View Full Version : Wheel hop?

E-Ticket Ride
10-29-2006, 01:55 PM
This is my first question post. I just recently purchased an 04 Terminator convertible from Texas. This is my first IRS car (and my 4th mustang -'66, '85, & '00 vert). Everything appears to be bone stock. When I get on it, even from a mild rolling start, I get what feels like a really bad wheel hop from the right rear. Is this a bad IRS alignement, bad shock, or something else? Car seems to track pretty well in the corners, and the tires seem reasonable (fair tread, no apparent unbalance at speed, etc). Car has a bit over 16 k miles on it, and was a lease turn back. Any thoughts on how best to proceed would be appreciated.
I intend to "fix" the exhaust soon, and a dyno tune is in the wings, but I want to get this first issue sorted out before I start to play. :D
So far it has been a gas to drive!:thumbsup:


BTW - Any good ideas on a dyno tune place near Huntington Beach in So Cal?

10-29-2006, 05:57 PM
is your traction control on or off? with it on they tend to hop more. But wheel hop is a downside of these cars unless you do the work to the IRS. Urethane subframe bushings, differential bushings and brace.

10-29-2006, 08:22 PM
Like Mike said, the IRS can be the downfall of these cars...here's a few tips to get rid of the hop:

Diff brace (for protection/reinforcement)
full length subframe connectors
sticky tires (ie: BFG drag radials or M/T drag radials)

10-30-2006, 06:34 AM
It seems like many have the wheel hop problem. The only time I ever had wheel hop was when spinning the tires in the rain. Other than that it never became an issue. Everything on my car is still stock other than the cat-back. My 01 hopped easily but my 04 does not. :scratch: Even at the track I do not have the issue. I have already spun the tires past the 60ft mark and no hop. It would probably be different if I got into the water box but with street tires that would not help matters.

10-30-2006, 01:52 PM
The problem is the IRS itself. It is an "after thought" of the mustang. Your car was designed to have a stick axle but Ford came up with a goofy cradle that attaches to the stick axle torque boxes and bolted the IRS to the cradle. The result is garbage suspension geometry which is the reason you are getting wheel hop. At stock power levels (430rwhp or less) a fresh set of nitto 315/35/17's will get rid of the hop without any other mods to the IRS. On street tires you'll never get rid of the hop 100% unless you put a stick axle in there.

Level 5 halfshafts
Maximum Motorsports IRS bushings
Full length subrame connectors
Billetflow IRS brace
Horsepower by Hermann anti-hop rear shocks
Aftermarket rear springs
Sticky tires

That will work well for 99% of the IRS users out there but it's not cheap really. The halfshafts alone will cost ya $1250 (on sale right now) plus everything else.

If you run it at the track, you'll have good results with sticky tires (et streets) and minimal suspension mods on the IRS.

10-30-2006, 02:47 PM
My vote is for the IRS to Solid mod :D NO wheel hop and lost around 125lbs :thumbsup:

E-Ticket Ride
11-03-2006, 04:27 PM
Thanks guys!

I thought it was probably a symptom of the IRS, but I didn't have a feel for how sensitive the car was, or if it was an issue of the setup/alignement of the IRS, etc. Evey time so far that I have had the hop the TC was still on, and I wasn't trying to do a burn out, just getting on it hard. The tires on it now are Goodyear F1's. So far I love the feel of the IRS compared to my '00 in the corners/twisties. it feels much more stable. I will be updating the tires soon, and will look into the bushings as part of that. Since it is a convertible, I was also considering a shock tower brace for the front.
The car will mainly be a daily driver with some punch to it, and the occasional canyon run. It is a "tide me over car" unitl I have time to build a Factory Five Roadster (427 Cobra replica).

11-06-2006, 07:31 PM
I dont have any issues with stock irs once i went with bfg kd tires and bfg drag radials for getting on it...