermarket alternatives. Plenty of discussions on cam choices, ones that compliment the TPI format.
There should be plenty of info in this forum as well. I can't say I have any experience with building a TPI based engine although I can say that the basic principles when choosing a camshaft still apply no matter what the induction is as long as it's it's NA. Compression ratio and port flow are universal constants in the calculations. Tuning to the strengths of the TPI is where the expertise is needed.
Somebody here has some direct experience I'm sure.
Which AFRs are you considering?
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Old Jul 4, 2016 | 10:08 PM
  #10  
EDGE's Avatar
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From: Mississauga, Ontario Canada
Car: 1987 GTA
Engine: 5.7
Transmission: T5WC
Axle/Gears: 3:27
Re: Looking for a bit more power

Originally Posted by skinny z
Check the Southern California forum. Those guys have gone a long way with TPI and it's derivatives. Making good power with the OEM parts or the aftermarket alternatives. Plenty of discussions on cam choices, ones that compliment the TPI format.
There should be plenty of info in this forum as well. I can't say I have any experience with building a TPI based engine although I can say that the basic principles when choosing a camshaft still apply no matter what the induction is as long as it's it's NA. Compression ratio and port flow are universal constants in the calculations. Tuning to the strengths of the TPI is where the expertise is needed.
Somebody here has some direct experience I'm sure.
Which AFRs are you considering?

The 180/65 ones for the L98
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Old Jul 10, 2016 | 02:39 PM
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Re: Looking for a bit more power

just finishing a build like you are considering .. ill let you know how it goes ..
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Old Jul 16, 2016 | 07:55 PM
  #12  
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Re: Looking for a bit more power

I am also trying to get the most out of my stock tpi. How much horsepower can you gain by upgrading the exhaust, headers, intake, fuel injectors.
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Old Jul 18, 2016 | 03:22 PM
  #13  
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From: North west Fl
Car: Corvette ZR-1
Engine: LT-5
Transmission: 6 sp
Re: Looking for a bit more power

Guys read my thread. I spent a lot of time and money and very happy with the results. Never went into the engine and after every mod had it dynoed to see what was what.

https://www.thirdgen.org/forums/afte...s-any-one.html
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