Carl Fausett

A MUST FOR LOWERED CARS: Lowering your 928 sure does look good, and the lowered center of gravity always helps high-speed cornering. But lowering your car also adds angularity to the tie rods ends and takes your steering geometry out of its optimum, intended range. Toe-in on droop and toe-out on bumps is magnified, and the car becomes darty during cornering. The more the car is lowered, the worse this becomes.

Our Bump steer kit will put your steering geometry back into the center of its range, and accurate toe settings and road/track feedback is restored.

QUALITY COMPONENTS: Made from the best of everything for your 928. Pintles are machined from hardened steel billet, fasteners are DIN980V alloy with yellow chromate plating. Spherical rod ends are made for us by Aurora Bearing, and the selection of spacers we provide are also yellow-chromate plated for lasting good looks and corrosion resistance.

EASY INSTALLATION: Bolt-in installation, no modifications to the car are required. Complete instructions provided.

MjRocket

Very nice! And the price is?

Lizard928

$364.........
http://www.928motorsports.com/parts/bump_steer_kit.php

Then you compare bump steer kits for other cars....
http://www.summitracing.com/search/p...and-components

MjRocket

Wow!

Bart-Jan

I doubt whether you actually remove bumpsteer. From a mechanical point of view, actually you are INTRODUCING bump steer by doing this. All wheel support elements should have the same angle compared to level. If the length of all elements is equal, then lowering a car will move the wheel inwards more when it hits a bump. If you deliberately introduce differences in angles, this will also change the toe-in/-out during movement due to the bump. I think Porsche did a very good job when designing our cars. Why change that design?!?

I know this comment could start a big discussion, so let's bring it on!

Mike Simard

You are correct.

This seems to be a common misperception that tie rods and control arms must be level.

They infact must NOT be level in a well designed unequal length system like the 928.

This should only be a misperception to those who have no mechanical leanings at all though, I can't believe we see this from people who are selling suspension parts, and this isn't the only case.

The idea of spacing out a single shear tie rod end is horrible, it's among the most basic things to not do when designing suspensions.

If the theory is so flawed as to brings us to this point, it's conceivable that the fabrication methods are as well with such fatal mistakes as cut threads on a single shear suspension part that's already itself a fatal mistake.

69gaugeman

I wouldn't go so far as to say cut threads will be fatal. In this application they are so much stronger than the forces applied that it likely will not be an issue, BUT the fact remains that this will do nothing for you except lighten your wallet....a lot.

xschop

If the stud dia. is not 5/8" I wouldn't touch it. The steel on steel heims wear out REAL quick too. I would want a chromoly teflon-lined heim as well.

Cosmo Kramer

Let me get this straight, replace a tie rod end that is factory greased and has a dust boot with a steel on steel bolt/eye with no lubrication on the ball and increase the leverage applied to the stud.

I hope you have general liability insurance on your company. One of these break and causes a multi-car pileup and the lawyers will be all over you!

Adamant1971

That just looks scary to me, the physical forces on that are definitely going to cause extra torsional stress on the mounting point of that extension.

Many great products Carl, but not all can be winners.

Just sayin.

Speedtoys

I dont need a Bump Steer kit..but what Carl's selling here isnt much different than racing kit for the same purpose, on hugely more powerful cars, on racing slicks, much larger tires, and with longer adjustment "bolts" for lack of the right term in my head.

They're not as weak as you think they are...and yes, a heim joint is *shocking* going to need more maintenance than a just-short-of-forever sealed joint.

The collars (spacers) move the load from the end of the shaft to the hub steering arm..the complete sheer load is not fully borne by the full length of the shaft.

Ive been towing race cars off tracks or as late, over-seeing safety response in road racing for 15yrs. Have never seen a bump steer kit break without something much larger breaking it for you. (Wall, another car, etc).


The geometry in action..I cant debate, I dont know 928s that well.

The price...ehhh...it is what it is, sure, they're like $120 for your Mustang..but there is _some_ savings in selling 10000 instead of 50 I suppose, but...again, not my thing.

But I bet he races with it..and I bet it works for him..so..there ya go I guess.

Rob Edwards

Found this on my new racer, should I be concerned?

Speedtoys

They're dirty?

But other than dirt causing wear over time, which requires race kit to be inspected and maintained, nope.

FredR

If one reads the Porsche spec you will see they quote a range of ride heights- with stiffer suspension I set mine to minimum. I have not experienced bump steer but I am probably not low enough to warrant it becuase I am just in the allowable window. The 928 steering geometry design is brilliant but it is not infinitely adjustable.

Carl has posted a pic of a lowered car with the track rod ends pointing upwards-is anyone daft enough to think that is a good thing to have? if so where do you think the thing will be when cornering hard. The tie rods should be parallel- preferably when in the operating [loaded position]- would anyoen disagreee with that?

I have seen pics of 928's on track cornering hard with the front wheels pointing in radically different directions- now I might guess they may need a bump steer kit.

if one wants a Mustang bump steer kit then buy one and the POS it fits on- I can guarantee it won't fit a 928! Similarly I did not see Carl claim it was going to improve longevity [did i miss something?] or even suggest it be fitted to a street car.

Heim joints will not last anywhere near what a stock unit does but then how many hours does a track car drive in snow and slush?

Does a lowered 928 track car need bump steer compensation?- well let the chaps who have lowered suspension, fitted sticky tires and actually track their cars comment on that.

Bump steer happens- it is not an imaginery concept. I do not know at what lowering point or boundary conditions it is required but I would be interested to know if anyone can enlighten us of that parameter.

I dare say if Carl does manage to sell any he will be lucky if he hits double figures. 10 kits at US$350 = $3500. If he spent 30 hours of his time developing the kit at $100/hr he would just about recover his design effort [maybe].

Oh- ...then price the parts he has to buy!.

Schizophrenics of the world unite!

Rant over-

Best wishes

Fred

Speedtoys

"if one wants a Mustang bump steer kit then buy one and the POS it fits on- I can guarantee it won't fit a 928!"
---

I didnt say it would.

But the material/kit differences are very very...very..minor. Negligible.