Hey guys. my setup is tanabe catback, stillen HFC, and Stillen y pipe. i installed the y pipe today, and after that i can just hear so much more rasp. what do you think are my options? do you think i should give it a couple of weeks to settle down, or the rasp is gona be there still. i always thought rasp was only there from test pipes, but i guess i am wrong. Do you guys think there could be other reasons involved like improper installation maybe. Let me just know what would be the best bet. btw i can smell a lot more fumes.

 

i heard there was a lot of rasp from the y pipes due to the thickness/skinniness of it. Also the opening I think may be either too big or too small where it connects to the midpipe. Chris (g35papa) had a y pipe on at one point but took it off because it created a rasp. Not sure since you have some HFC's, but my bet would be because of the y pipe.

Do you have any videos of it? I would like to hear it

 

ill take some vids n show u. hmmm thats soo weird, but the y pipe could be the culprit.

 

Rasp won't get better, it will get worse.

 

The collector on the Stillen is 3 inch and the Tanabe piping is 2.75 inches. The transition from one to the other is not smooth and is causing the rasp. Think about it in terms of water. if you have water flowing in a 3 inch pipe and it suddenly goes into a 2.75 inch pipe the smooth flow will be disturbed and slow. I say return the Stillen and get the Tanabe y pipe. They both have a 2.75 inch collector and should eliminate the rasp. You could have an exhaust shop make a smoother transition, but you will have a hard time selling the parts they alter later.

The only potential issue I can see it the tanabe Y pipe has a 2.36(60mm) inlet. If the Stillens are 2.5in (which I think they are) you will have another location where the flow is disrupted. You might just get rid of the Tanabe exhaust and get a 3 inch y pipe back to avoid these problems.

 

put a resonator on the y-pipe

 

damn!!! What do you guys think the most cost effective solution would be. the stillen HFC and the stillen y pipe should fit properly, but the tanabe and stillen are not mixing. should i tell a exhaust shop to maybe reduce the diameter of the y pipe from 3.00 to 2.75, so that there will be better transition? or just not mess with it, and maybe just wait to get a stillen catback? so everything is just one brand.

 

That would probably be the most cost effective solution. Something like this: http://store.summitracing.com/partde...5&autoview=sku

The only problem will be 2.75 is an odd exhaust size so your shop will probably have to custom make it. You want a smooth transition, not abrupt like there is currently.

Edit: Just found what might be what you need. There are no pice, but it is a 3in to 2.75 reducer: http://store.summitracing.com/partde...5&autoview=sku

 

k thanks for your help man. really appreciate. im gona go talk to the exhaust shop today. hopefully they can reduce the y pipes diamter on the catback side. shouldnt be too expensive. Do you know any place in OC, cause i see that your from SOCAL as well. i shouldnt tell them to touch the side where the HFC and the y pipe meet right, cause that should be a good transition. Ill make him sit in my car, n make him hear it first lol, and then tell him to fixx itt.

 

Anything else i need to do so that i can tell rasp to f off?

 

Since the parts were not made for each other you will have to go with trial and error. Hopefully the reduction will work, have your exhaust guy listen and see what he recommends. I live in the Palm Springs area so I have no idea about shops in OC. Go on the SoCal section and ask there, someone will have preferred shop.

 

i had this same problem when i added FI HFC to my impul system, i took the impul y-pipe out and put in the MD xyz pipe with resonator and it got rid of the rasp. So its probably your ypipe

 

yup looks like the y pipe has to be fixed. i will let u know what my exhaust shop tells me

 

It's amazing how a pair of turbos can get rid of all the rasp.
Even with 3" test pipes...

 

Getting a Y-pipe with a 2.75" outlet won't fix the problem.

Some exhaust systems are more susceptible to rasp than others when HFC's or test pipes are used.

Apparently your system is one of the more sensitive ones. It may be the only way to fix it is to put on the stock cats or a resonated XYZ.