will i have enough back pressure
its not back pressure. its exhaust scavalaning[sp]. oversized exhaust will slow the air down to point youll lose lowend. to small of exhaust will restrict exhaust up top creating backpressure and causing harm to motor.
this is why right size tubing is cridical... stepped headers is good example of this. they help aid in torque by having smaller tubes intially then by stepping up they help the gases escape creating more topend
this is why right size tubing is cridical... stepped headers is good example of this. they help aid in torque by having smaller tubes intially then by stepping up they help the gases escape creating more topend
Even that import forum I posted said, it is about exhaust size porportional to flow. You only making 200 hp, stick with 2.25 or 2.5 inch exhaust....up to 400, 3" is good (somewhere along the lines, I need to find the link that is in this section for it). We do NOT want back pressure, we want scavanging. Pull the exhaust out fast, but not too fast so we don't lose low end...but we too restricted, we lose top end.
+1
Even that import forum I posted said, it is about exhaust size porportional to flow. You only making 200 hp, stick with 2.25 or 2.5 inch exhaust....up to 400, 3" is good (somewhere along the lines, I need to find the link that is in this section for it). We do NOT want back pressure, we want scavanging. Pull the exhaust out fast, but not too fast so we don't lose low end...but we too restricted, we lose top end.
Even that import forum I posted said, it is about exhaust size porportional to flow. You only making 200 hp, stick with 2.25 or 2.5 inch exhaust....up to 400, 3" is good (somewhere along the lines, I need to find the link that is in this section for it). We do NOT want back pressure, we want scavanging. Pull the exhaust out fast, but not too fast so we don't lose low end...but we too restricted, we lose top end.
airflow is relation to waterflow. why heads are flowed with water. to big of a hose and not enough pressure wont get you no where.
Yep, exactly. To bad there is so much miss informed **** being spread around, not just here, but the car community itself, about this subject. This is why people blow **** up, because they hear this, hear that, don't do actual research..then boom.
but youll always hear why did i lose power. you didnt lose power just moved the power band higher then your used to. todays vehicles can be tuned to regain most of lowend back. now your 85 astrovan and you cut the cats off and run a dump and expect it to run the same, your highly mistaken and that guy goes says i need back pressure. no its just that the little heap of a motor you have cant keep up with the improved air flow. a motor can only supply so much air
That is why exhaust is also so expensive, because of the R&D that is required to create a nice, balanced exhaust system. A good set up creates power throughout the power band, while a cheap, small one helps low end, and a overly large one helps top end.
In the end....No back pressure= good. Balance and exhaust exiting fast, smooth and free flowing is what we want.
In the end....No back pressure= good. Balance and exhaust exiting fast, smooth and free flowing is what we want.
TECH Enthusiast
Joined: Feb 2005
Posts: 734
Likes: 0
From: south jersey. again
like i said in my first reply i suggested he or she grab a book. and im sorry to inform you there will always be some kind of backpressure on a car with normal exhaust on it. unless you plan on running straight pipes out your fenders. but as far as the original question putting cutouts on the y pipe shouldnt hurt it.
Yes, this is true. There will be some back pressure, but we want as little as possible. But about there always will be back pressure, this is true, unless running a completely retarded exhaust system, like 5" on a stock 346 motor. But then, that exhaust is just not a proper match. It is all in the set up. Proper set up=little to no back pressure, with good flow and scavaging.
Cutouts on Y pipe will work, but why not just on the I pipe where everyone else does? Two on the Y pipe.....would have ALOT of drone and cabin noise I think.
Cutouts on Y pipe will work, but why not just on the I pipe where everyone else does? Two on the Y pipe.....would have ALOT of drone and cabin noise I think.
wow i didnt know every 4cyl turbo car had 3 in pipng. what exactly is exhaust processes, some kind of pressure? what exactly spins the turbine in the turbo- oh yeah those little japanese kids. is that why there called ricers? yes i know we want freeflowing exhaust but there will always be some sort of pressure.
A 3" exhaust is ideal in most 4 cyl turbo applications. It's a combination of heat and flow that spins a turbo. The heat is built from back pressure. The heat that comes from the combination chambers cools some before it gets to the turbo, causing turbo lag. Which really effects 4cyl motors. That's why you are highly unlikely to see a rear-mount turbo on a 4cyl engine (or atleast until the technology catches up). Not all 4cyl turbo cars are ricers.
You can say I've messed with a few 4cyl turbo imports.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
I have never heard that no.
I didn't mean to say every 4 cylinder turbo car has a 3 inch exhaust from the factory....aftermarket exhausts for 4 cylinder turbo cars are generally 3 inch, you'll see some 2.5 or 3.5 but they're generally not the ones used.
I didn't mean to say every 4 cylinder turbo car has a 3 inch exhaust from the factory....aftermarket exhausts for 4 cylinder turbo cars are generally 3 inch, you'll see some 2.5 or 3.5 but they're generally not the ones used.
A 3" exhaust is ideal in most 4 cyl turbo applications. It's a combination of heat and flow that spins a turbo. The heat is built from back pressure. The heat that comes from the combination chambers cools some before it gets to the turbo, causing turbo lag. Which really effects 4cyl motors. That's why you are highly unlikely to see a rear-mount turbo on a 4cyl engine (or atleast until the technology catches up). Not all 4cyl turbo cars are ricers.
You can say I've messed with a few 4cyl turbo imports.
You can say I've messed with a few 4cyl turbo imports.
