How to eliminate raspiness from 3.0R?

[legacyshawn]

Hi guys. I've been reading through these forums a while now and thought I'd join to ask you all a question since the 3.0R is more prevalent in Australia.

Anyways, I recently had my raptor headers installed and the shop didn't have much expertise as I first thought. Long story short, I ended up completely catless. The instant I revved it, I cringed at the tinny rasp. I'm getting some 200 cell magnaflow cats installed soon. But that won't be enough. I have Perrin straight through mufflers and the stock midpipe with the stock resonator.

My question is what else can I do to eliminate the rasp? I've been looking into a borla XR-1 oval and vibrant ultra quiet resonators. Should I replace me stock resonator with two of these guys? Otherwise I can't see how I'm going to fit another resonator in there!

Oh and here's video of it during the storm.
http://youtu.be/ffPdH4fj4Q8

[Swipez]

Mate, xforce centre muffler and Y Pipe Assembly, pair of xforce single outlet mufflers, or tcp auto Quads. Done problem solved. Put the Aftermarket cats back where the stock ones were. Keep 3rd cat deleted tho...

[vertix]

Not quite that simple I have exactly that setup, but still have rasp.

The 200cell cats will definitely help, though I would not recommend going below 200, the more free flowing/less restrictive cat = less effect on the sound. I have raptor headers, 100cell cats, xforce centre & Y pipe with hurricane quads (also have xforce mufflers, but prefer the quads) and still have a fair amount of rasp around 2.5k rpm. Though other cars I've heard at meets with identical setup, but with 200cell cats definitely have far less noticeable rasp than me.

Any form of muffling, as close to the headers as possible, will greatly help in reducing the rasp.

[Rustedhentai]

Also did you get it tuned to suit the new headers? I have heard that a good tune can make all the difference and should be done regardless when fitting the raptor headers.

[legacyshawn]

Yeah I do have it on a base tune with Matt from Kido tuning but I haven't logged it yet since I wanted to finished doing the exhaust first.

I had it up on the lift today and noticed the shop stripped the O2 sensors and they were seated all the way making the crush washer rattle. When I have the cats welded on, I'll get some new upstream sensors put on with downstream sensors removed from the tune.

Does anyone have any side profile views of their exhaust? Mine seems like it's hanging a little low even though I'm using a part of the stock y-pipe (just the outer pipe).

[Tradewind]

I may have already told you by email, if not then .......

Cats always remove a certain amount of harshness from the exhaust note but are not going to provide any real muffling as such

You need to be fitting a decent muffler/silencer directly after the point where the 2 pipes come together, before the sound starts down the straight mid section stretch.

This problem exists with ALL small capacity V6, H6 and straight 6 engines. You have to provide decent muffling up front.

If you are just going to rough out a system with used pipe and no mufflers or cats much at all, prepare yourself for the worst sounds in your life, guaranteed you will get them lol

Regarding height, the stock pipe that feed into the cats has a slight up kick in it before it goes into the cats, this is how Subaru keep the pipe "up" under the car after it leaves the exhaust header section, you have removed this - meaning now your system is slightly low all the way through.

Hope that helps

[legacyshawn]

Thanks for the input Tim.

Yeah it was never in the plan to adopt the old pipes or go catless but the shop had already cut everything up and seemed too incompetent to cut the cats and weld them on. I didn't really have much of an option at this point because i know about the upward bend to the cat and didn't want it to hang even lower.

I'm livid after seeing this yesterday and I've confronted the shop. This was my first dealings with exhaust work at a shop... I guess you live and learn. Here's to hoping others can learn from this and know what to watch out for.

[Daytona]

With my findings with exhaust shops, it's hard finding a good one.
My journey with the exhaust:

viewtopic.php?f=16&t=29542

First shop I went to did the headers and replaced the cats. Second shop I went to did the front and mid resonators. Third shop just had a look.
Fourth shop fitted the Vibrant 1141 resonator near where the 3rd cat was (thanks McDoof for info on the Vibrant).

I used to have some pics on here, but ended up having a clean up of all my crap on the internet and they went away. I'll try and stick them on Imgur if you want to see.

I was in the same sort of boat as you - rasp. As Tim points out - muffling up front is important. My setup isn't totally ideal, but most of the rasp is gone and I love the sound now.
Took a lot of time and patience to get it sorted though!

Fingers crossed with lotto, if that happens, I'll be getting a supercharger!

[Swipez]

Not quite that simple I have exactly that setup, but still have rasp.

The 200cell cats will definitely help, though I would not recommend going below 200, the more free flowing/less restrictive cat = less effect on the sound. I have raptor headers, 100cell cats, xforce centre & Y pipe with hurricane quads (also have xforce mufflers, but prefer the quads) and still have a fair amount of rasp around 2.5k rpm. Though other cars I've heard at meets with identical setup, but with 200cell cats definitely have far less noticeable rasp than me.

Any form of muffling, as close to the headers as possible, will greatly help in reducing the rasp.

Haha, I apologise then I have TB STi Quads and they have eliminated ALL rasp from my system...

[legacyshawn]

I ended up putting the two vibrant 12" 2.25" bottle style resonators in the Y-pipe after the cats. That pretty much killed the rasp 80% between the 2-4K RPM.

Then I went ahead and installed a Borla cat back that I bought with a resonator delete thinking the rasp would return... But lo and behold it's sound smooth and beautiful! Slightly race carish so I may put a resonator in the midpipe but for now I'm happy.

The advice going around from Tim held true: attenuating the rasp by installing resonators or cats closest to the headers will have best impact.

https://youtu.be/-G8n-0QkDiE

[JBM3.0NZ]

just bought some two vibrant 12" 2.25" bottle style resonators ....after reading your post

[applegeek897]

For comparison this is my set-up

- Raptor Headers
- 2x Highflow Maganaflow cats
- 3rd cat delete
- custom 2.25" Stainless mid section
- 2.25" XForce Mild Steel cat back.



And the video of the final product with E85 tune - https://www.youtube.com/watch?v=KMjPVt23lwI -

[Housemusic1]

Any pics of the rest of the setup?

[owen]

This is how you get rid of the rasp

[owen]

K2 Gear make a full system to suit 3.0R-B