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Can a C3 compete with a C6 Z06? Video added 8/10/12

44K views 205 replies 32 participants last post by  phantomjock 
#1 ·
Can a C3 compete with a C6 Z06? That was the question some one ask a year or so ago. And if yes at what cost.

So I set out to find out. Including the cost of the car I set myself a budget of 30K and I am well below that figure.

Here is what I have so far.



1971 Corvette coupe
383 ci sbc
Eagle rotating Assembly
KB 18cc dished pistons
Comp forced induction cam
MSD 6AL ignition
MSD boost timing control
Edelbrock 750 CFM carb.
Holly 144 blower
AFR heads
Oil cooler
Long tube headers
3" collectors
2.5" exhaust



NV3500 5 speed trans.
3.08 rear end
C5 rims and tires.



Front suspension VB&P
Rack and pinion steering with hydro boost
Dual mount 8 pt. adj. transverse spiring
1.125" anti sway bar
Tubular off set A arms
QA1 single adj. shocks
Ploy Bushings
C5 rotors and calipers
Hawk pads



Rear suspension VB&P
Dual mount 8 pt. adj. transverse spiring
No sway bar
Off set trailing arms
Adj. smart struts
QA1 single adj. shocks
Ploy Bushings
Rear brake bias adj. valve
C3 calipers and rotors
Hawk pads



Holly 14 lb. 95 GPH fuel pump
fuel pressure regulator.



Hand built Cold air cowl induction hood.
Aux. elect. fan
HEI distributor



Custom built Dash
Sparco seat
5 pt harness.



Roll Cage. Coming as soon as I complete my TIG welding class.:D


 
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#155 ·
Any more details on that engine moved aft?
Suddenly I have an itching case of teh , uh oh...While-I'm-At-Its!!

I am wondering if they used a forward and mid engine plates - or reaccomplished the motor mount locations? I suppose a new shorter Drive Shaft will be in order, and a Tranny Cross Member! New firewall in the plan anyway, now to cut up the floor pan and move the seat ALL the way back. And yes, I've got the airbox planned too.

But it looks 'Smart." And can't argue with those weight numbers - mind you - I'll forgo the Magnesium and other Unobtaniums.

Cheers - Jim
 
#157 ·
The out front Duntov Corvette brings a new level of disgrace to any promotor that lets cars like that compete at all. It is not even in the spirit of historic racing.

We have a few Vettes that race out of our shop. My friend out of San Diego owns and races the #75 Greenwood Corvette. So at big events like the Monterey historics over the years I have got to closely exam them.

Right off when you look at the Greenwood cars you will notice the tiny front tires 23 or 23.5 inches tall. It was the only front tire size available back in the day and widley used by all the European fast race cars that were purpose built and upt to 1000 lbs lighter.

These tiny diameter front tires were always a problem and limitation for the heavy IMSA Corvettes. It slammed the nose way down and that is what gave them such a poor front to rear ratio even with the motors made of aluminum and moved back 6 inches. 47 % front and 53% rear are poor by racing car standards. Especially when you consider that F1 cars are 30% front and 70 % rear. Your typical IMSA 956/962 were @37% front and 63% rear depending on the year and the fuel load allowed. Some of these endurance cars caried 90 gallons of fuel.
Would you explain the physics of that?

You're comparing apples and oranges. It's a piece of cake to get a lot of rear weight bias when the rules allow you to put the engine behind the driver, and the transmission behind the rear axle centerline. I don't believe IMSA would have looked kindly on Greenwood trying to enter a rear engine transaxle Corvette in the series.
 
#171 ·
Yea,, like a engine block, can't get much better than that.... Pure stealth. well done! Would you mind sharing your scale numbers or pm me. WOW!
Thanks. :thumbsup: The car was 2875#, but I recently ended up putting about 20-25 pounds of aluminum sheet under the car doing the bellypan. I'm hoping the aero improvement (less drag and lift) helps the handling more than the extra weight hurts it. :laughing:

I was mentioning some lighter stuff I put on the car. The first is a tubular sway bar off a '93 Firebird. I had to cut and shorten (and reweld) the arms to make it fit, but it ended up about 4# lighter than the 1 1/8 inch bar I had on it.



I also put a later (Grand-Am) p/s pump on the car. Six pounds off the front end.



And for amusement (because I was running out of other ideas), aluminum hood hinges. This is a picture during fabrication, prior to final shape and a proper pivot pin (and a coat of black paint, of course).



Didn't take off a lot of weight (3/4 of a pound for the pair), but hey, it was reduced weight up front and up high.
 
#173 ·
Ivan -

You were taking a welding course -- AND, were planning some "cage" action.

Any Updates?

Cheers - Jim

I have put the Vette on the top lift for the winter. Just completing the TIG semester at school, now I need to come up with about $1500 to $2000 for a good AC/DC TIG welder. I love welding aluminum with the TIG. So I see a lot of weight reduction coming. I like the Aluminum radiator support in the earlier posts.

Going to take stick welding next semester, as I already know stick it will alot of free time for projects at school(they have all the good equipment to work with.). will get the bars bent and notched ready to go in next spring.

Been spending a lot of time on the big block project. Its about road ready.
 
#176 ·
Iburke, How happy are you with the suspension set up you have, if you were to do it over again, would you have went with a coil over setup instead? I'm getting ready to upgrade my suspension and I'm just looking for some honest feed back from someone that actually uses thier car on a track. I will be doing alot of auto crossing next year and look forward to having a better setup and wasn't sure if I was going to go with the same type of setup you are running, or go with a coil over setup at all four corners.


Riggs
 
#177 ·
Iburke, How happy are you with the suspension set up you have, if you were to do it over again, would you have went with a coil over setup instead? I'm getting ready to upgrade my suspension and I'm just looking for some honest feed back from someone that actually uses their car on a track. I will be doing alot of auto crossing next year and look forward to having a better setup and wasn't sure if I was going to go with the same type of setup you are running, or go with a coil over setup at all four corners.


Riggs
You are asking me to open my mouth and get 100 tongue lashings from the coil over people out there.

Oh what the hell. Yes I would do it again. I have a car with coil overs on it. They are a royal pain to adjust. The transverse fiber glass springs and adjustable shocks on this car can all be adjusted with out even jacking up the car. The only thing that requires jacking is if I want to change the actual spring rate. The springs can be adjusted to 4 different spring rates. A coil over spring rate can not be adjusted.

Is it as good or better than Coil overs. I will not say. The only way to tell that is to build two identical cars one with coil overs and one like mine and put them on the track. If some one wants to pick up the tab I would be glad to do that and report back...:rolling:

When not on the track I can soften the spring rate, raise the ride hight, and soften the shocks. Which allows me to take momma to the store to get eggs.

All of my cars are street legal. and daily drivers.

Just one old mans opinion...:D
 
#178 ·
You are asking me to open my mouth and get 100 tongue lashings from the coil over people out there.
now just wait a cotton-pickin' minute! :devil:




:laughing: seems like that VB&P kit is a pretty hot setup. If I ever get off my ass and get my car put together I might have to work up a coil-over setup for the comparison.

Just bought a Miller Dynasty 200DX at work. Pretty neat, compact little setup. Brand new it was $5000 with the water cooler, torch, coolant, cart, regulator, wireless footpedal, etc. Hook up a bottle and you're ready to weld. And being an inverter welder it saves on power. Maybe you should see what Santa says? :huh:

http://www.ebay.com/itm/Miller-Dynasty-200DX-Complete-Wireless-package-Demo-unit-/121038469177?pt=BI_Welders&hash=item1c2e747839
 
#183 ·
Ivan, any Corvette updates?
 
#184 ·
bump
 
#186 ·
I'm trying to button mine up to take to MAM for a test and tune session sometime soon.
 
#201 ·
Made a rear geometry change to the '69. I didn't like the excess rear toe gain of the stock C4 suspension. Here's a several years old picture while I was putting the suspension together, and have been using this "stock" setup while I've been sorting out other aspects of the car.



Note that the toe-rods are noticeably longer than the halfshafts. This insures a nice safe understeer for the production C4 suspension, but the transient response with this geometry has always been a little less crisp than I like.
I picked up a pair of C6 toe links and made a bracket to attach it to the current bracketry. I needed to have the C6 setup bolt to the same brackets as the C4 toe rods so that I could retrofit the C4 setup at the track in case the new geometry was unacceptable. This quick swap-out would save me from wasting a day at the track.



I made the bracket adjustable in several dimensions to allow some tweaks to the handling. I went up to MAM in Iowa a week ago for the test and tune day and ran the car all afternoon. To my great relief the handling was very crisp and predictable. I still need to do a little more bumpsteer measurement to help me decide whether I want to tweak the link length or inner pivot location.
 
#203 ·
I went up to MAM in Iowa a week ago for the test and tune day and ran the car all afternoon.
Holy smokes, I saw you out there from the interstate! Was headed down to KC for mother's day with Donna's parents and saw a blue C3 exiting the track. Didn't even consider that it could have been you until I saw this :laughing:

Glad to hear the change went well. I'm fairly familiar with the C6 suspension, but know nothing about the C4. So they still use the half-shaft as a suspension link?
 
#205 ·
c3 vrs c6

I read a drivers report reguarding the traction controls on a c5 'traction control off he bested the car than with it on, his name is Mario Andretti'. and the c6 is better. I run in a HPDE event at Road America with my 68, weight balance is 50.5% front 49.5% rear 411rwhp sbc. 4.1 mile track hitting top speeds of 145. every c5 and c6 will pass me in time, they are just that much better of a track car. It only took 1.5 laps for a c6ZR1 to make his pass and the first lap is under yellow. Guess I only need another 60, 000$ to keep up with them. An equation: how fast do you want to go = the amount of money that you want to spend.:cheers:
 
#206 · (Edited)
... every c5 and c6 will pass me in time, they are just that much better of a track car ... Guess I only need another 60, 000$ to keep up with them. An equation: how fast do you want to go = the amount of money that you want to spend.:cheers:
You may have that right - But every C3 out there is a tribute to those that went before us beating Porsche, BMW, Ferrari and countless other well funded teams. And, it all counts as seat time - any of which is so much better than sitting on the side lines.

Steve McQueen said;
Racing is Life - everything Before and After is just, Waiting.

Teddy Roosevelt wrote it so eloquently - I think I'll place it on the inside of my T-Top as a reminder:
"It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, who comes short again and again, because there is no effort without error and shortcoming; but who does actually strive to do the deeds; who knows great enthusiasms, the great devotions; who spends himself in a worthy cause; who at the best knows in the end the triumph of high achievement, and who at the worst, if he fails, at least fails while daring greatly, so that his place shall never be with those cold and timid souls who neither know victory nor defeat. "

And on the Dash:
"Don't Worry Baby..."

And, a reminder attributed to Hemingway:
"There are but three true sports--bullfighting, mountain climbing, and motor-racing. The rest are merely games."

So I may be counted a "Moving Chicane" - but - Count me the Game.


Me and my 'ole C3

Cheers - Jim
 
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