Are there any replacements for the Tanabe Sustec that have a similar stiffness increase over stock? I currently have one on order, but the company I ordered though haven't responded to me since ordering it almost two weeks ago. I'd like to run the Tanabe (or something similar) along with the Mazda Motorsports .188" front bar I just picked up at a track day on November 5th.

Thanks

 

I hope i did my math right.

The problem with swaybars is that there is very little in published information even from aftermarket makers. The 93 stock rear has a OD of 17.3mm and a wall thickness of 2.6mm per Yamaguchi's Rx7 book. Tanabe's rear swaybar has an OD of 20mm. If we assume a wall thickness of 4mm which is pretty common among aftermarket sway bars, then it is (20^4 - 12^4)/(17.3^4 - 12.1^4) or 104% stiffer than stock. With the same math, if we assume that the Tanabe has a wall thickness of 2.6mm like the stock bar, then the stiffness is 64% over stock.

The racing beat rear swaybar has a OD of 19.1 and wall thicknesss of 4.8mm according to the Racing Beat website. So this would be (19.1^4 - 9.5^4)/(17.3^4 - 12.1^4) or 81% stiffer than stock. But the RB rear swaybar also has two holes on the arms so one can mess with the setting a bit.

and FWIW i have a used racing beat RSB i plan to post to the classified sooon, just in case u are interested.

 

I guess my real question is if I plan on running the Mazda Motorsports 1.25 O D X .188 wall bar, which should put me approximately 60% stiffer in the front. If I then ran the racing beat rear bar at 83%, is it going to be too far out of balance? In Howards chassis set up thread he calculated the Tanabe bar to be 36% which he then recommended with a front bar of 1.25 O D X .188. I wasn't able to find any math on how that was calculated though.

Below are some number right off racing beats website for anyone else who stumbles upon this thread.
Stock Rear Bar:
1993- 17.3mm OD/12.19mm ID Tubular
1994- 13.8mm OD/12.19mm ID Tubular
1995- 15.9mm OD/12.19mm ID Tubular
Racing Beat Bar: 19.05mm OD/9.53 ID Tubular
1993- 1.83 times as stiff (83% stiffer than stock)
1994- 3.63 times as stiff (263% stiffer than stock)
1995- 2.95 times a stiff as (195% stiffer than stock)

 

Some people put a '93 bar in their newer cars. If you have a 94 or 95, you'll feel the difference.

 

I do have a 94 and saw that as an option as well. I have the Tanabe bar coming, but the company has yet to return any of my emails about status of the bar. I'm attending a private track day on November 5th and was looking to get all the bars on the car, so I can do some fine tuning during the event.

Also found out about 30min ago that there are no 93 rear sway bars available in the US. Looks like the only way to get one is for sale thread or ebay.

 

Wait... so we're supposed to believe that a sway bar with a 0.8mm wall thickness wouldn't just collapse like a cheap broom handle? That OD/ID has to be wrong for the 94.