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Discussion Starter · #1 ·
I keep going back in forth about doing the IRS swap in my GT.

I really just want a comfortable ride since the roads in my area are horrific. I know that there are a few die hard IRS people on here that drag with them with no problems.

Now the car is my DD, but i'd like to take it to the track maybe once a month during the summer and beginning of fall.

How bad is the IRS for track duty really? I plan on adding an IRS brace and all the bushings. I've heard that DRs are really killer on the IRS and instead use a tire with a soft sidewall. Thanks!

-Ray :tip:
 

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Discussion Starter · #3 ·
I'm pretty diehard for irs when it comes to drag racing. Put a soft sidewall tire on it and let it ride
What RPM are you dumping the clutch at the track? How many runs have you done on the stock axles? Thanks!

-Ray
 

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I ran for two years leaving around 5500. I just now started to break the stock shafts. Never had a problem with the eaton
 

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the irs is ok..its something like 150+ pounds heavier than an 8.8.. long as u have all the braces and bushings it helps a lot..the aluminum pumpkin is the weak spot without the brace..once all that is strenghtened the stock halfshafts will snap before that will break..NORMALLY..
 

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Discussion Starter · #6 ·
Hmm, thanks for the info. I think it may be cheaper to just build my rear.
 

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Its not so much that its "bad" for the track, you just have to treat it differently. It will stand up to a lot of power as long as you stay away from wheel hop.
 

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irs does well for me. cut 1.5 60's consistantly with a soft wall slick leaving at 5k sometimes 5500. id be willing to trade u my irs for solid in the coming months.
 

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irs does well for me. cut 1.5 60's consistantly with a soft wall slick leaving at 5k sometimes 5500. id be willing to trade u my irs for solid in the coming months.
Yep! Just what he said.
I have a best 60' of 1.52.
The IRS hooks, squats and launches!

I am still on the stock half shafts after 5 years of racing.
 

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Discussion Starter · #10 ·
Yep! Just what he said.
I have a best 60' of 1.52.
The IRS hooks, squats and launches!

I am still on the stock half shafts after 5 years of racing.
What kind of IRS mods do you have?
 

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What kind of IRS mods do you have?
I have poly bushings in the IRS sub frame and diff.
A BF brace is installed and Steeda IRS brackets are welded in.
I think running the 15" bias ply tires has saved my half shafts by absorbing the shock on launch.
 

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Discussion Starter · #12 ·
I have poly bushings in the IRS sub frame and diff.
A BF brace is installed and Steeda IRS brackets are welded in.
I think running the 15" bias ply tires has saved my half shafts by absorbing the shock on launch.
Awesome, thanks for the info man!
 

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yeah the irs can squat & hook good. I simply didn't like the way the stock toe bars would flex & torque steer. I also didn't like having to remove the catback everytime I had to mess with the diff.
 

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I'd think you have better luck without issues becuase you're pushing less weight. I love mine and have no intentions of getting rid of it. Like you I live out in the country and the IRS rides like a Caddy. Until I have catastrophic failure it's not going anywhere.

Mine is built and it's had at least 50 hard launches on it and counting.
 

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Ive been on a pretty much stock IRS since I have owned my car in 03. 250+ passes I would assume, I only run an IRS brace and a set of adjustable shocks. Just recently added MM Poly Ureythane Forward and aft diff mount bushings. No plans on swapping anytime soon.

Low 1.5's on a stock IRS with a brace is pretty common on a sticky soft sidewall slick.

Wheelhop is what kills most of them (halfshafts) I have had good luck with both 17" DR's, but I prefer a soft sidewall slick now.
 

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I need to do all the braces and mods to mine still. I use the traction control in mine, it has saved me many times and with my daughter in the car all the time, its staying.
 

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As noted above some poeple haven't had any issues with the IRS. From my times at the track, I would say atleast 80% of them leave on flatbeds. If you are going to race on the IRS I would take a spare shaft and the tools to change it. Better to be prepared for worst case then leave on a flatbed.
 

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doing it with a 2v..
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irs in my car.. 1.62 60fts a few times in a row on a 275 17inch radial tire...

hooks 100 times better on the street too...
 

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I have launched like a bitch for the past 4 years owning the car and just bought some 28x10x16 slicks for it. Going to let it go this year and see what happens at the track. I will keep the irs for as long as I can, I spend way to much time on the street to go solid.

I do hammer the shit out of it on the street powershifting and cracked the splines on the driverside shaft this past summer. Only issue with it so far.

I think staying away from a really hard hitting clutch with a tall sidewall slick will help the halfshafts live.
 

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The problem with the IRS is not if the halfshafts will break but when they will break. Sure you will hear some success stories, as some have shared in this thread......but eventually they will break, plain and simple.

I know of countless times I have been to the track and witnessed an IRS car snap a halfshaft.......I have yet to see a solid axle car break.

I like to drive my car to the track and beat the shit out of it. Some tracks are 3+ hours away from me. The peace of mind I have, knowing that it is highly unlikely I will not break an axle with my solid is good enough for me.

--Joe
 
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