so i was talking to the guys at shine racing today about the setups they use on the vw chassis. i got some interesting information about how they do things and was wondering why they do what they do and we do what we do. (as far as which end has the stiff springs)

the typical vw setup for a 2300lb car (with a 64% front weight dist., about the same as a civic chassis) that they use is 650fr/450rr, no front swaybar and a 1" rear bar.

the typical honda (in this case civic) setup for the same car is something like 550fr/900rr with a 23mm rear bar.

the wheel rates for the honda setup work out to 245fr/495rr. the vw sees the actual spring rate at the wheels. so with nearly the same weight, the honda setup has less then half the front spring rate with nearly the same rear spring rate.

i wanted to toss this out and see what you guys think the reasoning behind the differences in wheel rate and roll stiffness distribution is. i have my own thoughts but i've proven myself to be wrong a majority of the time so the validity or lack-thereof makes my thoughts mute. these are both typical track setups. all replies are welcome.

nate

edit: trying for clarity. don't know if it worked though...


[Modified by solo-x, 10:01 PM 2/28/2003]

 

Nate: After debating what spring rates to go with for countless days I have one last suggestion:

Try both setups and use which one you like better.

I thought of this last night when I was play some pool with a friend. He liked to measure the angles and try to calculate where to hit the ball where as I just "visualized" where I wanted the ball to go. End result, we both sunk the same number of shots over the evening.

I feel that cars are the same way. Stop stressing about the numbers and just try it. Use what works for you.

 

while that is all well and good, as well as the game plan for this year. i'm not looking for justification or approval for an unorthodox setup. i've always been a "why does it work that way" kind of person. i'm not just satisfied that it works, i really want to know why. i think it is interesting that two different chassis types that have similar setup problems approach it in a different way. i don't know why they do things differently though, and that's what i'm curious about.

nate

 

curiosity killed the cat??

 

well, not yet at least.

nate

 

I can understand wanting to know the "why" but it just seems to me that there is an endless amount of debate of front stiff vs. rear stiff on this board and that at some point every question on the subject has been answered. If you really want to know why those VWs are running front stiff I thik you need to get more data like, alignment, ride height, center of gravity, tire/wheel sizes. I'm sure if you had a more complete list of specifications then the answer would show itself easier.

 

Nate,

Somewhere recently there was a shot of what looked like the first turn at the ARRC. It looked like ITB - there were Volvos and VW's.

What was interesting was that the Volvo's were just barely lifting the inside front, and the VW's were just barely lifting the inside rear. The VW's were all running BSI markings.

You'd have to do a full numeric study of the VW's to figure out why they work like they do with the rates. Most Honda front roll centers wind up at or below ground, on the VW Mac struts they might be higher. At the rear the story on the Honda's is about the same, on the VW's it might be higher too. Alot of VW's run multiple rear sway bars too.

Take away all the peculiarities of the specific suspension layout, and think about the picture I mentioned - it tells the whole story pretty well.

Scott, who talked to all the VW guys about all this a couple of years ago when Jason Saini's posts on the VW Vortex caught his attention....

 

but i don't see the reason, that's why i asked. i would assume that you would run a rear stiff setup on vw for the same reasons we run a rear stiff setup on a honda, but they don't. i'm not debating which is better, just trying to figure out why they do it differently.

from what i know of vw's, rear toe and camber are fixed. the stock beam seems to have a large amount of rear toe in and somewhere in the neighborhood of -1.5* camber. for the front suspension they typically run about -3* camber, stock caster +5* i think, and 1/8" toe out. i would imagine the cg is higher then on a civic at IT legal ride heights, but i have no idea by how much nor how it would affect anything other then increasing the total amount of weight transferred. i think the track is very similar in width and the wheelbase is pretty close as well compared to my coupe.

nate

 

i saw that same pic and noticed that as well, though i don't know who bsi is or how they setup cars. they are definitely getting all the weight off the inside rear, but how? is it through the swaybars?? it would be nice to know the tortional stiffness of that rear beam with a single 1" bar or even multiple bars. therein may lie the "secret".

nate

 

Remind me again... when was the last time a VW won a SoloII national championship

 

In 2000, 1st and 2nd in FSP...

2001 and 2002, 2nd in FSP...

 

Ok, now name the Honda products that won a natl champ. last year.


My point is, the suspension on the VW just isn't a good setup and comparing rates from a VW to a Honda is like apples and oranges. Sure, you can make a vw work, but in no instance (IMO) could you call it superior to the Honda double wishbone. Heck, even the strut Civics seem to work better.

Just wait until more folks start to jump on the 92-95 Civic Dx bandwagon in FSP...

 

[QUOTE]
so i was talking to the guys at shine racing today about the setups they use on the vw chassis. i got some interesting information about how they do things and was wondering why they do what they do and we do what we do.
[QUOTE]

I think you might query some other VW prep folks before considering Shine Racing's suspension set-up as typical for VWs. I think you'd find things much more conservative at the average and Shine at the edge of the envelope, especially on the front rates. I've met and talked with him and will not go into it much farther than that. He has a very strong opinion about set-up and nothing is likely to change it and he sets his customers up that way.

At the KONI office, I am the token Honda guy is a pool of VW guys and one in particular has done a ridiculous amount of development, measurement, insvestigations regarding a lot of things. If you are interested in setting up a VW suspension, Jay at KONI R&D is one to talk to. He has talked with Mr. Shine as well and could give some insight to their set-up. Be ready for either a very long or very short discussion on that topic.

If I was going to build a VW IT car, I'd talk with the BSI folk. They have a pretty good handle on a lot of things. For the record, BSI are regular KONI users and Shine is a die-hard Bilstein man but that is not the reason for my comments and opinions.

The ultimate answer is that a driver should driver the car set-up that he likes best, suits his style and gives him confidence to push the envelope. If you can learn to drive fast and hold on to a Shine prepped car and it works for you, go for it. I'd be cautious about copying the set-up though.

 

Shine's setup is rather unusual when compared to other VW tuners' ideas. Most of the other companies out there will tell you to get a huge rear swaybar (like Neuspeed'd 28mm adjustable), use the stock front swaybar regardless of the springs you choose. If you go GroundControl then run higher rates in the rear. Shine's ways are often viewed as a bit "out there," but that doesn't mean they are without merit. Those that get their suspensions done by Shine tend to have lots of good things to say about the results. *shrug*

-Adam (who has the huge rear bar, stock front bar, and Konis!)


[Modified by mityVR6, 10:34 PM 2/28/2003]

 

more and more i'm getting the impression that shine is not of the "typical" vw tuner type. i take that the _true_ typical vw setup is rear stiff?? at which point this discussion becomes mute.

nate

 

You're pretty much right. Shine is respected, but not a commonly-chosen setup.
-Adam

 

Normally the rear is stiffer but not at the rate thayt we see on many Hondas. Remember also that most of those VWs are a beam style rear suspension that is linked side to side and not truly independent side to side like the Honda is. '84-87 CRX/Civics with the beam rear axle tend do run less rear rate than to the independent suspended later cars too.

 

check this thread and sroll down to about the 3rd post. really good info!

actually, go here for tons of good stuff on vw suspensions.

david

 

The write up in Grassroots about following a novice through the year, from picking the car, to his accomplishments, had some info about BSI's set-up. I don't know if it's typical, of BSI or VWs, but it had some numbers. Then, if memory serves, Koni doubles, 425f, no bar, 450r some bar. Article pictures always showed the rear lifted.

 

I wasn't familiar with VW rear suspensions, and I looked under a Golf at PIR this weekend, and it's obviously clear why there is some confusion: the rear twist axle with cross tube contributes significant roll stiffnes.

Looking over all those VW threads, and in particular the unusual Shine bar that stiffens the cross tube makes it all that more clear.

I don't know how many of you looked over those threads, and I don't mean to beat a dead horse, but I want to point out that this is a prime example of why it's helpful to start at the beginning on comparisons.

Scott, who says "twist axles?.....Ack!"....

 

All the aftermarket swaybars for rear-beam VWs do the same thing: they stiffen the rear beam against twisting. Shine's just happens to fit inside the beam while Neuspeed's (among others) is mounted on the outside. Shine really believes the internal mounting is better (doesn't bind like others supposedly do) but others say it's just a PITA to install and not worth the trouble when a Neuspeed bar takes 20 minutes to install.
-Adam

 

i've driven my roommates a3 with a shine setup. his car has 300#fr/200#rr with the shine rear bar and bilstein hd's. i screwed around with it on the street, and just my impressions of the way the car felt was enough that when he offered to let me drive it at an autocross, i refused. the best i can explain it was that the car would enter a pendulum effect in hard transitions. i originally attributed it to the shocks, but after reading those vw threads i've begun to change my mind.

nate-who was looking at protege spension today. ssc trunk kit-385/600 w/custom valved bilstein's. for a little over $2k. i want a protege.....