rws.1

I'm looking to buy a C4 for Auto-X ( can't afford a C5 just for Auto-X)
I am trying to figure what is the best year to buy.
I plan to start stock and over the next couple seasons to modify it.
It may eventually end up race prepared for low speed and high speed ( but that is only a possibility)

I know that the '84 Z51 had the highest skid pad results, BUT a cross fire engine
'89 brought the 6 speed
'92 brought the LT1

So what is your advice?
Rich

racevett

I would say buy my 96 that has won practicly every local event and placed 4th in a national event out of 28 cars in class. Garaged, no rain in 6 years,49000 miles Z51, perfect interior,near perfect exterior,2 sets of rims, sorted and ready to go.

Bill Dearborn

Roger Johnson the one time perennial Pro Solo champion used a 1986 for years. Supposedly the 88 through 96s with the zero scrub suspension did not do as well. This is what I picked up in a post in the bimmer forum from May of 2005:
Quote: Originally Posted by CABimmer
There is no way in hell a stock ~ 20 year old C4 would win in any kind of race with an M3. It would take one hell of a driver. in the 1/4 they will be low 14s new I have never seen one do well at any auto-x and Im not impressed with any stock c4 or c5 for that matter at the track.
Close Quote:
Reply:
Have you ever heard of Pro Solo National Champ Roger Johnson? Are you aware he often swept ALL stock classes running a 1986 Corvette with auto trans? Are you aware his impressive C4 winning streak lasted well into E36 production cycle?

Do you know what FTD is?

Are you a member of the SCCA? Just looking for some background....

The early L98 C4 is a very capable car in autocross with it's John Deere torque. It was a winner until around '99/'00 when the C5 gradually took over. The early C5 and later C4 cars were not significantly faster in autocross. Roger Johnson tested many LT1, LT4 and LS1 cars and found them to be no faster in a parking lot venue. The E36 M3 is not a serious competitor in this contest.
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Bill

rws.1

OK racevette... I'll bite ... How much $$
e-mail asking price and pics along with list of any mods to
rws.1@comcast.net

peanut

The C4 is very competitive in AS, and I believe the winning AS car at nationals last year was an 89 C4. There is an arguement for the L98 versus the LT1, the 6spd versus the 4+3, the zo7 packed LT1s versus the Gran sports w/lt4, etc. It seems any 85 on car can be competitive locally.

There are many Corvette and C4 related posts at the SCCA's forum and I believe there is a which c4 is best thread also.

Mike Patterson

XPC5R

Here is the one you need, '87 Z52, I think it's still for sale. Campaigned by a very good autocrosser and meticulous owner.

http://sccaforums.com/forums/thread/187502.aspx

69autoXr

I know of a nicely set up '92 with LT1 upgraded to LT4 with 6-speed. Very fast, setup for autocross and track with roll bar. Currently receiving some paint freshening and a new exhaust. In the Detroit area. PM for details.

peanut

What class are you looking to run in? Stock, street prepared, street mod?

vader86

84 will handle like a slot car, but is a bit low on power. On a tight course this will not be a big problem though.

Then again, you can take any suspension part off of 84 and put it on the 85-87s. 87s had the most factory BHP of the early C4 at 240. (35 over 84) The suspension in 84-87 is identical in design.

89 Z51 6speed is also a very good handling car.

Tighter courses will lend themselves more to L98s, whereas the really high speed stuff may lend itself to LT1/4s.

Cashmo

Actually it was a Porsche 911 although an 89 C4 had fast time on the dry south course. Every year C4 seems to have it's strong/weak points, just choose which warts you prefer. It'll be interesting to see what happens with the new site/surface at Nats this year.

Jeff

Solofast

The 93-95 (they made a cam change in 93 that helped the low end torque) six speed is the best starting place. In stock it can hold it's own with any year, and has the stiffer springs and sway bars (if you get a Z07 car) that you want in stock class that you can't get with the Lt4 cars. Add to that the bigger brakes (much better for high speed work) and that kinda defines the platform.

As you mod the car (going to SP and higher groups), you have most of what you need. The Lt1 can be upgraded to essentially an Lt4 without a lot of work and you still have the stiffer springs and bars so you don't have to do as much with the suspension. It will cost a bit more in the long run to start with an Lt1, but you will have a more competitive car while it is stock. When you seriously go into SP and Group II you are going to have to build a motor anyway, even if you had the Lt4, you are going to have it all apart and can upgrade the Lt1 then.

If you want to start modding right away start with an Lt4 six speed and upgrade the suspension. You will need a big brake car, not sure what the options were on the 96 and later, but you may need a Z51 or GS to start with.

If you are interested at all in higher speed events don't even think about an L98. It is so down in power compared to the LT motors that you will wish you had the bigger power to start with....

Yes Roger was very competitve with the L98 auto when 16 inch tires were the hot setup, but times change and the available 17 inchers are now better, so that kinda rules out the earlier 16 inch cars. The do have more grip in really low speed high steering lock conditions than the later cars, due to better king pin geometry, but most folks have gotten past that with better tires. Besides they all had the MISERABLE 4+3 (ever shift one and you will know what I am talking about here), the ZF is a world better tranny....The auto tranny cars are really soft off of the corners compared to the six speeds. Yes somebody will mention Rita Wilsey this past year at Nationals, but one day was in the rain, where power meant nothing, when it's dry a six speed is the right tranny.

I've tried to distill almost 20 years of C4 racing experinece into three paragraphs, but that's probably what I would do if I was starting out in a C4 all over again...

peanut

Yup, I was mistaken. It was 04 that the 89 placed 1st and in 05 took 2nd. Damn 993, took first

I'm currently looking for 93-95 LT1 for AS. No L98 or non-6sp for me.

rws.1

thanks guys...I need to digest all these thoughts...
Rich

Vetracr

I couldn't agree more!! After years driving a very fast Solo II DP Midget I bought a duplicate of Roger Johnson's car, an 86 Z-51 Automatic. I was very successful with in SS (at the time) in Northern California with that car. On an autoX course I could make that car dance on the head of a pin. I then bought Jim Martin's 90 C4 that Shauna Marinus drove to the SSL title. I couldn't come within a second of my 86 with the 90. The late suspension can't hold a candle to the early cars. I now have a 93 and torque wise ita dog relative to an L-98 down low. If I could find my old 86 I'd swap my 93 for it in a flash. Best handling Vette ever. One mans opinion.

Larry

AUTO_X_AL

If you are going to start with an early C-4 they started putting aluminum heads on in late 86. Ours is setup with 84 Z-51 springs and it seems to handle very well. Our car prior to us owning it was taking overall FTD's as a IE car. As it progressed in to a group 2 car it got faster until we bought it. Even with a L-98 at ntionals in 04' the prior owner took sixth place in BSP. And the 4+3 we were a bit unsettled with and we have beat on it pretty bad for 2 years and it has held up very well. The L-98 with so much usable torque is awsome for Auto-x. Then you can smile and say "How could you let this little 235 hp car beat you!" Everyone loves that one!

greendot

As the current owner of Roger Johnson's 86 Corvette, all I can say is that I would consider selling it.

73-84 IMSA Widebody

For the right price I know were you can get a pretty darn fast C3

AUTO_X_AL

After watching Greendot's car run if I were in a position to buy one I would strongly consider it. Very fast car!