True Duals Rasp???
07-13-2009, 08:25 AM
#1
TECH Enthusiast
Thread Starter
iTrader: (8)
Join Date: Jun 2008
Location: Stockbridge, MI
Posts: 724
Likes: 0
Received 0 Likes
on
0 Posts
True Duals Rasp??? Not really sure if this belongs here or not, as i am not sure the exhaust is the problem. Anway i'll explain my situation.
Stock Long block LS1 with 65,000 miles, 2000 Camaro Z28.
This spring i installed a Fast 90 and NW90 throttle body. I also removed A.I.R and EGR.
I then installed race style Pacesetter headers, and a complete TSP true dual system with Dyomax bullets.
My question is, why do i get so much rasp and popping on decel? From what i understand i shouldnt have any rasp, but on decel or the engine comming down in RPMs i get backfiring and rasp. Is this just because i have almost no backpressure? I have a set of high flow cats, and i'll most likely get an exhaust shop to install them eventually, do you think this will help?
I'm also wondering if it isnt a tuning problem. I Sent the computer out to Brian at PCM's for less, and havent had any complaints, but im wondering if my A/F is off. The car doesnt seem to make any power until about 3000 rpms. If i take off from a dead stop without dumping the clutch, i get barely any wheel spin, but if i take off from a 30 roll in 1st gear, it will blow the tires off!
I'm also wondering if i dont have an exhaust leak problem somewhere and that is causing my rasp, i dont hear any popping under the hood from the headers, and i tightened the f^ck out of all the band clamps that came with the kit.
If anyone can give me any insight i would appreciate it. Unfortunatly a dyno tune is out of the question finacially right now ( i just bought a house).
Stock Long block LS1 with 65,000 miles, 2000 Camaro Z28.
This spring i installed a Fast 90 and NW90 throttle body. I also removed A.I.R and EGR.
I then installed race style Pacesetter headers, and a complete TSP true dual system with Dyomax bullets.
My question is, why do i get so much rasp and popping on decel? From what i understand i shouldnt have any rasp, but on decel or the engine comming down in RPMs i get backfiring and rasp. Is this just because i have almost no backpressure? I have a set of high flow cats, and i'll most likely get an exhaust shop to install them eventually, do you think this will help?
I'm also wondering if it isnt a tuning problem. I Sent the computer out to Brian at PCM's for less, and havent had any complaints, but im wondering if my A/F is off. The car doesnt seem to make any power until about 3000 rpms. If i take off from a dead stop without dumping the clutch, i get barely any wheel spin, but if i take off from a 30 roll in 1st gear, it will blow the tires off!
I'm also wondering if i dont have an exhaust leak problem somewhere and that is causing my rasp, i dont hear any popping under the hood from the headers, and i tightened the f^ck out of all the band clamps that came with the kit.
If anyone can give me any insight i would appreciate it. Unfortunatly a dyno tune is out of the question finacially right now ( i just bought a house).
07-13-2009, 12:14 PM
#4
TECH Enthusiast
Thread Starter
iTrader: (8)
Join Date: Jun 2008
Location: Stockbridge, MI
Posts: 724
Likes: 0
Received 0 Likes
on
0 Posts
Welli suppose the rasp isnt on decel, but it definately pops and backfires. IDK i'll make a video tonight and post it. The more i get to thinking about it, i think the tune might be off. IDK i dont think i will ever Mail order tune again.
07-13-2009, 09:04 PM
#6
TECH Enthusiast
iTrader: (1)
Join Date: Sep 2008
Location: Fairfax, Virginia
Posts: 584
Likes: 0
Received 0 Likes
on
0 Posts
Can someone please explain what is actually meant by the description of "rasp" from exhaust? I'm looking to get my full exhaust installed here pretty soon and I see this word thrown all over the place.
Last edited by Adam2001WS6; 07-13-2009 at 09:46 PM.
Trending Topics
07-13-2009, 10:23 PM
#8
To me, its simply any unpleasant noise your exhaust can make.
http://www.merriam-webster.com/dictionary/rasp. Thats the best I can do.
07-14-2009, 05:15 PM
#10
TECH Enthusiast
iTrader: (1)
Join Date: Sep 2008
Location: Fairfax, Virginia
Posts: 584
Likes: 0
Received 0 Likes
on
0 Posts
A little off topic, but thats actually a pretty good question.
To me, its simply any unpleasant noise your exhaust can make.
http://www.merriam-webster.com/dictionary/rasp. Thats the best I can do.
To me, its simply any unpleasant noise your exhaust can make.
http://www.merriam-webster.com/dictionary/rasp. Thats the best I can do.
07-18-2009, 06:37 AM
#13
12 Second Club
iTrader: (4)
Join Date: Aug 2004
Location: Cape Cod, MA
Posts: 336
Likes: 0
Received 0 Likes
on
0 Posts
That sounds normal. I have TSP true duals and I get popping on decel, and I AM dyno tuned. I don't have much power down low either, I think its due to the QTP long tubes and duals. I dont think your FAST is helping you either. Seems overkill for a stock cammed/cubed motor.
10-02-2009, 03:48 PM
#15
12 Second Club
iTrader: (21)
Join Date: Jun 2007
Location: Muskegon, MI
Posts: 1,102
Likes: 0
Received 0 Likes
on
0 Posts
That sounds completely normal to me for dynomax bullets, I had them and hated them. I know have custom H pipe with spiral flow duals with side exit boom tubes and it sounds like sex to me. I am not a fan of the x pipe dynomax bullet set ups. To nasty sounding to me but some people love it. Swap your bullets for spiral flows and I bet you'll be happier.
10-03-2009, 01:37 PM
#16
TECH Fanatic
iTrader: (17)
Join Date: Nov 2001
Location: SPRING, TX
Posts: 1,387
Likes: 0
Received 0 Likes
on
0 Posts
10-03-2009, 02:39 PM
#17
TECH Enthusiast
Thread Starter
iTrader: (8)
Join Date: Jun 2008
Location: Stockbridge, MI
Posts: 724
Likes: 0
Received 0 Likes
on
0 Posts
Well since my thread got revived i guess i'll say the reason i have a FAST intake is because i got a good deal on it. Eventually there will be more mods to necessitate that intake, but for now the internals must stay stock (lack of funds) It was purchased as part of an over all plan
10-04-2009, 04:34 PM
#18
Staging Lane
Join Date: Oct 2006
Posts: 79
Likes: 0
Received 0 Likes
on
0 Posts
Well since my thread got revived i guess i'll say the reason i have a FAST intake is because i got a good deal on it. Eventually there will be more mods to necessitate that intake, but for now the internals must stay stock (lack of funds) It was purchased as part of an over all plan
10-20-2009, 11:50 PM
#19
Staging Lane
Join Date: May 2007
Location: houston, Texas
Posts: 83
Likes: 0
Received 0 Likes
on
0 Posts
So I am in the middle of ordering a TSP td system cant decide on the muffler to go with. I take it from you guys that the dynomax bullets are pretty raspy... A few of you recommended the spiral>> Any other recommendations??
