Ryder Gaenz

I am planning on buying a corvette at the end of summer, but I am not sure what style of c4 to buy. I like both styles very much, although I believe I prefer the 1991-1996 a little better than the '84-'90. But my main question is, besides looks, which style is better handling wise, build wise, reliability wise, etc. I know that from '92 the lt1 motor was introduced, which improved speed, but when is there really a big difference in the two cars or is just mostly aesthetics? Sorry, I don't know too much about cars, but I would definitely like to learn more, so please use terminology that a newbie could understand! Haha

Thank you,

Ryder

Joe C

the newer the car, the more refined. there's a world of difference between the 84, and 96. I've had both - an 85, and a 96. I've got to tell you, the 96 was a much better car than my old 85. you'll be better off getting the newest, best maintained, you can afford, as far as early C4 vs later C4, it's just a matter of preference.

Ryder Gaenz

So what I understand is newer is better, but the two styles have nothing to do with performance? So a '90 vs. a '91 would be very similar because they have the same engines and styling has nothing to do with it? Any changes in handling? Also, do all models have good automatic shifting? I cannot afford a manual, but I have heard that the '90's have good automatics. Do you know anything about the '80's versions having good autos?

Thank you so much for the response!

GKK

90-91 Vettes both use the MAP sensor L98 's vs, the MAF sensor used in the 85-89 L98's. I like the cleaner looks of the 90-91 L98 engine. The 90-91 air intake tube is wider and sleeker looking.

90's Vettes have the older style front and rear bumpers but, the Newer Interior and one off Cuisinart Open Lug wheels.

91 is the First year with the Redesigned front and rear bumper covers.

Ryder Gaenz

What is the difference between a MAP and a MAF sensor?

Goldcylon

Joe C is correct only advise I could offer is to buy the best C4 that you can afford. 92 was the first year of the ASR along with the departure from the L-98.

GKK

A MAF (Mass Air Flow), sensor measures the incoming air and sends the information to the computer.

A MAP (Manifold Air Pressure), sensor measures manifold air pressure and sends the information to the computer.

Notice the different air intake tubes...

MAF sensor L98 engine


MAP sensor L98 engine

AVID

If you have a preference between early and later style C4s go with what you like. As far as performance is concerned, a late model with the LT1 will give you 60hp more than the best L98. Will that difference matter to you? Depends on how you intend to drive it. L98 cars are just as much fun on the street as an LT1. If you're intending to upgrade to get the most out of the engine it definitely makes more sense to start with a more powerful base. I own a 94 and couldn't be happier. Drive a few examples of each car if you can and see what you like!

Ryder Gaenz

Thanks a lot guys! Are there any particular years besides '84 that I should stay away from? I know the '84's are slow..

Also, how much of a difference would having the newer MAP sensor make? As a regular driver and not too car savy, would I be able to notice any kind of difference in performance or would it be something I would not actually notice?

Again thanks so much guys! This really helps!

C4in mesa

One of the first things I thought of when reading this thread is that from 1988 on the J55 brakes were an option so no modifications required to install. Just put the bigger rotors and calipers on. I would definitely go with the LT-1 engine if I could go back and do it over. Then the biggest difference is the interior. I think the 1990 on interior has more room or at least it feels like there is more room with the dash slopping down rather than in your face. And of course the digital dash versus dials.

FOURSPEEDVETTE

You might want to rethink the idea that the 1984 is "slow". I'm pretty sure some 84 owners have a different opinion.

Ryder Gaenz

Alright I will take all of this into my consideration when buying!

Not that the '84 is slow, but that it lacks compared to the other c4 vettes. At least that is what I read. I believe they still used the motor they were using in the c3 when they made the '84? Correct me if I am wrong, because I very well could be!

FOURSPEEDVETTE

You are correct. But with just a few engine modifications, the 84 can be very quick. Although in stock form, it will still put you back in the seat when you jump on it. Lots of members here have later years of the C4 run which in their stock form can take down an 84 performance wise. And they will be the first ones to tell you that. But that's just the nature of the Corvette engine evolution. It doesn't mean the 84 is a bad car by any means.

Paul Workman

Changing the MAP (or MAF) will not improve performance, unless the unit is defective. So, someone claiming "X" hp increase by changing either should be view with a good helping of suspicion.

Essentially, MAP equipped cars derive the air intake from a variety of sensors; Throttle Position Switch, manifold air pressure, rpm, displacement (in some cases), O2 sensor (when in closed loop mode) and uses an algorithm to drive a "look-up table" that has been populated (calibrated) with the proper injector dwell (opening) time (assuming a particular fuel pressure and injector size is not altered*).

The MAF system directly measures air flow itself and derives fueling dwell from the look-up table.

The advantage of the MAP system is reliability. Atmospheric conditions or dirt on the sensors, etc are less of a problem, as well as the simplicity of the pressure sensor itself. But, the disadvantage is that any changes to the air intake, e.g., intake porting or headers, etc. require the look-up tables to be re-calibrated to provide the proper injector dwell value for the new conditions.

The advantage of the MAF, is greater accuracy, over all, and it can accommodate some minor mods to the induction system, perhaps without having to be re-calibrated. The disadvantage are related to deterioration of the sensor performance itself; the reason some use a combination of both systems as a check and balance or backup.

I believe that for any C4 owner, required reading should include "Corvette Fuel Injection and Electronic Engine Management" by Charles O. Porbst (ISBN 0-8375-0861-9) which will go into a plethora of important info regarding FI in your C4 Corvette.

Ryder Gaenz

I didn't mean to say it was a bad car, I just think I can get a little better performance for the money that's all!

Anyway, thank you everyone for helping me!

N42375

Ryder G. - I was in a similar situation as you are in 6 months ago before I bought my first Corvette- A super clean 90 coupe. The best advice that I can give you is become knowledgeable in the history of the C4 and do your research in to the changes and improvements in the Corvette from year to year. You can than determine what improvements ( softer suspension, better brakes, interior improvements, etc) are the most important to you and how you plan on using the car. This may help narrow your search to a model year or years. With that said, finding a Corvette that had a detailed and complete service record can go a long way in finding a car that won't turn into a money pit. Drive a few different year C4's to see the differences. Good luck on your journey and welcome to the forum. Keep us updated on your search and don't hesitate to ask questions.

mcnulty95

Read this http://forums.corvetteforum.com/c4-t...lar-basis.html

solaris_vii

i love my 89, but to be honest if i had to do it again i would get a 90. the map setup leaves more room for modification (and i mean physically more room) and the newer interior is better, but i really dont care for the later bumper styles. so 90 is kind of the best of both worlds!

KYC4

Absolutely!!! This is a terrific book and really ought to be required reading for any C4 owner.

Speaking for myself I initially preferred the '91-'96 but as the years have moved along I find that the original design is more attractive. I also came to find that I do not like the way that the console/lower dash 'separates' the passenger from the driver on the '90-'96 models. Aesthetically it's a turn-off for me.

Performance-wise the L83, L98 and LT1 are all terrific performers within the parameters of their performance envelope. Making mild changes like an improved fuel pump (L83), custom chip tune (L98) and exhaust improvements (all) make a world of difference and really are not that expensive nor that difficult to do. All of them can handle awesome and can be upgraded. Keep in mind that the '84'-87 models are, in some important respects, different than the '88-'89 models. The '90 is a bit of a creature all its' own as it's a combination of '84-'89 bodywork but '91-'96 interior and minor operating systems upgrades. The '91 is also a bit of an oddball in that it's L98 powered but everything else is all '92-'96 in styling and content. I've always broken the models years down this way...but I'm OCD.

As for as operating costs the LT1 can be a bit of a PITA if you have Opti-Spark issues. Corvettes are less prone to this but both F-Bodys and B-Bodys have had some strange failures with Optis. Some last 100K or more and others crap out at 40K. I've worked on enough of them (and owned them) that I tend to avoid them anymore. I don't care at all for the unpredictability that I experienced in the past with the Opti. It's a great idea but lousy execution. The L98 and L83 are both straightforward SBC stuff. Big deal with the TPI is tracking down/trouble-shooting stuff ad the intake system has lots of gaskets and spots that you can have a leak pop up. The L83 is bulletproof. Big issue here is less and less support for it and next to no options to upgrade outside of a ported intake and porting your TBs.

If you want a stick either the 4+3 or the ZF 6-speed will be fine. The OD units had some changes in the '84-'88 models with the '87-'88 units being the most reliable. The T-10 4-speed is pretty solid...it's the Doug Nash OD unit that winds up blowing apart. Support is a bit tough to find for the 4+3 but it is out there.

The ZF is like shift thru butter...smooth, smooth and SMOOTH. But it's pricy to work on. And the 4+3 can be too.

On autos GM got the 700R4 straightened out by '88 to handle the torque/power levels. The '84-'87 trannys had a bunch of upgrades done to improve reliability.

I'd recommend that you follow what most have said here in that you ought to drive one or two of each (including the '84) and make you choice after some quality seat time. The other advice I would offer is that you also get some passenger seat time too and see what it's like from 'the other side'. Most buyers forget that they will have passengers too. Again, I'm OCD so I think of this goofy stuff!

Keep up posted and good luck!

Later,

Lee

Ryder Gaenz

That is all good stuff to take into consideration! I will definitely do some research on the different years and drive different models.

Also, I found '94 on Craigslist, but it has some damage. I was wondering if anyone has any idea how much it would cost to repair. I don't know how to upload pictures, and it won't let me paste a URL. ??? But it has been wrecked on the back left and the damage looks like it goes down to driver door. Does anyone have any clue as to how much a repair for that would cost?