Did a search and could not find the specific answer...
Is flexpipe only needed if you do a custom downpipe setup? Or can I use a testpipe with the original greddy downpipe? Why is this?

Going to 3" exhaust and need to know. Setup is a 18G Greddy turbo kit on B18b, 4 door LS. Thanks for any help. Going to order from Kteller most likely or go with Thermal Turbo from K-S..

Jay

 

the flex pipee alows some movement and flex in the dp so it helps prevent cracking of the manifold.

 

Ok, well if I am going to 3 inch exhaust do I need to weld flex pipe onto my greddy downpipe and hook the cat back on from there or is a test pipe OK to use with the greddy setup/downpipe? I hope I dont sound like a ... Thanks

 

you can either use a flex pipe or use spring bolts like they put on the cats from the factory, its user preference though. some use thme , some dont i just used one just for peace of mind.

 

Anyone else have any other opinions on this? Another post says 3" is too big for a basic Greddy setup. Running stock boost.

 

like i said i run a 2.5 inch apexi n1 i had with my na set up . i amde my pwoer on my 1st tuning session i coulda got more on the next one . mie didnt hold me back much , it staying on too , i will just open the dp via cutout when i need the rest of the umph.
its a **** load cheper then getting a new ex system

 

i just made a 3 in downpipe and exhaust for my car. i didnt use a flex pipe, yet. i will once i break a weld, and i am sure i will. you would be suprised how much your motor torques on stock mounts.
i would you use one if i were you