Exhaust?
05-13-2008, 05:33 PM
#11
6th Gear Member
Join Date: Aug 2007
Location: Elk Grove, CA
Posts: 5,896
RE: Exhaust?
There is a large benefit to a balance pipe on ANY v-type motor. As has been mentioned, it balances the pressure between the two banks. Can't remember where it went to, but Flowmaster did a comparative study a while back that showed anywhere from 5-15hp from simply adding an H-pipe to a straight dual exhaust system, the closer to the collectors the better.Not only does it improve peak power, it improves power across the rpm range. This is why pretty much every vehicle with factorydual exhaust has a balance pipe somewhere in the system.
There's also a sound difference between the three types of exhaust. Straight pipes tend to sound more raspy and/or blatty, more like two 4 cylinder engines running together. An H-pipe helps remove some of the raspy tone and gives you more of the signature V8 exhaust note. I was VERY happy when I finally got an h-pipe welded into my dual system.
I don't like X-pipes on classic cars. I think they sound great on the newer OHC motors with cats, but they give a weird almost tinny (that's tinny, not tiny) sound to the exhaust on uncatted cars. They do make slightly more power at high revs, but the performance difference will be negligible on a street car.
Edit: This is directly from the Flowmaster FAQ
-----------------------------------------------------
Do I need to install an "H" pipe to my dual exhaust?
Flowmaster strongly recommends using an "H" pipe, commonly known as a "balance tube" on all "true dual" exhaust systems. An "H" pipe equalizes the pressures between both banks of the engine giving a broader and flatter torque curve throughout the rpm range. It also eliminates "back-rap" common on deceleration, and creates a deeper mellower tone both inside and outside of the vehicle.
Is an "X" pipe better than and "H" pipe?
Over the years, Flowmaster's testing of all types of crossovers, including "X pipes", has revealed no substantial benefits over a properly installed "H" pipe on street driven applications. However, in race applications with small cubic inch engines and /or restricted (small bore) carburetors, will respond well to the addition of X pipes, tri-y styled collectors and/or properly designed single exhaust systems.
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There's also a sound difference between the three types of exhaust. Straight pipes tend to sound more raspy and/or blatty, more like two 4 cylinder engines running together. An H-pipe helps remove some of the raspy tone and gives you more of the signature V8 exhaust note. I was VERY happy when I finally got an h-pipe welded into my dual system.
I don't like X-pipes on classic cars. I think they sound great on the newer OHC motors with cats, but they give a weird almost tinny (that's tinny, not tiny) sound to the exhaust on uncatted cars. They do make slightly more power at high revs, but the performance difference will be negligible on a street car.
Edit: This is directly from the Flowmaster FAQ
-----------------------------------------------------
Do I need to install an "H" pipe to my dual exhaust?
Flowmaster strongly recommends using an "H" pipe, commonly known as a "balance tube" on all "true dual" exhaust systems. An "H" pipe equalizes the pressures between both banks of the engine giving a broader and flatter torque curve throughout the rpm range. It also eliminates "back-rap" common on deceleration, and creates a deeper mellower tone both inside and outside of the vehicle.
Is an "X" pipe better than and "H" pipe?
Over the years, Flowmaster's testing of all types of crossovers, including "X pipes", has revealed no substantial benefits over a properly installed "H" pipe on street driven applications. However, in race applications with small cubic inch engines and /or restricted (small bore) carburetors, will respond well to the addition of X pipes, tri-y styled collectors and/or properly designed single exhaust systems.
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05-13-2008, 07:15 PM
#12
5th Gear Member
Join Date: Sep 2006
Location: Australia
Posts: 2,266
RE: Exhaust?
+1Starfury,
I would point out that an H-pipe is not some expensive item either. Its just a piece of pipe the same diameter as the rest of the exhaust, welded between the two pipes. If its done during construction of the exhaust it wont cost more than 10- 20 bucks.
X-pipes have numerous designs some of which are good and some which can hurt performance.
Neither an h or an x is going to give you a massive seat of the pants feeling in performance but will give a few hp and a tiny bit better mileage.But i agree that an h will give a better sound over nothing. I did it to my car about 2 years ago and the sound was much less boat like.
As far as restrictions in the exhaust, most of our cars are pretty mild so we tend to over engineer the exhausts...2.5" and up. To give you an example, our rally car is550hp (flywheel), 7200rpm limited and has headers into a single 3" pipe. No trip to the dyno has ever resulted in the tech telling us to put bigger/ more exhaust.
I would point out that an H-pipe is not some expensive item either. Its just a piece of pipe the same diameter as the rest of the exhaust, welded between the two pipes. If its done during construction of the exhaust it wont cost more than 10- 20 bucks.
X-pipes have numerous designs some of which are good and some which can hurt performance.
Neither an h or an x is going to give you a massive seat of the pants feeling in performance but will give a few hp and a tiny bit better mileage.But i agree that an h will give a better sound over nothing. I did it to my car about 2 years ago and the sound was much less boat like.
As far as restrictions in the exhaust, most of our cars are pretty mild so we tend to over engineer the exhausts...2.5" and up. To give you an example, our rally car is550hp (flywheel), 7200rpm limited and has headers into a single 3" pipe. No trip to the dyno has ever resulted in the tech telling us to put bigger/ more exhaust.
05-13-2008, 07:45 PM
#14
6th Gear Member
Join Date: Aug 2007
Location: Elk Grove, CA
Posts: 5,896
RE: Exhaust?
ORIGINAL: Aussie66Fastback
As far as restrictions in the exhaust, most of our cars are pretty mild so we tend to over engineer the exhausts...2.5" and up. To give you an example, our rally car is550hp (flywheel), 7200rpm limited and has headers into a single 3" pipe. No trip to the dyno has ever resulted in the tech telling us to put bigger/ more exhaust.
As far as restrictions in the exhaust, most of our cars are pretty mild so we tend to over engineer the exhausts...2.5" and up. To give you an example, our rally car is550hp (flywheel), 7200rpm limited and has headers into a single 3" pipe. No trip to the dyno has ever resulted in the tech telling us to put bigger/ more exhaust.
05-13-2008, 08:12 PM
#15
5th Gear Member
Join Date: Sep 2006
Location: Australia
Posts: 2,266
RE: Exhaust?
hahaha, actually its a (gm) product. we had a local made v8 in 253 and 308 cubes. this one is stroked to 355. it does go pretty hardnow with some assistance from Ford. It has a 9" true trac and ran a toploader for the first 4 years campaigning.
05-13-2008, 08:22 PM
#17
4th Gear Member
Join Date: Nov 2006
Location:
Posts: 1,195
RE: Exhaust?
you should do what i did...get some longtube headers and a pair of purple hornies that bolt straight onto the headers w/turndowns. it'll be around $250 and it'll sound awesome!
heres a clip
http://youtube.com/watch?v=hw4cWuqibKg
heres a clip
http://youtube.com/watch?v=hw4cWuqibKg
05-13-2008, 09:15 PM
#18
2nd Gear Member
Join Date: Aug 2007
Location: Unstable
Posts: 213
RE: Exhaust?
ORIGINAL: Starfury
There is a large benefit to a balance pipe on ANY v-type motor. As has been mentioned, it balances the pressure between the two banks. Can't remember where it went to, but Flowmaster did a comparative study a while back that showed anywhere from 5-15hp from simply adding an H-pipe to a straight dual exhaust system,
Edit: This is directly from the Flowmaster FAQ
-----------------------------------------------------
Do I need to install an "H" pipe to my dual exhaust?
Flowmaster strongly recommends using an "H" pipe, commonly known as a "balance tube" on all "true dual" exhaust systems. An "H" pipe equalizes the pressures between both banks of the engine giving a broader and flatter torque curve throughout the rpm range. It also eliminates "back-rap" common on deceleration, and creates a deeper mellower tone both inside and outside of the vehicle.
Is an "X" pipe better than and "H" pipe?
Over the years, Flowmaster's testing of all types of crossovers, including "X pipes", has revealed no substantial benefits over a properly installed "H" pipe on street driven applications. However, in race applications with small cubic inch engines and /or restricted (small bore) carburetors, will respond well to the addition of X pipes, tri-y styled collectors and/or properly designed single exhaust systems.
-----------------------------------------------------
There is a large benefit to a balance pipe on ANY v-type motor. As has been mentioned, it balances the pressure between the two banks. Can't remember where it went to, but Flowmaster did a comparative study a while back that showed anywhere from 5-15hp from simply adding an H-pipe to a straight dual exhaust system,
Edit: This is directly from the Flowmaster FAQ
-----------------------------------------------------
Do I need to install an "H" pipe to my dual exhaust?
Flowmaster strongly recommends using an "H" pipe, commonly known as a "balance tube" on all "true dual" exhaust systems. An "H" pipe equalizes the pressures between both banks of the engine giving a broader and flatter torque curve throughout the rpm range. It also eliminates "back-rap" common on deceleration, and creates a deeper mellower tone both inside and outside of the vehicle.
Is an "X" pipe better than and "H" pipe?
Over the years, Flowmaster's testing of all types of crossovers, including "X pipes", has revealed no substantial benefits over a properly installed "H" pipe on street driven applications. However, in race applications with small cubic inch engines and /or restricted (small bore) carburetors, will respond well to the addition of X pipes, tri-y styled collectors and/or properly designed single exhaust systems.
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I take anything they claim with a grain of salt................
Jav
05-14-2008, 01:20 AM
#20
6th Gear Member
Join Date: Aug 2007
Location: Elk Grove, CA
Posts: 5,896
RE: Exhaust?
I don't see how you can really be biasedwith that report. They're not making money off of 8" of tubing. If they wanted to be biased, they'd tell you their expensive X-pipe systems give you 20hp over an H-pipe.
Pre-bent systems are a PITA anyway. Flowmaster is primarily a muffler manufacturer. Telling you that it's better to add a small crosstube to your exhaust doesn't really benefit them as a company.
I find it more important that auto manufacturers install them on every car with dual exhaust. Auto manufacturers are not in the business of wasting money. They don't do things like that (usually) without a good reason. If they can squeeze a little more power and efficiency out of a small crosstube, which costs say $10 a car, they're going to do it.
Pre-bent systems are a PITA anyway. Flowmaster is primarily a muffler manufacturer. Telling you that it's better to add a small crosstube to your exhaust doesn't really benefit them as a company.
I find it more important that auto manufacturers install them on every car with dual exhaust. Auto manufacturers are not in the business of wasting money. They don't do things like that (usually) without a good reason. If they can squeeze a little more power and efficiency out of a small crosstube, which costs say $10 a car, they're going to do it.