Jump to content
TEAM SHELBY FORUM

Wheel hop!


aaronlstiles

Recommended Posts

  • Replies 91
  • Created
  • Last Reply

Enough said, it is BAD real BAD, I finally got on it during lunch today and I thought my teeth where going to fall out of my head, are their any more bad things about the car you guys aren't telling anyone? I love the car as a whole, but I think that it has a lot of issues. Brake dust, BAD wheel hop, and a really noisy transmission, at leat when it is in neautral at idle, Let me know what you all think.

 

 

You think this tranny is noisy??

 

I've been driving a 6 speed 7.3 liter F-350 around since I bought it new in 2002.... now that tranny is noisy!

 

I was pleasantly impressed with the trans in my GT500 and after driving my wifes 07 GT/CS, the GT500 tranny shines!! The shifter in my wife's car has a lot of slop in it and the gears are'nt tight like they are in the GT500.

 

It's a lot easier to miss a gear in the GT. but her car does not have the growl of the gear mess at low speeds like my car does.... not to mention that her car does not have any power to speak of!

 

I got used to my car and I have no complaints since I found out (by reading the owners manual) that the sounds are normal for this car.

Link to comment
Share on other sites

Basically, the traction control works like this:

 

It senses wheel spin (obviously), however, because it is a "hot rod" the engineers didn't want the traction control to be too intrusive, so a feature called "hard launch" was built in (or called something like that). What this does is in addition to sensing wheel spin it also measures acceleration, i.e, if the car is spinning the tires, but is continuing to accelerate, it will not step in and ruin the fun. However, if the car is not accelerating, or is decelerating it assumes the intent of the driver is not to be racing and attempts to regain control of the car. This is why you can still spin the tires even with the TCS on, although it may still step in when not invited - that's why you can turn it off.

 

On the other subject, the reason you get wheel hop is because the GT500 is built to allow the 2/3 of buyers who will never race it a quiet comfortable ride. The softer bushings in the stock upper control arm make for less transmitted noise, but allow the 3rd member to rotate slightly under hard acceleration - the dynamics are complicated (I can't fully explain what happens), but this is where wheel hop ultimately comes from even if the pinion angle is good. Good aftermarket upper control arms (usually adjustable, I have a Steeda unit) have harder bushings that virtually eliminate flex and hold the 3rd member steady. The only downside is a bit more noise from the back end, although most of us wouldn't care I think.

post-5356-1163568877_thumb.jpg

post-5356-1163568877_thumb.jpg

Link to comment
Share on other sites

Sorry Dave -

 

I'm a bit edgy about this issue.

 

I could have had a Shelby - but...some family issues changed that.

 

We're cool. :shift:

 

No problem...I promise I won't call you roller boy if you promise not to call me goat boy. :hysterical:

 

Oh wait, that's not you. :ohsnap:

 

I'm dizzier than a blonde playing tetherball after drinking a bottle of Nyquil.

 

Dave

 

The softer bushings in the stock upper control arm make for less transmitted noise, but allow the 3rd member to rotate slightly under hard acceleration - the dynamics are complicated (I can't fully explain what happens), but this is where wheel hop ultimately comes from even if the pinion angle is good.

 

Good explanation rat, thanks.

 

You have a 3rd member? Last I checked, I only had one....and it did not rotate slightly. :hyper:

 

Dave

Link to comment
Share on other sites

Rat: Thanx for the tech. info.

 

It really did help.

 

I now understand.

 

I appreciate that.

 

Rob Out - Nite

 

Oh I see.....Dave responds to your "HELP" PM with a quick response, and he gets nada, zilch, or in Spanish.....cero.

 

rat gets the big pat on the back.

 

I see where I fit in.

 

I'm gonna go sit in the corner and cry. :cry:

 

I hope they invent a surprise glove box trunk monkey and test it in your car. :hysterical:

 

Dave

Link to comment
Share on other sites

Dave: I have a question about the TCS. Do all the Mustangs have it. I noticed that my wifes GT/CS has it but I have never messed with it. In fact I went out in the garage the other night to look and see if it had it. Don't laugh. Tell me, if it is "on" does it act like limited slip ?

 

 

TCS 101

 

Rob, this link will help you understand TCS. It gives a reference to "Applying brake pressure" but in our case, the computer senses the wheel spin and decreases the voltage sent from the TPS (Throttle Positioning Sensor) located on the Gas Pedal to the TB(Throttle Body). If you mat the gas pedal with the TCS on, you'll feel the tires break loose, then you'll hear the engine decelerate, the tires stop spinning and the engine will accelerate again and repeat the process until the tires keep their traction.

Link to comment
Share on other sites

 

As far as how it works, I'm not sure, but there's no way it's limited slip only. I would think it has wheel accelerometers that measure tirespin, then reduce engine power to modulate the slippage.

 

Where is Jet when you need him?

 

 

 

Jet is having a hard time finding technical threads in the midst of the land of a thousand posts.

 

Good data here, but have any of you considered the fact that changing the throttle response with a less than fully though out tune can have an affect on the ability of the TCS to act as its code is written?

 

 

PS. Rat that looks like another nice Steeda part. Is that tab/washer on the pumpkin end designed to be bent over as some sort of locking device for the bolt? And is that pinion snubber shorter than the stock one for a lowered car? Thanks.

Link to comment
Share on other sites

Jet is having a hard time finding technical threads in the midst of the land of a thousand posts.

 

Good data here, but have any of you considered the fact that changing the throttle response with a less than fully though out tune can have an affect on the ability of the TCS to act as its code is written?

 

 

 

I don't think it matters. The TCS system will intercede as necessary to achieve the desired results which is to stop wheel spin (when not activating "hard launch"). In other words, it's an active results oriented feature; closed loop - the system takes an action, then evaluates the effectiveness of that action to decide the next action - all hundreds of times per second.

Link to comment
Share on other sites

With the colder air temperatures here in the Mid West the car makes more Horsepower & with the roads & tires being cold it's hard to get them to stick with the recommended tire psi. All I get is wheel hop no matter what I have tried, but it's only been 362 miles now. Now second gear is another story...it pulls like a rocket heading to the moon.... Alice

 

How about some input from the warmer southern crowd

 

 

CW,

I'm in the south. First hole shot since I got her (1200 miles) on smooth surface, TCS on, 3000 RPM dump and punch. Very little tire spin great launch with a little spin hitting second. TCS controlled tire spin and engine RPM well. Second hole shot same conditions as first with TCS off. Smooth tire spin rear-end kick out slightly, RPM jumped to redline quickly; throttled back to control, good smooth tire spin hitting second until she started to hook up and she leaped forward like a good colt spurred into motion. I have no complaints about these experiences. I've done a couple of 15 MPH stomps and experienced some wheel hop with TCS off. It appeared to me that as she begins to hook up she bolts forward.

 

I'm not into using the car up on hole shots. My drag racing days are history. It just cost too much money. I like the rolling stomps at 30-60 MPH at about three grand and running her through the gears.

 

The whine of that blower is intoxicating.

 

Drive fast and safe . . . :shift:

Link to comment
Share on other sites

I'm hoping to do pulley,CAI,3.73 gears and have a tune that will allow me to leave the traction control on when Im on the street and pulloff some low 12's maybe high 11's on stock rubber. Possible huh?

 

 

the issue is going to be with the stock tires; dgussin over on svt performance is running pretty much that setup, and did some experimenting recently. Almost a full second slower in the quarter mile with stock tires versus tires meant for drag racing. 12.7 vs 11.6-11.9. He did have some problems with his pulley and had to put the stock one back on, but that clearly points out the relative traction weakness of the stock tires.

 

John

Link to comment
Share on other sites

the issue is going to be with the stock tires; dgussin over on svt performance is running pretty much that setup, and did some experimenting recently. Almost a full second slower in the quarter mile with stock tires versus tires meant for drag racing. 12.7 vs 11.6-11.9. He did have some problems with his pulley and had to put the stock one back on, but that clearly points out the relative traction weakness of the stock tires.

 

John

 

 

 

I think when he gets his pulley situation fixed his car will be low low 11's maybe 10's on drag radials.

I'm just hoping I can sacrafice a little performance with traction control on and keep some traction on stock tires and maybe be in the high 11's around town. I think its doable. Is doable a word?

Link to comment
Share on other sites

Is that tab/washer on the pumpkin end designed to be bent over as some sort of locking device for the bolt?

 

 

Jet, most of the nuts on the body and suspension car have that tab. It allows for one tool assembly, since the tab will rotate and stop on some part of the car. It's not any kind of safety/locking device.

Link to comment
Share on other sites

Jet, most of the nuts on the body and suspension car have that tab. It allows for one tool assembly, since the tab will rotate and stop on some part of the car. It's not any kind of safety/locking device.

 

TAHOE GT,

 

I was told that those bolts were "one-n-done" bolts also. That they have to be replaced each time. Do you know if that is the case? :sos:

Link to comment
Share on other sites

Perhaps a stupid question, but would lowering the rear tire pressure some (5-10psi) help with wheel hop?

 

 

 

I can't help but feel you're all avoiding my question. (Maybe it was stupid :cry: )

 

The questions comes from observing top fuel drag cars which have low tire pressures. I don't usually see them bounce up and down in one place when they get on it. Just curious if lower tire pressure on the GT500 would help it hook up better...

Link to comment
Share on other sites

I can't help but feel you're all avoiding my question. (Maybe it was stupid :cry: )

 

The questions comes from observing top fuel drag cars which have low tire pressures. I don't usually see them bounce up and down in one place when they get on it. Just curious if lower tire pressure on the GT500 would help it hook up better...

 

I don't have the knowledge to answer intelligently...I draw pretty pictures for a living. :baby: But I would guess that the stiffness of the tire sidewall has a lot to do with lower pressures helping on launch. The OEM tire has pretty stiff sidewalls. I was hoping more knowledgable members would chime in?

Link to comment
Share on other sites

Lower tire pressure will help it hook up but still might get wheel hop since wheel hop is caused by the rear trying to rotate upwards untill the leaf springs spring back kinda like slapping up and down (axle wrap) causing the tires to hop. Traction bars would help this. If you were going to do a lot of drag racing you could change the shocks.Put like 90/10's in the front to help transfer weight but they would not be very good on the street

Link to comment
Share on other sites

I didn't answer because I don't know. I just know that everyone is TALKING about wheel hop, but no one has done anything about it that I can see. Many have suggested a new upper control arm that's adjustable...but I don't know of anyone who's actually tried this.

 

BMR (and others) make such a device.

 

Dave

Link to comment
Share on other sites

I didn't answer because I don't know. I just know that everyone is TALKING about wheel hop, but no one has done anything about it that I can see. Many have suggested a new upper control arm that's adjustable...but I don't know of anyone who's actually tried this.

 

BMR (and others) make such a device.

 

Dave

Dave, Since you don't smoke, it should be no issue. :hysterical:

Link to comment
Share on other sites

I didn't answer because I don't know. I just know that everyone is TALKING about wheel hop, but no one has done anything about it that I can see. Many have suggested a new upper control arm that's adjustable...but I don't know of anyone who's actually tried this.

 

BMR (and others) make such a device.

 

Dave

 

 

 

hey Dave

 

I think dgussin1 has put one in, and suggests that it has fixed the issue. Plus, that's supposedly how they are marketed for the 05-07 mustang. That's certainly where I will start if mine ever shows up.

 

John

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...
...