Straight line stability

Has anyone had experience with installing the tie rod ends from underneath in order to eliminate "bump steer" and improve the straight line stability? According to "Performance Handbook" by Keith Seume, copyrighted 1997, relocating the tie rod ends on a lowered front end changes the angle of the tie rod ends back to their initial angle and "greatly improves the straight-line stability of your lowered VW" The auther suggests the purchase and installing of a bump steer kit to accomplish the conversion. Your comments will be appreciated.

How about installing caster shims? Inexpensive, quick and easy install, and are said to greatly improve highway speed "weaving," etc.

Rich, I'm in the process of optimizing the front end of my car too. I did the camber shimms (2), then had it realigned. That made a big difference. My car is quite low in the front, so I an going to install shorter shocks to get more travel. I also plan on ball joints that have more movement, and a bump steer kit too. I already have a 19mm sway bar, so we'll see.

I forgot, I also have a set of camber bushings to install so I can get a little more neg. camber.

There are a few different issues here.
Bump steer is caused by going over a bump with one or both wheels, body roll and braking. The wheel moves up relative to the car, since the tie rod is fixed at the steering box it moves in an arc and pulls the wheels in. The tie rod is attached at the back of the upright so it causes the wheels to toe out which causes the car to dart around. The best position for the tie rod is around horizontal because there you get the most vertical movement with the least motion relative to the center of the car. The bump steer kit allows you to lower the outboard end tie rod relative to the upright. It is possible to rotate the steering box up as well. If your car doesn

Thank you all. The information that you supplied is most informative and obviously based on experience. I will definitely go with the caster shims. Any advice on where to get them?

Richard Saccocio

Bruce, your post was right on target. I havn't heard of raising the steering box, how is this done? Have you done this on your car?

Richaard, any of the parts mentioned can be purchased from any number of companies. I'd look in Hot VW magazine.

Yes I have moved my steering box but it is not for the faint of hart. When I put dropped spindles on my car I ran into some tire clearance problems (only on one side though). Dropped spindles are 3/8

Bruce: Obviously you have gone to the limit to improve the front suspension. Do you feel that lowering the front end by use of torsion bar adjusters along with the caster shims in not sufficient. i.e. that dropped spindles are also required or necessary for good handling?

Richard

Richard: These cars have a reputation for a harsh ride and average handling. Some of it is deserved but most is due to bad set up. It is very easy to lower the front and most people do. The problem is that there is only 4

My new IM Speedster is being built with non-assisted VW rack and pinion steering and stock VW spindles (the new "wide-five" wheel pattern disk brakes from So Cal don't require dropped spindles). I was very pleased with the rack and pinion steering on my IM "D" - very stable feel and great feedback.

Some/all of the torsion leafs in the top tube will be removed form the ball joint front axle assembly and a 19mm front anti-sway bar will be used.

Using 22 or 23 psi front tire pressures and Bilstein shocks the front suspension should have reasonable travel and road surface compliance under most conditions.

(Message Edited 3/17/2003 3:59:05 PM)

Bruce- Wait a minute.My car came from Vintage with the welded in adjusters already in place and one caster shim behind each of the lower adjusters. I have no knowledge how far the front was lowered. But for discussion purposes let's say it was lowered one inch. Does that mean that I have only one inch of wheel upward travel before the limit of the ball joints are reached? Also, how can I determine how much upper travel is actually available. Per your suggestion, I will jack up thr front end and determine the wheel downward travel. If this measures two inches, do I have two inches of upper travel? And, If I measure three inches, does this mean that I have one inch of upper travel?

Richard

Richard: The only way to tell how much travel you have is to measure it. You are correct however; since there is only 4

Bruce
Since I've just recently put my car on the road, I'm trying to sort out the items that I percive to be problems. The first thing I noticed is that the car wanders all over the road, hence my original question. I had an original 356 coupe that I bought new in 63 and I know that it did not have the steering effect I am now experiencing. I also know that the front suspension was very similar to the VW set up. I therefore expected good handling with the Speedster kit. Another problem I encountered was too much play in the steering wheel. I tried adjusting it without success. I bought and installed a new TRW box. That eliminated the slop in the steering wheel. The handling is still bad. I've scheduled a front end alignment in the next two days. Maby, that will help some. I will keep you posted
Richard Saccocio

Bruce
What a difference. I just returned from Street and Sand Toys where I had the front end aligned. Would you believe that the toe in on one wheel out of spec by two full inches. The other was not quite as bad -about one inch. The mechanic showed me the same. I could'nt believe it. This is the way it came from Vintage. Can you now understand why I was concerned about staright line stability? I had it up to about 70, it did'nt seem to wander much, but I was on a busy interstate so it was not a good test. More later.
Richard

Good to see such great info. I will be ordering a bump steer kit from John @Aircooled.net early tomorrow. I\These posts answered why my car seems to dart around when I'm hard on the brakes! Can't wait!

Bruce, you also said something about camber adjusters. Where can I get these?

And lastly, who is the maker of the long travel ball joints as I'd like to get a set but not the ones you have as they don't have enough travel for the effort expended. I called around today and it looks like Bugpack carries these. I'm just hoping I would luck out and find some that really do give long travel to the suspension.

I took you advice and quickly checked out the sus. drop on my Vintage, looks like 3" however the nose of the car could be a little higher than now as the car has a bit of a slope to it. I think your right about the cars are capable to handle OK it's just getting them set up right.

J-P

Whenever the car is raised or lowered using the adjusters on the torsion tubes, an alignment is needed.

Richard seems to have discovered the extent of one builder's quality control, and he is not the first buyer to have done so...

Richard: What did they set the front toe to? You may also consider getting the rear aligned, if the front wasn

The Bugpack (and EMPI) front camper adjusters are now standard equipment on all new Intermeccanicas.

Richard installed a new steering box. I would expect that much error in alignment is more likely caused by changing boxes as opposed to manufacturing errors. I guess the manufacturing quality issue is with the quality of steering box not the alignment.

I just measured the travel on my front suspension, it's close to 6 inches. This is lock to lock and I measured at the spindle without the shock bolted on. Also, this is with standard ball joints, not the longer travel ones. If you're measuring only 4 inches, the shocks must be limiting travel.

Ron, good call!!! Sounds like your doing some homework here too. That's really good news to here. So if I replaced the front shocks with lowered untis that may give me a little more room for the suspension to travel. Has anyone tried the shocks for lowered front ends? Do these shocks make the front end too stiff or are they simply shortened bodied shocks?

Thanks, J-P

I see that I opened a subject where many of us have or had problems. I agree that the info being developed is most informative.
Regarding the insatllation of a new steering box. Why would that affect the toe in or camber? One end couples with the rubber u joint,the other end mates with the steering links. No change was made to the camber adjuster nor the tie rod ends. Moreover, the directional stability of the car was terrible both before and after installation of the new box with the steering wheel offset by some 30-45 degrees from the vertical (before and after). The new box tightened the play in the steering wheel to a reasonable amount. A very slight turn of the steering wheel made the tires squeal-both before and after the new box. The squealling disappeared after the alignment.

The mechanic that did the alignment adjusted the chamber to neutral on the left side and about 1/2 degree positive on the right side. He claimed that his vast experience dictated this unique setup so that the car does not wander to the right because of the slope of the roads. I woul have preferred about one degree negative on both sides , but he was not to be argued with. I will see how this setup works when I doo some extensive driving. Right now I seem to have an overheating problem. Yes I made absolutely certain that the engine is well sealed and the tins have no significant gaps or unsealed holes. I even put two openings in the fire wall to allow the 44 Webers to get enough air. I have not yet hooked up the cyl head temp gauge so I inserted a thremometer into the dip stick hole. The temp read 120 C. I am installing an Empie 10 inch fan and 16 pass cooler this weekendand switching to a synthetic oil. Any suggestions on the oil?More about that later.
Richard Saccocio

Bruce
I don't know what the toe in was set to. I believe that he measured the back distance and set the front, as he stated, about 1/8 to 1/4 inches less at the front of each wheel. Actually, he indicated the amount with his hand by showing a space between his thumb and first finger.

What's this about camber adjusters? The VW manual shows the presence of adjusters. So why install new ones?

Richard, read the "Knowledge" article on cooling; there are many things that can cause overheating and several fairly easy ways to improve cooling. I would double check your ignition timing, carburetor jetting, and fan belt tension first. If jetting appears to be correct check for vacuum leak(s).

Then check for air leaks into the engine compartment from under the car (sucking back in, or recycling spent hot cooling air). An exhaust system that's too small can be restrictive enough to cause overheating.

Oil temp of 120 C (248 F) is much too high for comfort with "petroleum" oils and also too high for synthetics; I would guess your cylinder head temperatures are very marginal. These temp definitely indicate a problem (or problems) you should correct ASAP.

My 165 to 170 BHP ex-2,110cc type 1 engine will run at 210 F on a hot summer day cruising at 70 mph (3,250 RPM) running 20/50 AMSOIL synthetic. This is with full-flow filter, 30mm oil pump, 1.5 quart bolt on sump, modified doghouse shroud with type 4 oil cooler, and a Porsche 356/912 alternator belt pulley. No auxilliary oil cooler is fitted. Fall and winter are cool/cold enough to swap back to the larger VW alternator belt pulley.

(Message Edited 4/2/2003 12:04:24 PM)

Ron: When I measured my vertical front suspension travel I had the shocks, springs and sway bars removed. I could easily move the suspension arm through its full range of travel by hand. My long travel ball joints were brand new though, perhaps they loosen up with time.

George
How do I access the "knowledge" article on cooling?

Richard