Alltoys,
you may have the best idea here since you did supercharge your p650, but I would like to hear from as many people as possible on this one. First would a ram air system even be a possibillity on the p650 or p700? At one point, I had a scoop rigided up on top of my front rack, but I was severely underjetted, and would bog out right away. However, on the up side of things, you could tell it was bogging because a huge amount of air was being forced into the engine. My only concern is that driving different speeds cause differing amounts of airflow, which could make it impossible to get the jetting right for all speeds.
Second, would sealing the airbox and running some sort of airpump into the box be able to create a possitive pressure in the box, in turn forcing air through the motor, similar to a supercharger, but without the high cost and difficulty of instillation. My iniatial thoughts were to run a coulpe of big air matress inflators into the air box for a test. Anybody have thoughts on this kind of stuff? A pool of knowledge could reap huge rewards here.

 

I think a ram air would work if jetted right, I doubt if the pumps will work, turbo and supercharger turn at several thousand of rpms to get psi and how would you regulate pressure

They would have to pump more than 32 CFM's per carb, to make any pressure at all.

If you raceing, look at methanol. It requires less air, you can double the amount of fuel without adding any more air than your getting, it will also run cooler. You would have to increase your jet size by .40 to double the fuel.

Cons on Meth, are storage, price and handling

Pros are power gain and power gain and power gain.

I don't recomend Meth for anything but racing or pulling [img]i/expressions/face-icon-small-wink.gif[/img]

 

me and my friend were bored one day and decided to make a suprcharger. we got one of those baseball stands that blow the ball in the air so little kids can hit it. it fit perfectly in the stock snorkel but when it was turned on the engine stalled it would have worked if i re-jetted. it was probbaly giveing off like 15psi, so we drilled some blow off holes and it still bogged it down alot, but it still ran normally without the blower turned on

 

Nightryder,
Ha Ha that was in interesting concept you are right if you had the right jetting it would work but only for a short time. Turbos and Super Chargers are directly proportional to the needs of the engine. As the motor speeds up it needs far more air than any fan blade can project. To produce the required amount of air and pressure the motor would need with a fan blade that would measure over 3 feet in diameter. The reason blowers are used is because they rotate at such a speed they can get away with a smaller size. The impellers on a blower are a very hard rausin material or brass or steel. The blades have to force the air into the combustion chamber to almost 10 times its normal pressure to get any advantage at higher rpms. The shape of the blades in a blower allow for the air to one direction. The blades on a fan have spaces between the blades so even if they could get close to supplying enough air for the motor the pressure would leak past the blades negating any benefit they could produce. Blowers must have pop off valves to divert over pressuring the cylinder as they rotate so fast it takes a long time for the blower to react to any rapid fluctuations in rpm.

I have talked about positive pressure in air boxes before especially when naturally aspirated. The most an air box can achieve with a tunnel ram is close to O.43 atmospheres at 80 mph. This has been documented many times with 1/4 mile racers you would have to go well over 200 mph to come close to a 0.9 rating. At this speed if you could go that fast the motor would need far more air than a 0.9 rating would produce. Boring out your carbs slightly can help, a ram collector is a definite boost. All these things you do will help to achieve a higher amount of positive pressure in the air box but you sacrifice dust stopping ability as well. I usually go without an air cleaner in the winter for drag racing as there is very little dust in the air but would I do that in the summer, not chance. The greatest fear I have is ingesting a lump of mudd through the Super Charger as soon as you see it go in the motor is toast. You don't have time to say, oh Darn.

Leaf blowers, any type of fan oriented device will not supply enough pressure to go along with the volume, volume and pressure goes hand in hand!!

 

Does anybody have a suggestion as to what jet size I could try for a ram air system. My collector is going to be about 30 square inches and will sit on the top of the front rack, with a tube going strait into the snorkel, which will be a napa radiaitor hose. I also have the exhaust mod.
Thanks in advance.

 

Actually, most are aluminum....even the Roots-style. 10 times? That would be 140.7 psi of boost on top of 10:1....what? 1407 psi? Sorry, not gonna happen. I've been well over 156 mph in the quarter....my test instruments never indicated anywhere near (nor will they ever, unless I've posthumously won the Nobel for Physics) 6.3 psi (0.43 ATM)....quit stating that you can, unless you can provide the data...period.

I'm not trying to be ugly or offensive, but keep to the facts. I'm sure there are alot of people out there that trust what you have to say....even if it's incorrect.[img]i/expressions/face-icon-small-wink.gif[/img]

 

CRANKDOG... look at the picture of my quad, in Dirt Wheels ( page 159, Feburary '04 issue )... the box in place of the front rack, is a "Ram Air" type induction system... it is also, actually the filter box ( I use the unfiltered, stock filter box as an acumulator )... installing a Dial-a-jet will help you out alot with the jetting... of course EFI with an air sensor would work even better...

 

n2xlr8n,
Only 156 in the 1/4 I made that mark over 20 years ago I guess you have some catching up to do!! 10 times the amount of air into the intake is not a big deal. On my P650 with 6.25:1 pistons I ran 40#'s of boost at 11,000 rpm, on my Diesel I run 40#s of boost as well go figure. I could show you a dyno run with roughly 8#s of boost on my P700 coupled with Nos putting out 80HP to the rear wheels at 9000 rpm. Facts, these are my facts they work for me and have done so for a long time!!!

 

[img]i/expressions/face-icon-small-happy.gif[/img] Yeah, I bet you did.....in a Pro-stock car. Not a street car.

I'll buy your chest-thumping when you provide some scientific evidence. 10X the amount of air.....right. Maybe in volume....at atmospheric pressure +/- 1 psi.....

Diesel engines (though I am a bit knowledge-limited when it comes to diesel engines) quite often run 3 bar of boost.....though I would love to see your evidence of a P650 with even 1.5 bar of boost. 40 p.s.i......right. What kind of fuel were you running? How much timing did you have to pull out of it? BTW, how DID you pull timing out of it? Electromotive? Motek?

What will a dyno run showing you spraying your P650 ON TOP of 8 psi prove? Nothing that you have said. Nothing. [img]i/expressions/face-icon-small-smile.gif[/img] Show the facts or quit propagating B.S.

 

I hate to through fuel on the fire but.........
Just a guess, but, I think Alltoys is talking PSIG and n2xlr8n is talking PSIA. Just different terms (and quantites) for the same thing. 1 atmosphere X 10, n2xlr8n math is correct, you would have to show 140 something pounds PSIG of boost on your gauge!!! Don't think that will happen!!!!

Hu? Probably 80% or more of the blowers in the world are roots type. As n2xlr8n points out, they are aluminum. Sure, the dynamic types are made out of steel, but how many of those are out there? For every dynamic supercharger I see I must have seen 50 positive displacement blowers. A brass impeller?? Hmmmmmmm, never seen one of those. Who makes one of those? Brass is very heavy; I don't know why anybody would make an impeller out of that? But, maybe someone has?

Hu? What about turbo's or Paxton's, or that 747 I flew in? They have spaces between their blades. Believe me, my turbo shows pressure in the manifold!!! No pump makes pressure. It is the restrictions down stream of the pump that make the pressure you see. The less restriction, the less pressure.

Theymust hu? Where is my pop off valve on my 6-71?

Like n2xlr8n says, (again his math is correct) .43 some odd PSIA of positive pressure in ram induction. That ain't going to happen. .43 PSIG ya, could be. But you did say "atmosphere" not gauge. The fresh air (cooler air) will give you more HP than the ram effect; at least when your going quad speed!!!

Hu? Turbo or Paxton "fan type"dynamic superchargers do an excellent job.

There is too many scam artistes on E-bay selling "electric" superchargers to let this go by without clearing up some inaccurate statements. Just trying to educate the masses out there.