DavidNJ

Because the Torsen differential requires both tires on the ground and the stock setup doesn't always maintain that, a large front bar is a standard first modification. These bars can be very stiff.

For example, the characterization of the OEM springs article in the sticky of this forum has front bar for my '04 at 300 lb/in. For an 01 it is 394, but with softer front springs (219 lb/in vs 262 lb/in on the 2004). Karcepts anti-roll bar, a very clever design (guys, you should sell a version of those arms for late model stock cars), has rates of 400 lb/in to 715 lb/in for their recommended .25" wall bar. Their stiffest goes to 822 lb/in. Only their softest (263 lb/in to 471 lb/in) goes as soft as the stock 2004 bar. The Gendron bar is rated a bit differently. In their scale the stock AP1 is 168 lb/in and their .25" wall bar ranges from 389 lb/in to 582 lb/in. They have a "Monster" bar that ranges from 452 lb/in to 776 lb/in on their scale. The implication is that it would be about 950 lb/in on the Karcepts scale.

With the square setup I'm sure some front bar stiffness is necessary just to keep the back behind the front!

Now my question: how much do these big bars affect the ride on the street? If using a square setup (say 255/40 or 245/40 on 17x9+63 rims) presumably some significant additional front stiffness would be necessary to restore balance.

Thanks,

David

matthugie

Bars don't affect the ride per se. They do affect the handling, which is related, but if you're not pushing it you're unlikely to notice much of a difference. I run a solid Gendron bar on the 3rd hole setting (~400lbs by their rating) and it has greatly increased the car's stability. It's very apparent on an autox course, but on the street there isn't much change. You can feel that the car is more composed when turning in, but that's about it.

Car Analogy

Think about what a sway bar does. It adds 'spring' from one side of the car to the other, but adds none if both wheels move up and down together.

Drive straight, go over an undulating road, very little extra spring effect from bar. No real change in comfort.

One wheel hits a bump, that will experience some extra spring effect from bar.

Go around a corner, where car wants to lean over, suspension on one side wants move up, other side down, you will get maximum spring effect added.

So will you notice a change in comfort? Yes, but it depends on driving dynamics. Some circumstances there will be very little perceived change.

s2ka

I tried a Saner 1" bar for a while on my AP1. It affected the ride a lot on the street, stiffer, harsher. I could definitely notice the difference. If you care about ride comfort a giant front bar is not so good. I went back to a stock bar for the comfort and less hassle with clatter, hitting the shocks etc. But I run staggered wheels & tires.

Karcepts

David,

If you ask customers on our new Karcepts S2000 FSB, I think you will find that most say the comfort level on the street is unchanged. We paid careful attention to the geometry and endlink angles throughout the entire suspension travel, such that you will not observe any endlink clatter. I believe that may be a primary complaint for DD use on some of the other large front bar setups.

Please let me know if you may have any further questions about our product.

Thanks,
Brian Karwan
Karcepts, Inc.