Ford Shelby GT500 Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
133 Posts
Discussion Starter · #1 ·
I am looking for a video that shows a 2007-2014 Mustang GT500 (2011-2012 preferred) showing what laptimes were with a solid rear axle and then again with an IRS.

Or even drag slips with times, both with a solid axle and without.

Does anyone have something like this? Trying to see how big of a difference it makes, and yes I know you can get other mods (i.e. Watts Link) to make the live axle perform much better, but I'm specifically looking for factory solid axle vs. IRS differences. Want to see if it makes much of, if any, difference on track times with these cars specifically (yes, I know for most cars it does make a big improvement, but not all).

Thanks

John
 

·
Moderator/Admin Dude!
2020 CFTP Red! 2011 Kona Blue
Joined
·
32,658 Posts
I am looking for a video that shows a 2007-2014 Mustang GT500 (2011-2012 preferred) showing what laptimes were with a solid rear axle and then again with an IRS.

Or even drag slips with times, both with a solid axle and without.

Does anyone have something like this? Trying to see how big of a difference it makes, and yes I know you can get other mods to make the live axle perform much better, but I'm specifically looking for factory solid axle vs. IRS differences. Want to see if it makes much of, if any, difference on track times with these cars specifically (yes, I know for most cars it does make a big improvement, but not all).

Thanks

John
I don’t recall ever seeing an S197 Mustang with an IRS swapped rear end. Does an IRS make a big difference...? You bet it does! It makes a big difference on the street and the road course. A solid rear axle would be at home on the drag strip, with zero turns or bumps. I see a night and day difference between driving my solid rear axle Mustangs vs. my IRS cars. I much prefer an IRS setup.
 

·
#1 Mike!
2019 Shelby GT350
Joined
·
8,621 Posts
Same here. I can't recall reading about a IRS swapped into a 2007-2014 GT500. The live rear axle was fine for the drag strips but less responsive and stable on a road course or public road. My 03 Terminator had the IRS and was much better when carving corners on back country roads. All my past GT500's were a handful if you encountered irregularities or bumps in the pavement when negotiating a corner. I would think trying to put an IRS in the past GT500's would be quite costly and difficult, to boot! That said, on a closed road course, with no pavement surprises in corners, the GT500s do pretty well compared with similar IRS cars.
 

·
Registered
Joined
·
63 Posts
Back in 2005, Maximum Motorsports developed a prototype IRS system for the S197 Mustang, but I haven't heard anything further about it and suspect it was deemed too costly for what they believed was a limited market.
 

·
#1 Mike!
2019 Shelby GT350
Joined
·
8,621 Posts
Back in 2005, Maximum Motorsports developed a prototype IRS system for the S197 Mustang, but I haven't heard anything further about it and suspect it was deemed too costly for what they believed was a limited market.
Yes, this is exactly what happened to Shelby American in 1965 when Mr. Shelby was asked by Lee Iacocca to make a race car out of the Mustang! Shelby American also tried a IRS in the Mustang and has some working prototypes. What they found was that the IRS was not worth the financial outlay necessary to make the changeover and, more astoundingly, the live rear axle was almost as stable on the smooth surfaces found in most race tracks! It would have been a handling benefit for the Shelby's sold to the general public whose roads were not nearly as smooth! But the cost would have been prohibitive, so they slapped in the good old 9" Ford Galaxy rear end and the rest is history!
 

·
Premium Member
Joined
·
1,384 Posts
IRS will help you get faster lap times. But, in higher HP cars, beefier IRS components must be used, which add weight.
 
  • Like
Reactions: 03reptile

·
Premium Member
Joined
·
1,384 Posts
I do recall one review said the factory setup on the 13/14 rear axle was about as good as you could get without being an IRS.
 
  • Like
Reactions: 03reptile

·
Registered
Joined
·
63 Posts
Some more info on installing an IRS in the 2005-2014 Mustang. Cortex has done it, but it's a major and expensive project. However, they do seem interested in the potential market for making a kit.
 
1 - 8 of 8 Posts
Top