I need some opinions on exhaust piping size. At the moment Im running a 5zigen cat back system that uses a y-pipe and a 2.75inch center section. This then splits to to 63mm outlets and goes into the rear boxes.

Im having a motor built at the moment for use with my APS TT and I need to get a better flowing exhaust. Im looking into having a custom center section fab'ed up using 2.5 inch pipework with an x-pipe. My tuner said that dual 3 inch would be better but Im only looking for 500-525WHP. Dual 2.5 inch pipe work cant be a bad flow restriction at this power level can it? Dual 3 inch pipework is HUGE and will be alot harder to fit under the car with the x-pipe.

What do you lot think on this? Thanks for any reply's.

Tim.

 

Time, are you dead set on the crossover pipe?

I have the APS true dual 3" exhaust and it is loud, but fits under the car with no issues. It is beautiful at idle, sounds like a V8, at WOT it screams too. The issue is at around town speeds there is a good bit of resonnance (sp?) that can be a bit annoying.

The 2.5" should be fine for 500whp (DJ) and with the crossover should be relatively quiet as well. You could always get the 3" duals and then just cut and weld in the 2.5" crossover too

 

Cass the X pipe was recommended by the exhaust fabricator. Ive been trying to work out what sort of CFM a twin 2.5 inch will flow vs. a twin 3 inch.

I dont want the exhaust to drone badly i just need extra flow. The numbers im looking for will be DD numbers a little more like 550DJ.

I can't see a dual 2.5inch system being a problem? I know the less back pressure down stream of the turbo the better but twin 3 inch seams a bit OTT ??

Thanks for helping out.

 

wait for the motordyne tdx exhaust, should flow really and shouldnt drone

 

+1 you should just wait for the TDX and have a full 3' exhaust. Its made for FI setups. Plus it will sound so awesome!

 

any one have a link to the TDX exhaust??

 

go to youtube and search for motordyne tdx

they have it for g35 just not 350z.

 

Is the TDX for FI going to be a Y pipe configuration or a true dual? All the ones I've seen for the G35 so far are Y pipe. For a twin turbo I would rather have a true dual with no cross over pipe. I'm not saying that there is anything wrong with the Motordyne exhaust by any means, just that I would personally rather go with a 3" TD with twins.

 

true dual

 

I am in this same situation with my Greddy Ti-c dual and APS TT

 

A 2.5" true dual exhaust will flow plenty for your needs at this time. I've been running a modified stillen exhaust with my aps tt with no restrictions in the flow for a while now.

 

2.5" is PLENTY for what you're looking for. No need for 3" imo