terrible wheel hop 2007 GT500

You can eliminate the rear wheel hop with aftermarket rear control arms. All three should be replaced as the rubber in them is too soft. I put metco control arms on my supercharged 06 Mustang GT and they completly eliminated all wheel hop. Because the bushing are much harder they do transmit some road noise into the cabin but, I feel the trade off is worth it. Also you should get the adjustable upper because the pinion angle in Shelby's is slightly different than regular Mustangs.

 

Wheel Hop

Gentlemen: We finally got enough rain to get most of the salt and sand of the road. Therefore, I have put a few kilometers on my GT 500 this weekend. I have read a bit about the wheel hop in 1st gear. The pavement is obviously still pretty cold in my area and the wheel hop is real. I do not know if it is made worse by the cold pavement. Is Ford going to address this issue? If not which after market product seems to work best to correct this. I know a lot of you guy's have had your car for a few months, put some miles on and must have found a solution.

thanx

doug

 

Get ahold of the guys at Evolution performance, and ask what they did to their car. Obviously their GT500, now into the 9's in the 1/4, has no wheel hop.

In the 02/07 Hot Rod article that features their GT500, in mentions that in addition to an 8 pt S&W Race Cars 8 pt. rollcage, Steeda subframe connectors, and modified BMR K-member, their car apparently has: Santhuff drag struts with 3" lowering coilover springs in front and Steeda Competition springs and QA1 double adjustable drag shocks on the rear. The positions of both the rear lower and upper control arms were also modified using BMR equipment and are adjustable.

This is probably farther than you want to modify or more than you want to do with a daily driver or if you have a collector vision of your car in the future, but it gives you some idea, depending on where you want to go, or rather where you want to end up, with your Shelby. Of course then you have to dial in any of these pieces that are adjustable.

http://www.evoperform.com/


Look on their site and click on Shelby GT500 power packs, then go down near the bottom right under GT500 Ultimate Suspension, and click on it. I'm sure there are many other vendors, but this is one that has dialed in their 2007 GT500 as good as anyone, and is now offering parts.

Good luck

Doc

 

if I had just laid out 55K + for one these new "Shelby's" I'd be wondering why this problem wasn't fixed by the Ford engineering dept before they left the factory.

Z. Ray
'66 GT-350

 

Unfortunately wheel-hop is not pecular to 2007 GT500's. The 04-05-06 GTO's, even my 06 Cobalt SS S/C with Stage II + front wheel drive all suffer from the same malady. I suppose it has to do with the higher H/P as much as anything, although the road surface, and tires also have a lot to do with wheel-hop issues. Could be that the manufacturers feel that traction control is the answer, even though my Cobalt does not have T/C. My Oldsmobile muscle cars which are putting out a lot of power, have never had a wheel- hop problem, nor did my old SS396 Impalas and Chevelles. So maybe it is the newer suspension designs as well. I still think these extremely low profile tires we use on our cars now contribute to wheel-hop. There is just no cushion with the new tires as with drag slicks or even the old higher aspect tires of the 60's and 70's. The tires on my 1969 H/O though on 15" rims (big for the time) dwarf the tires on the Shelby GT500 18" rims. I'm talking about how much tire there is from the outer rim to the outside of the tire tread. These new tires are rock hard compared to the old tires, and I suspect that is directly reflected/transferred into the suspension, which contributes somehow to wheel-hop. JMHO. I'm sure some tire engineer might tell me I'm full of crap. I'd be curious to know how the V-6 Mustangs with aftermarket S/C, or the 4.6L 300 H/P Mustangs do with regard to wheel hop, although I'm sure their suspensions also differ significantly from the GT GT500's underpinnings. I wonder if the Shelby Mustang GT's that are being modified by Shelby have any wheel-hop problems? I understand they tweak the location of the Shelby Mustang GT's suspension components. Again, I am anything but a Mustang or Shelby authority/expert, as my GT500 is my first Mustang. Just throwing out some possibilities. Ford engineers may also figure if the GT500 owner is going to drive their GT500 in a manner that induces wheel-hop, (I'm sure not recommended or condoned by the factory) any GT500 owner that can afford to purchase a $60,000 car, can spring for another $500/$1000 necessary to purchase the proper aftermarket parts to negate any wheel-hop that results from that type of non-recommended driving. Could also be that the GT500 suspension is more tuned/intended for road racing rather than for WOT off the line acceleration as in drag racing. As far as I know, Shelby only made 8 Cobra's with the DragonSnake package destined for drag strip duty, which pretty much cleaned up on the competition back in the mid-Sixties. I do not know if any Shelby Mustangs were made specifically for dragstrip use. The suspension tuning requirements for these two disciplines of racing differ greatly.

The most obvious reason, other than the difficulty of making one suspension which works well for all uses, is of course $$$. I'm sure that with the cost of the Shelby's being as high as it is, Ford tried to keep the cost down wherever possible on the GT500, (and weight as well-witness no spare tire) and another $500/$1000 or whatever tweaks necessary to reduce wheel-hop would have increased the MSRP proportionally. Again, JMHO.

Might not hurt to see how the Shelby Mustang GT suspension is modified, providing wheel-hop is not an issue with those cars. Of course there is also a world of difference between trying to smoothly put 500 H/P on the ground and 325 H/P, or whatever the Shelby Mustang GT puts out.

Doc

 

The wheel hop is from the soft rubber used in the upper control arm. This is a compromise as it has to be soft for ride quality and maximum articulation. This is good for a handling, bad for straight line acceleration. Remember 2 bushing are doing the job that 4 used to do on the fox body Mustang. The factor upper control arm is designed for maximum noise repression and best ride characteristics, not for full throttle launches. Ford figures true performance oriented owners will change the control arms and others will enjoy the quiet, smooth ride. If you plan on drag racing aftermarket control arms are a necessity. If not changing the upper bushing may be the answer. I am putting down 440 rwhp on my 06 Mustang GT which about the same as the Shelby. I have no wheel hop at all with the metco aluminum arms on my car.

http://www.bmrfabrication.com/2005MustangSUSPENSION.htm
This is off the BMR website.
3 link suspensions place excessive loads on the upper link bushings. In the '05, two bushings are responsible for handling the same torque load that 4 bushings had done before. Additionally, these bushings are subjected to more "twist" than before since the rear end can better articulate as a 3 link design. In order to allow free articulation, the OE rearend bushing is designed to flex. This flex is great for handling but under straight line acceleration, it contributes to wheelhop and inconsistant launch characteristics.

Energy Suspension offers a no-compronise solution with it's dual durometer 5 piece polyurethane replacement bushing. By designing the bushing as a multi-piece unit, it allowed them to keep the inside portion stiff for great straightline acceleration load and the outside portions soft for bind-free handling. NOTE: requires use of existing bushing shell

EN-1 Energy Suspension Dual-durometer rearend bushing $34.95

 

Nice write up

However, I would like to offer that there is no such thing as a no-compromise solution when it come to altering the factory developed suspension from the use for which it is intended. Whether it is more noise, vibration, handling quirks, whatever, there is always a price for tweaking what the factory developed. Sometimes it is for the worse, sometimes it is for the better, but it is never ever the same once changed with aftermarket parts made of different composition/materials. Whenever you trade off hard ployurethane for the softer composion rubber used by the factroy, there is going to be an increase in engine vibration and noise transmitted directly into the interior of the car. If you are using the car for drag racing, 1/8 to 1/4 mile at a time, with loud exhaust or headers, probably doesn't make a lot of difference. If you plan on Sunday drives with your wife/girlfriend/significant other, whatever, the additional noise and vibration may not be as welcome.

How well the alterations made work varies as well. I installed an Ingalls Stiffy torque damper on my Cobalt SS S/C. Many Cobalt owners who had installed it sang it's praises, as the solution for unwanted WOT wheel-hop. So I installed one, tried all the settings, and guess what? Yep, I still have wheel hop. Helps a little I suppose, but still hops. Then there are those Cobalt owners that say the factory engine mount is substandard, needs to be replaced with a polyurethane engine mount. So Some Cobalt owners installed it, and guess what. Yep, still have some wheel-hop. Still other Cobalt owners installed the polyurethane control arm bushings. Still some wheel-hop. Polyurethane transmission mounts have been tried by other Cobalt owners. Some success, but still some wheel-hop. I guess if maybe a person used all of the above modifications, it might cure the wheel-hop, but the Cobalt SS S/C, which is an outstanding handling car from the factory, would ride like a cement truck, having had it's suspension (the Cobalt's) all but locked up. All I am trying to say is to beware. One change frequently leads to other changes, and before you know it you may have a screwed up mess, a car that handles like crap, and end up taking all the after market parts you bought off and trying to sell them at 1/2 to 1/3 their value, if you are lucky.

Doc

 

Thank you gentlemen for your feed back I will follow up on your suggestions. I do not have enough miles on this puppy yet to know exactly what I am going to do. Certainly with the TC on the hop is reduced significantly. I am also going to see what the warmer weather does. We use 100% compressed nitrogen at work and I will switch the rear tires. I will be surprised if it has any effect but that is an inexpensive test.

thanx

doug