iceracercrx

Joseph, why don't you write a book on turbocharging? What is your backround anyways? I have known Corky for many years and he is about the smartest guy around. With out heat, a turbo will not work in a car, on a bench maybe but not a car.

Randy

Tom-Guy

You're not the only one in the last 24 hours to ask me to write a book.

http://www.honda-tech.com/zerothread?id=1225182&page=24

Turbines work without "heat," as you percieve it. Pressure-enthalpy conversions are a bit more complex than all that.

Give Corky my love, and ask him if he could get off his slack *** and return Dave Bennett's S2000 Helms? It's been a couple years, and Dave was calling pretty steady about it there for a while.

iceracercrx

Joseph,
That's funny that you got asked about the book thing before. Why in the hell should I call Corky and ask about a deal between Dave and Corky. It's not my business and will never be. With my personal business with him has always been good.
I understand what you are saying about pressures. But in a gas engine like we run in our normal cars, heat makes pressure that drives the turbine. The book that he wrote was for the common man learning about street turbos. Not a engineer's handbook by any means.

Randy
P.S. My girlfriend is like a english goddest, so if you need her to read your ruff draft, she will.

Tom-Guy

Let me guess, you live local to him?

Nope, it's air displaced by a pump - the engine itself.

The flow (and all related dynamics ie quality of flow based on keeping close as possible to ideal port velocity) from compressor selection, plenum, IM runners, port design, combustion chamber, camshaft(s), manifold design, and turbine itself all determine flow, which is modified by the IM pressure and TIP (Turbine Inlet Pressure) as the engine goes through the rpm and load ranges. Flow is based on volumetric efficiency of the system, with an eye to pressure. The pressure being more determined by engine displacement and VE than heat, however.

Now, you say, heat is directly related to pressure. Well, yes, but for the purpose of a pressure-enthalpy conversion across a turbine (translation: the inefficient conversion of heat into pressure as potential energy gets lost all across the system, deflected by turbine restriction), no. You get further off of air displaced than off of heat energy entering the turbine. To correctly illustrate this, observe the 4th gen F-body asshats who can't find underhood room to mount a turbo, so they stick it behind the rear axle. At that point, most of the heat in the system is gone. ASSuming 1500 degree EGT, we can safely ASSume 80% of the temp differential above ambient is gone.

As far as di-rectally manipulating temperatures for pressure at a lower temperature, this can be done by way of fuel selection or water/diluent injection. Which further explains my point.

For a given airmass, in a given engine, you *always* make more power with alcohol than you do with gasoline, when adjusted for stochiochemic. Despite having to inject nearly twice as much alky as fuel, which somewhat displaces intake charge. There is no extra oxygen in alky, btw, so this is not a monopropellant effect such as the 20 mL hydrazine per gallon of gas for 10% more power trick. Alcohol burns cooler - less heat. In fact, some drag only domestics entirely fill their block and run no coolant, as they don't overheat at idle on alky, and the run down the track is too short to heat anything appreciable. You see where I am going?

Given enough water injection, you entirely do away with an engine's cooling jacket. At 1:1 ratio of water-fuel, it is not uncommon for the area of cyl head between valves to be sub-200 deg F. Same with piston faces. At 1:1 ratio, EGTs are significantly lower than regular pump gas - yet it is flow which is driving a turbine in this situation.

Yup. I've told a lot of people to buy that book, then forget everything theory-wise and prepare to relearn it. It [i]is[/i[ and excellent primer... but translating the language of machines into layman's terms always leads to misinformation. There is a reason why engineers use jargon.

There's also a flip side to it, which Co rky's fallen prey to. A majority of information in Maximum Boost is cited works Corky skimmed the overviews of, and used to prove his views. Views he didn't take the time to question and test to make sure they were valid. Not enough of it is his own blood, sweat, and tears.

Tell her I was terribly influenced by Bukowski, and I have a mouth like a toilet. :P

Jcushing

to get more direct to the actuall question (not that i dont like the debating) what ------- motor are you talking about?


instead of asking a generic question why dont you say what your actually doing with your setup.
id like to assume that the motor you have in your SN is what your actually running however thats usually not the case when you see a question like this. i dont know ---- about d series but on b vtec, id recommend at least type-r cams but never a "turbo" cam. on LS motors turbo cams are fine (anything is better than stock) but theres nothing wrong with 404's or 403's. in reality it has to do with how much duration you need is how high you need to rev. if you have a small turbo and a low rev limmit then use a low duration cam. if you have a big turbo and a high rev limit then use a high duration cam.

Jcushing

i had to go back and re-read everything you just said one more time. i could not possibly dissagree more with every word you said. its just not possible. in fact i really dont know what the point was. you seem to say that "turbo" cams should be high lift low duration but then you say that stock cams are better than turbo cams. i dont get it... but what i do get is that generalized answers are ------- gay. and as oftem proved hondas dont fall under the same rules of physics as other cars.

iceracercrx

The book that Corky wrote was many years ago. It has been many many years ago that I read it. The thing he said was something like this. Turbo cams are different, than NA motors. Stock cams are pretty good for turbo motors. He said there was improvments with a special turbo cam. In a street not looking to make max power a stock cam should be fine. If you are trying to make huge power than look and talk to the cam grinders about there special turbo cams.

Randy

fourthgenhatch

hey jcushing, everything falls under the same rules of physics...but i think i know what you meant by that, like other engines don't behave the same way as honda's when you change certain physical properties such as lift, duration, and so on

Jcushing

its a ------- joke lol, people think mainstream run of the mill turbo setups, not stupid honda people like us that slap huge turbos on small motors and run them to 9K+, for this you NEED the duration to keep making power. "turbo" or stock cams WILL NOT make power high in the RPM range

Tom-Guy

It's very difficult to get high lift in a B-series application. JUN 3's illustrate this perfectly.