I know it has been asked...I have searched and read and most of the threads I found are old...so here goes.

What are the best engine upgrades and mods that can be made to an 1981? At a low price...lets say...below 2k! It has already had the Cats removed and has true dual exhaust...now which direction do I go? For under 2k which is more easily attainable higher HP or higher torque?!? The car still has all the computers and emission controls installed excepts for the Cats...what are the pros and cons of removing them and how much of a difference does is make?

 

does the 2k include someone else's labor or are you doing the work? that will make a huge difference.

 

That can go either way....So lets say 2k with me doing the labor...3k with with someone else doing the labor...

What could I do?

 

If the cats are gone, the other emission control stuff is not going to hurt performance much.

If I had your budget and wanted better performance, I'd add a set of headers, do everything to make sure the car was in as good of a tune as it could be and spend the rest on a rear gear and (if it is an automatic) a higher stall converter.

It's not going to be a world beater on that kind of a budget.

 

I know this is my "starter mod" budget to hold me over for a little bit...After I do 2k worth of stuff...in another 6months or so I will probably do another 2k more

 

headers, cam and head work or heads maybe. a gear. a converter is better with a cam a cam is better with free breathing heads heads are better with more compression. and so it goes....

 

If you're up for spending more down the road, then that makes a big difference. Not sure how healthy the bottom end of your engine is, but that is a big one to plan for. $3k worth of engine mods can quickly lead to the need for a $2k rebuild, so be careful there.

This is how I would go, assuming the bottom end of your engine is good to go.

- Headers, tune, gear, stall converter
- heads, cam

 

I bought an unmolested '81 a few months ago. here's the mods I have done so far:

Corvette central exhaust kit (true duals with H pipe and Cat delete) $250
Summit brand headers $110 + $50 for VHT paint and collectors and misc.
Poly engine mounts $55 (original mounts were broken so this was more of a repair then a mod)
removed AIR pump FREE
set base timing to 14 degrees FREE

So I spent about $465 and I can spin the tires a little from a stop now. I didnt include maintenance parts such as plugs , wires, cap and rotor, etc. dont overlook that stuff if you havnt done it already.

My next big mod is going to be a 5 speed manual, but if I was going to spend around $2K on engine stuff, it would definitely be a ROLLER CAM and aluminum heads next.

 

Yeah I am def up to spending more down the road.

 

Higher compression and better flowing heads; better cam (to match heads); headers would be of some help, but they add a lot of heat to the engine compartment; an upgraded PROM for the '81 ECM (since your system still works.

There is no good reason to change out the Q-jet and/or ECM control system as long as the system components are still working well. You will get better cruise mileage and better idle/start quality with the ECM doing the engine management for you. And if someone tells you to install a 650 cfm Holley, tell them "No thank you, I already have a 750 cfm Q-jet on the engine."

 

I will probably do the headers...What good is removing the AIR pump? I have heard ppl say it just adds extra space in the bay...some say it increases hp...others say it only uses 1 hp in the first place.

 

MY suggestion:
Don't spend any $$ now, save up ~$6k's then buy yourself a ZZ4 crate turnkey motor and install with hedders and dual exhaust for that figure I stated. This is with YOUR labor (of love)... Dont piece meal the mods and when you finish you still have an old tired pig with lipstick. The crate is NEW and has a NEW warranty. You can get similar crates for lesser $$ also.

 

Umm do you have cheaper suggestion...what about an lt1 swap, an LS swap maybe...It's going to be hard to save up 6k to spend on an engine...

 

Unless you are a skilled fabricator with a line on parts for nearly free, a swap with an LS or LT engine will likely cost you more than a ZZ4 ($4400 at Summit), to say nothing of the time involved.

 

Gotcha

 

You didn't say how many miles on your engine?

My 1975 had 90,000 miles and it was a slug.
No ridge at all so I was able to simply hone the cylinder.
The ring end gap was twice what the new gap was.

ZZ4 heads $700.00 (lightly used) 10,000 miles
Roller Cam 800.00
Intake 130.00
Oil pump 50.00
Headers 130.00 Summit
Dual Exh. 200.00 Bought 45's and straight pipe from Kragen.

Rings, bearings and gasket kit from Summit, add another $200.00.

I used a Lunati hyd. cam but wish i'd gone roller because of the new oils.
My cam was about $280.00 if I remember right, plus new longer push rods $20.00

$2000.00 doesn't go as far as it should, but this is what you need.
Nothing fancy but everything you need.

At 80mph I can punch it and get sucked back in my seat.

I did everything with the engine still in the car
Simply rolled the main bearings out and rolled the new ones in using a cotter key.

I gas welded the exhaust myself and saved about $100.00.

It took about 4 days to get everything completed with 2 of us working long days.

I had all the parts before I started and that helped.

I decided to go with roller tipped rocker arms to help ease the pressure on the cam, $85.00 and I'm getting ready to install a one piece pan gasket.

Pulled the pan once to stop a leak it helped but it still leaks some.
The one piece gasket look like it will do the job. $35.00

By the way welcome to my world.

Ralph

 

Take all the pollution control stuff off.

Disconnect the ECM
Replace the distributor with a vacuum advance unit.
Replace the non-adjustable carb and put a good intake on it.
Put headers on with true dual
Put a decent under .500 lift cam in there so you won't need head work.
And lastly get rid of those 2.72 gears and you will love the car. Go with maybe 3:55 or 3:73.
You just spent your 2K without getting broke.

 

Take a look at this:

http://www.superchevy.com/technical/...er/page2.html:

"Replacing the stock 882 iron heads with 200cc RHS aluminum heads, an XE274H hydraulic flat-tappet cam and Pro Comp dual-plane, aluminum intake resulted in some serious power. Fed by a Holley 750 HP series carb (we should have tried a test with the stock Q-Jet-sorry), the upgraded L82 produced 414 hp at a slightly higher 5,900 rpm and 415 lb-ft of torque at 4,100 rpm. The upgrades to the L82 improved power throughout the rev range, from 3,000 rpm all the way to 6,500. The gains would be even greater on a milder small-block (from, say a truck) since the stock cam timing would be even milder than the L46 cam used in the L82".



Read more: http://www.superchevy.com/technical/...#ixzz1O1N4za9J

For 2-3K, doing the work yourself, there are big gains to be had! I am thinking about AFR aluminum 64 CC 180 heads, stock aluminum L-82 intake, using my current Holley 4175 650 CFM spreadbore vacuum secondary carb, already have Mcjacks shorty headers, 2.5 true duals with Monza turbo mufflers, no emissions at all, and roller tip rockers. I am hoping for 400 Gross HP with this combo. I am betting you can get pretty close with heads ($1,800), headers with 2.5 true dual exhaust ($500), intake ($150), and cam ($400). A ZZ4 crate motor makes 355 Gross HP as a comparison!

You will save a ton of money (assuming your engine is in good condition) over the crate motor and a ton of time not to mention the headaches changing the engine. Just my 2 cents!

 

Almost 80k miles on the engine

Thanks a lot for that...that isn't too far above my price range...I plan on ordering everything periodically...then install once I have everything.

Thanks again

 

Thanks for the link...some good info.

How much of a difference does it make by removing the ECM and all the emissions components?