01+ factory bracing... how effective?

[Doppelgänger]

So I've run into a problem lately with the underside of my car. It seems the FM exhaust and my factory "butterfly brace" (the one standard on sport pkg and MSM) are always getting into fights under my car. This causes a lovely resonating vibration throughout the car at various rpms and while crusing. I also suspect these high-frequency vibrations on the exhaust are some of the cause of the turbo-to-manifold nuts coming loose.

Anyway, after spending a couple of hours under the car racking my brain and trying figure out where it was coming from (checking every nook and passage the exhaust takes) and not seeing any place the exhaust was rubbing, I just decided to take the brace out. Wouldn't ya know that the damn noise went away too. So I suspect that the 1/8" of clearance between the brace and the downpipe isn't enough. So this makes me wonder, how much of a difference does that brace make? Would it be a good idea to put it back on for my upcoming track day? I still have all of those other braces/bars...which seem to be more sturdy than the stamped-steel butterfly that Mazda stuck under the car.

discuss.

[RotorNutFD3S]

I've always thought they made a difference, but at the same time, not enough to have to deal with the noises/vibrations they cause with aftermarket performance parts.
Further, when I asked for opinions about FM's frame rails vs. the whole butterfly setup, almost everyone that responded said they noticed a difference between the two, but the people with roll bars said that there was no difference between the frame rails and the butterfly setup. Guess the roll bar helps the same way a butterfly brace does.

[Doppelgänger]

Yeah, if this was the FM butteryfly brace, i'd leave the frame rails but the oem brace just bolts up under the car. I've thought about their rails, but i'm simply too lazy to pull my seats and carpet to do the install.

[RotorNutFD3S]

So ditch the brace and get the rails. Honestly, they take next to no time and effort to install. If I were you, I'd jump on that frame rail group buy that's going on over at mt.net. $107/shipped.

[Jack-MX5ATLanta.com]

How about if you just put something in between to insulate.... actually it would probably melt.

[Doppelgänger]

Ahhh, I did. I put some header wrap around the DP right there..because its soft, yet burn proof. But I guess there is enough force pushing the DP into the brace to make noise. Come to think of it, I might be able to get slightly longer bolts for the front mounting points and put some shims and effectively lower the bace down a few mm for more clearance.

Eric- that's a damn good deal, but ATM I think I need to spend that $100 on some ss braded brake lines :(

[wildfire0310]

Ahhh, I did. I put some header wrap around the DP right there..because its soft, yet burn proof. But I guess there is enough force pushing the DP into the brace to make noise. Come to think of it, I might be able to get slightly longer bolts for the front mounting points and put some shims and effectively lower the bace down a few mm for more clearance.

Eric- that's a damn good deal, but ATM I think I need to spend that $100 on some ss braded brake lines :(

I was wondering that myself, if you could shimmy the brace or maybe somehow lift your exhaust a few mm in that area.

[RotorNutFD3S]

Eric- that's a damn good deal, but ATM I think I need to spend that $100 on some ss braded brake lines :(

Always a good idea as well. But just in case you decide otherwise, they won't be collecting money for the group buy for another 6 weeks or so. So you can get your name on the list and pay much later. :D

[jesseealexander]

just try to find the spot where the contact is happening and take a BFH to the brace. or cut a chunk out of it even. those braces make a pretty big difference and you will hate the car without it.

[Doppelgänger]

I am enjoying the silence of having it removed so far :D
I already took a BFH to the spot that I had suspected of contacting the DP, it's the forward most section that runs from frame rail to frame rail and is pretty beefy... so cutting is no an option :( I'll try some washers when I put it back on tomorrow after replacing the manifold.

[mustangtomiata]

You could also take a SFH to dent the downpipe next to the brace and that may provide the extra clearence you need. I know this sounds hick as hell but I had to do it on the Oldsmobile because the header rubbed the steering column and well, can't move the column so the header took the hit(pardon the pun)