Gen III Front Anti-Roll Bar Stiffest Hole

[Dave Tabor]

Got the 'stiffest' hole by use of a 1/3" thick spacer which effectively moves the ARB pillow block mounts rearward.

Car handles as it should, at least so far on the street.

Dave
Gen III #17
800lb front / 500lb rear springs, no rear ARB

[Ltngdrvr]

Got the 'stiffest' hole by use of a 1/3" thick spacer which effectively moves the ARB pillow block mounts rearward.

Car handles as it should, at least so far on the street.

Dave
Gen III #17
800lb front / 500lb rear springs, no rear ARB

Did you mean a 1/4" spacer?

[Dave Tabor]

Did you mean a 1/4" spacer?

Right! Sorry!

Dave

[Gordon Levy]

It the track you will have a pretty serious corner entry push.

[Logan]

Gordon - do you have any experience with running a rear swaybar on a Gen3 Coupe?

Like Dave Tabor, I ran the FFR/Miata front bar as stiff as I could get it, which was hole 3 of 4. Couldn't use the 4th (stiffest) hole due to bad geometry. Looks like Dave solved it with some 1/4" spacers under the mounts. I solved mine by starting from scratch and engineering a custom splined swaybar. If the front gets pushy, normally I'd add rear bar until it's balanced, but the rear bar doesn't seem to work right. Maybe it's binding? Any time I hook it up (even in the softest setting) it creates oversteer.

Dave - nice and simple, and inexpensive solution to be able to use the 4th hole on the Miata bar. Your solution is about 1/100th the amount I have into mine...lol. Let us know how it does, I'm very curious.

[J R Jones]

Gordon - do you have any experience with running a rear swaybar on a Gen3 Coupe?

Like Dave Tabor, I ran the FFR/Miata front bar as stiff as I could get it, which was hole 3 of 4. Couldn't use the 4th (stiffest) hole due to bad geometry. Looks like Dave solved it with some 1/4" spacers under the mounts. I solved mine by starting from scratch and engineering a custom splined swaybar. If the front gets pushy, normally I'd add rear bar until it's balanced, but the rear bar doesn't seem to work right. Maybe it's binding? Any time I hook it up (even in the softest setting) it creates oversteer.

Dave - nice and simple, and inexpensive solution to be able to use the 4th hole on the Miata bar. Your solution is about 1/100th the amount I have into mine...lol. Let us know how it does, I'm very curious.

Logan, I have not noticed it mentioned by the racing experts on this forum, but your differential type will influence oversteer. Open is least likely to oversteer, locked is the worst. I ran a Trans Am at Elkhart Lake running a Boss 351 in place of my 302. My 3.89 gear on a Detroit Locker (9 inch live axle) was not holding the engine on the straights in practice. I set up a 3.5 gear set but did not have time to find another locker and used a spool. The resulting oversteer was incredible and un-linking the rear ARB made the car more drivable.
With increasing magnitudes of axle lock the outer (loaded) tire dictates the axle RPM. The inner tire, turning on a smaller radius must skid to compensate, leading to oversteer.
The experts here may disagree, but their emojis will not make me rethink my experience.
jim

[Dave Tabor]

Gordon - do you have any experience with running a rear swaybar on a Gen3 Coupe?

Like Dave Tabor, I ran the FFR/Miata front bar as stiff as I could get it, which was hole 3 of 4. Couldn't use the 4th (stiffest) hole due to bad geometry. Looks like Dave solved it with some 1/4" spacers under the mounts. I solved mine by starting from scratch and engineering a custom splined swaybar. If the front gets pushy, normally I'd add rear bar until it's balanced, but the rear bar doesn't seem to work right. Maybe it's binding? Any time I hook it up (even in the softest setting) it creates oversteer.

Dave - nice and simple, and inexpensive solution to be able to use the 4th hole on the Miata bar. Your solution is about 1/100th the amount I have into mine...lol. Let us know how it does, I'm very curious.

Logan- the car handles much more like I'd like it to on the street. With 100TW tires I can't get near it's limits to test it. I had to cancel a track day last week or I'd have tried the last two hole positions at the track. It looks like the first autocross even will be in three weeks.

I hope it pushes- I'll then add in some rear bar which is already on the car just disconnected.

Dave

[Logan]

Jim - Interesting correlation between oversteer and differential types. I have kept my Torsen T2 differential the same during my tuning phase, so that variable is unchanged. I have no doubt an aftermarket diff such as OS-Giken would change the handling characteristics, possibly even for the better, however I still consider swaybars, springs, shocks, and alignment to be ahead of differential type in the order of influence on oversteer or understeer. A locked diff (spool) would definitely result in oversteer, that's for sure!

Dave - I'm glad to hear that it is better even on the street. My new swaybar was put to the test for the second time this past weekend, this time with brand new tires, and it is incredible how it has improved. This car definitely needed more front bar. I'll do a full writeup of this now that I've confirmed everything works as I expected, and post it to my build thread. I'd still like to hear how yours handles at the limit at the next autocross event you go to. I have a feeling that even if you get some push, when you reconnect the rear bar it'll be too much (it will oversteer). On my car, ANY amount of rear bar is too much...even the softest setting. And even with a super stiff front bar. Something seems fishy about the rear bar config, maybe it's binding... I'll investigate.

Keep us posted!

[cgundermann]

Logan, I have not noticed it mentioned by the racing experts on this forum, but your differential type will influence oversteer. Open is least likely to oversteer, locked is the worst. I ran a Trans Am at Elkhart Lake running a Boss 351 in place of my 302. My 3.89 gear on a Detroit Locker (9 inch live axle) was not holding the engine on the straights in practice. I set up a 3.5 gear set but did not have time to find another locker and used a spool. The resulting oversteer was incredible and un-linking the rear ARB made the car more drivable.
With increasing magnitudes of axle lock the outer (loaded) tire dictates the axle RPM. The inner tire, turning on a smaller radius must skid to compensate, leading to oversteer.
The experts here may disagree, but their emojis will not make me rethink my experience.
jim

Interesting! Makes sense...

Chris

[Logan]

For those interested, I've just posted the writeup on my new over-engineered custom splined front swaybar on my Coupe-R. It's in post #68 of my build thread, linked HERE (https://thefactoryfiveforum.com/showthread.php?34792-Logan-s-Gen-3-Coupe-R-Build)and also in my signature.