03 Cobra 12 mm IRS bolts vs 14 mm bolts, no difference.

[jordanvraptor]

Well after writing a scathing letter to my dealer customer relations manager, they talked to me about the wheel hop issue and the 14 mm vs 12 mm IRS bolt issue. I gave them part numbers for the 14 mm bolts and explained to them about the 14 mm holes in the frame and even showed them the pics of a worn set of 12 mm bolts that were posted here a while back. They agreed to examine the stock 12 mm bolts for wear to see if this may be a contributor to the wheel hop.

They removed the stock 12 mm bolts and they found no wear indications. I have the bolts and can see no indications of major movement within the frame holes. They replaced the bolts with the 14mm bolts, part # W704939-S426, and the nuts, part # N801670-S100. The 14 mm bolts fit right into my Maximum Motorsports IRS bushings. I still have hop so these are not the cure all, but I did not expect them to be.

I don't know how much further I'm going to go to try to reduce the hop. I'm considering rear coilovers and thats about it. Just thought I would give a heads up that the 12 mm bolts may not be as big an issue as rumored.

The total cost to me: $18.64 for the Ford bolts and nuts, labor and car rental covered under warranty......

 

[Lsredy2kstang]

We had a guy in our club that was launching at 5500 rpm with ET Streets with no wheel hop on his 01 Cobra. He put in the 03 halfshafts, upgraded to adjustable QA1 fronts and rears, line lock and best he put up N/A was 12.84 IIRC.

It can be done! He did it and I saw it with my own eyes.

I think that better shocks/struts, halfshafts, tires you can get rid of it!

 

[mikey99cobra]

did you notice how big the stock bushing was? On my 99 cobra you could not fit a 14mm bolt into the stock bushing. the front stock bushing was the same size as the rear stock bushing. Only after i put the MM irs bushings in could i put the 14mm bolt up front.

 

[iskybantilus]

I am going to be putting the crossmember with steeda poly bushings into my 01 cobra. Does the kit come with these nuts and bolts, or will i have to go buy them. from the sounds of things, i'll need two 14 mm nuts and bolts. If i need to buy them, what length, so i can aquire them ahead of time?

 

[iskybantilus]

oops, sorry bout the double post

 

[99CobraJMS]

Question, I just bought two 14MM Bolts and Nuts (parts number listed above). I am replacing my IRS Diff bushings with KennyBRown Alum ones, plus adding MM Coil-Over all next week. I figured since I was having this done I would check out my IRS Front Bolts to see if they are 12s or 14s. I have decided to now add IRS Bushings to go with this 14MM bolt because if I have 12MM the bushing will be too small plus I was to get the rubber POS out of there.

So, WHo has the best IRS Bushings that I need. I figured many are using STEEDA products, but I can not seem to find a part number other than a bunch of Stage 1-3 IRS KITS...Any know? I guess I should replace all 4 IRS subframe bushings, including the ones near the wheel (I guess I will grind that bolt head down while I am there since I just found some 315 GS-D3 tires too)...OK, that rear IRS bolt is 12MM correct, and that is OK??? so I don;t need to replace that one with 14s?????

JOhn

jOHN

 

[99CobraJMS]

FYI, Here is a pic of these (2 of them) $18.00 bolts/Nuts. They are 10.9 grade, I assume that is what the 10.9 on the head means...

John