Going catless but keeping the noise not too obnoxious?

**Alex** · 03-20-2004, 09:34 PM

Tips for efficieny, perfomance, and not too too too much noise?

dmacalot · 03-21-2004, 12:59 AM

catless dp and stock exhaust is not obnoxious at all. i actually like it much better than the blitz nur spec exhaust that i took off when i installed the dp. damn that thing was loud.....

renichms · 03-21-2004, 08:55 AM

Godspeed downpipe with stock cat-back is very quiet, relative to a full exhaust system (aftermarket). I commented on how loud my brother's WRX wagon was (stock everything) when my dad pulled up in it and he told me my STi, with or without the downpipe, was loud anyways.

RN

olappa · 03-21-2004, 12:37 PM

Quote:

catless dp and stock exhaust is not obnoxious at all.

Same here.

Although it would be interesting to lose the other cat as well and not be too loud. Suggestions?

titsataki · 03-21-2004, 02:29 PM

I think Godspeed downpipe does make you catless. Replaces both downpipe and mid pipe cats.
How much is hp gains with Godspeed downpipe and stock exhaust vs a full aftermarket turbo back say Turbo XS or Vishnu with one high flow cat.

On the other hand how smell etc? is it very obvious when one is behind a catless car?

Cheers

Nick

renichms · 03-21-2004, 05:42 PM

Quote:

Originally Posted by titsataki

I think Godspeed downpipe does make you catless. Replaces both downpipe and mid pipe cats.
How much is hp gains with Godspeed downpipe and stock exhaust vs a full aftermarket turbo back say Turbo XS or Vishnu with one high flow cat.

On the other hand how smell etc? is it very obvious when one is behind a catless car?

Cheers

Nick

Not sure on hp gains, but pre-downpipe, I went 8.3 @ 81 mph and post-downpipe (stock cat-back) I went 8.6 @ 88 mph. If I remember right, TXS TBE is supposed to be something like 27 whp.

RN

titsataki · 03-21-2004, 06:37 PM

Quote:

Originally Posted by renichms

Quote:

Originally Posted by titsataki

I think Godspeed downpipe does make you catless. Replaces both downpipe and mid pipe cats.
How much is hp gains with Godspeed downpipe and stock exhaust vs a full aftermarket turbo back say Turbo XS or Vishnu with one high flow cat.

On the other hand how smell etc? is it very obvious when one is behind a catless car?

Cheers

Nick

Not sure on hp gains, but pre-downpipe, I went 8.3 @ 81 mph and post-downpipe (stock cat-back) I went 8.6 @ 88 mph. If I remember right, TXS TBE is supposed to be something like 27 whp.

RN

So u are catless right? Any boost creep?

cheers

Nick

renichms · 03-21-2004, 08:53 PM

No boost creep for me with stock cat-back. Tuesday, porting wastegate, retaining stock muffler, adding 3" piping to fill out the rest of the exhaust.

RN

TreyS · 03-23-2004, 07:11 AM

I have the GT-SpecII header, Godspeed DP, and Blitz NUR Spec Touring and it's quiet driving around normal and sounds mean when I'm hard on the gas but not abnoxous like the NUR Spec R. It's a lil more louder than using the OEM cat back exhaust with my setup. I was surprised at how it sounded. I can meet you if you want to go for a ride.

whiplash306 · 03-23-2004, 07:40 AM

Trey, is there any way you could post a sound clip of that combination....I have the godspeed dp on it's way now and will be ordering a set of XXtuning headers tomorrow...I am very much interested in the Blitz Nur Spec Touring Catback kit, but am a bit weary of the sound...so a clip would be GREAT!!!!!

SnowbordrWRX · 03-23-2004, 08:23 AM

Can you still pass emissions in CA with a catless dp? I sorta recall something about the dp cat not being effective once the car warms up or something like that but I'm not sure...

titsataki · 03-23-2004, 09:18 AM

It will fail the visual. the moment you remove any cat u are in violation.
An if you are catless you will fail the sniffer. And if you have a CEL for cat inefficiency is an automatic fail as well.

I think we have emissions tech's from CA on this board or Nasioc that mentioned that info.

Cheers

Nick

dmacalot · 03-23-2004, 02:35 PM

Quote:

Originally Posted by titsataki

It will fail the visual. the moment you remove any cat u are in violation.
An if you are catless you will fail the sniffer. And if you have a CEL for cat inefficiency is an automatic fail as well.

I think we have emissions tech's from CA on this board or Nasioc that mentioned that info.

Cheers

Nick

yep...a catless dp will definitely fail emissions in all sorts of ways...that is unless you know some people 8) PM if you have any ?s, i can point you in the right direction

**Alex** · 03-23-2004, 03:09 PM

Yeah, I know people 8) or I could have the car transferred to another county where no emissions testing is ever done, period.

titsataki · 03-23-2004, 03:37 PM

hard to find solutions like that in CA. They sent your emissions results straight to the DMV. But I am guessing there are ways.
Most people go back to stock and then re-install. Pain but a straightforward way to pass emissions.

Cheers

Nick

03-20-2004, 09:34 PM	#1
Alex Authorized Vendor Car: 2004.5 STi Fav Mod: Alcantara...Everything! Location: Atlanta, Ga Posts: 2,020 IWSTI Addict since: Nov 2003 Trader Rating: (11)	Tips for efficieny, perfomance, and not too too too much noise? This ad is not endorsed by this member. Please register or login to hide this ad.

03-21-2004, 08:53 PM	#8
renichms Professional STI Racer Car: 2004 Subaru Impreza Location: Birmingham, Alabama Posts: 651 IWSTI Addict since: Oct 2003 Trader Rating: (0)	Pink panthers.......... No boost creep for me with stock cat-back. Tuesday, porting wastegate, retaining stock muffler, adding 3" piping to fill out the rest of the exhaust. RN

03-23-2004, 03:37 PM	#15
titsataki The Next Petter Solberg Car: 05 STI CGM Location: New Haven, CT Posts: 984 IWSTI Addict since: Nov 2002 Trader Rating: (0)	hard to find solutions like that in CA. They sent your emissions results straight to the DMV. But I am guessing there are ways. Most people go back to stock and then re-install. Pain but a straightforward way to pass emissions. Cheers Nick This ad is not endorsed by this member. Please register or login to hide this ad.

New To Site?	Need Help?	More
REGISTER FOR FREE! IWSTI Rules/Signature Rules Create a Member Journal Bookmark IWSTI Tell your friends about IWSTI	Frequently Asked Questions Did you forget your password? Make a suggestion or report a bug Mark Forums Read Contact Us	Member Journals Forum Pictures & Photography Forum GR Series (08+) Marketplace GD Series (03/04-07) Marketplace Hot eBay Deals Forum Beyond Off Topic

03-21-2004, 12:59 AM	#2
dmacalot S204 Racer Car: 04 Fav Mod: teh hot wimmenz Location: so. cal Posts: 4,398 IWSTI Addict since: Dec 2003 Trader Rating: (0)	catless dp and stock exhaust is not obnoxious at all. i actually like it much better than the blitz nur spec exhaust that i took off when i installed the dp. damn that thing was loud.....

03-21-2004, 08:55 AM	#3
renichms Professional STI Racer Car: 2004 Subaru Impreza Location: Birmingham, Alabama Posts: 651 IWSTI Addict since: Oct 2003 Trader Rating: (0)	Godspeed downpipe with stock cat-back is very quiet, relative to a full exhaust system (aftermarket). I commented on how loud my brother's WRX wagon was (stock everything) when my dad pulled up in it and he told me my STi, with or without the downpipe, was loud anyways. RN

03-21-2004, 02:29 PM	#5
titsataki The Next Petter Solberg Car: 05 STI CGM Location: New Haven, CT Posts: 984 IWSTI Addict since: Nov 2002 Trader Rating: (0)	I think Godspeed downpipe does make you catless. Replaces both downpipe and mid pipe cats. How much is hp gains with Godspeed downpipe and stock exhaust vs a full aftermarket turbo back say Turbo XS or Vishnu with one high flow cat. On the other hand how smell etc? is it very obvious when one is behind a catless car? Cheers Nick

03-23-2004, 07:11 AM	#9
TreyS Spec C Club Car: 04 STi Fav Mod: Track Day! Location: Atlanta Posts: 1,432 IWSTI Addict since: Nov 2003 Trader Rating: (0)	I have the GT-SpecII header, Godspeed DP, and Blitz NUR Spec Touring and it's quiet driving around normal and sounds mean when I'm hard on the gas but not abnoxous like the NUR Spec R. It's a lil more louder than using the OEM cat back exhaust with my setup. I was surprised at how it sounded. I can meet you if you want to go for a ride.

03-23-2004, 07:40 AM	#10
whiplash306 Spec C Club Car: '02 ZO6 & '86 GN Fav Mod: Registered Nurse, BSN Location: Central Texas Posts: 1,146 IWSTI Addict since: Oct 2003 Trader Rating: (2)	Trey, is there any way you could post a sound clip of that combination....I have the godspeed dp on it's way now and will be ordering a set of XXtuning headers tomorrow...I am very much interested in the Blitz Nur Spec Touring Catback kit, but am a bit weary of the sound...so a clip would be GREAT!!!!!

03-23-2004, 08:23 AM	#11
SnowbordrWRX Drive True Posts: 3 IWSTI Addict since: May 2002 Trader Rating: (0)	Can you still pass emissions in CA with a catless dp? I sorta recall something about the dp cat not being effective once the car warms up or something like that but I'm not sure...

03-23-2004, 09:18 AM	#12
titsataki The Next Petter Solberg Car: 05 STI CGM Location: New Haven, CT Posts: 984 IWSTI Addict since: Nov 2002 Trader Rating: (0)	It will fail the visual. the moment you remove any cat u are in violation. An if you are catless you will fail the sniffer. And if you have a CEL for cat inefficiency is an automatic fail as well. I think we have emissions tech's from CA on this board or Nasioc that mentioned that info. Cheers Nick

03-23-2004, 03:09 PM	#14
Alex Authorized Vendor Car: 2004.5 STi Fav Mod: Alcantara...Everything! Location: Atlanta, Ga Posts: 2,020 IWSTI Addict since: Nov 2003 Trader Rating: (11)	Yeah, I know people 8) or I could have the car transferred to another county where no emissions testing is ever done, period.