I have noticed that some exhaust systems advertise "downpipe-back" and others advertise "Turbo-Back".
Is there an exhaust restriction issue with the stock cast elbow if I upgrade to a 4"?

 

It's negligible. The bigger turbos have a full 4" outlet flange on the turbos. The factory ones have a 3" neck on them since that's the size of the factory exhaust.

 

if you want to stay with an hx 35 or similar, banks offers a power elbow. i saw a decent improvemtent in response with the 4" and the elbow. they offer an elbow with a downpipe for much less. i think that's the way to go for the buck. i paid way too much for my exhauste system but i was ignorant back then. this site has educated me a lot.

 

so knowing what you know now... if you wanted to stick with the hx35, and run RV275's and either the EZ or the VA, what would you do for exhaust? 4 inch alum? which system, elbow, downpipe, etc...

 

If all you want to run is a set of 275's and an EZ then I'd stick with a straight piped factory exhaust. EGT's won't be a problem if you've got a good flowing intake.

 

I "should" be ok running the 100hp nozzles and the va box with my 5 inch exhaust and a bhaf correct? I'm sure that I would benefit if I had a PDR HX35 or something similar, but that is 3 steps down the line. (1 FASS,2 clutch,3 turbo upgrade) What do you think?

 

100hp jets and a VA box would probably have your turbo and your clutch both crying for mercy. My comp and 275's have my turbo screaming. I'd ditch the BHAF for a scotty 2 if I were you. Your gonna need all of the cool air you can get into that turbo to keep EGT's somewhat in check.

 

micah:

depends on how much you want to spend. i think the stock exhaust would suffice if u had a good intake. the stock elbow on the hx35 is a lot smaller than the banks one. you could see where it was restricting flow and had a lot of (carbon?) build up on some areas. i did feel i got my monies worth there. but if you think you're gonna have egt issues i'd go with the elbow and the downpipe they sell. don't know the price of it but there's some exhaust systems (whole) out there that might be close to the price they want for the elbow and downpipe. i don't think theres much out there for downpipes for the hx35? check with piers or rip and they will know more than i do. they seem to be the best people on this forum to deal with?