Original 84 C4 Owner with many DIY Questions

Stick the Corners

Active Member
Hi all.
I’m the original owner of a completely stock 1984 C4 with Z51, 4+3 stick with 40K miles. Obviously, I don’t use it much, and have replaced more batteries than I can count on my hands. I’ll probably get laughed at for this, but I thought you had to remove the diagonal crossmember and move the cruise control out of the way to pull the battery, and I got good at that. Only after reading these blogs recently did I see how easy it would be to remove the small louvered exterior panel instead.

I would love to figure out how to get more power out of the engine, but given my other hobbies, I have not paid attention to how Crossfire induction systems limit easy and lesser cost upgrade pathways to higher HP.

In truth, I bought the car after reading the specs and was enamored with the possibility of a great American road handling vehicle, which it was and is. Of course, one could not test drive the C4 before ordering it in 1983, but after test driving a new Porsche 911 from that era, I thought the new Vette would be a better car in handling and power than almost anything else out there, and it was. Over the years, after barely losing in a drag with my friends older big 6 cylinder XKE coupe, and after riding autocross in a 500hp Viper, it sure would be more fun to increase the power on my 1984. And I’m kinda shocked and impressed how power output has increased over those smogged up days and engines.

My main automotive experience has been completely rebuilding my 1962 1300 CC DOHC Alfa Romeo engine with Weber Carbs, alone at age 17. It ran great until I learned the valuable lesson about the need to retorque cylinder head bolts. No significant wrenching experience since.

I will probably be a more DIY owner going forward and have been reading your site and others for information.

I have realized that the induction constriction of the stock crossfire manifold is the main culprit,although the head is not far behind. The Renegade is not being made, but production could be restarted according to Xfire Performance. The quality control issues created various issues from installers. I’ve seen others try to port the stock manifold which no current shops will touch.

I’ve read others saying to leave it stock after adding up the costs for mild gains in power. I do have a low mile reliable old classic car of known maintenance history, which is not insignificant. I would have to sell mine, and get not too much given market prices, and replace with some other fire breather of probably reduced reliability.

Since I’m not that interested in wild 1/4 mile times, but would mostly enjoy Autocross, maybe doing a little stuff is all I need. Should I advance the timing; should I get rid of the smog pump; will changing to headers and free flowing exhausts with cross pipes do enough when the induction is so constricted. Increasing injector size or fuel pressure may not help for the same reasons. Yes, a blower, whether supercharger or turbo, could change a lot, but costs are probably crazy, if they exist for my stock set up at all. Intrigued about nitrous systems. Will removing the smog pump or doing a cat delete (or interior cat clear out) cause a problem with an engine light coming on or create other problems with the O2 sensor and input to the ECU. And what about changes to the ECU programming, like Xfire performance sells. Does it make any sense if not increasing intake air supply?

Also, my tires are old. Not many choices with 16 inch wheels (my tires 255/50 r16). I like my wheels 8.5/16 front, 9.5/16 rear, but what can I do to keep the geometry reliable and fit in the wheel wells that are not very expensive options? I saw that some newer corvette wheels could work with minimal changes, but like to know all viable options.

Lastly, my A/C needs a charge. Do I try to get R12 ( with minimal/no complications/modifications to my existing system) or convert to some other refrigerant. Will any of the newest refrigerants, like R1234YF, avoid the issues coincident with conversion to R134A?

I know, too many questions.
 
read these links/threads and sub links
theres a huge amount of related data in the links and linked sub links


http://garage.grumpysperformance.co...egade-intake-for-cross-fires.2796/#post-54235


https://garage.grumpysperformance.c...sfire-vette-won-t-run-right.10096/#post-39710

http://garage.grumpysperformance.com/index.php?threads/ported-crossfire-383.10240/#post-41065

http://garage.grumpysperformance.com/index.php?threads/got-a-cross-fire-corvette.640/#post-25767


 
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Grumpy, since your original 85 had similar wheel and tire sizes to my 84, what did you personally do with the wheels and new tire purchases?

Also, what did you do to keep your A/C charged? Did you modify that system in any way?
 
I had wheels from a 1987, on the car and amazingly the air conditioning worked, I still had a few cans of the original freon
 
I bought a 30 Pound bottle of R12 a couple of decades ago. I really do not like R134 and despise the new gas, BUT as the POWERS THAT ARE hae chosen to go to a Hydrocarbon gas for refrigeration I feel more free to do so as well and run one too.

So I have been using a gas based on Propane and some additives.

What I get is a colder A/C system....one that can ice up the evaporator in 112 degrees AZ heat...

Plus a bunch of other benefits...I will let them tell all about it here: https://www.duracool.com/

It is more costly that old R12 and R134, but not as much as the new crap, which IF you don't mind cheating will replace that new stuff, the USA IS the only country were it is currently illegal to do so, so keep it on the down low.

Also it is said to not cause 134 Black death...and runs with lower pressures...

There is one downside it cannot not be recovered and reused...so you have to use fresh new gas for any repair but few have a recovery and recycle systems...

I have used it for a year and will be using it is all my cars from now on.

And no I do not work for them.

Rich
 
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