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Boosting a L98 TPI

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Old 12-06-2008, 08:49 PM
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Boosting a L98 TPI

Ok so I have been searching and maybe I missed the thread that pointed it out but how far can you push a TPI unit till its useless on a L98. I have ported SLP runners and Ported Plenum, vortec heads, SD intake. I know It will need forged rods and pistons and probley crank but how far Can I push the TPI unit all together before its hurting the boost. I plan to go procharger evenutally. so let me know what you know.
Old 12-06-2008, 09:56 PM
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Re: Boosting a L98 TPI

Take a look at the topics and archives at the Power Adder furum. It might be enlightening.
Old 12-06-2008, 09:59 PM
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Re: Boosting a L98 TPI

Originally Posted by Vader
Take a look at the topics and archives at the Power Adder furum. It might be enlightening.
where are the archives? I searched in there and couldn't find a solid number where the TPI unit falls off and starts hurting boost.
Old 12-07-2008, 06:16 AM
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Re: Boosting a L98 TPI

The "archives" are all threads dating back to 1999, not a separate area. Perform an advanced search with no date resriction. You might not find a hard limit.

If you believe in the laws of fluid dynamics, flow is the result of area and pressure differential. Flow decreases as area decreases. You've evidently improved that with modified runners, base, and better heads. Flow increases as pressure differential increases, and that's what you are doing with a charger. As flow decreases, you can increase pressure differential. There may be a practical limit, but theoretically, there is no limit.

If you know the length and nominal cross sectional area of the runners and the amount of boost you intend to run, you can calculate the theoretical RPM at which the flow will not support power.
Old 12-07-2008, 06:29 AM
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Re: Boosting a L98 TPI

Originally Posted by david068513
how far can you push a TPI unit till its useless on a L98....
Pretty damn far, Click Here....
Old 12-07-2008, 01:37 PM
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Re: Boosting a L98 TPI

Originally Posted by Vader
The "archives" are all threads dating back to 1999, not a separate area. Perform an advanced search with no date resriction. You might not find a hard limit.

If you believe in the laws of fluid dynamics, flow is the result of area and pressure differential. Flow decreases as area decreases. You've evidently improved that with modified runners, base, and better heads. Flow increases as pressure differential increases, and that's what you are doing with a charger. As flow decreases, you can increase pressure differential. There may be a practical limit, but theoretically, there is no limit.

If you know the length and nominal cross sectional area of the runners and the amount of boost you intend to run, you can calculate the theoretical RPM at which the flow will not support power.
thank You. I'll try to figure the math out. I plan to run 15 lbs of boost.
Originally Posted by Street Lethal
Pretty damn far, Click Here....
Thanks for that link! I like the setup. I am confused though of why he stuck with the stock runners? intresting.
Old 12-07-2008, 04:47 PM
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Re: Boosting a L98 TPI

With adequate boost, stock runners are not a problem. Remember the laws of physics as set forth by Boyle, Lohm, Bernoulli, Avogadro, Forchheimer, and Charles.
----------
Good link to the boosted '92 Formy. And you gotta love this part:

He re-pinned all of the connections, and used a supercharger tune he found on Thirdgen.org to get the car started.

Last edited by Vader; 12-07-2008 at 04:50 PM. Reason: Automerged Doublepost
Old 12-07-2008, 09:39 PM
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Re: Boosting a L98 TPI

Originally Posted by Vader
With adequate boost, stock runners are not a problem. Remember the laws of physics as set forth by Boyle, Lohm, Bernoulli, Avogadro, Forchheimer, and Charles.
----------
Good link to the boosted '92 Formy. And you gotta love this part:
Yes but with upgraded runners wouldn't you be able to run less boost and make the same power as stock runners cause there is more flow room. With more room. The faster the flow. I understand the laws of physics. I also know you can cram alot into a small space.
Old 12-09-2008, 02:11 AM
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Re: Boosting a L98 TPI

Originally Posted by david068513
With more room. The faster the flow.
This is not true to the laws of physics. With more volume for a fluid to flow in comes smaller velocity.
Old 12-09-2008, 12:53 PM
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Re: Boosting a L98 TPI

I'd say until you dont gain any more power with boost and tune. Then you finally hit the wall of the TPI. Gotta remember everyones set-up is different and responds differenty.

Heres a great place for more info on boost. I dont think there anything these guys haven't put a turbo on.

www.theturboforums.com

They have been very helpful through my process of installing a turbo.
Old 12-09-2008, 02:17 PM
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Re: Boosting a L98 TPI

Your going to push the bottom end out of
a L98 block long before you come close to finding
the HP limit.

Tuning of course is the key
On when that happens, sooner or later.
Later

Last edited by jaykar; 12-09-2008 at 02:22 PM.
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