is it necessary to use a flex pipe to connect the downpipe to the exhaust?

 

are you using the stock exhaust with those spring loaded bolts? if not then i believe the answer is yes always.

 

It's a good idea, metal expands when hot and you need that "flex" in order to prevent cracking, etc.

 

the main problem is the engine rocking. if you have ever seen a dyno run on a stock engine (with stock motor mounts) you'll see the whole motor flex back and forth like +- 3 inches as it tries to rotate around the drive axles.

 

They are so cheap anyway, so why not. I can't see saving $30.00 only to crack your $300.00 header or worse break it off at the head! Go to JCWhitney, they have great prices.

 

I'm still learning, but IMO that's like spending big dollars on a Precision BB turbo and then putting rubber hoses with holes in them as your oil feed line

 

Im building a 3 inch exhuast for a daily driven car.

Im trying to decide whether to purchase a flex pipe. It'll be about 75 bucks extra installed.
My theory is since the car has more power and torque, the engine will want to move around more, and increasing the changes of braking a part of the exhuast system.

Is that a good theory or not?

 

from what i've seen, it's important to have one. my neighbor went through 2-3 greddy downpipes before realizing that they broke due to the absence of a flex pipe.

 

i need flex pipe. They completly screwed up the bolts on the turbo and I had to retap the exhaust housing.

 

good thing, because i just ordered a flex pipe....

thanks guys

 

I'm getting ready to order a 3" downpipe, but I've broken the weld from my downpipe to my cat 3 times. I will definitely put a flex pipe on my new downpipe.

 

Here's what happened to mine because of a broken <HaSport> rear motor mount, BUT the same thing could happen from lack of flex pipe!

 

Same EXACT ting happened to me when I first put turbo on.
I installed a flex pipe with the new downpipe, no problems since.

 

thanks for the reasuring thoughts that my 75 bucks wont goto waste...

 

how did you break your hasport rear mount?

 

please you personal messages for conversation off topic to the post