Yeah, I know, I'm sure that this has been posted sometime before, but i dont think anyones ever asked this question with these ideas/requirements, so here goes
89 Formula, 700R4....right now has a carburated 350, is being converted to TPI right now for fuel economy/reliablity...the engine is from an old truck, and its gonna need to be replaced sometime in the future.....my goal is to save up enough $$ by the summer to get it painted AND to get a new engine.
I'm gonna stick with the TPI, and yes, i know its restrictive over 4500 RPM's or whatever, but i'll probably be getting larger runners and stuff so hopefully it will be a LITTLE better....besides, i'd rather torque than high RPM horsepower.
Anyway, my goal is to have a reliable, somewhat economical, and fairly inexpensive engine that will be putting about 275 horsepower to the wheels, and be able to throw in a nitrous setup for a little more punch at the track....nuttin crazy, maybe a 100-150 shot.
Should I just rebuild this engine or should i look for a specific engine block? What should I do for a crank, rods, pistons? I couldnt use vortec heads, right? what heads could i get for cheap and maybe have ported and stuff? I'll have the full exhaust done by that time, so i dont need to worry about that.
I am running low on cash right now and having the electrical problems sorted out and getting the tpi swapped on is gonna end up costing about 800 bucks after buying everything, paying for the cars transportation down to the shop its being done at (was like 150 bucks or something...), etc.
I'm 17 (in 2 weeks) and am making like 500 bucks a month, so we'll say that i've got 1000 bucks for the whole engine by this summer (the car will need SOMETHING by then, I doubt i'll wanna drive around in a car thats dripping oil and crap for very long...lol) (also keep in mind that i've gotta do suspension/rear end/tires as well, so thast why its not a lot more...and if i wanna have the car look half decent, there goes a little more for paint, LOL...and thats not even touching the transmission, but i think it will last a while before i have to worry about it, thankfully)
What can you guys suggest?
Thanks,
-Chris

 

My combo when tuned will produce about 250 to 275hp at the wheels.

If you want to keep the FI, you can pick up a Holley Stealth Ram. Everything from TPI will work, all of the sensors and such. It will also allow you to build alot more power with that 350. Its about $550 to $650 to convert over to the HSR. There is also a converted LT1 intake to consider.

Otherwise to make 275hp at the wheels you can do it pretty easily with TPI. But the parts get expensive and you will be spending more on TPI parts than you would if you just went with the HSR or LT1.

For 275hp at the wheels a majority of your money and time will be spent getting the intake to flow. You will need a ported plenum, large tube runners, and a ported intake base at the minimum. More preferable would be a ported/siamesed plenum. A set of siamesed aftermarket runners: Ported SLP's, Accel, LPE, or TPIS siamesed runners will work. The best runners you can buy are AS&M Semi-Siamsed runners, but at $475 they are a tad expensive. A ported, aftermarket base is a must for maximum power.

You will need a set of heads that flow about 230cfm on the intake side as a minimum. How you get that number is your choice. Ported stock heads, or aftermarket heads. Vortec heads are a great buy.

For a cam I'd probably run one around ~215* @ .050" duration. That will give great mileage, and still provide plenty of punch. You can run more duration, but you won't make maximum power because TPI really doesn't want to peak where those cams like it.

Food for thought. One guy in finland with a converted LT1 intake, LT4 hot-cam, refreshed stock L98 heads, flow-tech cheapie headers, and a cat-back made 299rwhp and 350lb/ft torque. This is with no porting on the heads, just a good valvejob. That same combo with a ZZ4 cam, and a good TPI intake made 250rwhp, and 370lb/ft torque.

You can find info on that build here. http://www.lt1intake.com/dyno.htm

 

How difficult is the LT1 swap? I'd feel sorta bad doing that cause i'm paying to get the tpi swapped on right now, LOL
so with a stealthram or something, my goal would be fairly easy to reach?
Thanks,
-Chris

 

I have never been a fan of the LT1 swap. To me it is just too much work for too little benifit. Now, if that is all you want, the LT1 is ok. However, once you get further than that, the LT1 is not going to cut it. You are going to have to do headwork for sure. AFAIK, the valves are the same size as the L98 with the difference being aluminum. If you needed aluminum heads, get a vette motor because either way, you are going to have to port those heads.

The simplest would be to upgrade to the Holley Stealthram because it is the easies of the lot (miniram and superram) to install.

The bad thing about the L98 is the heads are not aluminum (weight savings and heat dissipation) and there is a distributor (drag) and the reverse cooling. from what I see, if you max the L98 and LT1 out, the total difference may be about 20 HP tops. For that you have to shoehorn the thing in, set up the LT1 harness and, if I am not mistaken, the AC system is going to have some issues along with you having to dent the crossmember. The great thing of the LT1 is that you can install it and have better power because of the intake, mostly, which you can have, if you wanted because there are people that modify the LT1 intake to work with the L98. However, when you want to go further, you will have to have a better intake like a Hogan Sheet Metal intake or ported Superram or something better.

 

Go here and buy one of these crate engines: http://www.gmpartsdirect.com/

Or build you own, almost any 383 will get you there.

 

Aklim, he only wanted 275rwhp. You do not need a sheet metal intake to hit that number. In my previous post I talked about a LT1 intake. I did not mean an actual LT1 motor swap. The whole TPI harness will work just fine with the LT1 intake. You only need to extend the CTS sensor to reach the remote thermostat.

How is the LT1 intake the limitation? The heads and cam are what is going to limit power production. This is relative to what a TPI setup can make.

He will not have to port the heads to hit 275rwhp if he goes with a HSR or LT1 intake. A valve job will cut it just fine. Granted, if he wants to make more than 300hp than he will need porting on those heads, or a good set of aftermarket heads.

 

there is a good chance the block from the truck is a 4bolt. so i would keep it and upgrade the rotating assembly.

have a shop inspect the crank, if it's in good shape have it refurbished, some decent rods and some forged pistons should help you out with the nitrous.

vortec heads with a fully ported TPI system and larger runners should be enough flow. and then a mild cam like suggested. check out www.TPIS.com for some good cams designed for the TPI.

 

The Lingenfelter 74216 cam would probably work great with what you want. I have the LPE 74211 cam in my car and it works idles just like stock, even without any tuning. Plenty of people have seen 12's with the 74211 camshaft,but I wish I would have gone slightly larger.

 

decent heads and cam, with some compression will get you 275rwhp with the stock TPI on top.

 

When I asked how hard the LT1 was to swap, i should have specificly said "LT1 Intake", but i was in enginering class and wasnt paying much attention, lol

 

Fruty, do you seriously believe he is going to stop at 275? I for one minute don't and won't even if he swore it on a stack of bibles. I once said that a stock 91 Firebird with a 350 is enough for me. Bill Gates also said we won't need more than 64K of ram.

I got 10 years use out of the Superram simply because I wanted something that would support the power I made without porting the stock intake and having simesed runners, etc, etc. Looking back, I wish I had gone with a sheet metal intake instead of the Superram. If I did, I wouldn't have to try get somethign better after the SR which is why I went to the HSR. What I spent on the HSR and SR combined could have bought me a sheet metal intake from Hogan which I believe is better than the HSR. When I wanted more power, it was either the HSR or a ported SR and I wanted a cleaner engine bay so I went with the HSR. Besides the HSR is easier to install. When my engine was stock, I went with the 58mm TB instead of the 52mm one because I realized that someday, I might be able to use it and instead of kickign myself in the butt for not buying it then and getting the smaller version, I'd do it now and get it over with.

LT1 intakes are ok. You can easily get one that is modified to fit the L98.

 

For what he needs though the LT1 intake, or even a fully ported aftermarket TPI setup will provide plenty of power for a long time to come. Sheet metal intakes take some $$$, more than I could justify spending on an intake alone for a car that isn't even going to run 11's anytime soon. Hell, I'd be extatic about a high 12 second pass.

The LT1 or HSR intakes will provide plenty of room for growth right now, he could easily make over 400hp at the wheels with either of those intakes if he wanted.

I'll be forced induction long before I have to worry about sheet metal intakes.