Front AR Bar, Adjustment Options

[J P Stein]

I've go the Parade AX coming up and its a fast course.
Several of the turns are 3rd gear sweepers......not a good place for oversteer, me thinks.

At the moment, I've got oversteer in abundance and lots of room on the front bar to dial it out. This is new territory for me. The bar is presently at full soft. I need to make a WAG at another setting as I may not have a chance to drive the car in anger till the Parade AX. So.....how far to move the thing? It's a 25mm Tarret bar.....effective 22mm IIRC.....300lb rear springs.

Any WAG is gud. I'm thinkin' at least an inch.

[nine14cats]

Hi JP,

Plan on 0.75 inches to 1.25 inches. Randal and I are going through this right now with Fritz. The fuchin courses in GGR have been so tight (see other thread) that they squeak when you walk between the cones. Then last weeks AX was a little more high speed and we had to tighten up the front to keep the butt planted.

On the 914-6 we had a 27mm smart bar, the same as on Fritz. For AX I had 375lbs Eibachs with the 23mm T-Bars up front. I just checked my logbook and I would move the bar .75 inches between track and AX. This gave the car quite a bit of oversteer which I liked for AX, but manageable.

On Fritz, the chassis is much more sensitive to the bar changes as anything between 0.5 inches and 1 inch makes the same type of change to the handling. I havent' thought about why yet.

I also ran a stock bar on the back of the 914 connected and I run a 27mm bar on the back of Fritz.

At least I wrote down what I did....I hope it will help ya!

Bill P.

[nebreitling]

you can adjust the bar in minutes -- ie between runs. (IMG:style_emoticons/default/confused24.gif)

[J P Stein]

you can adjust the bar in minutes -- ie between runs. (IMG:style_emoticons/default/confused24.gif)

One would think........but every time I loosen the links at the arms, I find the bar in preload. Every time I set no preload, I come back & it has re-preloaded itself. (IMG:style_emoticons/default/confused24.gif) tain't much, just enuff to fuck ya up. I think my car bends (IMG:style_emoticons/default/huh.gif) . Reaching around them tiars to get at "stuff" is possible, but a bitch. Much easier to take off the front wheels, but all this consumes time. Once it's on the ground, ya gotta check preload again....

All 2 driver cars are gonna be run a bit differently at the Parade....bout 100 of them.
All first drivers are gonna run first of the group ....all 3 runs in a row to cycle them thru.......with 5 minutes between runs as required by the PCRs. The second drivers can then run in the normal group order.

[drew365]

I carry 8 2x6x18" to adjust the front bar at the track. I put 4 blocks under each wheel, the 6" gives me enough room to squeeze under and make adjustments. I like the bar to be about mid point if possible, I feel there is less pressure on the droplinks. I have a 27mm smart bar. When I get my car back on the road after this last round of upgrades, I will change the bar out to a different size if it doesn't work out that mid point is the right spot. I broke my first droplink at the last event, and I feel it was because I had the front bar at near full hard trying to dial out oversteer. Still learning!

[J P Stein]

Bill:
It's prolly cause your 911 chassis is stiffer....which don't take much (IMG:style_emoticons/default/biggrin.gif)

Other stuff I've noticed:
I could use a bit more camber in front and some higher air pressure.
I've got more that 1/2 inch of unused shock travel up front.
If I drop the front 3/8 inch I get more camber....
I'm gonna fuck this thing up for sure.

I might "have" to go to the SCCA AX in Packwood next Sunday....rats (IMG:style_emoticons/default/biggrin.gif)

[nebreitling]

i drive my front end up on ramps, which keeps weight on the bar, adjust each side with a ruler to exactly the same (which usually keeps preload from becoming an issue), dial out any preload found (although just a bit of preload is fairly insignificant, me thinks). takes minutes.

if you lower the front end to grab more camber, you know you're gonna want to re-align and conerbalance the thing (IMG:style_emoticons/default/biggrin.gif) .

i say take a wager as to how much more bar to add, then fine tune it between runs. you and britain ought to do pretty well in that car -- even against the likes of provasi et al....