is rasp normal from a gt spec header?

adWRXi · 07-07-2008, 01:24 PM

i just installed a wrapped gt spec gen 2 unequal length header and uppipe onto my sti. it already has a catless downpipe and catless/resonatorless catback (invidia n1 race.)

now when hi rpms or low rpms in 1st and 2nd gear it sounds raspy, it sounds like cars flapping. i hate it! is this normal from this header? or is it because the car doesnt have a resonator? i know it was fine before this install. its embarrassing getting on the gas so i never do anymore =/

if it is the resonatorless catback, im probably going to get the street version of the same catback which has a resonator. or does anyone have recommendations for another very throaty, deep catback that has the canister look?

Evan · 07-07-2008, 01:25 PM

A flapping sound usually indicated a leak somewhere in the system. Might want to check all your connections

adWRXi · 07-07-2008, 01:27 PM

ahh are you serious?? i just paid a guy at a shop to check for leaks !!

its coming from the back of the car tho.

also, i had a bad launch the other day and i heard a "sputtering air" sound coming from the front. thats a for sure leak yea? im definetly going back tomoro.

Evan · 07-07-2008, 01:31 PM

Quote:

Originally Posted by adWRXi

also, i had a bad launch the other day and i heard a "sputtering air" sound coming from the front. thats a for sure leak yea? im definetly going back tomoro.

Depends, did you're rpm's jump when you heard this noise? Did you reach target boost when you heard the noise?

***VSGTS14*** · 07-07-2008, 02:03 PM

exhaust leak, most likely from the header.
use remflex header gaskets, they'll seal way better with your gt spec header. that's what i'm using with my gt spec.

adWRXi · 07-07-2008, 02:32 PM

well i had my vf39 p&p and a bigger tmic put on at the same time as the header/uppipe. i used to hit 18.5 psi but now it only gets to 14-15 psi. it DOES hold though.. and nothing acts funny, its all still ok. so i dunno..

i hate leaks.

Evan · 07-07-2008, 02:43 PM

From the sounds of it, you have a boost leak and a header or up-pipe leak. As for your boost, connect your AP if you have one and look at your wastegate duty cycle, if it's closed ALL the time that means you have a boost leak and the turbo is working as hard as it can to get you to your target boost

CarJway · 07-07-2008, 03:45 PM

I almost have the exact same setup, except my Cat-back is the Invidia Titanium. The exhaust is raspy when it's cold. (Muffler) But, once the actual muffler warms up, the raspy, 4 - banger noise is gone. Does the raspy sound persist after a good 10-20 minutes of driving?

***Szumita*** · 07-07-2008, 04:03 PM

yeah, definatly sounds like a leak...

and, non-res could be raspy, not sure though.

adWRXi · 07-07-2008, 08:29 PM

ya the rasp is really bad when you first turn the car on. after it warms up, its pretty much gone. ive also noticed that there is barely any rasp if i turn on defrost of a/c.

if there was a boost leak, wouldnt full boost be unstable? because this holds.

***VSGTS14*** · 07-08-2008, 07:32 AM

it can still boost, but it won't be boosting the correct amount.

bluedemon_II · 07-08-2008, 07:55 AM

If you have a boost leak you will still boost but maybe no hit target and the air will be a lot hotter from the turbo working harder to reach said boost. Use oem Gaskets on all your exhaust parts and have them torqued correctly.

I have never heard a raspy subaru before

if it sounds like a honda, id do anything in my power to fix it

.

my94saleen · 07-08-2008, 11:33 AM

my car is the same.real rapsy at low rpm/ or partail throttle.wot it sounds bad ass.i have an ebay (edge) header.i know its cheap but for the price and performance its deff worth it.me and my buddy have both had them for over 2 years w/ no problems or cracks like many other pricey headers out there.but we both thought we had exhaust leaks too.but there both leak free.i myself am not a fan of the raspyness though.

fourseasonsandles · 07-08-2008, 11:45 AM

Quote:

Originally Posted by adWRXi

well i had my vf39 p&p and a bigger tmic put on at the same time as the header/uppipe. i used to hit 18.5 psi but now it only gets to 14-15 psi. it DOES hold though.. and nothing acts funny, its all still ok. so i dunno..

i hate leaks.

def sounds like a leak to me as well. I installed my Maddad headers and UP. The sound changed some, but I only lost about .5psi. I talked to my tuner and he said this is normal when you swap to aftermarket headers. I have had my tune and I am running about 19psi right now.

Even on a base Stage 2 map, 14-15psi sounds way low.

07-07-2008, 01:24 PM	#1
adWRXi Amateur STI Driver Car: JBP 04 WRX Fav Mod: Coming Soon Posts: 24 Join Date: Feb 2008 Trader Rating: (1)	is rasp normal from a gt spec header? i just installed a wrapped gt spec gen 2 unequal length header and uppipe onto my sti. it already has a catless downpipe and catless/resonatorless catback (invidia n1 race.) now when hi rpms or low rpms in 1st and 2nd gear it sounds raspy, it sounds like cars flapping. i hate it! is this normal from this header? or is it because the car doesnt have a resonator? i know it was fine before this install. its embarrassing getting on the gas so i never do anymore =/ if it is the resonatorless catback, im probably going to get the street version of the same catback which has a resonator. or does anyone have recommendations for another very throaty, deep catback that has the canister look? This ad is not endorsed by this member. Please register or login to hide this ad.

07-07-2008, 01:25 PM	#2
Evan STI Driver Car: '05 WRB STi Fav Mod: Open Downpipe Location: back in Abilene, TX :( Posts: 273 Join Date: Dec 2006 Trader Rating: (2)	Re: is rasp normal from a gt spec header? A flapping sound usually indicated a leak somewhere in the system. Might want to check all your connections

07-07-2008, 01:27 PM	#3
adWRXi Amateur STI Driver Car: JBP 04 WRX Fav Mod: Coming Soon Posts: 24 Join Date: Feb 2008 Trader Rating: (1)	Re: is rasp normal from a gt spec header? ahh are you serious?? i just paid a guy at a shop to check for leaks !! its coming from the back of the car tho. also, i had a bad launch the other day and i heard a "sputtering air" sound coming from the front. thats a for sure leak yea? im definetly going back tomoro.

07-07-2008, 02:03 PM	#5
*VSGTS14* Muller Chevrolet Car: 08 Chevy 2500HD Fav Mod: a new 08 STi Location: Milford, NJ Posts: 9,844 Join Date: Oct 2004 Trader Rating: (11)	Re: is rasp normal from a gt spec header? exhaust leak, most likely from the header. use remflex header gaskets, they'll seal way better with your gt spec header. that's what i'm using with my gt spec.

07-07-2008, 02:32 PM	#6
adWRXi Amateur STI Driver Car: JBP 04 WRX Fav Mod: Coming Soon Posts: 24 Join Date: Feb 2008 Trader Rating: (1)	Re: is rasp normal from a gt spec header? well i had my vf39 p&p and a bigger tmic put on at the same time as the header/uppipe. i used to hit 18.5 psi but now it only gets to 14-15 psi. it DOES hold though.. and nothing acts funny, its all still ok. so i dunno.. i hate leaks.

07-07-2008, 02:43 PM	#7
Evan STI Driver Car: '05 WRB STi Fav Mod: Open Downpipe Location: back in Abilene, TX :( Posts: 273 Join Date: Dec 2006 Trader Rating: (2)	Re: is rasp normal from a gt spec header? From the sounds of it, you have a boost leak and a header or up-pipe leak. As for your boost, connect your AP if you have one and look at your wastegate duty cycle, if it's closed ALL the time that means you have a boost leak and the turbo is working as hard as it can to get you to your target boost

07-07-2008, 03:45 PM	#8
CarJway Amateur STI Driver Posts: 15 Join Date: May 2007 Trader Rating: (1)	Re: is rasp normal from a gt spec header? I almost have the exact same setup, except my Cat-back is the Invidia Titanium. The exhaust is raspy when it's cold. (Muffler) But, once the actual muffler warms up, the raspy, 4 - banger noise is gone. Does the raspy sound persist after a good 10-20 minutes of driving?

07-07-2008, 04:03 PM	#9
*Szumita* i eat cones Car: 08.5 GTI MKv Fav Mod: 18x8 Location: ma & ri Posts: 6,478 Join Date: Oct 2006 Trader Rating: (16)	Re: is rasp normal from a gt spec header? yeah, definatly sounds like a leak... and, non-res could be raspy, not sure though.

07-07-2008, 08:29 PM	#10
adWRXi Amateur STI Driver Car: JBP 04 WRX Fav Mod: Coming Soon Posts: 24 Join Date: Feb 2008 Trader Rating: (1)	Re: is rasp normal from a gt spec header? ya the rasp is really bad when you first turn the car on. after it warms up, its pretty much gone. ive also noticed that there is barely any rasp if i turn on defrost of a/c. if there was a boost leak, wouldnt full boost be unstable? because this holds.

07-08-2008, 07:32 AM	#11
*VSGTS14* Muller Chevrolet Car: 08 Chevy 2500HD Fav Mod: a new 08 STi Location: Milford, NJ Posts: 9,844 Join Date: Oct 2004 Trader Rating: (11)	Re: is rasp normal from a gt spec header? it can still boost, but it won't be boosting the correct amount.

07-08-2008, 07:55 AM	#12
bluedemon_II Senior STI Driver Car: 04 Sti Wrb on Silver Location: Hatillo, Puerto Rico Posts: 385 Join Date: Jul 2007 Trader Rating: (0)	Re: is rasp normal from a gt spec header? If you have a boost leak you will still boost but maybe no hit target and the air will be a lot hotter from the turbo working harder to reach said boost. Use oem Gaskets on all your exhaust parts and have them torqued correctly. I have never heard a raspy subaru before if it sounds like a honda, id do anything in my power to fix it .

07-08-2008, 11:33 AM	#13
my94saleen Amateur STI Driver Car: 06 sti blue Posts: 20 Join Date: Oct 2006 Trader Rating: (0)	Re: is rasp normal from a gt spec header? my car is the same.real rapsy at low rpm/ or partail throttle.wot it sounds bad ass.i have an ebay (edge) header.i know its cheap but for the price and performance its deff worth it.me and my buddy have both had them for over 2 years w/ no problems or cracks like many other pricey headers out there.but we both thought we had exhaust leaks too.but there both leak free.i myself am not a fan of the raspyness though.