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'84/L83 questions

M

MyC4Project

Guest
I have recently bought an '84 at a really good price and am interested in restoring/upgrading it. I admit that I am a newbie in this area, but I learn quickly. Why is it that there are so few aftermarket upgrade parts for the L83 engine? I know the history of the car and know the problems associated with it, so I did know what I was getting into when I bought it. Everything I've seen so far (internet forums, Eckler's catalogue, etc.) has a dearth of products for the '85 and newer C4's, but the '84/L83 is left out in the cold! What gives????
Right now I don't have a lot of cash to sink into it, so right now I'm doing all the research I can until I can afford to start doing some modifications. I am not looking to get it "show ready", just to make it fun for a Sunday drive in good weather. Where would you suggest I start? I was looking at starting with a new control chip and possibly a new ignition. Luckily for me the previous owner just sunk some cash into a performance exhaust, but not a cat-back. : (
Any guidance or suggestions would be greatly appreciated.
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
Welcome To The Corvette Action Center MyC4Project!

Don't worry, you'll get plenty of feedback on the L83 here before long. There are a few guys that made some power with the "Cease-Fire" injection. ;)

Glad you found us and I do hope you find this place helpful. :upthumbs
 
D

Drewser

Guest
Hey hey hey, hey HEY hey hey!

Ken said:
Don't worry, you'll get plenty of feedback on the L83 here before long. There are a few guys that made some power with the "Cease-Fire" injection. ;)
HEY now!---I resemble that remark. Actually mine has never failed to perform for me. You wanna know why they don't make aftermarket performance products for the xfire? Cause it is already perfect. (I await the heckles). Actually since they only put it in 2 years of corvette, they didn't make much other than an x-ram or two. I put a chip in mine and it helped, but what you have is about as good as it is gonna get. Twinnie has a monster with a twin turbo that you could fit under your hood and the guys at the crossfire vault can help further. Tell us what you want to accomplish and we can go from there.
Good luck and welcome to the CAC.
--Drew:w
 
H

HOWSER

Guest
I was able to get some decent performance out of my 82' with some basic mods. They consisted of

1. Exhaust - I rans true duals back from the headers, through gutted cats, into a nice set of mufflers. I used Big Boar (I think that's the name).

2. Installed an 85 fuel pump, the 82/84 are not the best in my opinion. This was an easy swap.

3. Removed the intake and port matched/polished it. The mismatch between the intake and heads would make you wonder "WTF were these engineers thinking". This made a noticable difference for me in power.

You should check out the crossfire web site, they have alot of useful information for you to use. I haven't been there since I got ride of my 82', maybe someone will post a link since I have forgotten it.

Good luck,

Eric
 
E

evolution

Guest
Welcome to THE Corvette community!

First off, get an 85 fuel pump! This will insure that you get full power on demand, something the stock 84 pumps cant do. If you have questions on that, email me at schumann@sdsc.edu. I just did the swap last week and it is still fresh in my head.

Next, K&N air filter.

You can also stick a Hypertech Stage II chip in there too, This will help with the torque converter lock-up (making shifting WAY smoother and predictable, if you have an automatic) and reset the throttle position for better acceleration. You will also have to install a 160 thermostat and fan switch too with the chip or run high octane fuel (I honestly dont know whats cheaper LOL)

Finally, the intake manifold. If you can yank it and port out the runners you will be in buisness. The crossfire engine has runners that are blocked off by %40 so it cant breathe very well. Like HOWSER said.....WTF?!?!?

You have come to the right place for all of you Corvette needs!

P.S. For Goodness SAKES quit reading this and get an 85 fuel pump!
 
M

MyC4Project

Guest
wow!! I guess I came to the right place! Thanks for the quick replies!
OK, I knew I had to replace the fuel pump. The previous owner went thru 2 of them. Should I go with the stock GM '85 or later pump, or is there a better aftermarket pump?
I also had already planned on the 160 thermostat and the Hypertech chip. But from what I've read, I thought I'd go with the Stage I chip since I am keeping the engine stock, or does it really matter?
Ok, stupid question: why K & N instead of Purolator air filter?
And on this porting the runners, like Desi used to say to Lucy "why don' you try an' 'splain it to me?" I admit I don't quite follow y'all on that one...
Once again, thanks for the advice!
 
E

evolution

Guest
Fuel pump--- Go stock Delco (stock) 85 pump, nothing else. Period. And get a new sock with it too, no new sock, no warrenty. I think through Ecklers, with shipping, your total will be $101 something. Thank you drive thru.

Intake--- the runners (ports) are the rectangular channels that the intake manifold sends the fuel/air mixture into the heads with. These, in the crossfire engines, are smaller than the head opening are thereby creating a bottleneck and consequently loss of power. GM decided to limit HP and emmisions with this little trick and it really just starves the engine. You can do a lot to the crossfire (headers, chip, hot cam, etc..) but with no throat, how can it breathe? Go to www.x-ram.com for more info.

K&N's--- High airflow, reusability and a million-mile warreny. I think said enough.
 
M

MyC4Project

Guest
One last question about the porting: is this a fairly complicated job? I have 2 friends that could do it, but I don't want to impose a PIA job, know what I mean? And is this something that can be done without the use of an aftermarket product like the x-ram? And what kind of time frame am I looking at to do this job? I visited the site and got the nice little lesson on the 350 CF.
Thanks for the answers on the pump and the filter. Now I know why the damn thing is so expensive! Is there another supplier that I should check out besides Eckler's for the little projects I have planned?

Thanks for the info and the education!
 

polish41

Active member
Joined
Dec 8, 2001
Messages
33
Location
Watertown, SD.
Corvette
former1961,1964,1975.1984 current 1985
M

MyC4Project

Guest
thanks! looks like loads of info there too!
 
E

evolution

Guest
You may try the dealer. Funny as it sounds, sometimes they have better deals than the catalouges.

And, yes, porting the heads is a PIA job. Well perhaps not a total PIA, just count on spending the better half of a weekend or at least a solid day completing the task.
 
M

MyC4Project

Guest
What should I go with when I tackle the porting, the x-ram? Or is there another product?
 
M

mb6970

Guest
Time for me to jump in!!
Here's another reason to by the K&N filter for your 84... Stock replacement filter runs about $30 so by the time you replace it 3 times you have paid the $70 for the K&N.
Now, I have a question, does changing out the fuel pump to an 85 make that big of a differance?
I'm also interested in the porting issue that was brought up, any more information on this would be great.

Mike
 

BigRed

Well-known member
Joined
May 23, 2001
Messages
948
Location
Edmonton
Corvette
1985 Bright Red Rocket
CEASE-FIRE LOL:L :L

Thats bad man..lol

If your into losing the plumpness of your wallet try a stroker kit.!

Welcome to CAC Btw!
:D
 
M

MyC4Project

Guest
Nope, married with kid, so I gotta watch the bucks, so keeping the cost down is important.

And that's good economic thinking on the K&N filter!

So, the x-ram is the way to go for now?
 
E

evolution

Guest
The only thing about an X-Ram is the smogability issue. I am not sure about the emmision requirements of Illinois (thats "IL" isnt it?) but here in Cali you need a working EGR to pass the visual and mechanical inspection. Thats what the X-Ram is lacking as of now, otherwise I would have dropped one into mine by now. The major thing about the X-Ram that I see is that it uses a Weiend Xcellerator intake that is machined to fit under the hood. The Xcellerator intake manifold has full-size runners (YAY!). The X-Ram plenum is then dropped on top of that. Full size, matched runners = full breathing capabiblity resulting in the increase of higher RPM performance. But the Xcellerator manifold has no cooling channels (helps with the overall height) so my suggestion would be to use phelonic intake manif gaskets to keep the heat off.

mb6970:
85 fuel pumps do help a lot as far as I can tell. I just talked to a proud new owner of an 84 today at the gas station and I brought up the issue of doggyness on WOT. He replied with a "How the f#$% did you know?" look. I then suggested he get the new fuel pump. It seems that almost everyone with xfires have the same issue. I did forget to tell him to buy an 85+ pump though, DOH!:hb
 
E

evolution

Guest
Another thing, do yourself a favor and buy those modified clips for the retractable "trunk" cover. They are designed so that the cover does not slip underneath the trim when you hit a bump in the road. A very worthy purchace for $7.
 

polish41

Active member
Joined
Dec 8, 2001
Messages
33
Location
Watertown, SD.
Corvette
former1961,1964,1975.1984 current 1985
There are folks on the Crossfire Injection Forum that are just porting the manifold and boring the tb's. They are getting approximately 800 cfm. Maybe this is the less expensive way to go. That is if you are watching your dollars. :w
 

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