Dirty 1990

I want to take a 1990 l98 motor and make it 400+ hp & Tq. I'm aware that is probably gonna take some money but just try and show some parts, recommendations, etc to make those kinds of numbers that are good for 7k rpm and run hard very often that I can use as a daily driver

FAUEE

Engine swap.

James93LT1

LS7 Conversion.

Dirty 1990

Ok realistically by the time I'm done with the car probably won't have more than 450 hp & Tq and I was just planning on doing different things at different times as I get the money. What should I do to start with I was thinking a new intake (miniram, lt1, stealth ram, etc) but what should I do after that ?
Might I add I'm also looking for more experience with working on engines

1stVetteFinally

fastest and easiest way to make more HP and torque in a C4 Vette is new exhaust and headers. don't have any recommendations for myself. I just got my first Vette a couple months ago.

Dt86

Exhaust is probably the biggest restriction on the motor that you can change with the least money. Then if you want to drop a lot of cash for not a lot of hp gains change the intake, heads and cam. With the L98 you're going to spend a lot of money and not get results that are worth it. At least in my opinion. I've wanted to do all of that but the expense just doesn't justify it for me. If horsepower is your goal buy a later vette with the lt1. Al least you're starting out around 300 hp. I'm saving for a 96 lt4. The 86 is a fun cruiser for me.

lt4obsesses

Cheap
Fast
Reliable

Choose two.

When my engine started to go south, I did some looking around. For the power and reliability that you're looking for, an LS swap is probably going to be the route to go. An LQ4 was the direction I was thinking about. It's an iron block 6.2 truck engine that could be fitted with LS2 or LS3 heads, a cam and you're close. Rebuildable short blocks around here were going for 600-800 range, fully rebuilt or low mile and ready for about double that. Found some LS sort blocks in the 2K range. It's the heads and intake that will run up the bill. Than probably another couple grand to make it all fit and fire. I wound up buying an LS3, and the rest of the Camaro that was built around it.

rocco16

There's so much truth in that.

Yes, cheapest way is a larger, more modern engine.
Horsepower isn't cheap, by the way. If you want to get another 150hp our of your engine, you'd best budget about $7000-$8000. It's not just a question of bolting parts on your tired old engine; it will never live and will never produce to its full potential if you do that. You have to have a solid basis for building real power, which means going through your engine completely.

A fresh LS engine installed will be at least that amount, but you'll have a reliable, driveable powerplant instead of a tempramental, potential grenade.

Dirty 1990

Ok thanks
Excluding the exhaust what should I do if I have $3k

rocco16

I know you don't want to hear this, but I'd advise you to have your engine professionally rebuilt to factory specs. That should take most of your $3k and you'll have a good running engine that will live for another 200,000 miles.
It ain't sexy, it's reality.

John A. Marker

Even buying a short block and then good heads (like AFR or Trick Flow), cam, intake, new tune your into the $7000 range doing the work yourself.


As stated HP costs money.

lt4obsesses

I would have to agree with this. If this is your daily driver, reliability is going to have to be a priority. Maybe during the rebuild you can do some things that will help it breathe a little better. 1:6 rockers, port intake, and add headers. Then perhaps look into a taller rear end gear which will add some seat of the pants fun.

Exhaust is always a a good upgrade, but a lot depends on how strict the emissions policy is in your area. But keep in mind the age of the car. There are many other things that may need attention. Suspension parts, brakes (which if your going more go power, you'll want more stop power).

The thing about the C4, is that even if you get it up to say, around 300hp, you'll be suprised how well it can keep up w/ most of the cars out there, as long the whole package is sorted out well.

corvetteronw

http://temp.corvetteforum.net/c4/vader86/

Tom400CFI

All of those criteria (400 hp, 7000 RPM, and $3000.00) do not intersect. In other words, unless you're an excellent fabricator, porter, and engine builder, I don't see a 400+ hp, 7k RPM motor coming from $3k. Eliminate the unnecessary 7k criteria, and I still can't see it happening for $3k.

For $3k, IIWM and I KNEW I had a solid bottom end, I'd do LT1 manifolds and dual exhaust (assuming emissions can be met where ever you live), port my own heads, cam and a converted LT1 intake. If you do all the work yourself, that might fit in your budget and get you between 350-400 hp.

Then hope that you're right about the solid bottom end, and don't go past 6k RPM's (there is no need to).

Tom400CFI

Most of today's cars, even though they claim big hp #'s, they are also burdened by 500+ lbs more weight.

Paul Workman

with every word!

OP: I've built everything from SBC overhauls to 9000 rpm alcohol track engines, and the one thing they have in common is a comprehensive build plan (read: goal) established before buying the first friggin nut or bolt.

And, that gets back to the ol' "fast - cheap - reliable; pick two". And one more too: "Speed cost money...How fast do you want to go?"

I guess what we're alluding to is the approach which amounts to bolting on something and then asking, "What else is next" is usually a hodge-podge and a waste of $$ and more expensive in the end than if you'd done it right to begin with. If you reach your goal that way, it will be in spite of your "planning", not because of it!

Good luck. In the mean time, there is an excellent book for the beginner or the experienced alike named "How to Hotrod Your Small Block Chevy". I've seen it in the automotive section of bookstores and at auto parts stores. It can keep you from making many expensive mistakes and put you right on the parts and machining, etc you need in order to meet your goal.

vettespecial

I have owned my 90 L98 coup for almost 3 yrs and i also had the ambition
to upgrade the engine. mine was bone stock i would go back and fourth on rebuild with new heads and cam or put a 383 engine in. By all means the car is a fun cruiser and with a 6 spd just stock. with 270k on it the first thing i did was pull the oil pan change out the timing chain and gears
reseal intake changed all the coolant hoses. a cylinder leak down test of all cylinders indicated it was worth running this engine for another 100k
I did the A.I.R pump delete I ordered a pair of Headmen headers
from Summit I wanted to keep the EGR so i cut off the air pipe from headers and capped and welded. It had been yrs since i did a set of headers but these headmens went on so easy! all i had to do was trim a heat shield for fuel filter. the exhaust cats were long gone so i have pipes out to the mufflers. I really love the performance now and i moved my timing up to 8*BTC and it don"t ping. I agree with everyone else i would have to upgrade to a LT1 or LS1 for more power then i have, plus i dont want to mess up the great fuel economy.

ch@0s

There is no such thing as cheap horsepower.

Bandit's C4

Afraid the OP got it from both sides - asked a similar question in the tech section, too.

https://www.corvetteforum.com/forums...-or-caste.html

aDigitalPhantom

Fixed it for you.

After all you could buy a couple of the 200$ ebay special mystery turbos, some ebay special turbo headers, and get a good power increase for about 15 seconds to a few days or more. After that probably need a new engine block and all.

PS
In case anyone thinks the above is a good idea...It's not but if you do think it is a good idea, and do that please record on video what happens and show us.