81$$pit

L81 with Edel 600 CFM carb, EPS manifold, CL12-242 Comp Cam, smog stuff stripped including cat, Pacesetter Mufflers, Spectre air filter / lid.

MelWff

download comp cams software
http://www.camquest.com/

Sam and Jess

That is a pretty neat link. Fun to dork around with.

a1sensei

190hp
-15 hp (this carb is NOT an upgrade)
+5 hp (stock manifold is equivalent to Performer)
+15 hp (good cam, but it can't do much with the rest of what you have)
+2 hp (if anything)
+10 hp (the front half of the exhaust has already choked all the performance out before you get to these)
no change.

Total: 207 hp (net change 17 hp)

Suggestions:
Headers and 2.5" duals: +40-60 hp
Heads: +30-40 hp
Re-install and tune original carb/ ignition: +25hp

God bless, Sensei

qwank

what are you smoking, because I want some? (not really)

I installed long tube headers and a full dual exhaust on my '81 and barely noticed a difference. I'm sure it will help with my future head and cam change, but there's no way you get that much HP from just an exhaust change. I don't think it even give you more HP, it most likely frees up HP that's already there.

I think you are spot on with everything else you said though

a1sensei

The stock '81 exhaust was very restrictive from the get-go. The headers had very small primary tubes, then everything converged into a single 2" pipe. When I got my '81 it was bone stock. Soccer moms would laugh at me as they pulled their mini-vans past me (with my accelerator to the floor!). I replaced the stock exhaust with headers, 2.5" duals (no cats) and a pair of cheap turbo mufflers. The only other change was to tweak the timing and I may have done a little adjusting on the carb, Then I was spinning tires! The difference was HUGE! I have since replaced the heads, cam and pistons, heavily modified the carb and added MSD/ Mallory ignition. Yes, the car is faster, but nothing made as big a difference in the seat of the pants as the exhaust. For these cars, exhaust is the #1 bang for the buck performance mod.

God bless, Sensei

P.S. 40-60 hp is considering he already has an XE268 cam that is not doing what it is capable of because of the stock heads and exhaust.

qwank

Ok, I can see it helping with a cam and head upgrade a lot.

My car was also bone stock when I bought it. It ran perfectly, the PO had a great mechanic and the CCC is working as designed.

I set my initial timing at 14*, installed long tube headers and the Corvette central exhaust with the magnaflows, removed air pump, and EGR for a cleaner engine apperance, swapped out the 160* for a 190* for optimum performance of the CCC, and installed a 4 wire heated 02 sensor. my car runs excellent right now, and I can spin the tires, but it really doesn't feel much faster.

I'll eventually do a roller 270 cam and some new heads, and I think that's what going to really wake the engine up. but before that, i'll be installing a 5 speed, since the engine runs flawlessly at the moment.

81pilot

Getting the Timing adjusted away from stock to about 12-14 initial and 36 all in will also help a bunch. The EPA settings don't allow the engine to perform very well. Also a few carb adjustments help, even with the E4ME carb.

a1sensei

A properly modified and set up E4ME will outperform any other carb on a street driven car (combination of fuel efficiency and WOT performance, you can even use a turbo to blow through an E4ME). I used to hot-rod E4MEs for people with '81s and I've made believers out of a lot of sceptics.

God bless, Sensei

81pilot

Perform well but outperform never. You could never convince me that the trouble you have to go through to live with one is worth it. They can be made to possibly perform at par with a regular Qjet but there is no reason to even suggest they can outperform one.

Ganey

CARBS Tests TQ/HP
http://www.corvettefaq.com/c3/carbcomparo.htm

a1sensei

I'm really not looking to argue, but with all respect, here are the facts:

E4ME Quadajet:
Reliability: This may be subjective, but after years of working with it, the entire system is quite simple and reliable.
Fuel Economy: The E4ME is absolutely without peer among carburetors.
WOT Performance: Any carb can be tuned to deliver optimum fuel/air at WOT. The only difference is cfm. At 800, the E4ME is no light weight. In addition, unlike other Quadrajets, an E4ME can run a blow through turbo! (In other words, say "bye bye" to anybody running an older q-jet)

Well there you have it and I'll not argue the point farther. As Ripley would say, "Believe it or not."

God bless, Sensei

81pilot

I agree with reliable and really have no vendetta against them, when they work fone they are a good carb, but simple? As you say subjective.

I was unaware of the 800 rating, but on the stock L81 that 800CFM will never ever be needed unless the motor gets really worked then this whole discussion becomes moot. But I will give you the potential factor.

Fuel Economy? Mine gets as good as any well tuned E4ME that I have any knowledge of, but maybe they are a tiny bit better, but if so it can not be much at all. Its not like the est MPG jumped by 5 or 10 MPG from 1980-81.

And the fact they can handle a turbo, well thats good news for all the guys who run turbos on 1981 c3's and want to keep the computer, a small sub group for sure. But once again another point for potential.


So if those facts are what you weigh the outstanding attributes of a one year only computer controlled carb on thats fine, but not enough to convince me they are worth the trouble they cause, since I get great mileage(with an earlier model Qjet and no Comp),I also have no need for 800 CFM and don't plan a turbo with it, I would think I am a rather normal 81 owner in those respects. Thanks

81$$pit

I have to take the Edel 1706 back. The needle stays open and floods out in traffic. Runs great once you get into it and the cleaned up engine comp looks great. I tried adjusting the floats and cleaning out the seat with Gumout but it still floods out after sitting. Only right side still spitting gas after the engine is off.
Back to the orig point, seat of the pants feel is there. Much louder w/o the cat, sounds like glass packs w/o the popping and backfire. Everyone who rode in it before says its def faster, Pacesetter mufflers were already on it.
Anyways before all the purists hate on me. It needed a new carb "possibly" or a dist or the the comp was not functioning properly so I felt the best way to fix was replace it all.

81pilot

Tim81

You didn't say anything about your heads or pistons, if they are stock then IMHO you threw away your money on the cam and intake. The move to true duals was very smart, but with stock 624 heads and low compression dished pistons the cam and intake will never reach their potential. Get some good heads and flat-top pistons with what you already have and you are way over 300 horses running pump gas.

Good Luck Tim