Marcum_Marley

My silver '86 is about to need a rebuild. I would like to add much needed horsepower. I am tired of getting beat by LT1's. What are the capabilities of the L98 engine, and tricks to get the most out of my existing engine? Or, would I be better off doing an engine swap! It would be great if anyone could give me some numbers on their rebuilt L98's :mad

scorp508

Wha'cha wanna spend? :reddevil

Marcum_Marley

I am looking anywhere from 3k to 6k!

scorp508

You be in luck my friend!! :) There are lots of go'fast goodies for that price range. For example I will post what I've posted a lot of times before for other people. It's a proven combo, good for SOLID low 12s, possible high 11s with traction. Beach Bum, Ralph, L98 Terror, and others will back that up.

Accel / Lingenfelter SuperRam Intake : $800
Accel / Lingenfetler SuperRam Intake Manifold: $500
Lingenfelter Camshaft: $340
AFR 190 Heads: $1500 (could be more less, depending on what you order)
Comp Cam Pro Magnum 1.6:1 Roller Rockers: $260
Pushrods: $35
Guideplates: $20
Timing Chain: $90
Custom Chip: $150-200
Misc Gaskets Etc: $255

That right there is $4000, for all brand new parts. Put together and tuned right, you should put out about 400hp, and even more torque at the crank. The engine should have power off idle and pull HARD all the way to 5800 or so.

Give or take a few more $$, the outcome can be a little different. :) Also the SuperRam intake and manifold can also be found on sale on here or ebay for about 1/2 the original cost. They are metal non-moving peices; so used is basically just as good as new!!

vader86

while you are at it, replace rods, pistons and such with better parts. A set of TPIS headers will run about $650 and 22lb injectors for $200 i think, lemme know how it turns out since my 86 is in need of a rebuild also.

scorp508

How the heck oculd I forget the headers. :)

Marcum_Marley

I like the 400hp! It is nice to know that the ram air intake makes that much difference. Also, are the heads suggested aluminum.
I know I am asking a lot of questions but that is why I am here. I bet you probablly know the limits to the rpm range of this engine. Are there any was of raising them. :cheers:

scorp508

Well the SuperRam is just it's name, not really ram air. You could add a ram air system for $260 though that might help a little more. The heads yes are aluminum. Do you know if you have aluminum heads or not? They changed in the middle of hte 86 production. Easiest way to tell is the valve covers. If they are perimeter bolts, you have iron heads. If they are centerbolt, you have aluminum heads. You would be shifting this combo around 6200 RPM. No need to go higher as there is no power up there. If you wanted the redline to be higher though (probably is about 6500 now), you would want to build up the bottom end and valvetrain with more solid parts.

Marcum_Marley

I don't have aluminum heads! That was on my list of parts to get. I was going to ask about the headers, but you guys beat me to the punch. I asked a local corvette specialist here in pensacola, and he said that it was a waste of time to buy headers. I have looked at the stock exhaust manifolds and they seem really restrictive. :flag

Marcum_Marley

I wish that I would have known about this forum before I put new injectors in my car. I could be the stupidest corvette owner alive. just from doing my recent research. I think that I spent twice as much for stock injectors instead of getting high performance ones. I replaced all the intake gaskets, and should have done all these mods then. But it is my daily driver. Hopefully I will get some good results from the advice of my new found well of knowledge! :cheers:

Aggravated4life

Welcome to the forum marc! Ditto to what scorp said. Give yourself some time and research,read,read,read until youve got the main idea what works.

Btw headers ARE a waste of money,but thats on a stock engine with NO mods.Once you get your mods,headers will bring it alive.Only then will it be worth your time.Headers on a stock engine may gain about 10 HP.Modified engines, it will allow it to breathe and flow to its potential.Thats more HP then for ya.

The stock exhaust tubes are too small to support HP over 300-325.
Keep in mind our L98 engines are torque motors...they make good torque at low speeds but not much HP.Btw HP is in fact a mathematical equation of torque anyways.

Pushing the torque to a higher RPM closer to 5250 results in more HP.THe LT1 peaks out its powerband at a higher rpm speed resulting in more HP across the board.
The reason for that is in its short style intake manifold.With the L98's,the large/long tubes cant flow enough air to make HP over 4800 and the Super Ram fits the bill nicely.
But do they feel so torquey around town.

Hang out here for a while and keep learning.Soon youll have a combo to choose from that fits the budget.

Never think youre stupid for spending alot of money on parts like injectors and etc.
Many of us did the same before we found the forum and the new ideas.AT least you know the car has the right injectors you need.

Not all aftermarket injectors have proven to be any better or successful,even though theyre cheaper.

Now the guys here can guide you to save alot of money from now on.It will balance itself out then.
:)

importeater

you guys have made me curious on one thing. the TPIS miniram on paper looks to be the superior manifold in design but almost everyone spoke of the accel superram? am i missing something? is the miniram just not all it's cracked up to be? as it sits i haven't used either just read up on what's out. it also seems like a miniram would make the intake tract quite a bit more simple to work on as you don't have all the pieces or gaskets.

Springer's LT4

The miniram has a strong following on the forum as well... just depends on who you talk to. If I still had my 86, I would be going with a Miniram myself, mainly for underhood appearance and easy of working on it.

h rocks

Unless you're building a high winding stroker, the Superram is the hot ticket. If it's high RPM's you want, and are prepared to work out the computer tuning, the Mini could be your intake. There are many guys who have gone in the 11's with the Superram (and some with big tubes). The SR will give you maximum driveability without sacrificing too much hp on a street motor. For all out HP however the MR is it.

I've also been studying a rebuild parts list, and the one thing that's absent on the list's I've seen above were good, forged rods. Every single engine builder I spoke to has told me that even in a 6,000 RPM or less motor, rods are critical. They have said that while not ideal, even the two bolt mains and cast crank would live longer than poor rods.

vader86

the reason we all like the super is because of its torque and drivibility. The miniram has kind of a crappy idle and doesnt run right unless youre over 55mph or so. Superram is very good for a daily driver and makes almost as much hp as the MR, if theres a difference at all.

1991Z07

You can also get the same HP numbers out of the stock-style TPI intake system. As you can see in the signature, 400 HP & 500 lb/ft is VERY do-able with the right planning. Follow the link to my web site and go to the "Recipe for a 400 HP L98". It gives you the P/N's and what I did to get it there.

It's really fun to have someone ask you "What have you done to make it Group 3?" when they look under the hood. It looks completely stock, and only a sharp eye can pick out the Arizona Speed & Marine Big-tube runners :D

I really like the sleepers. That Super-ram is a pain to work on, and advertises the fact you've really changed something. Those that go with the S/R have my sympathy when it comes to getting all the bolts in....but it does give you a really good flat surface to set your beer on :lol:

And if you do your homework, you can still get great gas mileage...mine sits at 26 MPG on the highway.

phrogs

Just want to say welcome to the forum and just listen to what these crazy people have to say lots of great knowlage to have here...
Oh hows pensacola doing ????havent been there in a long time but loved every second of my time there :cheers:


[Modified by phrogs, 8:41 AM 12/6/2001]

Marcum_Marley

Pensacola is doing great, I however I did not like the fact that this weekend I got destroyed by a stock 2000 Camaro ss. It was a very humbling experience. I knew that the ss would beat me, but I didn't know that it was going to be that bad. At first I jumped ahead and was gaining ground, or at least I thought I was. At about 90 mph, I was three car lengths ahead. Of course I got a big jump off the line on him. I think that he gave me a little head start. Any way I look back and here he comes. My car didn't even stand a chance, I lacked so much top end power. Hopefully in a couple of months that will not happen again. It is good to know that these mods are fairly inexpensive to a engine swap. Thanks for the advice! Next time the story should be different!

1991Z07

Hey Johnny! How's the "Rock" doing? I was stationed at Kadena (Air Force SSgt.) from 1983-1988. Which post do they have you at? I loved it there. Sand, babes and motorcycles!!

The worst part was the Typhoons, if you didn't supply yourself well from the Class 6, you ran out of beer too fast :lol:

Don't get yourself in any trouble with those LBFM's out there. Stay cool and get back to the U.S. of A. in one piece.

Racer78

Don't over look GM Performance crate motors either. Like their 385 fast burn.
http://www.paceparts.com/


Add the intake system and exhaust and ready to go :)


Keith