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

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Old Jun 22, 2010 | 01:46 AM
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1986 4+3 CORVETTE's Avatar
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I just got an off road h pipe for my car and am wondering what other mods to do with a 500$ budget im thinkin a throttle body or injectors tell me what you think thanks, by the way i have an 86 TPI
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Old Jun 22, 2010 | 02:06 AM
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Well if you have the original Injectors Id definitely check them out to see if the meet specs OHMs etc Fic sells em pretty damn cheap. If the car is running well, Idles well, you can probably skip injectors. I only mention this because you mentioned Injectors

Id do a set of under pullies and a chip from hypertech or superships and a ported throttle body. That should make you feel nice for now and leave a few bucks in your pocket. Id buy everything on ebay for way less and id get it used. The pullies you probably wont find used but who knows perhaps you will. Hope that helps
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Old Jun 22, 2010 | 02:24 AM
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Originally Posted by Mikes1991
a chip from hypertech or superships .
All right if you want to turn fans on sooner

Most here wouldn't waste the $$ on a Hyper cr*p chip
http://forums.corvetteforum.com/c4-t...-are-exhs.html
http://forums.corvetteforum.com/c4-t...post1564778076
http://forums.corvetteforum.com/c4-t...tech-chip.html
http://forums.corvetteforum.com/c4-t...-any-good.html
http://forums.corvetteforum.com/c4-t...tech-chip.html

And a bigger TB is a waste on a otherwise stock engine
See here for mods what works and don't
http://temp.corvetteforum.net/c4/vader86/minormods.html
http://temp.corvetteforum.net/c4/vad...dstrategy.html

Best bang for $$$ on L98 is long tube headers and decent exh system
Cheapo painted ones $170
http://www.summitracing.com/parts/HED-68440/

Last edited by rodj; Jun 22, 2010 at 02:37 AM.
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Old Jun 22, 2010 | 03:27 AM
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do you know anyone that has used those hedman hedders and would it work well with an H pipe

.
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Old Jun 22, 2010 | 03:40 AM
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wow headers for pre 91 are cheap! i wish they were that cheap for the lt1
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Old Jun 22, 2010 | 03:44 AM
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Originally Posted by 1986 4+3 CORVETTE
do you know anyone that has used those hedman hedders
.
Did you read the modification links I put up above ?

"So the best bet is to install longtube headers, Most will show the same 10-15rwhp gain",

Long tubes are long tubes;
I doubt you will see any difference on a stock engine compared with the $600 ones
http://www.jegs.com/i/Hooker/520/2149/10002/-1

Last edited by rodj; Jun 22, 2010 at 03:49 AM.
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Old Jun 22, 2010 | 08:16 AM
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No throttle body, no chip, headers are a good idea. The coated Hedman Elites are only $360. Get the coated ones. They will work with a H pipe but you may have to adjust the length. Check out Summit. Don't replace injectors until they go bad.
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Old Jun 22, 2010 | 08:22 AM
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Originally Posted by 1986 4+3 CORVETTE
do you know anyone that has used those hedman hedders and would it work well with an H pipe

.
I have ran mine for nearly 10 years. Not dissapointed.
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Old Jun 22, 2010 | 09:17 AM
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Headers, 1.6RR, or perhaps a new set of runners or a base manifold with that budget.
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Old Jun 22, 2010 | 10:12 AM
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Originally Posted by 1986 4+3 CORVETTE
I just got an off road h pipe for my car and am wondering what other mods to do with a 500$ budget im thinkin a throttle body or injectors tell me what you think thanks, by the way i have an 86 TPI
Take a look at Vader's web site as he has a good analysis of what results you can expect to achieve from various low cost L98 modifications. FWIW


http://temp.corvetteforum.net/c4/vader86/
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Old Jun 22, 2010 | 11:00 AM
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I have uncoated Hedmans. If you live in a dry climate I think you'll be fine with them. Do you have cast iron or aluminum heads?
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Old Jun 22, 2010 | 11:22 AM
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Better mufflers? Flowmaster has a cat-back system for your car that is just under $500. http://www.summitracing.com/parts/FLO-17153/

I'm curious though - what brand h-pipe did you get, and is it mandrel bent?

Last edited by mcm95403; Jun 22, 2010 at 11:26 AM.
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Old Jun 22, 2010 | 12:59 PM
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Originally Posted by Paul Ruggeri
I have uncoated Hedmans. If you live in a dry climate I think you'll be fine with them. Do you have cast iron or aluminum heads?
Trust me Pullayup Washington is not a dry place.
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Old Jun 22, 2010 | 04:04 PM
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Exhuast seems to be the easiest and cheapest upgrade. Anybody used any of the duel exhuast setups? I have a friend with a Muffler shop but he always said he couldnt remove CATS even if I live in a state with no Emisions checks (North Dakota). Google searches make it look like the only lwas i have to worry about is "no bypass or cutout" so a standard mufflered duel exhuast should be fine. or am I missing some part? As long as I put in a bung for the O2 sensor shouldnt I be fine?

I was looking at some Headers, duels and 2 mufflers at the back in the standard spot.
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Old Jun 22, 2010 | 04:46 PM
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how much hp at the fly wheel do you think id get from an h pipe and long tube hedman thermal coated heddars

Last edited by 1986 4+3 CORVETTE; Jun 22, 2010 at 06:51 PM.
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Old Jun 22, 2010 | 07:07 PM
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IMO H pipe not much. Hedman Elites at least 15 maybe 20 CHP.
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Old Jun 22, 2010 | 07:31 PM
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with rodj on list of modifications and Vader86. If you read Vader's web site you will come up with a better understanding of what works and what does not.

Exhaust
1.6 RR
Better intake/runners/plenum
forget TB - the stock can handle up to about 400 HP and you are far from that.
Forget Hypertech chip
I don't think the "H" pipe will give you much, especially if you have installed the "test pipe". You should see a good gain with just this.
Cut out air cleaner box louvers.
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Old Jun 23, 2010 | 02:00 AM
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whenever my car gets to around 4000rpm it gets real shakey but everything else is fine and it drives great does anyone know why this happens
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Old Jun 23, 2010 | 02:06 AM
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does anyone know how much roller rockers cost to install

Last edited by 1986 4+3 CORVETTE; Jun 23, 2010 at 06:05 AM.
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Old Jun 23, 2010 | 10:15 AM
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What do you mean by "gets realy shakey"?

You can install roller rockers yourself, it's pretty low on the difficulty scale. If you have a shop do it, it should be 1 hour or less for a shop mechanic to do.
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