L98 motor work
Thread Starter
Instructor
Joined: Sep 2004
Posts: 210
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From: peoria il
L98 motor work
91 coupe with 103k miles(L98). want more power should i rebuild the motor it runs fine just need it faster, like everyone else!!!! if i should rebuild it what do i do? i need prices and it will have to be done by someone else (not a mechanic). the vet is cpompletely stock now.
1. on the exhaust side (i am guessing here) magnaflow-cat and catback system. then headers(from where) and/or exhaust manifold.
2. on the intake side(again guessing) new intake manifold/port and polish stock. new air filter. bigger tb. bigger injectors.
3. no idea on motor work????
any help thanks jeff
1. on the exhaust side (i am guessing here) magnaflow-cat and catback system. then headers(from where) and/or exhaust manifold.
2. on the intake side(again guessing) new intake manifold/port and polish stock. new air filter. bigger tb. bigger injectors.
3. no idea on motor work????
any help thanks jeff
Team Owner
Joined: Jul 2004
Posts: 28,431
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From: Hartford WI
www.lingenfelter.com is a good place to ask. Also I changed my setup to use the Holley Stealth Ram and a custom camshaft by www.hitechmotorsport.com on my LPE shortblock and unported heads and intake and made about 410 HP at the wheels on my A4 tranny which was mated to a LPE 383 SB
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
It depends on how much "faster" you need it to be.
You can get to over 300chp with bolt-ons, to over 375chp with those plus heads & cam and to over 400chp if you stroke it out.
First define your goals for the motor and drive train.
If it will be street driven the stock drive train will hold pretty well but if you want to take it to the strip on sticky tires you will need to build up the drive train too.
Also consider doing a little tranny work if you have an A4. A 2,000-2,400rpm TC and a shift kit will be very streetable and increase driving pleasure much.
You can get to over 300chp with bolt-ons, to over 375chp with those plus heads & cam and to over 400chp if you stroke it out.
First define your goals for the motor and drive train.
If it will be street driven the stock drive train will hold pretty well but if you want to take it to the strip on sticky tires you will need to build up the drive train too.
Also consider doing a little tranny work if you have an A4. A 2,000-2,400rpm TC and a shift kit will be very streetable and increase driving pleasure much.
Thread Starter
Instructor
Joined: Sep 2004
Posts: 210
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From: peoria il
i would like about 350 hp. maybe 375hp depending on cost and getting the right shop to work on it. if i want 300hp or a little what do i need to do? heads and cam which ones and where to buy? it will be a street driver but, i would like to "get on it" from time to time.
Last edited by rugby!; Oct 4, 2004 at 11:05 PM.
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
I would recommend you have the machine work and assembly by a reputable race shop near you so that if anything should go wrong, they can have the car there to examine it and honor a possible warranty.
If you bore the cylinders .030 over (which is standard) it will give you 355 CID (assuming you re-condition and re-use the stock crank and rods). The stock TPI intake was meant for a 305 motor, so you have the right line of thinking in wanting to replace it with something that flows better.
But moneterally speaking, a stroker crank and rod combo(yielding 383 CID -or more-) is about the same. So might as well get a stroker. Cast is cheaper, forged is more money. For what you want, cast is more than adequate and your wallet will be happy too. I'll let the others continue this. Let us know what you decide.
If you bore the cylinders .030 over (which is standard) it will give you 355 CID (assuming you re-condition and re-use the stock crank and rods). The stock TPI intake was meant for a 305 motor, so you have the right line of thinking in wanting to replace it with something that flows better.
But moneterally speaking, a stroker crank and rod combo(yielding 383 CID -or more-) is about the same. So might as well get a stroker. Cast is cheaper, forged is more money. For what you want, cast is more than adequate and your wallet will be happy too. I'll let the others continue this. Let us know what you decide.
Last edited by pablocruise; Oct 5, 2004 at 03:34 AM.
Team Owner
Joined: Jul 2004
Posts: 28,431
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From: Hartford WI
I'm not too sure about warranties. Other than LPE that knows you will beat the hell out of their 383 ci and up motors and still gives you a 2 yr 24K warranty, don't most engine shops simply dispense with the warranty unless they built something wrong?
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
For around 300chp use my mods or those of Vic'89 (in his sig); I'm building a little under 300chp while he is building a little over 325chp.
These consist of full exhaust mods (LT headers, hi flow cat & cat back), low temp T-stat & fan switch, underdrive pulleys, AFPR, ram air intake, modified intake base and LT runners and a few other bolt ons, but with stock heads & cam.
If you want to do heads, cam, and intake there is a recipe for L98 mods with results on my site. The work was done to the L98 in a '90 Vette 6-speed and race proven at a drag strip. According to the article from which I obtained the table data, the resultant Vette was very streetable and yet ran mid to low 12s at the drag strip on sticky tires. These table mods are my eventual goal for my '88 L98.
These consist of full exhaust mods (LT headers, hi flow cat & cat back), low temp T-stat & fan switch, underdrive pulleys, AFPR, ram air intake, modified intake base and LT runners and a few other bolt ons, but with stock heads & cam.
If you want to do heads, cam, and intake there is a recipe for L98 mods with results on my site. The work was done to the L98 in a '90 Vette 6-speed and race proven at a drag strip. According to the article from which I obtained the table data, the resultant Vette was very streetable and yet ran mid to low 12s at the drag strip on sticky tires. These table mods are my eventual goal for my '88 L98.
Advanced
Joined: Jul 2004
Posts: 98
Likes: 1
From: Maple Grove Minnesota
For what it's worth, I am also just starting my 1990 L98 and I purchased the Magnaflow catback from www.performancepeddler.com, got it for $400 which I thought was a really good price. Installation was a snap too! I love the sound and I do think I can notice a performance difference.
I had 3.73 gears put in which were somewhat expensive (paid $1500) but noticeable.
I also just purchased the Lingenfelter SuperRam today from Ebay, but obviously haven't installed it yet.
From what I've read here on the forum, I was planning on the LT4 cam, new heads possibly, header, removing the cat, cold air induction from www.corvetteramair.com and a new stall converter. I'd like to trade info with you as you move forward. Keep us posted.
I had 3.73 gears put in which were somewhat expensive (paid $1500) but noticeable.
I also just purchased the Lingenfelter SuperRam today from Ebay, but obviously haven't installed it yet.
From what I've read here on the forum, I was planning on the LT4 cam, new heads possibly, header, removing the cat, cold air induction from www.corvetteramair.com and a new stall converter. I'd like to trade info with you as you move forward. Keep us posted.
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Safety Car
Joined: Oct 2001
Posts: 4,763
Likes: 1
From: Connectivette
I don't think 103K on the clock is too late to start doing mods on your motor. I started out with a 110K mile motor and have had success with just bolt-ons so far. I think I'm at about 300hp at the crank with my mods by following the trail that Vic89 and 65ZO1's(and others) have blazed.
Burning Brakes
Joined: Apr 2002
Posts: 1,126
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From: Cleveland OH
Originally Posted by aklim
I'm not too sure about warranties. Other than LPE that knows you will beat the hell out of their 383 ci and up motors and still gives you a 2 yr 24K warranty, don't most engine shops simply dispense with the warranty unless they built something wrong?
Most reputable shops will offer some level of warranty of around 30-90 days depending on the shop.
Ron
Team Owner
Joined: Dec 2000
Posts: 21,094
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From: Phila., PA burbs
Depending on how fast you wanna be, you can easily mod your current motor. As 65Z01 suggested, check out Vic'89s sig for his mods. His car is running in the 12.7X range on stock heads/cam.
Safety Car
Joined: Jun 2000
Posts: 4,870
Likes: 25
From: Long Island, NY
Originally Posted by jzvette
Wow 12.7X on stock heads, very impressive.
We have many members here running high 12's/low 13's with stock heads/stock cam combo's (TA, 65Z01, and Chuck88 to name a few).
The 2 basic things any TPI motor needs are a 2500 rpm convertor and an aftermarket exhaust. Just these 2 items can knock 1/2 second off your current ET.
Vic
