Weak driveline issues(long winded)

motorhed · 12-24-2007, 01:14 AM

Hello people and thanks in advance for any replies,my question is that it's obvious the stock axles,stub axles and driveshaft are weak and are prone to failure even on slightly modified late model GTO's and I was wondering if anybody has heard of just dumping the whole IRS setup and switching to a solid axle housing type rearend with some type of four link setup..I realize the cost would not be cheap but after pricing all the components to beef up the rear drive assembly your looking at well over four grand(800.00 driveshaft,900.00 for stub axles,1000.00 for axleshafts plus a beefier diff carrier assembly etc.)I guess what I'm getting at is you could install a much stronger tried and true means of launching for probably less money than it would to upgrade the IRS not to mention the adjustability potential easy gear changes etc...Is there anything in the works from Chassisworks or similar companys that anybody knows about?Looking at the underside of the car it appears to have numerous ways to accomplish the tasks without hacking the chassis...Simply making parts bigger seems to be the way to make them stronger but brings nothing else to the table as far as adjustability,availibilty and lower ET's except for being able to maybe finishing the race without breaking something.....Most drag racers will admit that IRS has severe limitations thats why most people have had to replace thiers with a 9 inch,Dana or whatever they choose to deal with this issue..Or in short if my buddy spends all this loot on fatter components that may or may not not break will he be better off or should he just stick to my guns and be different?I'm asking this question for a friend with limited knowledge but he has one 550 horse(at the wheels)05 GTO thats gonna start breaking things soon..In for a penny in for a pound and he's already spent the pound....Thanks a ton people and sorry for being long winded but it seemed like a fair question...

Dan_E · 12-24-2007, 11:16 AM

Not an expert, but one of the "challenges" is most likely with the strut towers in the rear...I have see some discussion on those who have done some extensive work, and they had to really cut in to the body and do some unique things to get the suspension working.

Not saying it aint doable or worth it, but make sure you get the full effect of what has to be accomplished.

6QTS11OZ · 12-31-2007, 09:38 AM

Our driveline components aren't as weak as some may claim. There are guys running well above 600 rwtq through the driveline on a regular basis at the track and haven't had one problem with breakage. I have gotten on mine quite a few times at the track and on the street, of course, and mine seems to be holding up just fine and I'm pushing a lot of low end torque through mine with help from the supercharger. I think a lot of breakage is due to flat out abuse. If you do anything excessively for a period of time something is bound to break.

koman · 12-31-2007, 11:44 AM

i'll agree with 6qts, alot of idiot drivering. you have to know wheel hop when you experience it and know that's not what you want to do. people kill the 8.8 rear ends in fox body mustangs because they get hweelhop and keep on trying to get the car to go hopping down the track. you can kill the rear end with just stock power. you don't need massive amounts of it. even those 300m 800+rwhp axle halves will die with wheel hop.

good luck

Dan_E · 12-31-2007, 10:47 PM

I believe some has to do with your tranny...us M6 guys are more prone to failures. I know I have had my measly 450-500ish rwhp manual's rear end out and the rear stubs inspected...those dudes aint true.

Of course 4k clutch dump's at the tree on the juice may be a contributing factor.....

motorhed · 01-04-2008, 02:14 AM

Well it seems to be a mixed bag concerning this subject and I can't blame the people who who havent broken anything yet for standing up and defending the ability of thier car,you gotta stand up for your ride..But like it or not everytime you launch you car at the track it's being abused but only if your trying to go faster than the pass before or beat the person next to you,afterall that is the purpose of racing..Having to back out of the throttle or slip the hell out of the clutch to avoid hop is not allowing you to fully use all that extra power you paid for and when you live a $400.00 tow charge home (like most of you we have no car carrier/trailer etc.)you dont want to break..I'ts also curious that there seems to be sort of a dead zone where you have most everybody between lets say a 10.9 and 13.6 (stock to heavy mods)and then you have the rest of the cars going say 7.5 to 9.5 (psyco mods and above) but I,m having trouble finding solid 10 second dependable and streetable GTO's,there are tons of other cars doing it ,hell it's almost common today with whats available and I can only find that someone out there seemed to set this unspoken of wall you hit somewhere in the high tens leaving a whole lot of ground open..This cutoff point seems to coincide with the cars that are running IRS and the cars that went with a solid rear end because they reached the dependable limit of even the upgraded stock style.It seems that the wicked fast cars all have full framed chassis etc. and 4 link style rears while the not as wicked cars live within the limits of IRS..First of all you dont need a full tube chassis to get the benefits of a 4 link because it's nothing exotic and you dont have to hack the crap out your car to install one either although I will admit right now that there will be times of head scratching,cursing etc should we go for it.And thanks Dan_E's for the warning about the rear struts but one of the great things about a 4 link is that you would be using a coil over shock or air bag setup relocated far inboard of the factory mounting points with more adjustability/options than you could dream of...You people are all pure bread horsepower junkies,I can tell from reading your posts,a relentless urge for more power is what gets you up in the morning,it be sweet getting all that power hooked up hop free time after time and then drive home when done with no clutch stink or "I lost it at the line" excuses all the way home,you deserve more..Also I've kinda learned to listen to the people who take thier machines to God every race,they have learned the most by pushing the limit others might set and trying my hardest to weed out those who claim to push the limits but somehow take a 13.0 car and "push" it to a 13.7......I hope I've made a little sense here and lets see what happens when the 08 Camaro arrives built on the same Zeta platform I think a similar problem will happen but will be dealt with much better by the aftermarket due to demand...Oh and just a little background on me if you were wondering,30 years professional tech with mega experience with the old cut,grind and weld---after measuring of course and a life long need to go faster...Thanks people and how about some of you older guy's weigh in..Thanks for taking the time to read hopefully I can provoke a response.....

rnoswal · 01-09-2008, 08:11 AM

To bad there wasn't some way to put a MKIV Supra rearend in it. They start with 320 hp with the stock twin turbo and go up to 1,000 hp with no drivetrain problems. They are IRS too. I bet the Aussie's raced the Holden a bunch! I wonder how they strengthened the drivetrain, and stuffed bigger tires under the car.

Is the wheel hop stopped by putting stiffer bushings, poly, in the rear suspension, or are other mods needed as well?

Russ L.

t0ny · 01-10-2008, 12:22 AM

Though somewhat rare, rear end failure does occur in our cars with abusive driving. BMR Fabrication Inc. has a few answers to driveline worries. But as stated in the original post, the $$$ adds up.