no need for a new turbo, just turn your car into a golf ball

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1985 300D cali 190K

http://mercedes.thatchermathias.com/mw300d.jpg

... I always thought the dimples created air vorticies to improve accuracy, not distance...
I'm thinking the dimples would actually reduce mpg... but microscopically, and if you drive with your foot for better mileage, you get better mileage.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

heh

seems bogus to me...maybe you'll drive more accurately then

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1985 300D cali 190K

http://mercedes.thatchermathias.com/mw300d.jpg

heh, oh, and inorder for the dimples to affect the accuracy of the car... it would have to be spinning... heh, I gotta see the spinning car...
http://wings.avkids.com/Book/Sports/instructor/golf-01.html
HOLY MOLEY!!! the theory may be sound....
http://www.aerospaceweb.org/question/aerodynamics/q0215.shtml

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

None of you pointed out the fact that 1psi one one engine model cannot possibly be correlated to 1psi on a different engine model. Engines have different volumetric efficiencies at different RPM and very different flow rates from displacement.

Extreme Example Time
At 3000rpm, 1psi on a 0.9L Kubota D905 engine takes it from 48cfm to 50cfm, 2cfm difference.
A 6.0L SL65 AMG goes from 316cfm 336cfm, 20cfm.
A 39.1L Detroit Diesel 16V149 goes from 1242cfm to 1318cfm, 76cfm (more than the entire Kubota flows!)

The reasons bigger turbos allow more power is because they breathe less restrictively, flow the same air at lower speeds and operate at a more efficient point on the flow map. Pumping a T25 to 125,000rpm takes much more energy (exhaust manifold backpressure) than pumping a T4 to 75,000rpm. The engine WILL make more power at 40psi with that T25 but most of it is wasted as heat and pressure driving the tiny turbo inefficiently (FYI: A T25 can't pump 40psi without grenading from overspeed anyways, maxes out about 28psi at sea level, so I know Cervan pulled his example out his rear end).

In other words, 10hp:1psi is

Correct.

You fellows are confusing the capabilities of the turbo with the ultimate result: the pressure in the manifold.

The only thing that matters is the pressure of the air (and the temperature of the air) in the manifold. You can get 12 psi with a small turbo or 12 psi with a big turbo. The amount of air sent to the engine is identical (excluding temperature variation) at 12 psi. Naturally, the big turbo is spinning considerably slower to produce the 12 psi and the temperature increase of that air is probably reduced............thereby allowing the engine to produce more power from the colder air. Furthermore, the energy required to drive the smaller turbo to produce 12 psi is greater leaving less energy for driving the wheels.

I guess I don't understand that. CFM doesn't play a role?

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1985 300D cali 190K

http://mercedes.thatchermathias.com/mw300d.jpg

CFM at the same engine RPM and boost pressure is the same between a T25 and a T4, for example.

Yah 1psi means alot to different engines it might take 10x the volume to make 1psi on a large engine while 1psi on something like a vw diesel might not amount to much. Saying 1psi=10hp is kinda silly. Given maybe a engine with 40-45psi could make 2000-8500 hp

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2004 Infiniti G35 3.5L 6mt Coupe 73K miles 25.6mpg ytd
2001 Green Audi TT 225 AWD Roadster 71K 6sp 30.9mpg >>STOLEN<<
1982 300D Turbo 231K 120hp? 28.1mpg YTD

let's look at this example. Take an engine....any engine, a mercedes diesel, a Chevy 350 or even a lawn mower engine.

If you put a trick intake manifold, higher CFM carb, new high flowing breather but leave the stock restrictive exhaust manifold, half plugged up cat's, and a single 2" exhaust.....will you make more HP??? Maybe.

Now you unchoke the exhaust...add hedders, etc. now you will wake it up!!!

Point being...an engine is like a big air pump....the more air/fuel you can get in and OUT....the more HP potential the engine will make.

Now take a turbocharged engine...you could use a small turbo and YES put out 20 psi to the manifold. Maybe (now I am guessing) this engine could possibly be seeing 50 PSI at the exhaust discharge before the turbine of the turbo..... NOW let's take a larger more efficient turbo....again, same 20 PSI boost to the intake...but now let's say (again I am pulling numbers out of the air) the exhaust is only at 20 psi to the turbine wheel. The engine will lower psi backpressure will OBVIOUSLY make more HP.....period!

Again back to the original analogy....wouldn't 50 PSI of backpressure getting out of the engine kinda be like blowing through log type exhaust manifolds, plugged cat's and single 2" exhaust????

Remember an engine is just an air pump.

and 10 psi is NOT the same as 10 psi on another engine.....and above all 1 psi extra is NOT= 10HP automatically!!!

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Anything is possible if you don't know what you are talking about........

1985 Mercedes 300D
2007 Mercedes C-350
1980 Mazda Rx-7 (SA22C)
2005 Jaguar XJR
2007 Jeep Wrangler