You've had a broken race car every year you've been racing.

My current car is fun and I'll keep racing it for several years. Eventually, I'll build something with a 9" and a glide.

 

I most certainly have not. This year I blew my motor, but last year other than some minor tuning issues, the Tank and Leroy after I sold it, both ran great. The year before I broke an axle (stock 28 spline) at the end of the season after the points series ended.

More importantly though (since we all break) is to have a contingency plan. Which is a big reason why I bought the TBird.

 

Well I've had some seriously bad luck over the past few years. 2014 will be my year.

Look at all the other C5/C6 cars that run all season... No reason I can't do the same.

 

All true.

As long as you're not running opposite me, I'll be pulling for you.

 

This is true.

 

To put a 9 in under your car is easy and a simple trans support and you are on the road.
You will need to be a welder to install it and you will only have to adjust the front and rear shocks to get the 60 down where you want it.
NEVER repair an IRS it will never be worth it
A th 400 turbo a 9 in with 4:10 or 4:11 gears and you are done.You can race for years and never have a trans and rear problem again!
Been their done that .I had 8k in my irs and only spent total 6k for 9 in and shocks qa1's.
Don't try to install a 12in in a vett the drivers side never will line up right.The 12 in has a fin on that side that interfears with the body.
Just my O2 worth.

 

Would like to see pics of yours.......

 

12 bolt...Not as high as yours, but no fin problems.

 

My fin on the 12 bolt crushed the car when I pulled the wheels and it torked over ,just alot of noise for a second and after that it had good clearence.
The panard bar or wats link is a must with these set ups.Panard bar is the cheap way ,I see you did it the same way i did
What pics do you need, to see how it works or what ?

 

Looks like someone got Tony Robins motivational CD set as early Christmas gift.

 

Well, look at that.... My #1 fan showed up...

 

Man........the more I weigh the options.....the more I lean towards a 9"/8.8" IRS diff.
IMO, there maybe some IRS benefits in drag racing.....

I'm a manual C5.....and IMO, it needed a diff upgrade option before the auto version did. But as I understand it.....the physical dimensions are a little more challenging with the manual, as compared to the auto (out put shaft horizontal location).

But with todays diff manufacture's.....I feel it would be possible to have this fabricated. And I feel it is possible to stay under the "others" kits price tags (speaking of bolt-in solid axle kits and C6Z/ZR1 rear swaps). Also the gear options are not there with the C6Z/ZR1 setups either.

I'm also an avid off roader and the options for customs diffs today is really unbelievable.
.

 

For me the C4 Corvette IRS has been great for drag racing.

1.24 60ft all season and the only thing I have to keep check on is the U Joints... as they crush/crack the needles after about 70-80 passes.

BTW that is at 3120lbs on a 28X10.5 tire.

Heck before I put Nitrous on the car it was raced and street driven for 3yrs on a completely stock junkyard 1990 D44 center section... Even the U Joints were 101K mile ones orginal to the car - right out of 1984. Car ran mid 10's@125mph with a 1.40 60ft on a 275 radial or 28X10.5 slick.

Now of course I went and put 200HP worth of nitrous to it and busted the factory 1984 U Joints in about 10 passes.... then it exploded the posi unit.... but I knew that stock junk wasn't going to last forever and I was being cheap. Once I built a proper center section with a spool then set the rear suspension up correctly - No more problems.

People make a big deal about drag racing IRS cars but honestly if you just fix the problem areas it can be as good as anything.

I don't have anywhere near the $$$$ tied up in mine that a 9" or 12 bolt conversion would cost.

Yukon 3.90 gear, Yukon D44 spool, Spice Cold Forged U Joints.

Stock D44HD case, stock halfshafts, stock inner and outer stub axels.

Koni Double Adjustable rear shocks, Energy Suspension extended Poly Bump Stops.

Stock 84 Z51 rear leaf spring.

My car dosen't do anything crazy on launch (unless I put a 275 radial on it) except blaze a 60ft number most people can't get their heads around.









I'm not here to knock anybody that converted their Corvette to a straight rear end and went drag racing. Hell I'm honestly just glad I'm not the only guy at the track in America drag racing with a Corvette - Its no matter to me how somebody else got their Corvette there.

I also like the IRS and thou it really wasn't much of a challenge for me to make it work, other people flip out when they look under my car and see all those stock alum suspension arms and rubber bushings. I honestly built the 84 because I wanted to dispel the bad press about how sucky IRS is for drag racing.

I race in a heads up small tire class and I even get a 75lb weight break for having "leaf spring" suspension... but they know if I put a straight rear under there with the "Stock Suspension" lay out I now have a real 4 link... The rule makes say no way to that. I could put ladder bar 3 link suspension under it but I'd loose my 75lb weight break.

I am always willing to help other C4 guys with their IRS set up. I give out info freely to anyone that ask about my car and what it took to make it work as good as it is. Heck we have a pretty good discussion thread over in the C4 section where I explained what to do to increase the AS% in these cars, why I think some of the aftermarket suspension brackets are wrong for drag racing and even gave specific 4 bar (trailing arm) pick up point heights, AS%, IC height measurement examples fom my 92 Corvette street car so they can better relate the info to what they need to do to their C4s when they take them to the track.

If other people that know how to make these cars work would just share SOME of their knowlege, maybe there wouldnt be such a feeling of it takes F'n Magic (FM) to get an IRS drag car to work. In the end there is no Magic involved and IRS is not inferior to a straight axle, it's just that the people who are going fast with IRS are offering any pointers to others having problems....

Now the boat we are in, is that people are stuck listening to the no nothing folks, or the not knowlegable enough folks, or those who broke a bunch of stock junk - Saying IRS sucks, just get a 12 bolt if you want to drag race.....

Will