I am a new Corvette owner. I just bought a 1991 Coupe that has 70000 miles on it. It is pretty clean, but needs some nitnoid stuff done to it. I have a few questions for you experts. Need recommendations.

1) What are the softest, best riding shocks?
2) Best plug wires?
3) Best coil?
4) Best plugs?
5) Best Synthetic oil for the rear differential?
6) What size speakers are you replacing the stock Bose speakers with?


I am getting a resonance, sort of a crunching sound at times. It seems like the exhaust somehow but it doesn't sound like an exhaust leak. Exhaust pipes? Is this a common problem? This weekend I will be changeing all the fluids with synthetics, new wires, plugs, cap, rotor, coil, and all other tune up type parts.
Shocks will go on next weekend along with a complete brake job. Any recommendations?

I love the car and just want to get it to be as good a performer as I can. Thanks

 

First welcome to the Forum :cheers: You will find lots of help here so ask any question and you should get a quick and helpful reply!!

For shocks, you can go with a set of the factory Bilstein shocks for the standard FE1 suspension. Van Steel, one of the supporting vendors has great prices and service. Expect to pay around $65-70 per shock. Another option is the KYB Gas-A-Just shock. This is a good replacement shock and costs much less. Summit Racing has them for $27.95 http://www.summitracing.com

For the tune-up parts, unless you are going to race the car, I would go with AC-Delco wires, plugs and a good cap and rotor with brass contacts. The factory coil will work fine as the L98 just doesn't rev that high to need the benefit of high voltages. If you want a nice set of colored wires, MSD, Taylor and other aftermarket companies have custom fit sets that look neat. Sumit Racing has a good selection and good prices.

I use Mobil-1 75w-90 synthetic gear oil with a couple bottles of the GM posi additive in both my 87 and 92. For an auto tranny, use Mobil-1 synthetic ATF. For a ZF6m, use the GM recommended fluid or the wpecial-weight BMW Castrol motor oil

At 70K, you should also think about new coolant (50/50 mix of a good "green" coolant and water) and a brake fluid flush. Use somethng like Castrol LMA for a DOT3 or Ford high-performance DOT4 fluid.

Can't really suggest a replacement speaker for the BOSE system ans the BOSE system in both my 87 and 92 work just fine. The Audio/Electroncis section will have some really good information there for you. BTW, just a speaker change wont work; the BOSE system uses amplified speakers so you are looking at a complete system change. Speakers are repairable at a reasonable price so consider that option if you just have a bad speaker.

 

Welcome!

As far as parts, it's really a matter of what you want to spend.

A list of things I have:

Edelbrock Performer shocks
Moroso High performance wires. Great wires they keep the fire contained!
Bosch platnium Plus 4s. No problem with these plugs, ever!

You'll find that everybody has their own opinion though.

Can't help with the speakers, my Bose system is fine so I doubt I'll replace it any time soon.

As far as fluids, just useing what your owners manual recomends is your best bet.

Resonance is a problem with Vettes, especially if it has an after market exhaust installed.
:cheers:


[Modified by Kizmo, 4:03 PM 2/19/2004]

 

Why a coil? Generally a coil isn't a maintenance item. If it has given problems, the Delco, is tough to beat. Otherwise, I'd leave it alone. Good luck, and...

RACE ON!!!

 

Welcome to the forum. Unless you plan on racing, you will be fine with stock replacement parts.
The factory Bilstines with the FE1 suspension should give you the ride you want.
Plugs - AC Delco Rpaidfires #5
Wires - Stock AC Delco
Coil - You won't be hitting high enough revs (yet) to require an upgrade.
Speakers - If you need to replace a speaker, you'll need to repalce with Bose or send it out for replacement or look in the tech tip section for rebuild instructions.
Exhaust - Make sure that the pipes are not touching anything but the hangers. Also, make sure that the tips extend beyond the back bumper.
Fluids - Synthetic - most use Mobil procudts - some use Red Line. You choose.

Hope this helps.


[Modified by Steel Blue 91, 4:34 PM 2/19/2004]

 

C4Cruiser gave you some good info. I personally stay with GM stuff as far as fluids go. Wires: OEM works and the looms will be easy to use. Plugs: NGKs are the rule in LT1s, just stay away from the AC Delco pro-plats as the pucks tend to fall off and leave you with a huge gap.

BTW, Welcome to the forum, where we can spend your money faster than Uncle Sam can print it :cheers:

 

Welcome to the forum, where we can spend your money faster than Uncle Sam can print it

 

Thanks for the help and the welcome from all of you. I love the car and hope to learn a lot from all of you. Again. Many Thanks!

 

:iagree: with the above. Stock stuff works good. When I first got my '90 back in '93 I went to Red Line in the trans & rear. Seemed to hold up good in the trans but I think it oozed more from the seals. Mobil in the rear now & the castrol recommended by ZFDoc in the trans.

Taylor wires & bosche platinum plugs, accel cap & rotor kit has brass contracts.

I have a set of KY gas adjusts that may fit your car ('91 right?). Just took them off mine when I went to the coil overs. You can have em for cheap if your interested. Not sure they will be as soft as the FE1 shocks though.

I was just digging through my desk drawer but can't find the card for radio/speaker repair. Doctor somthing or other down in TX I think. He just rebuilt/upgraded my CD player & rebuilt a couple of speaker amps. Nice work & the system is better than ever. Even plays CD-R media now.

Have fun!

 

I have a set of KY gas adjusts that may fit your car ('91 right?). Just took them off mine when I went to the coil overs. You can have em for cheap if your interested. Not sure they will be as soft as the FE1 shocks though.

I might be. What are the softest riding shocks I can get. I know it is a sports car, but I will be using it as a daily driver. Won't be racing it.

 

Welcome to the Wild World or Corvettes! :cheers:

I'd have to agree with everyone else above. Some good advice there. Just to let you know what I did with my 1990 when I got it was some Taylor SpiroPro ignition wires, NGK TR55 plugs, and a K&N filter. If you don't already have a K&N, get one. Much better than the paper filters. As far as speaker replacment goes, I just rewired the entire car with a new deck, amp, speakers, and XM radio. I have never wired a stereo beyond a new head unit before, so I wasent that experienced. It is not to hard to do if you want to replace the BLOSE stereo...and if your driving that car daily XM radio is the best thing to ever happen to radio. Email me if you want more info on the stereo part. As far as oil and shocks, I havent replaced my shocks yet and for oil I use Redline Synthetic. Good luck!
:steering:

 

That would be Dr. Dons

sales@doctordons.com

 

BTW the Castrol in the ZF-6spd is 10w-60 synthetic. I recommend it and so does ZFdoc.com :yesnod:

 

:iagree: If it doesn't need replacing, don't replace it.
Welcome and good luck

 

Hey from Indy :seeya

 

I am originally from Indianapolis. Hello

 

WELCOME :thumbs:

 

An update on my quest for Corvette excellence. I went with the Bosch Platinum 4 plugs, MSD wires, MSD coil and cap, and Mobil 1 synthetic oil.
Put all this in on Saturday and the engine now runs great. Pulls hard and just runs smooth. I had to take the MSD cap back because it wasn't the screw in type. Got a top of the line Borg Warner cap. Had a great time with the passenger side plugs, but overall found working on this car to be much easier than a lot of other cars out there. Love those Bosch Platinum 4 plugs!
Found the resonance/vibration problem as well. A rear rubber hanger was broken causing the cat to rub against a tranny bolt. Anyone know where I can get a new hanger? Thanks for all the help.

 

Welcome from Vegas.... :thumbs:

 

Ecklers and Mid America both sell hangers. also look here in C4 restoration area. Also, there are some vendor sites on the sidebar...like VETTE TO VETTE that have some used stuff.

Welcome to the wonderful world of corvettes...you'll never regret it.