kha

First, as a new RX-8 owner, I would like to say this place is great. Just switched from Subaru a week ago and loving it.

I've been looking into getting some underbody bracing, and the only major ones I see is from gtspec. For Subarus, there were at least 3~4 manufacturers (Cusco, Rallitek, Avo etc.), but for RX-8s, is gtspec pretty much the only option?

I saw some braces real cheap on ebay, but I'm a little skeptical (I've never heard of TC sportline.). Has anyone tried it?

http://cgi.ebay.com/ebaymotors/04-05...mZ380299467457


Thanks,

- a happy new rx-8 owner

laythor

lots of better mods out there before bracing
If you're really serious about it, Carbing, autoexe, gspec.. bunch of shops make a brace kit for the 8.

kha

Yeah, I'm doing sways, springs/shocks, bushings then bracing, in that order. I know what to get for the rest, but I couldn't find much on chassis braces.

Thanks for the info. I'll look into carbing and autoexe.

kha

oh, and just to clarify, I'm looking for underbody braces, not tower braces. imho, I just don't see the need for anything beefier than the stock brace. I'm sure they make the chassis stiffer, but I just don't think it would improve the handling significantly in a double wishbone setup.

c0ldf1ame

iTrader: (5)

i got the eBay ones, fits pretty well, no complaint, I've scraped the bottom a couple of times but don't really care too much since its cheap. the braces make your under body lower by about an inch so be careful going over speed bumps

Beodude

iTrader: (3)

Did you notice much difference in how the car feels c0ld?

terch1

iTrader: (2)

Welcome I've seen a bunch of members jump ship and purchase a Subaru over the past year. It's nice to see a former Subaru member join the club. I was contimplating the gtspec myself. Not familiar with the TC sportline.

bumblebeerx8

iTrader: (7)

i went with gt spec the quality is top notch and it is aluminum unlike tc sportline and others that are steel. so there is weight to think about.

expo1

Five years later it's still in one piece, though not as bright red.

https://www.rx8club.com/series-i-do-yourself-forum-73/diy-autoexe-member-brace-61120/

Youwonder

I might get this from eBay as well but not sure if anyone brought this b4 or if it had a good fitment...

HiFlite999

iTrader: (2)

Then why did Mazda go with a beefier tower brace for the Series II RX-8's? Here's my initial take on it:

https://www.rx8club.com/showthread.p...ghlight=GTSPEC

I remain skeptical wrt rear bracing and further underbracing for n/a cars, but have no doubt it stiffens the front. Whether it's worth the money depends on your tastes. Aftermarket parts for RX-8s are def less numerous and more expensive than more common cars. The "upgrade" observed is also on average less, 'cause the 8 is already so good to begin with.

c0ldf1ame

iTrader: (5)

honestly i think anyone that tells you the underbody brace feels any different is lying, the rx8 chassis is already pretty damn rigid from factory, most additional braces are just extra weight and bling. I have a 6pt front strut bar and a 4pt rear bar, and a rollbar. I think the roll bar made the most difference in feel.

But also keep in mind that if your chassis is stiffer, it means that the suspension has to work more since there is less flex. You ought to get way stiffer springs and shocks that match to make it work properly

TopGear8

iTrader: (3)

Stiffer does not always mean faster...


Just sayin

kha

Yeah, your review was one of the first that I read, and I agree with you. It will definitely make the chassis stiffer.

What I was saying was, while the chassis is stiffer (and thus the overall spring rate, as you were saying), I don't think chassis flex would change the suspension geometry as much in a double wishbone setup compared to struts.

In any case, reading your review again makes me want to get the 6pt upper brace before the lower ones... I might just do that.

Highway8

iTrader: (11)

Mazdatrix sells and uses tc sportline products, not sure if they use the undercar brace.

The TC Sportline undercar brace is identical to the autoexe except for the badge and they dont include some 2 nuts (attached to tabs) for the front piece. Fit is good, it is lower but my exhaust will scape before the brace. Its not that heavy, IIRC it only adds about 15LBS over the stock pieces.

Performance: It wont make you faster. With the increased chassis stiffness, its possible the car will be more predectible (I only said possible).

IMHO: Well I installed the tc sportline brace on my car because for the price you cant beat it, and I have heard reports of some cars getting a little tweaked after years of hard track use. I figured it couldnt hurt to put it on.

TeamRX8

iTrader: (25)

don't waste your money, you can save some weight by dumping the front OE strut brace while you're at it ....

kha

Thanks. Subarus are nice and fast, but they don't exactly have the most sophisticated suspension. I just don't care about the raw power and speed anymore. Much more important for me now is the tactile feedback and power going to the right wheels.

HiFlite999

iTrader: (2)

A chassis has it's own spring rate. Back in the days of really flexible bodies, "solid" springs with the order of the day. Stiffer bodies allow softer srings to give the same "body+spring" rate.

edit: humm, I may be wrong about this - I see two different arguments leading to opposite conclusions. More thought/reading required.

The smartest thing to do with a street driven 8 is likely to leave it bone stock and use the money saved to buy beer and women.

Beodude

iTrader: (3)

In Mazda's defense, they did increase chassis stiffness by a ton... At least by their claim.

HiFlite999

iTrader: (2)

Well some anyway. Interesting that they also went from a 2-pt to a 4-pt front shock tower brace; I guess they are also under the "illusion" that it's beneficial.