CodingParadox

I found some old threads on the subject, but without much information. I'm wondering if, since then, anyone's picked up the Gendron/SmallFortuneRacing bar (http://www.smallfortuneracing.com/Pr...24/page24.html) and if it has any rubbing/smashing problems with Konis?

mwood

Looking at that bar, and price, I think I may have to start making some of those and selling them...looks like easy money, particularly using non aero grade heim joints to keep costs down...

Team has some opinions on the basic design (not optimal), but it does give the type of options that many of us autocrossers could certainly benefit from...I don't know about shock interference, but if they don't have that taken into account in the design parameters, I would be very surprised...and disappointed.

ChopsMcgraw

I'd like to try it in the 'offseason'. I have interference with the stock end links/bar and konis at full droop...

TeamRX8

iTrader: (25)

they use a wide center bar and straight arms rather than a shorter center bar with the arms bent in a fashion similar to the OE bar, I don't like it

Guy Ankeny was telling me about a new RX-8 bar from Tri-Point with adjustable rotating blade arms, it likely won't be cheap though

CodingParadox

I assume you have lowering springs or something then?

Edit: (intended for Chops)

CodingParadox

I mostly just want a bar with a bunch of adjustability, all the way from softer than stock to quite a bit stiffer than stock. I'll be trying to play with a pretty different setup for next year and would like to be able to use a bar to dial out the effects and have lots of range of adjustability to find the sweet spot i want.

PedalFaster

The reason he's asking is because the Gendron S2000 bar has really thick arms that need to be machined down to prevent interference with thicker-than-stock shocks (think Moton or JRZ). The RX-8 bar seems to have equally thick arms, thus the concern...

mwood

Yeah, I know...that's why I would be disappointed if that factor wasn't taken into account...

I'd be curious to see the Tri-Point bar design. I may just build one up myself, using my friend's CNC milling machine to create a "better" arm design

TeamRX8

iTrader: (25)

You can buy all the Gendron bar parts from the circle track parts suppliers, the arms have to be cut down and drilled ...

and bent if you go that way, this was the first TeamRX8 bar I made, the high cost and arm bending hassle is what made me go with a formed tubular bar instead

I could make a few with bent steel arms if there's enough interest, making them with the bent aluminum arms is expensive; they have to be heat treated properly after bending or they un-bend themselves. You can use the TriPoint/ProParts bent aluminum arm kit for the FD3 RX-7 sold through Mazda Motorsports, costs over $450 and then you still have to purchase the appropriate splined center bar

mwood

I was thinking of not going with bent arms, but cutting some pieces out of billet, but if the suppliers already have the parts made(with just final machining for application), that would be easier.

Why does the bent arm work better? Is it more progressive in kind of "ramping up" the full torsion capability of the bar? Does that make sense??

ULLLOSE

iTrader: (1)

It does not get in the way of the tires when you turn.

TeamRX8

iTrader: (25)

wheel clearance at full lock (probably not an issue with Stock wheel requirements), strut clearance, and endlink angle are the primary considerations

bigger consideration is that diameter/wall thickness of the available splined tubes is limited

mwood

So, whether bent or not, the effective length is the effective length of the lever arm and the bends have no effect on how force is transmitted to the center of the torsion bar?

Intuitively, I would have figure otherwise..

TeamRX8

iTrader: (25)

the bent arm has a twisting force exterted onto it

the straight arm with an angled endlink has a bending force exerted onto it

mwood

Right, so it is possible that with a bent arm, given the right bends, length and other factors, you could design in a rising rate, whereas the straight arm design would have to be purely linear?

TeamRX8

iTrader: (25)

it depends on a variety of factors, but I doubt the straight arm is linear; the more it bends the more the endlink is angled the larger the bending force that's applied

ChopsMcgraw

Nope, stock springs. Nice big contact mark on the Konis where the interference occurs.

TeamRX8

iTrader: (25)

I had the same problem with the Racing Beat front bar; endlinks gouged the aluminum body on my Koni 2812s. Either the bar is too wide or the centering stops are giving way under load and allowing the bar to move sideways while cornering.