Just like the title says, it is legal to drop a Cobra IRS into my 96 Cobra?
The potential problem with an IRS into a 94-98 is the rear IRS brackets. The rear frame does not have the blind nuts for the vertical bolts that the 99+ rear frame does. For a 94-98 car, one has to figure something out i.e. welding the bracket on or using extra long hardware and drill through the trunk floor. These problems exist for <94 cars but that swap would be 100% illegal in SP.
It is interesting. It seems that lots of people have done the swaps, but no one that is really 'competitive' has done any real testing. Not that I'm a pro, but I hope to get out there and doing some good testing with my friend's traqmate and then look for a good deal on a 01+ IRS. Once I get it, I can get the bushings and install it and hopefully have another round of testing with the traqmate.It will be interesting to see how the swap works out, on the clock. Solo surfaces tend to be smooth, but the transient is pretty severe...hmmm, does the lower unsprung benefit outweigh (no pun) the increased total?? In any case, it will be nice to be able to put an alignment in the rear, without resorting to tweaking axle tubes...which I (personally) think is illegal, even though it appears to be done pretty often.
Don't misunderstand my reply. I think it should fall into the update/backdate rule but if you change the text underlined in the rules you get a different outcome.We can swap an IRS from any Cobra (99-04) because the street prepared rules couple all SN95s together:
Mustang (SN95 chassis, NOC
including Cobra & Cobra R)
15.1 AUTHORIZED MODIFICATIONS
C. Equipment and/or speciﬁcations may be exchanged between different years and models of a vehicle if (a) the item is standard on the
year/model from which it was taken, and (b) the years/ models are
listed on the same line of Appendix A (Street Prepared Classes). The
updated/backdated part or the part to which it is to be attached may
not be altered, modiﬁed, machined or otherwise changed to facilitate the updating/backdating allowance. Standard factory installation
methods, locations, and conﬁgurations are allowed. The updating
and/or backdating of engines, transmissions, transaxles, and/or unibodies must be done as a unit; component parts of these units may
not be interchanged. Cars not listed in the Street Prepared sections
of Appendix A may not be updated/backdated until approved by the
SEB and published in the ofﬁcial SCCA publication.
Note the underlined statement, Doug said that this means that you may attach the IRS in the exact same manner as a 99 – 04 would have gotten from the factory, meaning bolt in, NOT WELDED. From what I remember, you have to drill a hole or something like that...
So, this is cool news. Yes, the IRS is somewhere in the neighborhood of 85 lbs. heavier (in the right place I might add) but a LOT less UNsprung weight. With the right bushings, bumpsteer set and some tuning, it would seem the IRS could be really fast.
Good point, but aren't the nuts you weld basically so you can install it in the same manner as a 99+ Cobra would? This should fall under minor cutting, welding, drilling, etc based on my conversation with Doug at the SCCA.Don't misunderstand my reply. I think it should fall into the update/backdate rule but if you change the text underlined in the rules you get a different outcome.
Don't you have to weld in the caged nuts to install it in a pre99 car?
It's just one of many times the rule book will contradict itself.Good point, but aren't the nuts you weld basically so you can install it in the same manner as a 99+ Cobra would? This should fall under minor cutting, welding, drilling, etc based on my conversation with Doug at the SCCA.