ratt_finkel

So I recently purchased a C5Z with APS TT kit installed. This car is being built with the intent of taking down the class record of 9:46.xxx.

You can see the motor build here.

https://www.corvetteforum.com/forums...hillclimb.html

While power is more important for this venue than most. I intend for this to be a well balanced, reliable and consistent race car. I do plan on tracking this car. But that not in any serious competitive environment. We'll call this a one trick pony.

Power goals will be somewhere in the 600-800whp range @ 9k feet.

Weight goals are 2,800 or less.

Big Aero: Including front splitter, rear wing and flat under-body pan with rear diffuser.

Tires are completely open. I do plan on running slicks. As a back up, I will run 18x12 fronts with 335 and 18x13 with 345 Hoosier R6's. Depending on the compound and model of slick, wheel specs may change completely.

I have a long list of things that need to be done to convert this street car into a proper race car. Like the necessary safety, reliability, fire and ancillary gear.

What I'd like to talk about is setup. Pikes Peak is a unique race. The best way I can describe it is: A 12 miles autocross. With much higher overall average speeds. And occasional triple digit squirts. There are no high speed transitions worth mentioning (think thread the needle or slalom type elements). And no substantial high speed sweepers. While there are some constant radius type turns. They are relatively small and maybe around the 60mph mark. Hair pins are 20-30mph affairs. It's a relatively grippy asphalt. And for the most part, is incredibly smooth.

The last 1/3 of the track has sections with significant undulations. A GT3 Cup car hit one a little too fast last year and literally "hopped" onto some boulders. If that section were non existent, you could run some significant spring rate and be fine. So being able to handle large bumps with ease is a necessity. And while I can handle a loose car. I'd rather have a car that isn't going to try and kill me.

I'd prefer to keep this thread on Topic to the build and set up of this car. If you have items you'd like to add to the other thread, by all means please do! I'd prefer to keep my past experiences, driving prowess, whatever else out of this thread.

Thank you,



Jeremy Foley

P.S. The starting point!

Captain Buddha

I wish you the best of luck with this! I've been kicking around the idea of doing it in my Howe ASA/GTA car (if it would fit in a class for next year)...but only so much budget. Looking forward to seeing your progress.

froggy47

Fun to watch this!

63Corvette

I recommend a strong cage. You don't want to find yourself halfway down the mountain (upside down) and in need of one.........

ratt_finkel

Been there done that. Let's keep this on topic to the build please.

Thank you.

chetly

I would look into doing a suspension similar to SSP or SSM. Maybe upgrade to a coil over setup if open.

Not sure if you'll be able to fit 335s up front but that'll be awesome if you do. A friend runs a 315 square setup on his SSP c5z.

Agree with the well built cage, something like more is better.

What kind of aero is available for the c5? Does LG have anything available?

mountainbiker2

I had 17x11.5 with 335/35/17 Hoosiers in the front. You have to cut the backside of the fender liner.
6" Homemade splitter. 335 sticking outside the fender. Dual element wing from Dauntless Racing.

ltborg

Just get some nice lightweight, flared fenders to fit all the tire you want: http://advancedcompositeproducts.com...tteracebod.htm

ratt_finkel

I have a feeling an autox setup may be too stiff.

I am considering coilovers. But I have heard bad things about the conversions. I really don't have any real experience though.

Why can't I fit 335's upfront?

Aero will more than likely be all custom pieces. Minus the rear wing.


Nice looking car! Any reason you're running 17's instead of 18's? Not afraid to hack up the car to get them to fit. I fully expect them to stick out anyway. And making the car narrower is not really a concern.

Lane, they have some awesome stuff. But looks quite pricey. I'm not real concerned with flares and what not at this point. Last on the list really.

lefrog

What bad things did you hear about coilovers?
I am running LG GT2s on my C5Z hillclimb car on roads much harsher than what you'll find at Pikes Peak and it works fine (although a bit too stiff for bumpy roads). Install is super easy. You might want to upgrade your sway bars if you go with that.
The cage build is kind of a pain in the neck on the C5. You can check my build thread here: https://www.corvetteforum.com/forums...ld-thread.html

It is going to be a challenge to be less than 2800lbs w/ cage+safety+aero. You will have to remove absolutely everything (lights, wipers, etc...) and go for lighter parts for things like the battery/hood/windshield/rim/tires and strip down the wiring to the bare minimum.

ratt_finkel

I've been told the shock mounting was never designed to handle the load of coilovers.

The closer I can get to 2800 the better. Below that would be great. I realize it might be a challenge ($$$$$)

trackboss

While I currently prefer leafs for my C5 I'd like to say that the shock mounts not having enough strength for coilovers is a myth. The loads transferred through the dampers impose far more force than any coilover spring. High speed bump spikes have multiple times greater force than any springs.

mountainbiker2

17" were real popular a few years ago. I would go 18" now. You can put on bigger brakes, plus if you go with drop spindles from LG they fit much better in the back. I got the car down to #2755. No roll bar though. Autocross only. There was still another #50 left to take out, if I trailered the car.

Steve

Supercharged111

0Anthony @ LGMotorsports

I think I saw that car once

lefrog

I think this is a myth. I had a crash at a hillclimb recently and the upper control arm broke but the coilover and mounts are fine!
See the pic below:






Upper control arm failure after hitting a rock when going off at a hillclimb

ratt_finkel

Yeah that video made me a convert LOL

2bridges

from a cooling perspective:

Is the TT kit in your car a single front mount cooler??
If it is I would consider dual corner mount IC that do not put additional heat in the radiator.

chuntington101

Individual cooling paths are always the best option! lets you manage the airflow better and prevents air stacking up.

Another option for the intercoolers location is behind the wheels. This area you want to remove the air from anyway. I have seen it done on a race Aston Martin. You would need to protect the intercoolers though.

Air to water is a option but it adds weight and complexity.

oil cooling is the other requirement that should not been skimped on. in fact arguably intercooling is the least of the worries and should be put to the back of the list (behind water, oil and brakes).

depending on the rules the OP might be able to get away with running a high octane fuel or even on meth. That would remove the need for an intercooler altogether, or at least minimize the issue of running a relatively inefficient one. In fact running methanol would also mean the engine runs cooler and thus puts less thermal stress on the radiator. A Win Win in my eyes.

chuntington101

Not sure how much weight you would save, but have you thought about having a go at making your own composite bodywork? A guy in the UK has basically done all the bodywork on a Noble M12, with lots of custom work, and he is an accountant by trade! lol

Could save a fair bit of weight and allow you to go to any extremes on the bodywork. Plus for some areas you can add more safety by using a different layup on the fiber.

For some some inspiration, and for the enjoyment of everyone else, below are the threads i posted in the C5 FI section.

600 BHP RWD SEAT Ibiza tarmac rally car build by a guy that has worked for several OEMs and Rally teams:

http://www.pistonheads.com/gassing/t...za+-+rwd+turbo

RWD Space-Frame Silhouette Racer

http://www.pistonheads.com/gassing/t...acer&mid=36792

Mid engined twin turbo (1000++bhp) tube frame car

http://www.pistonheads.com/gassing/t...+Answer+is+%21

lotus Exige with pretty extreme aero

http://www.pistonheads.com/gassing/t...Exige+S1+Turbo