C5 Pete

Why do drag racers of corvettes keep the IRS?

Is it to prove that with enough money, the IRS is capable of handling big power? Sure, Mark Carlyle has gone 6.5x at over 220 with an IRS, but at what cost? There are several others running 8s with IRS.

PG conversion is not anywhere near cheap.
9" IRS is even further from cheap.

Not that I expect racing to be cheap, but when you can buy the Moser C5 solid axle kit for under $7,000 with brakes, and a traditional PG trans for about $2k with a trans brake, why stay with IRS?

I'm just rambling... It's cold out...

Vettekid1992

i'd say my car is a good example of why to stay IRS. i would say roughly $2000 invested in my rearend setup. yes i've broken it a few times but havent since i've beefed it up some more

International Axle Axles
4.11 Richmond Gear Set
Eaton Posi
3" Halfshafts
polyurethane everything lol
and a few little Cupolo Tricks and Tips
best 60' with a powerglide 1.76 first gear and a 2000rpm ft brake 1.44 60'

as long as the transbrake is avoided i feel my rear will hold the power for a decent amount of time. would like to get it into the 1.3x next year

with ANY weak rear end, if you can prevent "SHOCK" it will last you

kazman

The solid rear was one of the major reasons for purching the blue drag racing corvette. I was worried on how an IRS would hold up bracket racing.

99ZX9R

Same here. I was about to dump a lot of money into my C5 to make it faster and more consistent, but I worried about how the drivetrain would hold up to the grind of a bracket racing season. Of course I ended up going in opposite directions and bought a Mustang.

LSOHOLIC

Very Valid thought process you got going on their !!

IIRC, there are a couple solid axle conversions available......do you know of which companies are making them ??

I've kicked the idea around but that's one of the those mods you cant go back on...lol. IMO Its a "big" decision.....

.

4DRUSH

Why?

Things evolve, if I known it would get to this point, I would've went solid in the beginning.

However, it's not just a solid rear.

It's enlarge tunnel for front mount trans
New trans, shifter, etc
Make trans support
Drive shaft & loops
Remove fuel tanks for axle support
Fuel cell & fuel system
Custom headers & x pipe to go around/under front mount trans

Just to name a few of the bigger stuff

C5 Pete

Moser and, I believe, Carroll's Rod & Racecraft make a solid axle kit for the C5.

I know I want a faster race car. Not now, but in 2-3 years, I plan to build one.

Jay, watching you, and others, progress has been a tremendous learning experience for me.

I hadn't thought about the need for custom exhaust work, but I've certainly considered the other work that's required.

My weakness is the corvette FRC body. I love it. I just need it to be bulletproof. Or at least as close as I can get.

Of course I'm rambling again. I'm really happy running the 10.0 index for now.

How long til April?

kazman

April ???? Our first point race at IRR is Dec 21st.

DOUG @ ECS

We have had many customers and ourselves thoroughly break down the difference between the two dollar wise and when it's all said and done it's very close in price between the two. That also goes for the track results afterwards, some IRS cars doing consistently better actually.

(speaking of C5/C6)

C5 Pete

No question some of the irs cars are getting it done. The 60' time and ET's that have been put down are impressive.

For a while back it seemed a number of cars switched to a solid, then as parts became available, the irs became stronger and racers were sticking with it.

Still, I think, starting from scratch, for max reliability, if the class allows, the 9" solid axle is a pretty good option.

joe11204

What about the guy running 7's with the IRS.

4DRUSH

and a ZR1 rear, even more amazing

joe11204

Upgraded by RPM. Still way past the limit of what it was designed for.

Hopefully we can soon get that GB on the 9" IRS setup.

C5 Pete

Joe, my deepest apologies. You're car is at the top of my list of awesomeness.

I'm looking forward to seeing your winter upgrades.

I have to live vicariously through you guys. My car is fun, but heads up is my passion.

Enjoy your winter gentelmen.

roger3

How many passes have you made with your setup. Your giving me hope. My IRS went about 300 passes before I broke ring gear. I am running much slower times than you (11.6x at 117mph, 1.61 60ft).

Do you take it apart routinely to check clearances, wear, etc?

My rear end is at Tracdoggs getting rebuilt to a super 10.

Roger

Vettekid1992

whats a super 10? never heard of it. i have BENT the stock trailing arms aswell but i straightened them out and reinforced them

i ran a 4.56 GM ring and pinion with stock EVERYTHING and ran low 11's @120mph for about 3 years (roughly 150 passes a year) and never broke anything with 1.60 60's

but once i changed the engine and put the car in the low 10's i broke the 4.56's and the stock axles, changed to 4.11's and put a 12bolt steel cap on the drivers side. all international hardened axles. i've run this setup for 1.5 years and havent broken anything with high 1.4 60's

HAVENT EVEN CHECKED THE REAR IN OVER A YEAR AND HALF. so i guess everything is still good lol. set my backlash at .010 and i run Redline High Shock Proof Gear Oil.

Vettekid1992

rear has looked like this ^ for 1.5 years and i havent touched it

HardcoreABN

mine is staying IRS due to cost and it is my DD. Even though I want to run 2 9.X passes - just to say my shop has built a 9 sec DD, I probably won't push for those times once I get them. I will be more than happy running 10.5ish on motor only lol...after all, this is a full weight C5 that I drive the hell out of every day.

I will probably break again, as it will be a bit before I can redo/strengthen the diff/trans. I will be putting in an ECS trans/diff brace. I eventually will upgrade the trans/diff once I get the money to do so. Gotta get the LS3 top end swap and N2O kit bought/installed, then I can worry about rebuilding the trans I broke about a month ago. Already replaced my diff with a Z06 3rib.

HotRodRed

If you're going to invest time & money to race, especially Bracket Race, IMO it would be hard to match the sheer rugged nature of a straight axle 9" Ford rear. Not to mention that once you get past the initial cost of the conversion, you can find ANYTHING you want after-market for the 9" AND the 'Glide. There is also almost unlimited support base/data that is available to help you build/buy/race these pieces.
If the total cost is almost equal, as some on here claim, the choice would be easy for me...but hey, I'm not exactly impartial. That's almost all I have ever raced with.

99ZX9R

I've been saying the same thing to this knuckehead for years. When racing a season long points series, you can't afford to be down.