ken_climb
TY 4 Stroke Junkie
snowy1 said:
Its ok to be wrong sometimes!
Turbo Tim
TY 4 Stroke Master
SuperTurbo said:
That would definately be a bummer! I haven't got that many miles on my frt mount turbo , I rode my Mountain sled with the Rear mount on it 10 times as much as I rode the other one ,because it's the mountain sled and I virtually always ride in the mountains.
the Rear mount's make more power. The bender rear mount at 8 pounds makes 220 hp. The front mount MC and the Simons only make 190 HP at theat level. Those are factual numbers I've seen both dyno sheets. The Bender sheet I saw was an independant companys sheet the CPR and Mc came right from them.
It only makes since that the more surface area of cooling the cooler the charge the higher the hp number.
That all said the front mounts flat out lay the wood to the rear mounts here in any distance. So take the 30 hp extra. I want throttle responce over ultimate HP.
there is nothing wrong with the rear mounts. Ride what you like.
It only makes since that the more surface area of cooling the cooler the charge the higher the hp number.
That all said the front mounts flat out lay the wood to the rear mounts here in any distance. So take the 30 hp extra. I want throttle responce over ultimate HP.
there is nothing wrong with the rear mounts. Ride what you like.
Turbo Tim
TY 4 Stroke Master
I think boost is cool in any form . 
What if you consider exhaust backpressure?
Rearmount-straight headers,frontmount-lots of twisties.
Rearmount-straight headers,frontmount-lots of twisties.
I would like to see someone develop a cast header for the front mount guys who trail ride. I dont think most guys would care if the cast weighed 3 times more as long as they werent cracking headers. Cat and Polaris have factory front mount turbos with cast headers. Ever hear of the T660 guys complaining about a cracked header?...BBY
hooper: Header design in a Turbo does nothing for you. That was the First things Mr Turbo taught me. I was super concerned about that. AS long as the header itself isn't restrictive you will have no problems.
Exhaust pressure isn't what causes boost. Heat from the exhaust in the Turbine housing causes boost. The reason the rear mounts have lag is the Long Charge tube and Inter-cooler. The Tube and inter-cooler are in a constant state of Vac and must be pressurized hence the more area in a state of vac the more lag you have.
Exhaust pressure isn't what causes boost. Heat from the exhaust in the Turbine housing causes boost. The reason the rear mounts have lag is the Long Charge tube and Inter-cooler. The Tube and inter-cooler are in a constant state of Vac and must be pressurized hence the more area in a state of vac the more lag you have.
According to all litterature I´ve read,header design have some importancejtssrx said:
for ex. pulssystem.The turbine works more effective with an even flow.
I thought the pressure of exhaustgases makes the turbine spin. How do you mean the heat is doing the job?jtssrx said:
TurboKeith
Pro
Actually heat and pressure work hand in hand to to turn the turbine. It just happens that more heat creates more volume which turns into more velocity to turn the turbine faster. (Pressure differential between the intake of the turbine and the exhaust of the turbine also come into play. The greater the differential the better.) More heat will spool the turbo sooner which explains why the front mount is supposed to be lag free, it's closer to the heat source. An example of the way heat is used to get a turbo to spool faster or even to build boost at near idle levels is to retard the timing. Ralley cars have been using this as an anti-lag technique for several years. Polaris came out with a little button for their snowcross sleds a couple of years ago that retarded the timing to get the pipe hotter quicker, I think A/C had a similar system.
hooper: The heat is what causes the Pressure int eh turbine housing which makes the boost. Boost is not made from Exhaust back pressure or exhaust velocity.
TurboKeith
Pro
"hooper: The heat is what causes the Pressure int eh turbine housing which makes the boost. Boost is not made from Exhaust back pressure or exhaust velocity."
So does that mean if you were to have a small exhaust leak between your turbo and the cylinder head, you could still build the same amount of boost? The exhaust gas will still be hot, should build boost right?
Are you also saying that pressure differential is not significant and that the size of the exhaust on the back side of the turbo shouldn't matter? Does that mean that a small exhaust pipe won't affect the ability to generate boost?
Does this mean that if I run the engine really lean and get my exhaust temp really hot, I should be able to build more boost?
Just curious on what you have found. I know I have had exhaust leaks, and a tight system definitely works better. I know that I have too small of an exhaust and a larger one works better. Heat is only one part of the equation.
So does that mean if you were to have a small exhaust leak between your turbo and the cylinder head, you could still build the same amount of boost? The exhaust gas will still be hot, should build boost right?
Are you also saying that pressure differential is not significant and that the size of the exhaust on the back side of the turbo shouldn't matter? Does that mean that a small exhaust pipe won't affect the ability to generate boost?
Does this mean that if I run the engine really lean and get my exhaust temp really hot, I should be able to build more boost?
Just curious on what you have found. I know I have had exhaust leaks, and a tight system definitely works better. I know that I have too small of an exhaust and a larger one works better. Heat is only one part of the equation.
The one thing I'll say about header and exhaust design is you don't want under size it even a hair. You want the ID of your tubing to be the same size as your exhaust port's and the exhaust exit on your Turbo charger. A restriction will cause to much heat and could cause a lean condition and you could melt something down.
Hooper had mentioned he though the strait header design might be better because it's strait. Bends don't hurt a turbo motor so there is nothing to be gained in design. the only place you'll gain is if you could build a equal length tubed header. Exsample a head with 4 individual pipes will make more power then a lets say a "LOG manifold" because it's less restrictive.
So lets look at this in volume. The more volume you can create in your header the more power you will make. So if you could enlarge the exhaust ports on the head "which you can't" you could make more power to.
Yes with an exhaust leak you can still make boost.
Hooper had mentioned he though the strait header design might be better because it's strait. Bends don't hurt a turbo motor so there is nothing to be gained in design. the only place you'll gain is if you could build a equal length tubed header. Exsample a head with 4 individual pipes will make more power then a lets say a "LOG manifold" because it's less restrictive.
So lets look at this in volume. The more volume you can create in your header the more power you will make. So if you could enlarge the exhaust ports on the head "which you can't" you could make more power to.
Yes with an exhaust leak you can still make boost.
Turbo Tim
TY 4 Stroke Master
Anything that flows better will produce more horsepower .........All boost is ........is resistance to airflow....... an engine that flows more air at 8 p.s.i will make more horsepower than an engine that flows less air at 8 p.s.i.
Ted Jannetty
TY 4 Stroke God
jtssrx said:
This is not a good comparison since they are 2 totally different turbos, If that bender turbo were mounted up front it would make the same or more power at 8psi.
Ted Jannetty: How do you figure it would make the same or more? The only reason it makes 220hp is the charge Tube is constantly cooled by snow therefore the Charge itself is cooler then what it would be if it was mounted up front.
If the CPR was mounted in the rear he would make more then 190 at 8 pounds. I'd be willing to bet he'd make More Then 220 HP Beaus I think his housing on his trail setup is larger then Benders.
If the CPR was mounted in the rear he would make more then 190 at 8 pounds. I'd be willing to bet he'd make More Then 220 HP Beaus I think his housing on his trail setup is larger then Benders.
