Watts Link, No joke..... Options

[Applejack]

Worked well, car was a little looser than I'd like in high speed transition, but that's easily put down to not great tires and a weak limited slip.

Does the 'little loose' comment apply to slaloms?

What shocks were you running on the rear?

[sgarnett]

I just took an educated guess on rear bar and slapped a 24mm on it. I think it's a touch too much, and will be going to an adjustable 22 for my own car shorly.

Which pivot hole did you use with that 24mm bar? Is it solid or hollow? Which pivot position(s) did you try?

If it is solid, and has stock-length arms, it should be just slightly (3~4%) softer than the Hotchkiss bar. On old tires with a weak diff, I'd expect hole 3 (1" from the top) to be pretty decent (maybe hole 4 if the tires and diff were really bad). Regardless, it might be interesting to see how low you have to drop the pivot with that bar before swapping it out.

I went to a test-n-tune yesterday with the prototype Hellwig 1" bar. I was at a slick site that never really gets the tires warm, though the sun was out all day and the grip was better than usual for that site (which isn't saying much).

I started at the softest setting, which is roughly 37% stiffer than the Hotchiss bar due to being solid and having slightly shorter arms (stiffness proportional to arm length squared). The Watts pivot was in hole 5 (1" from bottom). The car felt really good and stable with that combination. Getting power down was no problem at all, and on any other day I'd have been content to leave it like that. This could be a "set it and forget it" combo.

Solely because I was at a TnT with untested adjustments, I tried going to the medium setting on the bar, which is quite stiff. I also moved the Watts pivot to hole 6 (1/2" from bottom). The bar adjustment is coarser than the Watts adjustment. I expected that combination to be a little loose, and it was. It actually felt great in slaloms and high speed transitions. The tail felt just slightly twitchy under full throttle, but not enough that I had to lift, and it was easy to control. There was just a little wheelspin at the corner exits, but that was offset by being able to get on the power sooner without pushing out. It turned out to be faster, at least for that course. I don't know if I'll leave it that stiff or not yet, but it is a useful combination to have "in the toolbox", at least for a smooth course.

Philosophically, I have no intention of ever trying to dial it in with the bottom hole on a dry day; that's reserved for rain. As the roll center becomes better controlled (Watts+lowered), the car can tolerate a looser setup, up to a point. On the last run of the day, I had a very fast run going but went into the last turn kind of wild. I lost the tail coming out, but was able to hang on and fishtail my way through the finish for a clean run and my fastest of the day, and as far as I know, the fastest run for anything above 2300 pounds and all but three or so drivers. Not bad for my first event of the season. The point is not that it broke loose (I screwed up) but how easy it was to save.

"On paper" (Jon's roll rate spreadsheet), the setup I started with should have been looser than what I've normally run in the past, and the last setup should have been a LOT looser. In practice, it wasn't. Without the ever-changing balance of a "stockish" setup, you can get closer to the edge without falling over. That's why I only made a small roll center change to compensate for a big bar change, which was the main point of the experiment.

BTW, the 24mm bar (assuming it has stock length arms) should be just slightly softer than the middle hole on that 22mm adjustable bar (assuming it is the one you sell (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif) ).

This post has been edited by sgarnett: Mar 24 2009, 01:15 PM

[sgarnett]

BTW, along with redesigning their bar to fit with the Watts, Hellwig has now redesigned the mounts to clear without spacers. I test-fit the prototypes a few weeks ago. I have some pictures, but probably won't have a chance to get them up for a few days.

This post has been edited by sgarnett: Mar 24 2009, 12:41 PM

[shortbus]

Sean, great update.

[Sam Strano]

Worked well, car was a little looser than I'd like in high speed transition, but that's easily put down to not great tires and a weak limited slip.

Does the 'little loose' comment apply to slaloms?

What shocks were you running on the rear?

Wasn't really a true slalom. And it was directly related to wheelspin (as it was fine when I wasn't igniting a tire). And the fastest part of the course was over a rise which of course made wheelspin more prevelent. Car was predictable any time I tossed it. Only when the obviously toasted LSD was the issue was the car moving around what I'd consider too much.

Bear in mind this was one course, one day, on old tires, with a not perfect LSD, and at a completely new surface that I've never run before. I can make some judgements based on driving other know commodity cars on the surface and feel comfortable with knowing what the car was doing due to surface vs. setup.

FWIW, I trailered my Camaro and made some fun runs in the Mustang. It seemed to get faster based on other's times than it had been when I was running. None the less I could not run the time I had put down in the Camaro in the Shelby (which had better tires and a better differential). And since I ran the Mustang later when numerous folks when tangibly faster in the same cars vs. 2nd heat comp runs I think that's a pretty good indication we're on the right track.

[kookamunga]

thanx Sam for the write up. guess I'll be ordering one during our 3 month break as you have shown that a well driven and setuo car CAN FTD.

[axoid]

Finished installing the watts link on my car today. I still have more work to do on the front of the car so it's not ready to be driven yet. Hopefully by next weekend.

[Sam Strano]

Ran my car again with the Watts. Same crappy tires. Coned away my fastest run, and still playing around (hey it was only my 5-8th runs with it on my car). I ran FTD, but the event wasn't exactly filled with super fast cars and drivers. But the one benchmark was a well setup (by me) National Championship winner driven Shelby. I coned my fastest that would have had me PAXing around .4 off.

Dialing in will continue as time/events allow, but for a while my car will be back-burnered because the National events are coming and I need to tune up in the car I'm running all year.