The reason is efficiency. You just can't take a blower and bolt a gear on it to get tons of boost. Well........you can......but the efficiency goes to hell. There is a point where you are just beating the hell out of the air and are making more heat which you know is not good for power.
For example, a 8-71 underdriven by lets say 10% is a better choice than a 6-71 overdriven by 10%. The 8-71 beats the air less and puts less heat in the air charge which makes more power under the same amount of boost.
I think it was Armstrong that had a two speed blower. I think he did it with a spur gear (not sure?). It was the best of both worlds. It made a ton of boost down low and as the engine speed got higher it cut back on the overdrive. Worked great, but NHRA did not get the payoff so the rules said no multi-speed blowers. [img]i/expressions/face-icon-small-disgusted.gif[/img]

yjacket2001 a supercharger is not a silver bullet by any means. There is BIG downfalls to them. One is, they are a power hog. They eat up a ton of power. It takes fuel to make that power so I don't get where you are coming from when you say a super charger is going to save our planet? Huuuuuuu??????
A supercharger is always on.........whether you need the power or not, it is hogging power......and this makes it drink fuel; a lot of fuel!!!!!

Tuned up, and on it, my little 355 used 4 gallons/mile (that's no typo). And it was a street engine, not a ***** out race engine. I don't know what my turbo engines use but it was a ton less than that; and that's for sure.

Whether you talk nitrous, supercharger or turbocharger your going to have to use good fuel. Sure I could get my turbo to work on pump gas to about 8 PSI. After that it would rattle like hell. My supercharger would go maybe a pound or two higher because it did not have a hot section putting heat into the intake charge.
Sure, with modern puter control systems you can go higher, but that add's more weight and more systems to go wrong.

On the street, I want a turbo and or nitrous. [img]i/expressions/face-icon-small-smile.gif[/img] At the strip I want a supercharger. [img]i/expressions/face-icon-small-smile.gif[/img] If I had brass ***** I would go super compounded on N2O!!!! Ya baby!!!

 

I am glad you chimed in. [img]i/expressions/face-icon-small-smile.gif[/img] Why do you prefer the supercharger at the drag strip?

 

 

Two things,
From what I can remember, the Alba supercharger had some kind of problem with timing the lobe pulses with the intake cycle of the single cylinder fourstroke.
Doctorturbo is correct about the HP loss of superchargers. If you added 50 HP to a 50 HP engine, it might take an additional 20 HP to create that level. so you are going through fuel and engine stress of 120 HP. A supercharger adds stress to an engine at all times, a turbo only when under boost and only at higher rpms.

 

Weeeeell, hmmm. For me, and I know others will disagree, it's like this. A turbo will always make more gross HP than a supercharger because of the energy loss that a super has.
The problem with a turo is lag. Nowday's, talking about turbo lag is really splitting hairs. If done correctly, lag is "almost" non-exsistant Almost is the key word here. When your turning some of the times I see on here you don't have the time for boost to come up; not even for a split second.
I saw a supercharge engine on N2O one time in my life. That was about 20 years ago and I remember that thing like it was yesterday. It was a big block on the street and that thing wound from about 2 grand to 9 about a fast as an Indy engine!!! It was the most amazing thing!!! Just crazy!!! I was also thinking that if an intake valve hung open everybody within a 50' radius would have been killed by the aluminum parts that would have come off of that thing.

If I built an engine for competition and money was no option I would do several things. 1, put it on alky. 2, put a turbo on it. 3, compound it with nitrous. 4, put it in the lightest frame I could get it in. Get that little midget dude on TV to ride it. (I apologize to any midgets that read that)

I've said it once and I will say it again. If I raced quads (which I don't) I would really hate to race some of the people on this site. Some people have the knowlege but not the $$$$$$$'s Some people have the $$$$$$'s but not the knowlege. A lot of people on this site have both............and that would concern me if I raced in competition against some of these people.

With the knowlege some of you have, your only going to go faster. My hat is off to you.

 

has anybody considered or tried a VG turbo on a ds?

 

DoctorTurbo,

After further research, the super charger may be what I want due to efficiency, lag, tuning ease, and installation comparative ease. There are a lot of sc companies, where you don't need a 2 year tech degree to install. Turbo's are for experts and the rich(er than me). Finding a sc for DS650 will be the hardest part, without being a pioneer.

The only thing you have so is set boost limits down low for reliability. Trick Racing will be a good company to work with, without being a pioneer. I was on the right track, despite my ignorance, lol. I'm learning - it is relatively cheap, easier to tune, pump gas for street, and mild performance increase with low boost limits set - ecological friendly: that's me! [img]i/expressions/face-icon-small-happy.gif[/img]

And they CAN increase torque and improve gas mileage! That's what sc companies say, so it better.
Whew! I thought I was wrong, but only Temporarily mistaken.


Thanks for your guidance.

 

Rotax Seadoo (Rotax engines from airplanes to skidoos to Bombardier Snowmoblies (4-TEC Vee twin) have a long history of superchargers):

" ROTAX 1503 SERIES SCIC
Take on all challengers with the 215 HP champion. A supercharger force-feeds an optimal air/fuel mix into each compression chamber, resulting in a super-combustion that generates massive torque. Then an intercooler efficiently and reliably cools the air compressed by the supercharger, further boosting the intake charge density. In plain English, it's the best way to crank up the horsepower and torque of an engine while maintaining reliability and avoiding turbo lag. "

http://www.seadoo.com/en-US/SportBoa...gine.Specs.htm


================================================== ============

An airplane Rotax engine example (center and lower figures)

http://www.ultralightnews.com/engine...enrealteng.htm

================================================== ===========

Bombardier 4 TEC vee twin snowmoble.

http://www.amsnow.com/sno/default.aspx?c=a&id=1206


================================================== ============

Who's next? Bombardier DS650/F650 engine. .
The same engine for 14 years running.

http://trickracing1.net/

 

Well I hope they increase torque!!! It would be kinda silly to bolt a 2K piece of aluminum on an engine and get the same amount of power.
If you think a supercharger improves mileage I have a bridge to sell ya. It's real simple math. Everybody knows that you want around 14.5 of air to 1 part of fuel for best economy. If I put 15 LBS gauge boost to an engine I am doubling the amount of air that is running through the engine. My 650cc engine now thinks it is a 1300cc engine. Now I need twice the amount of fuel that my 650cc drank to keep the 14.5 to 1. That's why if you own a turbo engine and if you like to get into boost a lot you are going to get horrible mileage. If you are easy on the peddle, your going to get OK mileage.

The big three never bolted a supercharger on a pinto or vega. There is a reason for that. They did put them on cars like the Grand prix and T bird. They did not care about fuel mileage with these cars because they had other cars to get good fuel mileage. I think the new Vett will be 500hp and SC'ed. Again, they don't care about fuel mileage with these types of cars, they only want one thing..........power.

There is no free power in the HP game. If you give it air..........you need to give it fuel.