Swapping solid axle to IRS

[Chromedragon]

So I've been told that this is a no-no. My '86 Corolla comes stock with a puny, annoying, useless solid diff and I'm wanting to swap over to a Nissan independent rear suspension and differential so I'll finally be able to adjust my rear suspension and avoid shattering rings and pinions when the new engine goes in. I've already blown apart one ring and pinion with 1/2 the horsepower that I plan to be running in 2009.

Is there no way around this to stay within the GT racing rules while running the IRS? I'm honestly not sure where I'll be classed, nor do I really care for the first year. I just want to get out there and drive.

[Al36rx7]

Good Day.

If changing to an IRS when the vehicle was originally solid axle equipped, I believe this will force you to be classed in GTS.  But why switch to IRS??  There is allot of extra weight in an IRS over the solid axle.   

I would recommend trying to track down Gary Lowes.  Gary's Corolla is on rails....well driven.  The well driven part takes many years / allot of seat time.  Enjoy the car, and just get some experience driving if this is the first year.  The first year puts one on a very steep learning curve.

PS...Read the rules....There's always something in them that can help you....  http://www.wcma.ca/2008%20Regulations/2008%20Technical%20Regulations%20-%20Race.pdf

[Chromedragon]

Thanks, I did actually read through the rules again earlier today and sent my concerns to Wayne Schellekens. We'll see what he has to say.

I am installing a Toyota 1uz 4.0-litre V8 in my car, so the IRS will actually help restore some balance front to rear. Overall the whole setup will add about 80lbs to each end of the car, although a lot of weight has been deleted thus far.

Frankly I'm not really too concerned about what class letters are on the side of my car for this season. This is just the car I've wanted to build for a long time and I just want to get out on the track and race it. I'm not expecting to win anything, at best the car will have about 300-320hp, so it's not going to be able to keep up with many of the cars anyways.

[vintagebmw]

That is a TON of HP for that car...

and HP is usually the last thing that keeps you in front, OK at race city it helps alot

If the car already has a motor in it why not leave it be and see what you think of the car before you start modifying the car.

You would be surprised how much 80lbs can effect your handling if it is way out front over the axles.

[Sturat77]

I agree with Anthony on all counts. 

Keep it simple at the beginning; trying to develop as a driver while trying to tame a foul handling 300 hp, 2000 lb Corolla may not be the best move.  Unless you enjoy being frustrated!!  Its tough to figure out what the car needs when you are still trying to figure out the driving aspect. 

As Allen suggested, get ahold of Gary Lohues, he can give you some insights on how to make that Corolla go mighty quick without the V8 or the IRS!

Thats my 2 cents.

Sturat

[4kruzn]

to all... please scan through this thread on driftwest before commenting any more.

http://driftwest.ca/forums/showthread.php?t=3478

then.  use some educated info to try to answer the questions he asked.   trying to tell him to bring out a stock corolla really was never the question.........

matt.   read and re read rules chose for yourself which class to build your car from.  i know you have.  my thoughts would be gts would be a fine place to be. 

in alberta or even western canada the class your car falls into is of little importance.  you will not have more than a few guys in your class anyway.  with a 4.0liter you would be gt1 or gts so do the irs swap if you want. have fun with your car.   i would be tempted to say most of your frustration of having an ill handling car will be easier to tune out that way.  more adjustable and IRS is just simply a better system.   yes some have found a way to "stick" a solid axle but its not any easier than with an irs.    when i switched from a first gen rx7 solid axle i could not believe that a car could handle so good.   then i bought a gen 3 rx7 and wow......   

BUILD IT!!!!!!   have fun with the build.  more important have fun with the car when your ready.   then have fun talking about how much fun it is and was.....

[Chromedragon]

Haha, thanks Conroy. I've lapped the car for several years with the boosted 4AGE engine making about 170hp. This is a swap that I've wanted to do for many, many years and I have no intention of turning back on the engine side of things. I've just dropped $3k for parts to adapt the 1UZ engine to the fully built Supra R154 transmission, so I'm really, really not turning back, hehe.

A large part of the weight difference will be in the transmission, which will be close to the centre of the car. The V8 will be located about 10" further back than the stock engine, plus the whole front end, as you can see from the build thread, has been stripped and very little will go back into the car.

I've gotten my clearance to go ahead with the IRS swap now though, so I'll just be running GTS. I'm going to fully document every single step of the build and offer it up for full inspection on the rear suspension once it's installed. The mounting points actually sit directly in the frame corners on either side of the axle hump. These will be boxed and braced, plus the cage will tie into these same four points from inside the car.

Once the car is back from paint I will post up the specifics of what will be done with photos.

Thanks for everyone's help and concern. The last thing I want to do is hurt myself or anyone else out on the track.

[Sturat77]

... perhaps a few more details in the beginning would have had people not trying to convince you to take a different path!  You have obviously thought this out thoroughly and it sounds like the fabrication aspect of all this is not a threat to you.  Furthermore it also sounds like you are not a stranger to the race track! 

GTS is a catch-all class for cars like yours.  Have fun with the build and then go race it.

Sturat