"THE" Cobra IRS thread

ac427cobra

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I ordered and installed your full FTBR kit (w/ lowering mount) last June... will the lowering mount that I have now fit the new cover?

Unfortunately no. That rear bracket was made before the Ford cover officially came out. It will require a little bit of milling. We'd be happy to mill it for you for a nominal charge of $25.00 seeing you purchased the complete kit from us.

Let us know.

Bruce and Steve
 

wals9331

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Maybe a dumb question, but will the rear lowering mount work with the factory cover that just has a billetflow diff brace? Thanks
 

ac427cobra

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Maybe a dumb question, but will the rear lowering mount work with the factory cover that just has a billetflow diff brace? Thanks

Not a dumb question at all. The rear lowering mount will work with both the diff cover brace and the factory cover.

:thumbsup::coolman::beer:
 

wals9331

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Not a dumb question at all. The rear lowering mount will work with both the diff cover brace and the factory cover.

:thumbsup::coolman::beer:

Thats what i thought. Thanks

Also, for checking the angles. I would recommend buying the craftsman torpedo angle finder. Works awesome :rockon:!
 

shb5007

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1.) Do you have any milled covers in stock?

2.) Can you change the cover with the IRS still on the car?

3.) Should any of the bushings be changed while the cover is off? I plan to get the whole kit in the future...but are there any I should do now?
 

ac427cobra

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1.) Do you have any milled covers in stock?

Yes, we currently have 6 milled covers in stock. But............. we are currently out of stock on the FT 1401 Delrin isolated rear diff lowering mounts which are included in the FT 5001 bushing kits. :( They are on order and they are being machined right now. We are hoping to have them the first week in June but it's a little too early to call at this point.

2.) Can you change the cover with the IRS still on the car?

The IRS subframe can stay in the car to change the rear cover and diff mounts but the differential housing needs to come out of the car to do that.

3.) Should any of the bushings be changed while the cover is off? I plan to get the whole kit in the future...but are there any I should do now?

If you're planning on doing the new upgraded Ford Racing diff cover, at the minimum you're going to want to do the front and rear diff mounts. If your car wheel hops, you really have no choice but to do the whole kit. The control arm deflection in OEM rubber or aftermarket poly is the largest contributor to wheel hop. The subframe bushings play a smaller role as do the toe links but both are very important for the maximum stabilization of all of your IRS components.

Here is our informational speech for people contemplating buying the kit and wondering which parts are required for their application:

If you are interested in the IRS bushing kit, the best thing to do would be to go to our web site:

FULL TILT BOOGIE RACING

We have an order page that you can order parts paying via Pay-Pal or with a credit card:

FTBR Order Page

At the minimum you want the FT 5000 bushing kit, $645, which now includes the front subframe mounting bolts FT 1600. If you're doing the job yourself you're also going to want to get the OEM bushing removal tool set FT 2100 for $70. You will receive a $60 refund when you return the removal tools. In the rare case you have a driveline vibe now, you're going to want to consider the FT 5001 bushing kit, $745, which includes the Delrin isolated rear diff lowering mount FT 1401. This will allow you to completely optimize the driveline angles in your car.

If you have upgraded power and like to drag race, you're also going to want to consider a few other things. First would be one of our upgraded toe link and bumpsteer kits, FT 1800 or FT 1860, $159 and $239 respectively. The bumpsteer and upgraded toe link kits are very important for drag racing and road racing. Secondly, you'd want to consider protecting the egg shell thin OEM Diff cover with a rear cover brace at the absolute minimum. Or to do it right, upgrade to the new Ford Racing rear diff cover FT 1350 or the machined Ford Racing rear diff cover FT 1350M (see below for more info). This is essential for drag racing but is also has provisions for a diff cooler if you plan on road racing or serious track day duty. The rear cover significantly raises the durability of the IRS.

NOTE: If you are combining the FT 1401 Delrin isolated rear diff lowering mount (included in the FT 5001 kit) AND the new Ford Racing diff cover you are going to want to opt for the FT 1350M machined Ford Racing cover we offer because lowering the rear of the differential will cause clearance issues with the inner toe link mounts on the subframe.

If you're interested in saving 5% by sending a check, you can download the order form at the bottom of the order page. Fill the form out on your computer and it will automatically calculate prices, discount and freight for you, print it out and mail it in with your payment.

You will also find a link on our site for installation tips and photos:

Installation Photos and Tips

There are many benefits of the Full Tilt Boogie Racing IRS bushing kit. It raises the efficiency level of the IRS, it eliminates wheel hop, you will regain control of the rear end of your car which is important for everyday driving and it's also critical for drag racers, road racers and track day participants. The IRS is half as efficient as the front suspension because it has twice as many control arms. When these control arms are mounted in rubber, they deflect to the path of least resistance and not where you want them positioned for maximum efficiency. Something you don't have now with an OEM rubber or aftermarket poly bushed IRS assembly.

Let us know if you have any further questions, we'll be glad to address them.

Thanks for your interest in Full Tilt Boogie Racing products.

Bruce and Steve
 

Demonio

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so if im completly stock right now with just a diff brace, subframes connectors,h & r springs on 03 convertible cobra what do you recommend to do to complety lose that wheel hop, car is dd right now and ocasionally take it to the track..
 

ac427cobra

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so if im completly stock right now with just a diff brace, subframes connectors,h & r springs on 03 convertible cobra what do you recommend to do to complety lose that wheel hop, car is dd right now and ocasionally take it to the track..

Well, if you have a convertible, all of those things you already have are VERY important. In addition, the bushing kit is absolutely necessary. The only other things you 'may' need to address are your rear shocks and possibly tires depending on what you're running for tires.

Convertibles can sometimes be a challenge in the complete and total elimination of wheel hop due to the floppy platform. You may want/need to look into a Matrix bracing system to tie into your SFC's.

:thumbsup::coolman::beer:
 

ac427cobra

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I just wanted to inform the Cobra IRS owners here that we've developed a new part for the IRS. We now have an eccentric rear camber adjusting bolt for the IRS. We did this for a few reasons. The Ford OEM bolt had a tendency to strip the knurl off of the bolt and the eccentric and the bolt would sometimes separate. In addition, this replacement bolt is no longer available from Ford. So we decided to manufacture them. We also made some improvements to it as well.

Here is a photo of the OEM bolt in the slot of the UCA. Notice how much smaller the eccentric washer is compared to the width of the slot:

eccentric%20bolt%20OEM.JPG


Here is our new replacement part FT 1050. Notice how the larger diameter eccentric cam fills the entire width of the slot:

eccentric%20bolt%20FTBR.JPG


Also notice the TIG welding which will hold these parts together infinitely tighter than the press fit OEM parts.

This photo shows the increased thickness of the eccentric cam washer:

eccentric%20bolt%20comparison%20THICKNESS.JPG


In order to take full advantage of this new increased off-set in the eccentric, it will require making the slot in the UCA a bit longer. Here is how much longer it needs to be:

eccentric%20washer3.jpg


You can use a carbide burr on a drill, a Foredom tool or larger Dremel. If the UCA is off the car and you have access to a milling machine that would be your best choice.

We hope to have a video soon showing the incease in rear camber adjustment available with this new part.

Stay tuned.

:thumbsup::coolman::beer:
 

Carbon Driven

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Ive been wanting it for nearly 3 years now lol.

Since the cobra will be at teh shop next week I figure I could have them do the diff cover and I could install the FTBR kit myself at home
 

nextime

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I been waiting till the weather clears just to pick my car up from FTBR! I pulled the Trigger in November 2012 when I dropped it off!
 

UncleSAm

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Ive been wanting it for nearly 3 years now lol.

Since the cobra will be at teh shop next week I figure I could have them do the diff cover and I could install the FTBR kit myself at home

I might just start buying one piece at a time...stupid clutch going out first

It's going back to the shop?
 
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jpk

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How do I know for certain that a bit of vibration I get is the driveline vibration or possibly just need of alignment/bumpsteer fixes like balljoints and front and rear bumpsteer kits? Just do them all? Or do them in steps and see what corrects the issue?

If its steps, then recommendation for what to do first?
 

eaglesnick

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You can have the simple things like ball joints and bushing, wheel balance checked when you have the car aligned if you go to a reputable shop. If all checks out and the vibration is still there then you need to try and isolate the cause. Some cobras suffer from the notorious "driveline vibe" that vibration is usually at highway speeds at about 65+ mph. If that's the case your looking at installing the FTBR rear diff lowering brace to correct or optimize the driveline angle. If your going to drop the IRS to install the lowering brace then you might as well install the full FTBR kit to minimize/eliminate wheel hop issues. Installing the full kit is like knight and day from a stability standpoint especially when you start to bump up the hp.
 

FiveOhJoe

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I had terrible drive line vibe on my car. Got the wheels balanced and it fixed the really aggressive vibrations but it would still vibrate at high speeds. Then I installed the complete FTBR kit and got my pinion angle PERFECT and now I have absolutely no vibrations. All the way up to 120ish, it's solid as a rock.

A few things you can check:
Check your rear 36mm axle nuts. They come loose and cause vibrations
Get all of your wheels road force balanced. made a big difference on my car
Make sure the driveshaft to pinion flange bolts are torqued. Mine backed out once and it caused some nasty vibes, beat the hell out of my pinion bearing too.

See my thread about my FTBR kit install. I went into more detail on there.
 

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