Pics of my Cracked PPF!
 

Don't let this happen to you! Wheelhop is bad :D!

http://www.shoeflydesigns.com/rx7/satown/PB100001.JPG

Here you can see the large chunk in the upper right that was completely seperated from the rest of the PPF. While Alan used the air gun to take off the bolts that held the PPF to my R1, I held the PPF up so it wouldn't fall (the car was on a lift). Well, when he loosened two of the bolts towards the back, that chunk fell off w/the PPF still on the car! It was a clean break, and really dangerous to drive on...

Here you can see two more cracks. Suffice it to say, my PPF was definitely on it's last legs...

http://www.shoeflydesigns.com/rx7/satown/PB100002.JPG

Why do think it broke?

The fatigue over time and hard launches. Those things are weak they always break..I'm on my third one. Next time I get one it will possibly be a mazdaspeed one and I'll cryo-treat it for extra measures. Does anyone know the difference between the metal composition in the mazdapeed vrs the oem? I've never found out why one is more durable than the other?

You know I was thinking about this, and I might start a new thread on it if enough people don't see it here. I wonder if the PPF contributes to the breaking of diff's and axles? The force of a launch has to be absorbed somewhere and since the PPF doesn't allow for much "shock absorption" in the engine/tranny it all gets dissapated to the diff and axles. I know guys in Supra's putting down over 500 RWHP that can lauch all day without worrying about breaking diffs/axles, but get close to 400 on an FD and your breaking them left and right. I know the Supra is a "beefier" car, but there's got to be more to it than that. Anyone else want to comment on this?

Ok anyone else scared to take they're car apart???:eek: I know I am. I am pretty sure mine is cracked too... Hopefully when I take it apart it won't be. But that seriously scares the shit out of me.:eek:

That is REALLY disturbing. I've heard conflicting reports on the Mazdaspeed PPF. Somesay it is the exact same thing, but red. Other's say it uses a different metal composition with different weld points.

i read that the Mazdaspeed PPF is only 10% more rigid than stock. that means if youre running 337 RWHP (in Goodfella's case) and you break your stock PPF, get the Mazdaspeed and it will break when you get up to 370.7 RWHP!

well...not really. just a little thought. but 10% stronger doesnt seem like that much to make a difference. it is painted a pimp red color though!

0piston>> how effective is this cryo treatment you're talking about? what kind of process is it and what are it's benefits?

I'm almost 100% sure i have some hairline fractures on my PPF...wheelhop is a biatch.

Did you suspect it?

Were there any symptoms?

Should we be looking for something?

It happened from violent launches at the track. Basically, I was launching my R1 at around 4k on Potenza so2pp's (245/45zr16) and my frame was absorbing too much shock from the wheel hop. So it's basically my fault that it cracked; I knew I shouldn't have been launching like that on w/my current setup.

I definitely suspected something; as I blasted down the strip I could hear a very faint "metal shifting" sound. It sounded like shit was moving around down there.

A few days after that, I knew something was very wrong. Every time I revved her out, a bad vibrating sound came from the back of the car. It increased with rpms and was extremely loud.

I thought maybe it was the diff; I took Ari for a quick ride and he knew right away that my PPF was cracked.

A fellow customer who was at RP (thanks Dan :)) took pity on me and basically gave me an extra PPF he had laying around.

Ari suggested the Mazdaspeed; evidently it's much stronger than the stocker. Pluto kept cracking and breaking his PPFs, and he's been using the same Mazdaspeed one for over a year (going off of memory here; correct me if I'm wrong Steve). He's putting down about double the rwhp I am, and launches the shit out of his FD basically every weekend. I've been told the stocker is ~$600 and the mazdaspeed is ~$450. I was planning on getting the Mazdaspeed until I came by the used stock replacement.

Hope this helps; if you guys have any ?s, feel free to ask.

Rich

The reason it is killer on the PPF is:

Stock suspension is weak in that department. If you upgrade shocks/springs along with a drag launch kit then you can keep the suspension aligned correctly during hard launches.

also .... street rubber is a very hard compared to race compounds. Most guys that have big HP numbers seem to run on very, very soft tires. Well with a good soft tire you can absorb some of that energy in the tires.

The goal is to eliminate wheel hop and control the stress on the car. The PPF was one of Mazda's little tricks to the car light. It is very strong and holds up for road racing & auto-x just fine, but drag racing seems to be just too much for the stock piece.

The Mazdaspeed one I believe is "hot rolled" and this technique adds much strength to the piece. It is a process that is very well know and you can learn about it if you take a material science engineering course. This is how they can make it weigh and look the same as stock.

Ok, I will be the dumb newbie.

What does PPF stand for? I am assuming it is a reinforcing member in the rear of the car. I don't remember seeing it when I changed my fuel filter though...

Later,
Patrick

Power Plant Frame. It ties together the rear of the tranny and the diff. It runs along the center of the car, on the driver's side of the exhaust. You don't really see it unless you're looking for it.

Rich

Ahh...

Thanks.

Patrick

Ouch! I am having some type of trouble too, but it seems to be too much play in the reat (ring and pinion?).

Jason at the RX7 Store quoted me $347 for the MazdaSpeed PPF. Seems like a deal.

Is the bolt at the top by itself (on the part which is still connected) supposed to be screwed down all the way? Seems like my bolt is not flush with the PPF.