Exhaust effecting car's performance.
01-07-2009, 03:48 AM
#1
Junior Member
Thread Starter
Join Date: Dec 2008
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
Exhaust effecting car's performance.
2003 Honda Accord EX
K24A4 i4 AT
DC Sports Header (Ceramic)
Injen Short Ram Intake
*HKS Exhaust 3''
I recently got an HKS exhaust (just the exhaust) from my brother and I got it installed and welded on at a muffler shop. After the installation, my overall car's performance slowed down. Im unable to accelerate as fast as I would normally do. During the installation, the guys who welded my exhaust said that they needed to create a custom pipe since the exhaust is bigger than the STOCK exhaust pipe. I believe that since the exhaust is meant for higher HP or compression cars that it is releasing too much air and isnt giving enough back pressure. I am unsure what the problem is but I know that it has to do with the exhaust because with my STOCK exhaust, my performance was fine. The whole cat-back is STOCK and only the exhaust was modified. Please offer me some input. Thank you.
K24A4 i4 AT
DC Sports Header (Ceramic)
Injen Short Ram Intake
*HKS Exhaust 3''
I recently got an HKS exhaust (just the exhaust) from my brother and I got it installed and welded on at a muffler shop. After the installation, my overall car's performance slowed down. Im unable to accelerate as fast as I would normally do. During the installation, the guys who welded my exhaust said that they needed to create a custom pipe since the exhaust is bigger than the STOCK exhaust pipe. I believe that since the exhaust is meant for higher HP or compression cars that it is releasing too much air and isnt giving enough back pressure. I am unsure what the problem is but I know that it has to do with the exhaust because with my STOCK exhaust, my performance was fine. The whole cat-back is STOCK and only the exhaust was modified. Please offer me some input. Thank you.
01-07-2009, 04:21 AM
#2
My Name is Nobody
Re: Exhaust effecting car's performance.
Sounds typical to me... unless an exhaust is DESIGNED for your set up, you risk loosing what known as the scavenging effect. The results are often lower mid range torque in exchange for a free'er up range flow
01-07-2009, 04:43 AM
#3
Junior Member
Thread Starter
Join Date: Dec 2008
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
Is it possible to regain the back pressure because I am losing power and torque and its burning more gas. I am noticing the gas burn quicker on the meter. 
01-07-2009, 04:46 AM
#4
My Name is Nobody
Re: Exhaust effecting car's performance.
Not really, sorry. thats the trade off unfortunately.
This is one of the major reasons when that when I build a car... I start with the suspension and work towards the engine last. There is really very little to gain in the power category without spending big bucks... Go faster through superior handling and lighter weight.
Maybe someone else will log in that has more experience with that power plant
This is one of the major reasons when that when I build a car... I start with the suspension and work towards the engine last. There is really very little to gain in the power category without spending big bucks... Go faster through superior handling and lighter weight.
Maybe someone else will log in that has more experience with that power plant
01-07-2009, 06:35 AM
#5
Junior Member
Join Date: Jan 2009
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
01-07-2009, 10:33 AM
#6
Honda-Tech Member
Join Date: Jun 2007
Location: Westford, MA
Posts: 1,291
Likes: 0
Received 0 Likes
on
0 Posts
01-07-2009, 06:15 PM
#7
Junior Member
Thread Starter
Join Date: Dec 2008
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
Yes, I only changed the muffler to an HKS 3''. Sadly to say, the car's overall performance has greatly been reduced. I am hoping there is another way to gain back the performance, but so far, there has been no hope. I am hoping someone could give me some input before I take it back to the muffler shop and get it removed.
Sigh. Thank you. Bad news.
Sigh. Thank you. Bad news.
Trending Topics
01-08-2009, 07:27 AM
#9
Honda-Tech Member
Join Date: Jun 2007
Location: Westford, MA
Posts: 1,291
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
ya at first i thought you did an entire 3" swap which would result in loss of low end power but more in the top end. in your case though, it's just the muffler. the loss you would feel should be minimal.
01-08-2009, 10:51 PM
#10
Junior Member
Thread Starter
Join Date: Dec 2008
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
I dont think so because when I floor it on my car, my rpm raise but my car slowly moves, I barely can reach 100mph when I normally could achieve that. My rpm is at 4000 and im slowly getting to 90mph... I am removing the exhaust tomorrow and I will tell you the differences in performance. 
01-08-2009, 10:52 PM
#11
Junior Member
Thread Starter
Join Date: Dec 2008
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
01-09-2009, 05:03 AM
#13
Honda-Tech Member
Re: Exhaust effecting car's performance.
try removing the negative terminal from your battery so your ecu resets. maybe your ecu will relearn the 'new' airflow and won't burn as much gas
01-09-2009, 05:59 AM
#14
Honda-Tech Member
Join Date: Jun 2007
Location: Westford, MA
Posts: 1,291
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
I dont think so because when I floor it on my car, my rpm raise but my car slowly moves, I barely can reach 100mph when I normally could achieve that. My rpm is at 4000 and im slowly getting to 90mph... I am removing the exhaust tomorrow and I will tell you the differences in performance.
01-09-2009, 06:06 AM
#15
Honda-Tech Member
Join Date: May 2006
Location: NB, Canada
Posts: 2,788
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
People still think your car "needs backpressure"?
Guess what? By going to too large of an exhaust, you actually CREATE backpressure! It's called Bernoulli's principle. The larger the pipe, it decreases flow velocity, and increases flow capacity. If you don't need the extra capacity, all you're doing is hurting the flow velocity, or slowing down your exhaust gas. Creating backpressure. Which is bad.
Guess what? By going to too large of an exhaust, you actually CREATE backpressure! It's called Bernoulli's principle. The larger the pipe, it decreases flow velocity, and increases flow capacity. If you don't need the extra capacity, all you're doing is hurting the flow velocity, or slowing down your exhaust gas. Creating backpressure. Which is bad.
01-09-2009, 06:32 AM
#16
Junior Member
Join Date: Jan 2009
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
hks from what i know on my accord robbed power, so i got a greddy. and in doing research for an exhaust for my s2k the dyno shows that hks exhaust robs power on them as well
01-09-2009, 04:16 PM
#18
Junior Member
Thread Starter
Join Date: Dec 2008
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
Planning on buying a Nissan GTR. Can anyone give me some ideas on what car to buy. Price range is from 0-80k USD.
Going to part out my car.
Injen CAI.
DC Sports Ceramic header.
HKS axle back exhaust brand new.
Pics coming soon. THANK YOU! EVERYONE!
HKS ON ACCORD (K24) =
LOL. Sucks.Thank you again,
John
PS.
Here are some options:
Lexus IS 350
Lexus IS F
Nissan GTR*** <- I really want this one.
Infiniti G37S
Nissan 350Z, I dont like the 370Z look. -.-
_______________ <--- You fill in the blank. ($0-80k) THANK YOU.
01-09-2009, 04:21 PM
#19
Junior Member
Thread Starter
Join Date: Dec 2008
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
01-10-2009, 12:52 AM
#20
Junior Member
Thread Starter
Join Date: Dec 2008
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
01-10-2009, 02:16 AM
#21
B*a*n*n*e*d
Join Date: May 2008
Location: ca
Posts: 849
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
People still think your car "needs backpressure"?
Guess what? By going to too large of an exhaust, you actually CREATE backpressure! It's called Bernoulli's principle. The larger the pipe, it decreases flow velocity, and increases flow capacity. If you don't need the extra capacity, all you're doing is hurting the flow velocity, or slowing down your exhaust gas. Creating backpressure. Which is bad.
Guess what? By going to too large of an exhaust, you actually CREATE backpressure! It's called Bernoulli's principle. The larger the pipe, it decreases flow velocity, and increases flow capacity. If you don't need the extra capacity, all you're doing is hurting the flow velocity, or slowing down your exhaust gas. Creating backpressure. Which is bad.
01-10-2009, 06:13 AM
#22
Junior Member
Join Date: Jan 2009
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
Deff GTR or M3 E92. both awesome cars but car and driver ranked the M3 above the gtr. even a newer z06. Are you looking for more pure track car, class, or both?
01-10-2009, 11:07 AM
#23
Honda-Tech Member
Join Date: Apr 2006
Location: NJ -> Outside Denver
Posts: 1,267
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
He's not ragging. What he is saying is that at a given RPM, you can only do x amount of speed per that RPM, it's just how fast you get to that RPM.
01-10-2009, 11:22 AM
#24
Junior Member
Thread Starter
Join Date: Dec 2008
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
Im also looking for a car that has performance & suspension.
Im thinking of the IS F with its 5.0L and maybe plan on buying the supercharger for it. The GTR is something I want to own but man, I think insurance is going to KILL me on it.
Last edited by Honda Inspire; 01-10-2009 at 11:34 AM.
01-10-2009, 02:16 PM
#25
Junior Member
Join Date: Jan 2009
Location: San Diego, Ca
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
Re: Exhaust effecting car's performance.
so.....what happend with the exhaust and hi-flow cat? I've been toying with buying a project car but was just gonna start working with my '05 accord. There doesn't seem to be a lot of performance mods due to the MAF. I'm an old school muscle car guy.....fuel, compression, cams and exhaust. I'm new to the tuner scene.Any help??????