Is it a good idea to use a flex pipe when fabricating a downpipe? I would probably use about a 6" secont and weld the hard pipes on to both ends... I figure that this will allow for slight misalignment of the downpipe, plus, be nicer on my header and not make it jolt so much.

Good idea? Bad idea? If so, does anyone know where to get a 3" diameter section of flex, I just looked on Summit's site and they are sold out...

Thanks

 

I know alot of the DSM guys use flex pipe on their downpipes. I guess the engine torque on the DSMs makes it a good investment.

 

DSM's use it cause the engine rocks in a very bad plane relative to the exhaust pipe direction.&nbsp In fact, all the tranverse engine vehicles should be using it for this point.&nbsp A longitudinal engine doesn't torque the exhaust pipe(s) as bad - this is why exhaust hangers take most of the deflection.



-Ted

 

Thats some good info... I knew that about the transversely mounted engines....

But, the question still remains... good or bad idea in a rotary (A high horsepower rotary)?

Also, anyone know where to get a section of good flex pipe?

 

some are wrong wheel drive, some can get AWD, but there engines are still crooked

I'm proud to be RWD

 

What did you get?

 

I think it's a good idea regardless of the motor layout. I have a flex section on my Supra. Chances are good that sooner or later your exhaust will hit a speed bump, or a driveway lip, or something. When that impact occurs the jolt will be transmitted back through the exhaust system and stress the exhaust manifold/turbo. If the impact is severe enough you may end up cracking something... it's good insurance in my opinion. It certainly doesn't have any down-sides that I can see.

I bet any decent muffler shop would have some flew-pipe... if not check out Jeg's or some other place like that.

Good luck.

 

HHHMMMM that's sounds good, since i'm building mine as we speak. It shouldn't weight much more should it?

 

Nope...

 

Here is the flex downpipe I made with 2 45 degree elbows (3") and a 3" flex pipe from Hahn Racing (marine racing). They had the best price that I've found and many parts in stock. Very fast shipping and friendly sales staff.

You may want to check your state for the laws with flex joints in the exhaust unless this car is a full race car (not on the street).

In Texas, flex joint isn't considered illegal for inspection (for now).

I'll post pics of my flex wastegate dump pipe when it is fully complete (50% there).


The one major benefit that I've seen is when you fabricate your own piping, the flex joint gives you more margin for error since it is flexible. You have a bit of margin with the flared elbows as well.

J

 

I had a DP with a peice of "flex pipe" on my FD. Flex pipe is also great when installing the downpipe because as said earlier there is a larger margine for error when lining things up. I've never used a DP without it but I would think it would be easier to install a DP that had it.

 

where can i get the end flanges if i am having to make my own downpipe?

 

Here's a 3" flange that racing beat sells, maybe you can make something work out of this 2 bolt jobber? Other than this I have no clue where to get them.

http://www.racingbeat.com/FRmazda3.htm


I looked through a Jegs catalog but I didn't see any.

Edit* The link I posted only goes to Racing Beat's page, just select exhaust flange from the drop down menu and you'll see what I was refering to. They're $15.00 a peice.

 

racing beat and mazdatrix sell the two bolt flanges. You might want to call and ask them about the turbo flange

 

turbine has a v-band flange on it

i am supposed to have a downpipe already made for it through this fish guy, but I am having trouble getting ahold of him to get it shipped out....so i'm just tryin to plan ahead for worst case scenario....

THANKS GUYS!