performance sway bars for SVX soon

mbtoloczko · #1 01-28-2003, 03:30 PM

In about 1 month, larger diameter sway bars for the front and rear will be available. The larger diameter bars are in the design stage, and the first prototypes will be complete in 3 weeks or less. Here are some details:

*Front Sway Bar (stock is 18 mm diameter)*
It will of course be a two-piece bar with a design similar to the original bar. The original sway bar-to-suspension links will be utilized. Urethane bushings will replace the rubber bushings. Washers welded to the bar at the point where the bushings hold the bar will be used to keep the bar from sliding side-to-side. The bar diameter will be 22.2 mm (7/8"). For the same length of bar along the twisting axis, this ups the stiffness by 2.3x. The bar will be about 2 inches longer than stock along the twisting axis; this will lower the stiffness by about 6%. There will be two holes on each side for connecting the bar the links. One will be at the stock lever-arm distance and another will be at about 1 inch greater distance. The longer leverage arm will drop the stiffness by another 10%. So, at the softest setting the new bar will be about 1.95x stiffer than the original bar. At the stiffest setting, the new bar will be 2.15x stiffer than stock.

*Rear Sway Bar (stock is 17 mm diameter)*
The original sway bar-to-suspension links will be utilized. Urethane bushings will replace the rubber bushings. Washers welded to the bar at the point where the bushings hold the bar will be used to keep the bar from sliding side-to-side. The rear bar will also be 22.2 mm diameter. Along the twisting axis, it will be 2 inches longer just like the front bar. The rear bar will also be adjustable with two mounting holes, one at the stock lever arm distance and one at about 1 incher greater leverage arm.

*Cost*
There will be a production run if enough people are interested. I will want firm commitments to purchasing a set of bars. This means I will need a substantial deposit to show your desire to get the bars. The minimum cost will likely be about $500 for the set. How close we get to this price will depend greatly on the number of people who want to get in on this. I have not quoted a price for just the rear bar because I don't think it would be wise put a 22 mm rear bar on the car without changing the front bar. I will have more details on the cost in about 1 week. If you want to get a set of bars, please PM me.

drivemusicnow · #2 01-29-2003, 02:04 PM

so what will the end effect be on the car, with the lower and higher settings. Would the car lose the understeer? or would it be just better handling, with the understeer... i'm just wondering how exactly will it affect the car. Thanks

mbtoloczko · #3 01-29-2003, 04:07 PM

Quote:

Originally posted by drivemusicnow
so what will the end effect be on the car, with the lower and higher settings. Would the car lose the understeer? or would it be just better handling, with the understeer... i'm just wondering how exactly will it affect the car. Thanks

I guess the most beneficial effect will be less change in the roll center and wheel alignment because the car will not lean as much in the corners. This will increase grip in the corners. Another benefit will be a sharper steering response because less energy will be absorbed by the suspension when yanking the wheel. Having front and rear adjustable sway bars will allow the driver to tune the strength of these effects somewhat.

As for understeer, I personally feel that the car is pretty close to neutral with proper alignment and tire pressure. My experience is that it understeers somewhat at lower speeds but has a very neutral or slight oversteer tendency at higher speeds. The fact that the rear bar will be the same diameter as the front bar will move the car more into the realm of oversteer, but the adjustability will allow some tuning of the understeer/oversteer behavior.

wasions · #4 01-30-2003, 12:16 AM

Speaking from past experience, I would NOT upgrade the rear bar to 22.2, but would try to keep the same relative percentile difference as the front - or better, less. You realize, I'm sure, that with less weight in the rear, any stiffness change will be accentuated. (I was a little surprised to learn that the rear is already a 17.) How about trying a 19mm (3/4") with the same adjustability?

Our (heavy) cars are surprisingly neutral at speed. They are also quite stable, relatively speaking. Do you really want a short patch of sand/ice on a curve to cause the car to swap ends? That's just what you're asking for.

The most cost-effective handling modifications would first include: 1.) lower profile, wider, stickier rubber, and 2.) Lowering/higher spring rates. Throwing stiffer bars at either end, especially the rear, is liable to bring headaches and bodywork.

mbtoloczko · #5 01-30-2003, 09:04 AM

At this point, the effect of the larger sway bars on handling is purely discussion. In 2 weeks, I will be able to tell you how the bars affect handling. These will be prototype bars, and the shop has assured me that if the bars adversely affect handling in any way, there will be further prototypes.

Many of the other cost-effective methods that were mentioned for improving handling either don't exist or don't make sense to me. Lower profile tires paired with taller rims make good sense (and I have done this), but I can't see making the tires any wider. With brand new stock-sized Dunlop Sport SP5000s, the car already hydroplanes at 80 mph when crossing any part of the road that is anything more than just simply wet. I would happily install stiffer springs, but the only ones available either substantially lower an already super low car or require Koni inserts which add more dampening than what I think is necessary. There are supposedly Aragosta and Bilstein coilovers, but I have yet to hear of anyone who has them on their car, and I have a suspicion that these gems will also add more dampening than what I would like.

Paisan · #6 02-03-2003, 06:36 AM

Quote:

Originally posted by mbtoloczko
With brand new stock-sized Dunlop Sport SP5000s, the car already hydroplanes at 80 mph when crossing any part of the road that is anything more than just simply wet.

I'm gonna have to disagree on this one. I have 245-45-16 SP5000s on my ride with about 3000 miles on them and have driven through monsoon-like rains, standing water, and 400 miles through a blizzard in upstate NY. Only 1 or 2 times when I was going way too fast for the conditions did it effect me. The 20mm extra width and lower profile has enhanced handling.

-mike

Paisan · #7 02-03-2003, 06:38 AM

Quote:

Originally posted by mbtoloczko
I would happily install stiffer springs, but the only ones available either substantially lower an already super low car or require Koni inserts which add more dampening than what I think is necessary. There are supposedly Aragosta and Bilstein coilovers, but I have yet to hear of anyone who has them on their car, and I have a suspicion that these gems will also add more dampening than what I would like.

How much would it run to get a spring shop to make up some replacement coils? I can't see it being that expensive IMHO.

-mike

Paisan · #8 02-03-2003, 06:40 AM

Quote:

Originally posted by mbtoloczko

*Cost*
There will be a production run if enough people are interested. I will want firm commitments to purchasing a set of bars. This means I will need a substantial deposit to show your desire to get the bars. The minimum cost will likely be about $500 for the set.

I was interested up til this point. Seems a bit expensive for sway bars? Maybe I'm off base if so, then I'm sure I'll be corrected

-mike

mbtoloczko · #9 02-03-2003, 08:47 AM

Quote:

Originally posted by Paisan

How much would it run to get a spring shop to make up some replacement coils? I can't see it being that expensive IMHO.

-mike

I thought about that, and plan to look into it soon. My guess is that springs can potentially cost as such as the sway bars are costing me because the springs are not a simple coil-over style design.

mbtoloczko · #10 02-03-2003, 09:03 AM

Quote:

Originally posted by Paisan

I was interested up til this point. Seems a bit expensive for sway bars? Maybe I'm off base if so, then I'm sure I'll be corrected

-mike

I agree that the price is high. There are several reasons for the higher than usual cost:

1 - Small volume run
2 - Two-piece front bar design
3 - Adaptors need to be designed for the urethane bushings to mount onto the stock bushing location.
4 - The link mounting holes on the rear bar are not typical design.
5 - The bars are both adjustable.
6 - Zinc plating

Paisan · #11 02-03-2003, 09:54 AM

Quote:

Originally posted by mbtoloczko

I thought about that, and plan to look into it soon. My guess is that springs can potentially cost as such as the sway bars are costing me because the springs are not a simple coil-over style design.

The shocks on the SVX are std. mcpherson style? The biggest difference between it and the ones on other subies is that the lower mounting bracket is wider than on std. subies.

This shouldn't effect getting coil springs wound for em.

-mike

Paisan · #12 02-03-2003, 09:58 AM

Quote:

Originally posted by mbtoloczko
1 - Small volume run

That makes sense.

Quote:

Originally posted by mbtoloczko

2 - Two-piece front bar design

This also makes sense.

Quote:

Originally posted by mbtoloczko

3 - Adaptors need to be designed for the urethane bushings to mount onto the stock bushing location.

Not sure why?

Quote:

Originally posted by mbtoloczko

4 - The link mounting holes on the rear bar are not typical design.

Not sure on this either?

Quote:

Originally posted by mbtoloczko

5 - The bars are both adjustable.

A few extra holes drilled no?

Quote:

Originally posted by mbtoloczko

6 - Zinc plating

Why zinc plate them? We can always remove em every 5 years and paint them ourselves.

mbtoloczko · #13 02-03-2003, 10:21 AM

The quote system didn't work when I hit "quote". Here are my expanations for your questions:

The front bar bushing mount location is next to a piece of the car frame, and because of this, the *wider* aftermarket bushing (and strap) cannot line up with the bushing mount location. The mounting holes for the front bushing strap are also of different height. We had the choice of making a custom bushing and strap or making an adapter block. We went for the latter, but either way, it adds cost because of the R&D time.

Making the front bar adjustable is indeed a matter of drilling more holes for the link, but this is not the case for the rear bar. This bar has a large wide hole that houses a rubber bushing (with a metal insert). They can't just smash the bar into a flat at the end and drill a hole. I suspect they are going to have to machine end pieces and weld them onto the bar.

The zinc plating might be overkill. I just like to overdesign things. :-) Powdercoating will save a few bucks.

Paisan · #14 02-03-2003, 10:34 AM

Why even powdercoat? Why not just paint it? Whiteline paints theirs.

I guess I should be used to all the intricacies of the SVX having owned 2 XT6s having to re-engineer the whole suspension to get the RS struts to fit!

-mike

wasions · #15 02-03-2003, 10:36 AM

I really like the idea of new progressively wound coils that might lower the car - maybe 3/4 ot 1 inch. The problem with that is that the cost would be far more than the sway bars.

Has anyone considered making your own sway bars? A friend and I did that using stress-proof steel on a Capri II I once had. It wasn't too hard (in that case) to make two perfect replacements.

An even better plan might be to make smaller add-on bars that would u-bolt directly to the current bars. Mind you, I haven't even looked at our bars to see if that would be feasable, but it was a pretty popular remedy in the past, and also allows for removal if you begin to feel like it was a mistake.