Jim Dillus

I want to take my beater C5 corvette , strip it down and run it at HPDE and road races, etc. I know there are many people who have done this before, and I am looking for some guidance.

I have not found any good links or websites that chronicle the construction / stripping down of a C5. I found this awesome site:

http://www.mowhineracing.com/

But he is working with a C4. I'm looking for info regarding the kind of weight savings I can expect when stripping down a C5, where to spend money and time, and what kind of mistakes to avoid. Thank you for any help you can give me and links.

SouthFL.02.SS

If you wish to race with it, consult rule book for class which you will run in. There are things which you can and can't take out depending on class and series.

Mojave

iTrader: (4)

If you plan on actually racing it in a class, consulting a rulebook is by far the most important step. Ripping stuff out only to later find out you want it back is never fun.

I don't use my C4 for any particular class, so I decided that it all had to go. If you want to keep it street legal, obviously things light headlights, wipers, etc need to stay. If not, then it must go! I would bet a mildly gutted but still mostly legal C5 could reach 2900-2950. A complete strip to nothing more than absolutely needed to go fast would probably be below 2700.

Wires. I have leftover wires everywhere. Some time with a wiring diagram, removing stuff that you don't need, can really help.

Jim Dillus

I don't want to run in any particular class, just the anything goes events. I really like your C4, Mojave. Thats exactly the idea I'm going for, except with a C5. I want complete removal and strip-down. Ideally, I would leave on the lights and mirrors, but I intend to drive it to the track, race, and drive home. I don't really care if it is strictly street legal. We can get away with a LOT around where I live. So things like no airbags, low ride height, tires/slicks, super loud exhaust, no cats, etc. are all fair game. Besides, if I do get busted, I'll burn the title and trailer the car to the track.

If you say I can get down to about 2700 lbs by simply removing unnecessary crap from the car, then I will believe you. The problem is that with 350 hp and 2700 lbs, the power to weight ratio of my beater C5 is still not as good as that of my C5 Z06, which I don't want to risk at the track. I was hoping for a race weight of say 2500 lbs with 350 hp, but it doesn't sound like that is going to happen unless I dump lots of money into carbon fiber stuff or hot rodding the motor. Doing that is expensive, which is exactly what this project is NOT about.

So I guess my next question is, should I be considering another platform to begin with. Such as a Miata or something. This guy has stripped his down to 1900 lbs with 220 hp:

http://www.lightweightmiata.com/

Now thats with a turbo motor. If you put a v8 motor and kit into the miata, you could be looking at 350 to 400 hp. Now you will obvioulsy need upgrades to the drivetrain which are no doubt expensive. Clearly there are pros and cons to either the C5 or Miata route. Does anyone have any opinions on this? I realize this is LS1tech, but I'm still interested in what you all have to say as you are the experts.

EchoMirage

iTrader: (3)

who has a C5 vette and calls it a 'beater'?

SouthFL.02.SS

A heads/cam (or even a cam-only install can outpower your LS6) swap for your C5 will be 1000X easier than a V8 Miata conversion.

Jim Dillus

Good point on the beater C5 (differentiating that vette from my C5 Z06)engine mods. Once I get the cats out, put in headers and cam, it will be a hot fire motor, relatively speaking.

Well thank you guys for your help.

Mojave

iTrader: (4)

What is the power to weight of your C5 Z06? A 2700 lb car with 350 rwhp will be pretty quick; faster than most people can drive it. Besides, adding power with an LSx is not hard to do.

2500 lbs will be hard to do while maintaining any hope of street legality. To get there, you will have to start replacing the remaining parts with lighter (and more expensive) parts rather than just taking stuff off.


The problem with a V8 Miata is tires. A stock NA or NB Miata will only fit about a 225, 235 wide tire stock. Making more room is not that easy. A C5 will fit 315's stock (if you don't mind them sticking out a little), and with careful selection of wheel offset, you can probably go bigger.

Also, the Miata rear end will not hold up to a healthy LSx. Same goes for stock Miata brakes. These are examples of issues that need to be dealt with. A LSx E36 3 Series BMW or LSx FD RX7 are better swaps IMO. Both of these are heavier than a Miata, but much more easily accommodate an LSx and the power it will produce.

I, however, think you should stick with a C5. The power/weight ratio isn't everything. C5's have great suspension, good brakes, and since there are so many people road racing them, there are plenty of proven upgrades.



Don't take this the wrong way, but how much road course/auto-x experience do you have? If you are just starting out, even a stock C5 will be more car than you can drive. I know my first few tracks events, I was really slow (as are most people). A very well driven C5 weighing 2700 lbs with ~350-400 RWHP will be very, very quick.

mitchntx

iTrader: (14)

And 70% weight on the front tires

Typical rookie mistake ... gimme more power.

HP is a crutch. Just because a car has 400HP at 3200lbs doesn't automatically mean it will outrun a 300HP car at 2700. HP will allow a driver to mask poor driving skills.

Realize, 500 lbs makes a HUGE difference in cornering speed and braking distance. You have the same tire and same brake, but less mass to turn and stop. And you can lose more time braking and cornering than you could EVER make up accelerating.

In CMC I'm limited to 230RWHP in my LT1 Firebird. But, the car only weighs 3000#. But, because I can brake later and carry more cornering speed, I can hang with a C5 on Hoosiers. The C5 will walk away from me on the straights, but I can easily catch him going into corners and rolling through corners.

I would venture a wager (with very little risk) and say your 2700lb C5 would SPANK that precious Z06 on a road course.

BTW ... if you are this serious, you need a roll cage.

Arctic2002ss

Hey, Mojave, what's up? Took me a minute to realize that I knew you.

Guys, this C4 walks away from C6 Z06s, lol. Then again, they are not gonna hang it out there on the edge so much.

Mojave

iTrader: (4)

Sup Craig! You coming to any auto-x this summer/fall? We are having an auto-x practice in a few weeks (July 21-22). Practices are awesome!! Unlimited runs, tons of fun to be had.

DONAIMIAN

iTrader: (18)

Like said above I would just start pulling weight rather than adding power. Altho, the headers add power and save weight.

Jim Dillus

First off, thank you all for your valuable info. I'm new to this sport and you guys have already been there and done that.

The power to weight ratio of my C5 Z06 is 7.65 lb/hp, (3100 lbs +/- 40 lbs, and assuming 405 hp). Stripping down my beater C5 would yield a power to weight ratio of 7.71 lb/hp (2700 lbs, and 350 hp). So that was my point about the slight advantage of the Z06. But that of course is an abstract numbers game and isn't necessarily indicative of whats going to happen at the track. Like it was said the total mass of the car is actually more important, because you have inertia concerns in turning and even more so in braking.

You are right both cars are better at going fast than I am a driver. But I'm sure I will out grow that quickly and I want to know that I am not sucking on the track because of my equipment. I want to know that if I'm sucking, its my own damn fault.

OK, well I'm convinced that the Miata concept is not as favorable as the C5. Once again, thank you all for your help.

subtlez28

iTrader: (15)

My thaughts exactly!
That said more power to you for going racing w it!
And Mojave...NICE C4 project!
Makes me wish I scored a LT4 vette so inexpensively!

mitchntx

iTrader: (14)

6 tenths difference ... SIX TENTHS! ... and 400lbs less weight.

Think of it this way ... put 2 passengers in the Z06 and then would the stripped C5 stand a chance?

Mojave

iTrader: (4)

Thanks. The damn thing is just still too heavy. I need to weigh it again; I'm hoping for no more than 2880, give or take. Finding weight at this point is getting harder to do, while keeping it sort of street legal. The headlight motors are mocking me....

subtlez28

iTrader: (15)

I'm so jelous of you Texas guys...year round racing...clean, plentiful performance cars...nice roads...still kick around moving down there...

Until then I'll live vicuriously(sp?) through LS1tech and your site Mojave.

EchoMirage

iTrader: (3)

all this talk about hp/weight reminds me of something i saw when i delivered car parts for a while......had a delivery to a shop, guy did alot of vettes. there was a typical midlife crisis ******* standing next to his vette, with a ****-eating grin on his face, saying how he just saved 15lbs buy going with a $5000 titanium exhaust. meanwhile this pig had a gut down to his knees, and had to be every bit of 260lbs or more. point of my story is: if you rant and rave about power/weight, but yet you havent seen your own **** without lifting your gut out of the way, keep your mouth shut.

fastlt1

iTrader: (4)

Man I wished I would have done this to my old C4 instead of getting rid of it.

mitchntx

iTrader: (14)

I never regretted selling my street car and building a dedicated track car.

Echo ... when you turn 50 come back and explain just how easy it is to lose weight or even maintain it.