Jetta GLI suspension questions

[nuskool]

SO, I was a newbie to Auto-x last season. Did pretty well I think for my first season.

I have a 2003 Jetta GLI. The car tends to understeer to much. I know that probably has a lot to do with my driving too. I have proplems with the tires rolling over a bit even w/ 50 psi.

I have some bilstein sport struts on the way (used,12k miles on 'em) I also found some H&R sport springs (1 1/2" drop) for a very good price and they are also now on the way (only 6k on those) I still have to find some shocks though. But I have a few months to get them. I'm cheap and if I can find some w/ low miles for the right price I'll go that way. Otherwise I'll order some new ones.

My question is mostly about the springs. Should I even bother. If I do, it bumps me into another class. Would I be better off to just put in a rear sway bar? That way I stay in stock class.

I'm also considering bracing up the sub frame. There have been some very positive reports from doing this on the VW forum. If I'm correct, this should help a lot with the cars understeer.

As for the springs, they sell pretty fast on the VW forum. So it would be no great loss if I don't use them.

[slowgls]

i would go with a sway bar first.I believe that spring would put you in a high class.

[Washburn]

My question is mostly about the springs. Should I even bother. If I do, it bumps me into another class. Would I be better off to just put in a rear sway bar? That way I stay in stock class.

I'm also considering bracing up the sub frame. There have been some very positive reports from doing this on the VW forum. If I'm correct, this should help a lot with the cars understeer.
.

Rear sway bar will take you out of stock. Front bar is free. You would be better off putting a larger front bar on anyway...assuming your staying Stock. Things start to change once you go for springs. Sub frame beefy also a no-no in stock.

[nuskool]

Rear sway bar will take you out of stock. Front bar is free. You would be better off putting a larger front bar on anyway...assuming your staying Stock. Things start to change once you go for springs. Sub frame beefy also a no-no in stock.

I'll have to check, but I thought it was the rear I could do, not the front.

I don't completely understand all this, but someone who does told me that if I suffer from understeer then a front sway bar is NOT the way to go. Personally I would think the opposite.

OK, well, keep the comments coming!

[nuskool]

Just checked, you're right, I can change the front, not the back.

So you think changing the front bar might help?

[Hille]

Changing your suspension most of the time will just mess up the cars handling. Unless you spend a lot of time for development and $$$$$$$$$$ to spend.

As far as beefing up your chassis: It will take you out of stock class and I really don't see how that will dramatically reduce understeer.

It's a GLI and the boys from Germany know what they are doing.

I'd suggest getting a good set of tires. R-compounds or else there are some really good choices on the cheap of tires that are almost R-compounds.

Spend your money on track time and tires. A driving school is an excellent way to spend your $$$$$$$$ also.

[Dizmm]

understeer can be overcome with driving style.

[Hille]

understeer can be overcome with driving style.

Agreed.

[StarscreamS13]

Better tires, more aggressive alignment, and seat time will do you wonders in stock class.

Stock class allows very lil, but alot for a "stock class"
-Shocks
-Front Sway Bar
-Brake pads
-Tires: anything that can fit on stock sized wheels
-Wheels: as long as they're the same size as stock w/ an offset +/-.25"
-Cage (bolt-in)
-Radiator (stock style replacement)
-Any alignment you choice as long as it's done w/ OEM hardware
-Drop-in air filter (K&N, etc)
-Catback exhaust (not always the best for power, but sometimes can cut alot of weight out of a car)
-Battery (in stock location, but can be replaced)

There's probably more, can't think of any though. Basically stuff that over time NEEDS replacing and can be upgraded.

You have a car w/ say ~120k on it, probably needs new brake pads, shocks, tires, battery, exhaust, air filter, etc, etc. Still don't know why the front sway bar is in there, but whatever. Cage is more of a safety thing in the eyes of the rulebook writers, but has the added benefit of chassis stiffening.

Typical things that people do that bump them out of stock class
-Open element intake: cold air intake, ram air, bolt-on cone filter, etc
-Aftermarket cat: high-flow, test pipe, etc
-Aftermarket header
-Springs
-Bigger wheels

The basic bolt-ons by most tuners are illegal in stock class.

As for the front sway bar, that highly depends on you driving style and what tires you choose.

[Hille]

Most of the VW's I've aligned only allow for a front toe adjustment. Not much you can do there.

[nuskool]

On the alignment, I know there is no camber adjustment. So you're right, not much I can do there. I'm working on the driving style. Already planning the catback which as I understand gains about 10 hp on this car. So I'll look into the sway bar.
Tires I'm running are z rated summer tires. I'll replace with something better when they wear out.

I guess it's important to note that my plan is to keep this car for about 2 more seasons. (1 if I'm lucky) and then get an e-36 M3. That's the car I'll really get serious about.

I may look into lighter wheels. is the bolt pattern the same for VW and BMW? If it is then I would choose something that I could keep for the bimmer.

[StarscreamS13]

Jetta = 5x100
E36 M3 = 5x120

So no go there. Well if you're already planning on getting the M3, just get some tires or rims/tires and drive the car. No reason to put money into it if you plan on getting rid of it. Especially since a stock car sells alot better then a modified car. Unless you already have the shocks coming or need them, I wouldn't even bother w/ them either, same goes for the exhaust, unless you need them, don't bother.

I won everytime in D-Stock class, w/ a bone stock WRX Wagon plus an alignment and tires (Hankook R-S2). With the right tires a stock car will handle just fine.

[nuskool]

Shocks are on the way, and I would really enjoy a nicer exhaust note with a little more power. I don't mind spending a little money on this. But for the most part I'll save it for the M3. I'll probably be replacing some bushings too.

[nuskool]

I'm a little unclear on the rules for replacing my bushings to remain in stock class. I see that I can use whatever I want for the sway bar.

But what about other bushings? I plan to replace LCA and subframe bushings and possibly motor and tranny mount too.

Can I use Audi TT/VW R32 bushings? They are still factory, but not for that car. But they will stiffin things up a bit. If I do this and it takes me out of stock then I will just stick with stock replacement.

[Hille]

I don't think that you can. We better consult Hutch on this one.

[the-moss]

I'm pretty sure in stock class you can only replace suspension bushing with the stock ones or with those with the same dimensions and hardness.

[the-moss]

I just looked it up in the 2008 rulebook.

13.8C - Suspension bushings, including but not limited to those which
carry the weight of the vehicle and determine ride height, may
not be replaced with bushings of a different material or dimension.

13.8D - Replacement control arms for vehicles having integral bushing/
arm assemblies must be standard factory parts as per Sections 12.4 and 13.0.

[nuskool]

Well, stock it is then. Hey, I'm tryin'! The dimensions are the same but they are harder/ or made a little differently

Can't wait for that M3

[caprio]

Well, here's my suggestion...tires, tires, tires....and oh, did I mention TIRES!
Unless your car is high miles, and in need of over-due maintainence, tires will give you the greatest improvement in reduced time per dollar. Like Hille said, stay stock. Get an extra set of OEM or same sized after-market rims, and mount dedicated "R" compound DOT tires, and switch at the event, or mount a set of "nearly race" tires from the "Street Touring" tire list, leave 'em on, and plan on usin' them up by the end of the season...about the time you should be considering some dedicated snows for ice racing season...

Jim C.

[the-moss]

^ What Jim said.

On the 'stuff' side of things if you plan on taking this seriously once you get your M3 then there is a lot of money to be spent on equipment that will sit in the grid while you are out on course.

Get yourself the extra set of rims with some r-compounds or similar. Then you will need to get a jack, a portable toolbox, a socket set to change wheels at the event, a torque wrench, a portable air tank, a decent tire gauge are all what I would call necessary if you plan on taking this sport seriously. The nice part is it's pretty much all useful stuff to have at home.

I would highly recommend a battery powered impact gun, it will save you loads of time changing your wheels.

Then when you get your M3 you're gonna have everything you need, and all your autocross budget can go to the car.

On the 'non-stuff' side of things what Tom said about spending your $ on seat time and training will ultimately be the biggest pay-off. Milwaukee SCCA runs an autocross school once per year. It was about $100 when I did it but probably improved my driving more than an entire season of trying to figure it out by myself. Plus that's truly the only mod that can be transferred from car to car, no matter what you're driving.

[nuskool]

I already have all the tools I need. That's not an issue. I got some Bilstein struts and bushings are cheap.

Tires, well, what I have are not r compounds, but they sure seem to hold the road pretty dang good. The thing is the cost of rims & tires. If they would swap to the m3, I would be more apt to do that. I'll keep my eye out for something good used.

Ice racing, I'll save that for the M. Not that I wouldn't enjoy it now. I'll get some blizzaks for that.

The driving school for that cost sounds well worth it. I also hooked up with Mitch Bessette. I know him from years ago. He's a NASA instructor. He ran around the track a bit with me and I'm sure he'll be doing more this year. His son runs a silver Prelude.

[nuskool]

What about wheel spacers? I can use 1/4" and stay in stock. How much of a difference do they make? (Cheap on ebay too!)

[the-moss]

Yes, you can do that.

[nuskool]

I know I can. How much of a difference does it make?

[Hille]

I'd stay away from wheel spacers unless there is a good reason to run them.

Will they help make the car handle better? Probably a little bit, but not worth the hassle.

[marky967]

if you do spacers you may have to do longer wheel bots too... witch cost more money..all to make your car a 1/2" wider.

GLI's came perfect from the factory...they came with the sport tuned suspension, bigger sway bars and a bit wider wheels i believe too. Once you start changing things up you mess with the ride quality of it and usually goes down in resale value..and limits who might buy it..

[Hille]

Good point Marky967.

Plus if you modify it you will lose the cars excellent handling qualities.

[Washburn]

I'll throw in another suggestion for the FSB. Especially if you go with R compounds. To answer your question, conventional wisdom says that a stiffer sway bar equals less grip. So, if you have oversteer, stiffen up the front bar, right? There's a real big "if* with this though.....if your car is already set up and optimized for competition and is balanced, these setup guidelines are true. In Stock class, all bets are off because you cannot run the correct springs rates/valving for this kind of stuff.

Think of it this way, on a camber challenged car like the VW, you lose grip *mostly* because of excessive camber gain. Rolling 'er over on to the outer shoulders. Other reasons too, but this is by far the biggest thing. A large front bar will reduce body roll, and therefore camber gain, resulting in better contact patch/better grip. R comps actually can make the problem worse due to the additional grip/body roll from super sticky tires. They will be faster than non-R comps, but you will be giving up even more compared to if you had a big bar. You will ADD front end grip on a soft stock car with a big front bar. This has been proven many times. So, if your still interested in doing some setup tweaking, I would recommend this as a biggy on your car.

Oh yeah, like Hille says, don't bother with spacers unless you have a good reason...there's way more things to do first.

[nuskool]

Thanks Washburn, that was well stated and makes sense.

On that note, This weekend, Probably starting sometime Friday as I'll be off work, I'm going to install my new Bilsteins and LCA bushings, sway bushings and rear axle bushings. I should probably look into doing the engine mounts too. But I'll look into that after the first WIR event. I'll see how it feels then.

So if anybody wants something to do for a few hours and help me, I would love the company. (I don't need the help, I know what I'm doing, just nice to have someone to talk with while I'm working)

[nuskool]

Well I got my new struts/shocks and new bushings in the LCA's. I didn't manage to change out the bushings on the rear axle yet. I got tired and worn out. Plus I was having trouble getting it apart. So another day for that.

Course it's only my butt talking, but it sure feels tighter, firmer, more responsive. (what red blooded American male doesn't like that?) Actually my 12 year old son said the same thing (well almost, he said it feels firmer) I'm anxious to see how it is on the track now.