The Official Built IRS Thread

[BurnTire]

Well this tread is for discussion of beefing up the IRS.
Those will IRS mods post your experiences here.

[Lucafu1]

My IRS is built. Mods are :
BF Brace, MM poly subframe bushings, MM LCA/UCA delrin bushings, Diffrential aluminum and delrin bushings, H&R SS springs, BF Subframe braces/brackets (fulley welded) MM tie rod bump steer kit, Cobra R shocks.
The ride is ruff but there isnt any wheel hop (unless its very cold). just spins on the street and with sticky tires in the back it hooks. I love it.

[Gene]

Not bashing the IRS, but if your ride is rough, why didnt you switch to the solid? My solid is built and it rides just as smooth if not smoother than the IRS did. Clutch dumps all day long without wheel hop in this baby! Best mod I've ever done. Yes, even over the KB.

[matt]

Unfortunately I have done nothing to my IRS except Dr's and that seemed to cure the wheel hop problem. It's lasted for 60k with no problems (minimal abuse, but enough that if it were to break it would have) except I picked up a vibe around 20K miles at 60~65mph. Come to find out it was due to an egged shaped wheel. This brings me to a question, people with IRS and 17x10.5 +315/35/17 wheels and tires what setup did you use to mount them? I understand the Nitto run small so I'm interested in tires that are true 315's like BFG DR.

[Gene]

Matt, I used the OEMs 17X10.5 on the 315 BFG DR

[Lucafu1]

Not bashing the IRS, but if your ride is rough, why didnt you switch to the solid? My solid is built and it rides just as smooth if not smoother than the IRS did. Clutch dumps all day long without wheel hop in this baby! Best mod I've ever done. Yes, even over the KB.

i like it rough

[matt]

Matt, I used the OEMs 17X10.5 on the 315 BFG DR

No spacers on the IRS. I can barley get away with a 1/4 spacer and MM button head IRS bolt.

i like it rough

Your not my wife

[Gene]

Oh snap, I forgot I used a set of mr. gasket 5/16 spacers and a ground down IRS bolt. They're realy not needed once the car is on the ground, there is no way its going to scrape the IRS bolt unless I do some dukes of hazard jumps. You are more than wlecome to have them, I have no need for them any more.

No spacers on the IRS. I can barley get away with a 1/4 spacer and MM button head IRS bolt.


Your not my wife

[matt]

The 5/16 would eat up to many threads on the stud. I agree the bolt is really not the problem it is the bracket that the rear of the IRS bolts to.

Well long story short the tires are on I'm sure as soon as I lower it and get an alignment all will be fine. Its just so close it gives me pause.

[DavidHarsay]

I have a 1999 Cobra IRS installed in the car.

As a project, I currently have a set of 03 Cobra Knuckles and axle shafts to install (actually I'm short one axle assembly right now)... and working on building the rear end with a 31 spline Black Gold differential.

Currently instaled are MM urethane subframe mounts, but I also have a set of Delrin suframe mounts to install.

I have the Cobra R Bilstein shocks, with the MM coilover kit, and 600# coilover springs.

I also have the Steeda urethane front diff bushings, and a set of aluminum spacers to replace them when I get going with everything else.

I have a Mocal fluid pump for a cooler setup, and have the spare pumpkin drilled and taped for the AN fitings. Can't remember what brand of cooler it is, but it's the stacked plate kind.

I also have the Kenny Brown rear bump-steer kit and adjusted the bump steer with it.

I have the Cobra R diff brace, which is the same one that the 03-04's come with stock I believe.

I also have Delrin upper and lower control arm bushings.

here are the parts that I have from the friendly Cobra R flks on SVT Performance...
http://www.svtperformance.com/forums...=160766&page=1