edgalang

OK, so I pretty much pushed my car to its limits tonight (well almost) at the Golden Gate Fields parking lot (an SCCA autocross course on Sunday afternoons) @ 11pm. No one was around to see us (except these 2 cars...probably making out) and I wasn't driving. A friend of mine recently bought a 2002 IS300-M and we wanted to do a quick comparison between the bodyrolls (yes...he is done with his break-in) before we called it a night.

I must admit...ever since the accident, it's either I've lost my trust in machines in general or I'm simply getting older...but this experience definitely frightened me more than usual (enough for me to end the second drive short).

After circling the lot to identify the boundaries of the gravel area (made for testing out 4WD vehicles...and we were not about to mess up our new paint jobs) we proceded with the test. We went through a series of sharp and quick turns simulating emegency lane changes, a couple sets of wider series S-turns (with forces that could easily end up in a spin out if it wasn't for VSA), and a couple short straight way acceleration tests (so my guest can hear the CAI and exhausts at work).

Then we headed home, traded cars and did the very same thing in the IS300-M. Both times I was a passenger, and kept my mouth shut to let my guest make his own subjective opinion.

To my suprise, my guest thought that the TLS (Neuspeed equipped of course) induced alot less body roll than his stock IS300-M! The difference between the 2 was outstanding. He states, "My car would waste energy & momentum swaying and then turning, but ur TLS would go straight to turning". He was amazed how much just adding the sways improved the ride (his family also owns a TL). Ever since his first modding experience, he was a firm believer that the springs/shocks combo always played the larger part in body roll reduction...untill now.

I myself couldn't agree more...but one thing that's for certain is that the size and weight is were the TLS is hurting. The weight of the TLS shows when it understeers during full on turns, and according to my guest...his entry speed had to go down alot because he felt that the TLS tended to understeer at extreme speeds.

Both were fun drives. I have never personally pushed my car to these limits and it was a great experience comparing the 2 directly back to back. Having riden in both I felt a little safer in the TLS. Maybe it was the stiffer sways, or the overall wider track, but making sharp left turns with the IS300-M, where the rear is ready to break loose at any moment with just a little tap of the accelerator is what the TLS would never experience. But...the greater body roll and the fact that I was almost staring at the ground made the IS300-M test drive frightening enough for me to call it quits. In the end, all I could say is that the shotgun seat with an extremely sharp left turn equals to an unpleasant view...what more if done in a regular street.

Now to run these same test on new tires...then we're talking.

Beiruty

Sways and sticky tires.. Nittos, toyos or better S03 are the best mod for handling...

RandyL100

edgalang,

Good post! I always love to see comparison & testing like this, we all benefit from it, which of course is the point of forums such as this. Of course most of your testing was subjective, but that is very important too.

Couple of thoughts...
-You could reduce the understeer by installing a larger rear anti-sway bar only, leave the front stock. I've been considering this -- buying a set of Comptech bars and install the rear only for a while and see how it feels. FWD cars are notoriously nose heavy (the TL-S has a 61/39 weight distribution as I recall), and without the rear drive wheels to help steer with the application of, or removal of, power, you simply have less control. A larger rear bar will make the rear come around faster by unloading the inside rear wheel to a greater extent. Of course this makes the car trickier when pushed by a less competent driver.
-"Turn-in" can also be improved by installing a strut tower brace -- I've personally experienced the improvent with such a bar on a Jetta A3 I had. Trouble is, our cars (at least mine, a 2003 model) already have one. I don't know if an aftermarket bar would perform any better than the stock unit, but I suspect not.
-Stiffer springs will help reduce body roll also, but not nearly to the same extent as anti-sway bars. I will be installing Ground Control coilovers on Wednesday with custom selected spring rates (I chose 15% stiffer than stock both f/r). Based on what this does to the handling I may or may not try the Comptech bars. The only reason I wouldn't is that the urethane bushings used in all aftermarket bars do allow more road noise/vibration to be transmitted to the cabin. In my old age I'm really appreciating the quiet provided by the TL-S.

I will post the results of what I learned in my springs research once I get the Ground Controls installed. I have some data that has not been posted in this forum anyplace I could find.

evolaerok

you getting old...:p that oversteer is supposed to be fun fun... I miss rwd..

edgalang

Must be. But ever since I saw this video of a BMW doing a 360 then flipping over when it hit 270 kinda freaked me out. #1 it's a BMW...and #2 it was done on a flat and controlled area. If that can happen there, what more if you hit a small bump or an imperfection on the road you are sliding on.

Keep in mind I'm still recovering from my spinout accident.