42% front and %58 rear weight bias
 

I just thought that I would post a picture of changing my street tires over to slicks at the race track. All I have to do is place my jack about 6 inches behind my cross member and it lifts the tires nearly equally off the ground.

My street tires are Kumhos 275/17 and 335/17 rears. They rear hug the turns during every day screwing off.

My slicks in this day were 295/35/17 fronts and 12 width X27 dia rear Hoosier R6 road racing slicks. Road racing with big slicks makes all the difference. I've looped my Vette on the way home from the track because I was so used to driving at full potential and street tires break away at much lower "G's"

http://i124.photobucket.com/albums/p9/gkull/58-42.jpg

http://i124.photobucket.com/albums/p9/gkull/335g.jpg

Thats one heck of a spacer on the rear...guess that allows you to run the wider tire without switching to an offset trailing arm.
You ever have any issues with your rear bearings being that you're running that thick spacer on the track at high speed and heavy G's?

42/58 :thumbs: Just curious, whatcha running for weight?

That is a two inch adapter with all 1/2 inch studs. They must be over 10 years old because I had them before the forum existed. No bearing problems. Everything has been upgraded over the years. Those are 12 inch wheels with 7 inch BS Racing wheel manufacturers like to keep the wheel strong also by nearly centering the bolt on point.

Without looking at the spec on my wheels, methinks you are pretty close to the stock wheel centerline, or ??

I have 2.5" adaptors, but using '89 vette wheels, used to be '92 wheels...

78 &79 Vettes have a bad weight disadvantage. Even with everything I removed to lighten my Vette. But then I also added a very heavy roll cage, fire system, the interior was done in flame proof aluminum matting and then covered with short pile flame retardant carpet, and blow proof bell housing. The Motown 434 ci small block is heavy. When it adds up the four corner scales with a full 25 gallons of gas it is a porky 3167 pounds. It is the big heavy frame that I gusseted and seam welded. I really can’t think of anything to get it lighter unless I gut the doors and go lexan windows. For racing I pull out the monster 900 CC amp battery and put in a tiny racepack battery. I also try to only have 5-6 gallons of fuel in the tank and I pull out the stock passenger seat. Even with all that it probably only comes down to 3000 pounds

Some guy on here posted a 74 down to 2780# or some number. I can only wish of ever getting down to the SCCA class minimum of 2850#

As for safety. That big long nose and motor are pretty tough. Side impact your dead even with the late C-3 steel guard rail in the doors. I really feel safe in my roll cage.

I removed all the heavy steel and the opening head lights. I replaced it with aluminum round and square tubing to re support the front end. I work at a race shop so I had the chassis fabricator guy make it. Excellent aluminum welding and fabricating the ecklers fixed head lights. I'm a motor and race car setup person. I leave painting a fabrication to the pro's

What are you running for a fuel tank?

I just have the stock 1979 24 gallon listed tank. I've put 25 gallons in it when it was empty. Even with my big motor I go about 400 miles between refills at 18 mpg

wonder if that tank will fit in my 68. i sure would like to pass a gas station here and there.

We had a Grand Sport in the shop one day and I commented to my buddy about how massive the gas tank was (32) gallons. That was an optional tank back then and used on all the race cars for endurance racing.

I bet that the late 70's 24 would fit right in. Our frames in the back have similar dimensions:thumbs:

I must have missed this at some point, but why do you run the slicks (bias I assume) in the rear with DOT R6's in front? Why not run the same tire (model or compound, not necessarily size) all the way around?

Hey George, I never noticed your flares before. Nice, very subtle. I bet non Vette owners don't even notice. Who's are they?
Bee Jay

I knew I used to put more than 24 gallons in my tank. I thought I was crazy. 18 mpg? What am I doing wrong? I get 12-13 even with fi. and only 350ci.
Bee Jay

I've actually been looking to put a 30 gallon tank in mine but can't find a fuel cell or poly tank that would fit without modifying the frame or fiberglass compartment. Yes I'm aware how heavy a 30 gallon tank is full of gas.
Any idea where I could find the 32 gallon you mentioned in the GS or the 24 gallon in the late 70's? I'd like to find out the dimensions and if they're available for sale. Otherwise I'll be drawing up a custom tank over the winter and sending it out to Ricks Hot Rod shop, Rock Valley or some other capable shop. Wish I could afford a TIG that could do alluminum and I'd give it a go.

It was the last race day of the year and I was just out to burn up my front 295's and these rears. I usually run 335/18 R6's on the rear so it is radials all the way around. I'm done racing my Vette. So I wasn't going to spend an additional $800 for one day. Lap times mixed is right on with all radials which was just about the same as 4 bias. I just take out or add a few clicks of compression between side wall stiffness.

I read your comments on the weight and it got me thinking after looking at your pictures about ways to reduce that number, which I am sure you have thought of already but most likely due to dollars have not done. I do not race my 78 but was wondering about the weight of your motor, which you mentioned. How about an aluminum small block V8? Aluminum upper and lower control arms? Aluminum rear differential carrier and trailing arms? Aluminum racing calipers and lighter weight rims? I am sure that you have thought of all this and the dollars it would involve but do you think changing some of these items would get you into the 2700-2900 lb range?

See the blue 1972 GT1 vette in the top picture? He has a near 700 hp 496 ci with a circle track steel box with a 30 gallon fuel cell inside out back and down low. It has the roll over shut off and the three inch quick fill

Like I said before: You can't take a street car and make it into a race car. Waste of time and effort. Smart people buy a race tube chassis and put any body on it that they want to.

As to allot of aluminum. You are better off having a street rod Vette and a dedicated race car for what ever kind of racing you do. For drag racing sub 8 second vehicles are fun. For road racing you will never beat the open wheeled cars with wings.

So I'm going to race an older real open wheel F2 March chassis which can do 3 "G" turnes. It has bigger better wings than what it was raced with back in the day. Sub 4 pounds per HP

Either its a custom fuel cell or he modified some fiberglass.
I've searched everywhere for a fuel cell that would fit within the length and width of the vette without cutting anything and its either 0.5 to 1.5" to big. I don't care about the height b/c I'd build some brackets to whatever height it needed to be to run the 30 gallons of fuel. I'd also build a steel box like the GT1 vette had to protect a poly fuel cell if needed.

Makes sense, burn 'em up. I have too many 16" tires that I need to do the same.