Torque steer

[Ol'fogasaurus]

How do you get torque steer out of a modifid (in this case short wheel base) VW. In this case when you accelerate hard then let off the throttle the front of the car feels like it jumps to the left (swing w/K&L)

I have had cars before that did the same thing but wanted to pull/steer to the right. This is more of an interesting question than a personal problem.

Lee

[buildabiggerboxer]

Lee, I had a similar thing one time, it turned out to be mismatched rear tyre diameters, the car had a ZF limited slip, it was actually hard to notice it was pulling slightly right, and then diving left on the up shift or dropping the throttle suddenly, with matched tyres it was fine.

[Bruce2]

I'd say there's no such thing as torque steer in our cars.
My buddy's big hp street car goes perfectly straight when the front wheels are off the ground. Any diversion left or right is due to traction variations.

[Ol'fogasaurus]

I'd say there's no such thing as torque steer in our cars.
My buddy's big hp street car goes perfectly straight when the front wheels are off the ground. Any diversion left or right is due to traction variations.

When lifting the front wheels towards the sky (Look ma... I can fly ) I would lean towards your description of traction inconsistancies and maybe throw in tire pressure (diameter) variations but in this case at least 3 and probably all 4 tires were on the ground at 90 MPH.

[Piledriver]

My square pulled hard right on braking until recently.
Was a worn front upper trailing arm bushing, nothing at all wrong with the brakes.

Not tq steer, but demonstration that worn parts can cause this effect as well.

when everything is in good shape/set up right these vehicles are not subject of torque steer even with stupid power.

[Ol'fogasaurus]

Most of my experiece with short wheel base buggies has been with BJ and IRS so swing and K&L are still a potential mystery to me.

A "stupid thanks" to you Pile.

Lee

[Piledriver]

The high power drag cars frequently run swing axle by choice due to it arguably taking the launch hit better than CV joints.

Swing axles have their limitations, but i you keep the travel limited they work pretty well.

[Ol'fogasaurus]

I thnk this is heading in a direction that was not intended. The term "torque steer" that I used, something that was common with front wheel drive many years ago, was the best discription for what I felt at the time knowing that it was not that but was something that was clearly descriptive and recognizable. I am now sorry I used it. I was not driving so I could not get the feel of what was coming up the steering shaft but was a passenger. and that was the most descriptive feeling of what I felt the car do.

The car is a daily driver that shows a lot of power with the addition of injection and a turbo and was fun to ride in. I was being shown how it performed but the feeling I got during shifts and the feeling when coming off full power to slow down made me uncomfortable not only as a passenger but for the owner in general.

What I thought at the time and still think (maybe) was that the left (driver's side) front wheel was getting light due to torque then when the power dropped the weight dropped back on the front left suspension this is what I felt. The front end had been discussed during the ride but before the power test; I think your idea of maybe something worn would be a good warning to look at things from underneath.

Tie-rod end... maybe but I don't think so and the same with a loose pittman arm or settering box. Wheel bearings the same as the car;s steering seemed to be too tight for anything like that. Since my time with king-pins was a long time ago and was with Ford beam axles I was wondering if the feeling between the old Ford king-pins and K&L king-pins were the same when they were worn (if you have ever driven an old Ford with worn king-pins, it is something you don't forgetl that and how you get rid of the shaking that is).

[raygreenwood]

I thnk this is heading in a direction that was not intended. The term "torque steer" that I used, something that was common with front wheel drive many years ago, was the best discription for what I felt at the time knowing that it was not that but was something that was clearly descriptive and recognizable. I am now sorry I used it. I was not driving so I could not get the feel of what was coming up the steering shaft but was a passenger. and that was the most descriptive feeling of what I felt the car do.

The car is a daily driver that shows a lot of power with the addition of injection and a turbo and was fun to ride in. I was being shown how it performed but the feeling I got during shifts and the feeling when coming off full power to slow down made me uncomfortable not only as a passenger but for the owner in general.

What I thought at the time and still think (maybe) was that the left (driver's side) front wheel was getting light due to torque then when the power dropped the weight dropped back on the front left suspension this is what I felt. The front end had been discussed during the ride but before the power test; I think your idea of maybe something worn would be a good warning to look at things from underneath.

Tie-rod end... maybe but I don't think so and the same with a loose pittman arm or settering box. Wheel bearings the same as the car;s steering seemed to be too tight for anything like that. Since my time with king-pins was a long time ago and was with Ford beam axles I was wondering if the feeling between the old Ford king-pins and K&L king-pins were the same when they were worn (if you have ever driven an old Ford with worn king-pins, it is something you don't forgetl that and how you get rid of the shaking that is).

Hmmmmm....was this a beetle?....and was it raked forward (lower in front)?

This actually sounds not like torque steer as noted....but more like inertial shift similar to what the early 911's experienced. Though the bug in general does not have this problem....as you rake the front end forward, depending on how the rear suspension was prepped or modified, you can increase the propensity for the rear to want to lift quicker as power is quickly pulled off or during braking. If you are on any type of uneven pavement or have just a little steering in other than straight ahead....this can make the rear move a little laterally in one direction or the other. Along with the forward pitch feeling of the inertia shift....it feels alot like torque steer.

My 412 does this when you are high in the rpm band at peak torque and hp and you drop down a gear into overrun.....it is almost felt to "float" in the rear while at the same time you can feel the forward inertial shift as power is not totally dropped off.....but brought down to a level that is just maintaining rpm instead of being hard on the the throttle. Just some thoughts. Ray

[Ol'fogasaurus]

Its Clonebug's Safari bodied dune buggy. It really is a neat little short wheel base glass bodied buggy that Art had woofed it up to go like stink.

I was just curiou (and a bit concerned) about the way the front acted when the power changed (I hope he isn't reading this string ); is the first glass bodied buggy I have ridden in that does that but then most of them have normally asperated big bore engine too. My buggy rides quite a bit different than his but then it is BJ/IRS and it's use is off-road; sand only.

Since I come from American cars that have been rodded so I am fimilar with cars with enough torque to the to lift one of the front wheels so that the suspension on that wheel was fully extended. I was wondering if Art's buggy was doing the same thing (in the old days they used to have up-lift shocks which were lose on the extension but tight on the compression allowing the front end to rise quickly then stay up transfering more weight on the rear wheels. I don't think they are doing that anymore but it was fun while it lasted).

Lee

[Marc]

Rear toe change (due to movement of the outer end of the torsion bar) is a likely suspect for this condition, especially if you're running the soft stock rubber bushings. Unless you eliminate the bushing setup and use Heim joints, it's inevitable that the rear wheels will toe out on decel. In this case, if the RH side is sloppier and toeing out more than the left that's gonna drive the front end to the left.

Observe a front-engine sprint car coming out of the corner - with a "stock" configuration, the reaction to the clockwise twisting of the crankshaft pushes the chassis down on the RH side and the LF wheel comes off the ground; the right side tires end up doing all the work. It's an old trick to build the motor to run backwards (where not disallowed by the rules) so the left side plants on acceleration instead - but there's always a trade-off, while that can let the car come out harder it can also make it a handful on entry.

On our rear-engine cars, the torque reaction of the chassis to the engine tends to plant the left side slightly harder on acceleration; on decel that force is reversed so the right side suspension compresses a bit more than the left. That can cause the RR to toe out more too, if the geometry causes toe-out on compression. A "Band-Aid" fix might be to run stiffer bushings on the right side only to compensate. And, if the front steering geometry causes the RF to toe in on compression (and/or the LF to toe out on droop) this may well be a simple "bump-steer" issue that could be cured by relocating steering components.

And then there's shock absorber action to consider...but assuming you don't want to mess up the ride/handling under most other conditions, it's probably not a good idea to go too far with asymmetrical valving. But DO make sure that you don't have a weak shock somewhere - wouldn't it be nice if it was that simple?

[Piledriver]

They still make 90/10 shocks for drag racing

[Ol'fogasaurus]

They still make 90/10 shocks for drag racing

That shows you about how long it has been since I was on the track; say about '92 or '93. About the same time I got my buggy.

[Ol'fogasaurus]

Thanks Marc, that was a good explanation and what I think I wanted to hear.

We had talked shocks a bit but I think he said that they were fairly new but then I have had bad shocks out of the box too. Nothing is better than a good 4-way alignment especially by someone who really knows what they are doing.

Anyway, I am butting into someone elses business but we since have two rails with K& L/Swing setups so it could be considered germain to what we are doing also.

Lee

[Ol'fogasaurus]

Sorry about the bad grammar and spelling in places guys. I'm trying to learn how to use a tablet combined with a bluetooth keyboard and the screen keyboard popping up all the time is driving me crazy. No spell check (which I dearly need) and the curser keeps jumping all over the place and deleting anything from words to whole sentences to the whole post. I think I am hurrying now to beat the problems I know are going to happen. I haven't got cut and paste down yet so I haven't been able to work with w
Word yet which does have spell check.

Marc: the more times I read what you wrote the more reasonable your problem solving sounds. Your description of pulling to the right (remember I was not driving) isn't quite what I felt as passenger as it tracks very straight with the power on but the pull to the left when the power drops off momentarily while power shifting, that is pretty close to what I felt... again as passenger.

My wife is a tenacious backseat driver and this gives me a better appreciation of what she feels at times. The different feel of what is going on the passenger gets is more understanable (I usually drive due to a sensitivity to motion sickness) but while it doesn't justify it, it now is more understanable.

Since the strength of swing axles was brought up earlier (I'm not knocking them guys) there was a comment made on one of the "build shows" about CVs vs. U-joints that I thought was interesting. He was changing out the front drive axle U-joints for CVs and his reasoning (simplified) was that the CV had 6 contact points (the balls) where a U-joint had 4 contact spots. I thought it was an interesting comment. My posting of it here is not to start a debate but to give some information that I had picked up.

Lee