Hey all. I can already tell that this is going to be a fun post for some of you. I'm looking to modify my engine a little, but I'm really not sure what I want to do. Do any of you have any suggestions? I've got about 2-3Gs to spend (depending on how loose I'm feeling with my money) and I'm not sure what I can do to gain horsepower with that much money. Hit me up with some ideas. Thnx! :grouphug:

 

1st- Edelbrock Performer RPM Air-Gap.
2nd- AFR190CNC heads
3rd-CC XE-268 cam and 1.6:1 roller rockers.
4th- DynoMax ceramic coated headers and new exhaust system
5th- Speed Demon carb
6th-MSD 6AL box, Blaster coil and pro-billet dist.

That should make you VERY happy.

-Aaron

 

Factory 69 style chrome sidepipes, Comp Cams 268H, and four Dunlop SP8000 245/50-15's!

 

Wow. You guys respond really fast. This is giving me some great ideas. Keep 'em coming! :thumbs:

 

Your probably going to get 10,000 different answers. I would do one of the following:
1. Save a little more and get a crate engine - 383 (Unless you have a big block in mind)
2. Complete suspension

The second is what I am looking at once I return from this Stan. :flag

 

Zank, best bet for performance and also doubling your fuel economy is replacing the entire induction system with DPFI, say L98 style off a F body or C4 vette, it's basically a bolt on, going closed loop will like I said double your fuel economy, also extending your cruising range, obviously,....
depending on how/where you drive it...you may want to get an overdrive automatic trany 200 4r is way to go there, basically a bolt in....

all the rest of the mods worth doing are chassis/steering/brakes related, and out of the scope ofyour inquiry....

GENE

 

If your looking for better off the line performance, then I'd suggest in this order, performance rear gears, headers, aftermarket cylinderheads, cam.

These changes such be able to be done with your $3k budget and really change the personality of your Corvette :yesnod: .

:cheers:

 

Zankou77:
First, you reside in the Peoples Republic of California; are ANY modifications legal? If so, must you still meet emission-standards for a '77?
Next, what are your uses for the car (daily-driver, highway-cruiser, stop-light bandit, etc.)? No sense putting 4.11s and a big cam in it, to drive on the Interstate, right?
Is mileage a factor? Sheer horse-power? Are you willing to run high-test, or even race-gas? If beginning with your short-block, how many miles does it have?
Once these questions are answered, you'll get more informative feed-back, and be happier with whatever choices you make......

 

Not to hiijack this guy's thread but, what reccomendations can I get for a 81 with 100k on the short block, already modded exhaust and a desire for 1/4mi performance that is streetable enough to run pump gas and travel within 50mi to car shows. As cheap as possible but most bang for the buck in regards to durability.

I do want to abandon the computer control.

Would buying a LM1 short block be a better place to start than the original L81? What's more cost effective? Would heads, intake, carb and ignition make significant power and not blow up a tired block? I'd like to keep it around 9:1, maybe vortech heads and intake? What would be the cam suggestions on this type of setup.

 

3.55/3.70 gear ratio will make a bigger 1/4 mile difference per dollar than mods to your engine for equal 1/4 mile improvements while stil allowing some highway driving :) .

If your car is properly tuned, then NOS can also help ;) .

 

tersian:
I don't know 'what' you can do, and still have the computer-control certain aspects of your '81. Here is what I did to my '79 Z28 (equipped with the LM1) 20+ years ago, and the results:
swapped heads for 'junk' earlier heads w/ 64cc to raise CR to approx 9.:1 (TODAY, just buy good heads for a grand); mild hyd cam .450"/224* @ .050" (TODAY, get the 268H cam); 'old' 327"/365 HP intake (TODAY, anything is as good); 'on-sale' headers; 650 dbl-pump Holley; shift kit (THM350); and 'pitch' the cat.
In 'pure-stock' form (I never ran mine), the '79s were tested @ 16.40 @ 80 MPH (I think?). As above, with a 'one-wheel-peel' (posi was an option in the Z28) 3.42:1 gears, open headers, on GR70/15 UNIROYALS, the Z ran effortless 14.40s @ 97 MPH, leaving at 1200, shifting & trapping @ 5500, on SUNOCO 94/AMOCO93.
At inspection/emission time, I simply leaned-out the mixture screws until it passed, then, fattened it back-up, before dis-connecting from the machine. Highway mileage went from 15 to 18+, and I drove it ANYWHERE!!! Later, with 4.11s, it went a best of 14.11 @ 99+.
(P.S.: If you decide to get gears for your '81, gimme an E-mail. I got 3.73s for my '82 last week, new, in-the-box, for $125 + S&H. If you have 2.72/2.87s, the EASIEST way to 'wake-up' your Vette would be gears. It'd 'hurt' your MPGs, but you can go 50 miles with 'em. Hell, I once went 650+ miles, round-trip, on 4.11 & a 9"/4000 RPM converter {5 MPG :eek: }. I'd guess that ETs would drop 3-4 tenths {?})

 

Glennsgages:

Are you going to come east and help me put all this together? :)

-B

 

It's a universal fact for ALL smog-era corvettes that exhaust should be the first to change. Usually 2 1/2" duals, or the closest to that you can get if you have emissions to worry about. Next intake (I went with a performer, plenty for a moderate engine), then cam and heads (I went compcams 268 high energy because I got a kickass deal, and am very happy, but many recommend lower durations, or the XE line of cams. Also, changing to 64cc heads will increase static compression, increasing performance alot and should still be fine on pump gas.)

A last note, whatever you do, don't neglect the suspension! At least be sure your bushings, etc. are in good condition, or else you won't be able to enjoy that new power very well. There's a million ways to go with your money, learn all you can and you'll find the right one for you!

-Chris

edit: it's my opinion that you'd be wasting your money on a new carb, assuming your stock one is in good condition. Our quadrajets are rated at somethign like 750cfm and work very well. When you are doing your exhaust system, headers are a good idea as well, as some others have mentioned.


[Modified by RUXperienced, 4:41 PM 8/27/2003]

 

Well, I've already done duals(with slow bends to get around the crossmember issue) to some flowmaster 40's and the cat was last seen at the bottom of the scrap heap. All smog equipment has been removed(except the manifolds).

I guess I want to take this a step at a time, so what would be the next logical step in everyone's opinion?

 

GEARS!!!!!

You've already taken care-of the exhaust system; now, let the motor USE it's ability to breathe freely! With deeper gears, you'll be turning more RPMs at any given MPH; just what free-flowing exhaust is FOR!!!!!

Every modification you make after this point in time (cam, intake, carb, etc.) is made for turning more RPMs and/or making more HP/TQ. Gearing allows you to 'apply' it to the ground, and these later mods will appreciate the gears now!!!

Besides, swapping the gears is a one-day affair (if you're having it done professionally), or a weekend-project (good luck!); the Vette 'shouldn't be outta service very long. Cam/intake/heads, on the other hand, could lead to 'other problems', putting the car 'out', while the weather is still nice!!!

I'm told by other C3-owners that going from 2.87s to 3.73s is worth approx 3-4 tenths in the 1/4-mile, which (I'm guessing here) should be about 30-40 HP (?).

Just my $.02 worth.....

 

700-R4, Heads, Intake, BG Carb

 

Wow. Where to start. Ok, first, this is my only car, so I'll be using it for everything, but most of my driving does tend to be on the freeway. However, that does not mean, necessarily, that I'm not interested in increasing my low end power. To drive on Cali freeways, you kind of need a "stop-light bandit" to get any respect, especially with the frequent jams.

K, next, my concern for mileage is not totally out the window. After all, I'm currently a college student making $6.75/hr for 10hrs/week. On the same coin, I'd like not to have to run fuel higher than the 92 I've been using (or is Premium 91 now? Whatever).

Oh yeah. And, you know how I said in my first post that I have about 2-3Gs to spend? I'm beginning to think more around 2-2.5K Keep the posts coming; this is great stuff!

 

Oh yeah. Another side note: a lot of people have suggested suspension. Just to let you know, that can be checked off the list because suspension and bushings were the focus of last years big project. = )

 

Since you live on the left coast, you might try dual fart pipes, big spoiler, 20" chrome wheels with "rubber band" tires and stickers....lots of stickers....I heard an estimate that each one adds about 5 hp or so.

Oh! Sorry....I thought I was on the RICERFORUM.COM :jester

Make sure all your parts have CARB numbers so you don't get hassled at inspection time and enjoy all of your clean air. Maybe Arnold will get elected and repeal some of the silliness out there! Then you can buy some REAL speed parts.

Sorry for my sarcasm. I'm just jealous of the weather out there. Especially in January!! Who needs a fast Vette when you have beaches galore and all the silicone you can stand to oogle at? :thumbs:

:cheers:

 

First of all, you should be giving us a better idea of what you are starting with. How does the engine run right now? Is the 2-2.5k for the engine only?
Assuming your engine is running fine now, I would say to go for, heads, cam, intake, and carb. If you have any left, buy some extra back tires :jester