Hey guys. I recently purchased an '09 G37S Coupe (6MT) and have totally fallen in love with the car. I've done Eibach Pro Kit Springs and Tanabe Axleback so far. I recently purchased the Berk HFC and the ISR Y-pipe because I am hoping to continue building out the exhaust. I didnt buy the Tanabe Y-pipe because $500 is way too expensive for a simple y-pipe. Just wondering if anyone has experience with the Berk HFC/ISR/Tanabe combination, and if anyone has suggestions for future exhaust work/mods.

Thanks!

 

I have the Tanabe axle back, a Top Speed y-pipe (identical to ISR) and resonated test pipes not installed yet. Did you get resonated HFC? If not, its gonna be quite raspy... With just the axle back and y-pipe the exhaust sounds amazing, I really love it. My build thread has sound clips if you want to check them out. With high flow cats it'll just sound the same but throatier.

 

TopSpeed and ISR Y pipes are not the same, ISR has a formed merge, Topspeed looks like they just jammed the pipes up and welded them.

Topspeed:


ISR


That being said, they should flow roughly the same.

I run an ISR Y pipe on my car (stock cats, stock exhaust) and its very slightly louder but not really noticeable after you drive for a few days.

If you went with a high flow cat and the ISR Y Pipe the Tanabe would probably sound pretty good and not terribly raspy since you still have a cat. I tried the resonated test pipes out from ISR and they were pretty cool and the car felt more responsive/faster but they were a little loud for my liking so I will be going to a high flow cat to keep the car a little quieter.

 

Ah, I googled ISR because I never heard of them and must have been shown a Top Speed version lol, my bad.. BUT tomayto/tomawto, I could argue that the ISR has only two, more drastic angles instead of the Top Speeds four, less angled curves. Not to mention the Top Speed merges together in a larger area compared to the ISR, which is easily seen in your pictures, its a wash.. Like you said though, I'll bet money they flow within 2-3 CFM of each other in the exact same settings.

 

I like the merge on the ISR a bit more, internally its pretty large/smooth, compared to the other where it looks like they took the pair of 2.5" pipes and just smashed them into a 3" pipe, the merge on the top speed looks kind of crowded IMO.

Internally the ISR is really big.


I also dig the little dimple brace with the angle at the front, sort of acts as a skid plate so you avoid snagging on speed bumps and what not, instead it just skips over without really grabbing at the Y pipe

 

Ohhhh that IS sick, I didn't see that before, yeah ISR is def superior..