Best IRS / Suspensions upgrades?

[austin21]

What are the best IRS / suspension upgrades to improve handling, etc?

Looking at doing Bilstein B12 coilover kit but wanted to know if there is anything else i should consider doing that will make a noticeable difference in handling.

Thanks for any input!

 

[MG0h3]

Full tilt boogie racing offers a bushing kit that makes a considerable difference


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[austin21]

Full tilt boogie racing offers a bushing kit that makes a considerable difference


Sent from my iPhone using svtperformance.com

Whats the difficulty on the install? Will probably get my mechanic to do it but didnt know if it involved dropping the rear IRS to replace.

thanks!

 

[MG0h3]

IRS has to come out. You have to press the bushings in and out.

Not a job for a novice


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[austin21]

IRS has to come out. You have to press the bushings in and out.

Not a job for a novice


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I figured so, thanks for the advice !

 

[01yellercobra]

I think my car rode better after I did the bushings. Adding the coilovers just finished it off.

 

[bird_dog0347]

The FTBR kit is supposed to be the very best, I haven't personally tried it but I don't doubt it. On my car (92 coupe with 04 IRS) I used Prothane Poly bushings in the upper and lower control arms (installed myself), Poly bushings in the subframe mounts, MM diff mounts, and MM Koni SA Coil Overs. The front also had poly bushings everywhere and MM Koni SA Coil Overs. Now that it's in full build mode it's getting the MM K-Member and control arms too and I think we will convert the rear subframe to hard tail.

 

[52merc]

I installed the FTBR setup a few years ago. I would definitely recommend the whole package. Here is a picture of the assembly ready to re-install. The kit is pretty straight forward but it is not for the beginner. I even made my know puller tool to remove the bushings

 

[Blkkbgt]

As others have said FTBR hands down but get the rear toe links and bump steer the car. Yes it does make a difference.

I however have to disagree with others above. "Novice" is a very general term imop and I think this can be done by anyone who can change brakes or do their own springs, struts and shocks. It's not that hard but a little time consuming.

The only think I would have done is the drilling of the control arms for greese fittings because you need a drill press especially for the uppers.

There's videos on the FTBR site that explains how to do everything.

I will also say that you should rebuild your knuckles as well when you do the job. Plan on bearings and hubs.

 

[RX1Cobra]

The FTBR kit is supposed to be the very best, I haven't personally tried it but I don't doubt it. On my car (92 coupe with 04 IRS) I used Prothane Poly bushings in the upper and lower control arms (installed myself), Poly bushings in the subframe mounts, MM diff mounts, and MM Koni SA Coil Overs. The front also had poly bushings everywhere and MM Koni SA Coil Overs. Now that it's in full build mode it's getting the MM K-Member and control arms too and I think we will convert the rear subframe to hard tail.

I used the Prothane throughout mine too. I also changed to Koni shocks at the time so hard to say what helped more but overall car feels much more planted.

I bought my car new and was my DD in Chicago for 5 years. So saw salt/snow. Cleaned up pretty nice though. I did all this by myself in the garage. Found it easier to pull the driveshaft with the unit instead of fighting the bolts under the car.

Before:

After:

 

[HPLouis]

The prior owner did this to the IRS:
Full Tilt Boogie Racing FT5001 IRS Bushing Kit
FTBR FT1350M Milled Ford Racing Rear Diff Cover
FTBR FT1860 Deluxe Bumpsteer Toe Link Kit
FTBR FT1900 Adjustable Swaybar End Link
MM Rear Coilover Kit
MM Revalved Sport Series Bilstein Damper Package for IRS
Hypercoil 575lbs Rear Springs

It drives so differently than stock. More planted, more secure, no wheelhop.

 

[01yellercobra]

JMO....

Anything is an upgrade over the stock bushings. I went with FTBR as it was included with the car when I bought it. I'm sure I still would have gone that route either way.

A friend of mine went with poly in his 01. His car was his daily for years in CT. Shortly after moving out here he had to replace all of the bushings as they were wore out. He tracked his car too. So it wasn't an easy 120K (I think). I have yet to hear of anyone needing to replace the delrin stuff.

YMMV.

 

[Badaz01]

Whats the difficulty on the install? Will probably get my mechanic to do it but didnt know if it involved dropping the rear IRS to replace.

thanks!

I have the ftbr kit in my cobra. Night and day difference. I also have bilstien b8 shocks in the back with eibach sport lowering springs and the ford racing diff cover. Then I went with stifflers welded subframe connectors and a upr chromoly k member with the coil over koni orange sport struts. Car handles like a beast. As for the ftbr install put the bushings in the freezer while you beat your guts out getting the old ones out. LOL.

 

[01vert]

Best improvement for handling before you tear into the IRS is to add full length subframe connectors.

What is the purpose or intent of the improvements? Tightening up street driving, autocross, weekend track car, quarter mile car?

You may want to make a couple calls to Kenny Brown and Maximum Motorsports before buying a setup as they would have specific recommendations on spring rate on coil overs depending on your intent.

Kenny Brown and Maximum Motorsports both offer packages for handling. However, if just talking about the IRS I would also go with the FTBR kit. I did mine but it took several extra days as I had to order additional parts as I disassembled it when I found issues. The joints on the upper and lower mounting points of the knuckle have to be checked and may need just new boots or to be replaced. These are expensive and a consideration depending on timing and budget.
Taking out the IRS is relatively straightforward but having two people at certain points helps as well as having at least 4 jack stands, a dolly for the IRS and some blocking for your jack. I hand drilled the grease fitting holes without issue, didn’t use a drill press.