blah

[jibbijib]

Im not sure if you have devised a plan on how to run the super/turbo. My idea of prevent the supercharger from over-revving and stalling, is to use the same idea as engaging/disengaging an airconditioner. You would have to put a large pulley on the supercharger to compensate for the mechanism on the fron of the air compressor unit. You would also have to have it electronically preset at a certain rpm level (4000 rpm). Plus, with the turbo and supercharger intake, it would have to be two tubes into one, with a bypass flap closed by the intake pressure. That is so there is no extra air, or too must strain on the supercharger caused by the vaccuum from thye forced induction.

[Zgringo]

Your a day late and a dollar short, it's been done and it works great on a street car. At cruise it uses no power, and when you touch the gas, full boost.

Albert

[CBFryman]

Turbo's are still better.... :P

[Zgringo]

Originally Posted by CBFryman

Turbo's are still better.... :P

Please be as so kind as to provide us proof to this statement as I have somewhat of a difference of opinion.
I know it must be a personal feeling as it isn't fact.

Albert

[duplox]

Well.. turbos make more power, both peak and average, so yeah that pretty much says it all.. But sure, if you prefer less performance, superchargers are better...

[nissanfanatic]

Turbochargers can provide more boost just by adjusting a controller. More efficient(unless you count a lysholm). They don't take as much energy to drive. A single turbo can support over 1000hp without taking a 1/4 of that from the engine.

[Reed]

awesome...
i love when we do this.

(you know what im talking about)

[duplox]

Originally Posted by Reed

awesome...
i love when we do this.

(you know what im talking about)

Nothin like starting the 14 millionth turbo vs super thread on AF. I don't think we've covered every possible aspect yet.

[Zgringo]

Originally Posted by duplox

Well.. turbos make more power, both peak and average, so yeah that pretty much says it all.. But sure, if you prefer less performance, superchargers are better...

Gosh, you mean if I pull my Whipple supercharger off and install a turbo I'd have more peak and average power? I have 3 300ZX TT and on two of them pulled the turbo's and installed screw type superchargers. I also removed my intercoolers. On the dyno I made more power and had cooler inlet temp. didn't need as much nitrous to overcome the lack of power I had at low and mid range as I had with the turbo's. My Delta temp. was almost 50F cooler.
I wish I'd talked to you before I spent 100's of hours on a dyno and 100's of hours changing different setup's and mega bucks only to be told turbo's make more power.
Your statement is like saying Ford has more power than Chevy and Dodge, or Honda makes more power than Toyota or Nissan. I've read many story's on turbo's and superchargers and most are written by people pushing their product, in other words the turbo say there's is best, and the supercharger people say there's is best, but the bottom line is how there installed and there intended use. Both well make more power than most engines can handle.
Do yourself a favor next time your at the drag races and walk into the AA/Fuel pits and tell the owners there blowers aren't worth a crap and turbo's make more power.
Then to really fuck-up your day run over to the Indy track and ask them why they aren't using superchargers.
Both groups are working with unlimited funds and are seeking as much power as can be extracted from there engines.
My street car is a street legal 300ZX using street legal DOT tires with a automatic and turns the 1/4 in [email protected] which aint too bad for a lead sled. But if you want to get serious I've got one not street legal that runs 3 second's faster.

Albert

http://www.dragtimes.com/Nissan--300ZX-Drag-Racing.html

[caddycarlo]

was the drop in temp at the same boost level ?

was the turbo a factory or something you set up ?

I just got a inlet tempature gauge to test my blower setup and just wonder what you have seen ..............

[Zgringo]

Originally Posted by caddycarlo

was the drop in temp at the same boost level ?

was the turbo a factory or something you set up ?

I just got a inlet tempature gauge to test my blower setup and just wonder what you have seen ..............

It was alittle higher boost but lower temps.
And I just got tired of changing turbo's everytime I upgraded.

Albert

[duplox]

Originally Posted by Zgringo

Gosh, you mean if I pull my Whipple supercharger off and install a turbo I'd have more peak and average power? I have 3 300ZX TT and on two of them pulled the turbo's and installed screw type superchargers. I also removed my intercoolers. On the dyno I made more power and had cooler inlet temp. didn't need as much nitrous to overcome the lack of power I had at low and mid range as I had with the turbo's. My Delta temp. was almost 50F cooler.
I wish I'd talked to you before I spent 100's of hours on a dyno and 100's of hours changing different setup's and mega bucks only to be told turbo's make more power.

Didn't mean to offend you, but there is zero arguement that a s/c makes more peak power than a turbo. Your change in delta temp is most likely a result of a damaged or incorrectly sized compressor, or just a poorly designed one. The difference in efficiency between a turbo compressor and a screw type supercharger is not that great.. IIRC a centrifugal compressor is more efficient than a screw type, but I'm not positive on that. I know a roots runs roughly 50% efficiency, a turbo runs around 70%. The best turbos push 80%.

Originally Posted by Zgringo

I've read many story's on turbo's and superchargers and most are written by people pushing their product, in other words the turbo say there's is best, and the supercharger people say there's is best, but the bottom line is how there installed and there intended use. Both well make more power than most engines can handle.
Do yourself a favor next time your at the drag races and walk into the AA/Fuel pits and tell the owners there blowers aren't worth a crap and turbo's make more power.
Then to really fuck-up your day run over to the Indy track and ask them why they aren't using superchargers. Both groups are working with unlimited funds and are seeking as much power as can be extracted from there engines.

I'm sure they wouldn't be there if turbos were allowed in their class, or they'd be running turbos. When turbos were allowed in indy, anyone who had a chance was running one.

Originally Posted by Zgringo

My street car is a street legal 300ZX using street legal DOT tires with a automatic and turns the 1/4 in [email protected] which aint too bad for a lead sled. But if you want to get serious I've got one not street legal that runs 3 second's faster.

I ain't puttin down your car, believe me. For any application besides max output or equipment regulated racing classes, both systems will be more than enough. Pushing everything to its limit, a turbo system will make more power than a supercharger. All you have to look at is where the energy to drive the compressor comes from. Turbos largely use wasted heat energy, superchargers take energy directly from the crank. Clearly the turbo will create more power.

I didn't mean to offend you, I was just messin with ya. Nice job on your car!

[Zgringo]

Boy I love this conversion. I hope some boys with a physic background join in with some input. This was part of the subject matter for my masters degree from the University of Utah school of Engineering
First it takes a giving amount of energy (Power) to compress a giving amount of air.
Example: I want to move 500CFM at 20PSI. Now we have 4 ways of doing this. With a Axial, Screw, Centrifical or Roots supercharger (Compressor). Now any of them can and are driven off the crankshaft or off the exhaust as is the Axial and centrifical superchargers. Now all 4 are to be driven in the test with a engine to the point of 500CFM@20lbs of boost and the power measured to see how much power it takes to develop these figures. Guess what the results were? All 4 required the same amount of power to develop 500CFM@20lbs boost. The difference being efficiency which is directly related to the Delta temp. The more efficient the supercharger the lower the DT. The Axial being the most efficient at 98+% had the lowest DT and is no longer being built for cars as the Lathem is no longer built due to high costs, but is still being used in aircraft jet engines. Next is the Screw type which has a 90+% efficiency and the next higher DT. Now the popular Centrifical with a 70-80% efficiency and a higher yet DT, and last with the lowest at 50+% efficiency and the highest DT the Roots.
Now as stated before we have two methods of driving these superchargers. With the crank or the exhaust. For engine designers it's much easier to use a turbine or turbo and dump the exhaust to control the compressor output than it was to develop a system to control the output on a engine driven supercharger so the turbo supercharger has held the top spot for many years. But that is changing rapidly as engineers have developed a clutch similar to the one used on a cars A/C so the supercharger isn't using any power when not needed but there on demand, whereas the turbo is always inline and restricting the exhaust.
Which supercharger well make the most power. Well I'll put it this way, the screw type compressor can develop 150# boost where a normal turbo supercharger starts loosing efficiency rapidly above 35# boost. Now you can stack the turbo's and get more boost but then you run into other problems. But who the hell would ever need over 35# boost?
Someone came across a web page that described various DIY home brew octane booster formulas. One of which used toluene as its main ingredient. As a Formula 1 racing fan of many years, I recalled that toluene was used extensively in the turbo era in the 1980s by all the Formula 1 teams. The 1.5 liter turbocharged engines ran as much as 5 bars of boost (73 psi) in qualifying and 4 bars (59 psi) in the actual race. Power output exceeded 1500bhp, which translates into 1000bhp/liter, an astronomical figure.

A motorsports journalist, Ian Bamsey, was able to obtain Honda's cooperation for his book "McLaren Honda Turbo, a Technical Appraisal". The book documents the key role that the toluene fuel played in allowing these tiny engines to run so much turbo boost without detonation. The term "rocket fuel" originated from the Formula 1 fraternity as an affectionate nickname to describe its devastating potency. Thus I concluded that I should focus my research on using toluene for my octane boosting project.
With engineering moving forward in leap and bounds it won't be long we'll be seeing very high boosts on very small engines developing unreal power. When you can take a 150cu.in engine to a 300ci.in power we haven't even scratched the surface yet.
When engineer's develop engines for everyday use making 1000hp per liter you can kiss turbo's goodby.

[caddycarlo]

a turbo runs around 70%. The best turbos push 80%.

I don't really want in on this match but I have been watching the turbo cars on the dyno that I help at and none are anywhere close to 80 % most are 60 to 65 % when messured before the intercooler ........

[duplox]

I don't know about you guys, but I've been in wayyy to many of these arguements; one is far too many. Let me reiterate, I was joking. You can believe whatever you want, I'll believe what I want, neither of us are going to change our minds, so lets not waste our time, alright? I have zero problem with you liking superchargers better. But if you like getting in arguements, I can continue. Personally, I'd rather not.

I have a few questions for you though. What specific boost #s and IATs did you get with the turbo and supercharger systems? I ran a few numbers, and in order to get a 50*F temp difference with a change in efficiency from 65% to 90% was 25psi. This is with the same boost for both.

Whipple claims around 85% efficiency from their screw type superchargers. I was wondering if you knew what Eaton's screw types run.. the whipple looks much better made, which usually means more efficient. Eatons are just cheaper and I'd like to run a few little experiments.


Once the CVT is able to hold enough power, perhaps we'll see the demise of the reciprocating internal combustion engine alltogether. Gas turbines are significantly more efficient at their peak, but they drop of quickly on either side of their peak; they're not very good with a fixed gear transmission, since they have such a narrow powerband. They've only made an appearance in road vehicles back in the '60s in prototype big rigs with lots of gears. With a CVT the turbine could stay at its peak efficiency. I'm not lookin foward to that, despite the faster accelleration and better gas mileage... Whats the fun if you can't row through the gears, watching the tach fly up, hear and feel the engine roar.