supercharger

[steveinaz]

i did the searchbut didnt find any good info.

does anybody have any firsthand knowledge about installing one on a first gen truck?

 

[Greenleaf]

So you'r talk'n belt drive?



Scott

 

[SRadke]

Planin' to feed the supercharger with the turbo?



-Scott

 

[RGT]

like a 2 cycle Detroit... I was thinking, or musing more correctly, about a setup like that with the supercharger running inverse to engine speed so that when the turbo gets up to speed the driven 'charger drops out, but elliminates start up boost lag...

 

[formula]

Originally posted by RGT

like a 2 cycle Detroit... I was thinking, or musing more correctly, about a setup like that with the supercharger running inverse to engine speed so that when the turbo gets up to speed the driven 'charger drops out, but elliminates start up boost lag...

Systems like that do exist. They are frequently used on marine diesel engines. There is a supercharger that provides boost at low rpm and a bypass circuit that allows the turbo to take over at higher rpm/load.



Sean

 

[hdm48]

Ah, this is an old drag racing trick. But when it is done, the turbo feeds the blower and does not bypass it. Makes for a lot of boost quick. One of your biggest problems will be figuring out the overdrive % for the blower drive. You could spend a lot of time on this.

It could work, and if you do it, I would love to see how you managed to fit it in there and plumb it.

On drag cars we had no hoods or fender wells to deal with.







Dave

 

[steveinaz]

no bypass. turbo to supercharger.

i have on my jobsite a 12 cyl cat diesel(4 stroke) that has two turbos,one for each bank. it also has two superchargers that are gear driven(front of engine). around 1800 horsepower, drives a genset for a large, LARGE crusher.

i believe that it has a redline around 2000 rpm. the load on this genset varies greatly, there is no room for turbo lag.

i am sure that this technology could be used to enhance the performance of our engines.

i believe that the belt driven dynamics would be easily resolved.

fuel delivery may be the real stumper. i'm thinking an extra electronic injector upstream in the intake, just my thoughts.

 

[steveinaz]

anybody ever belt drive a large turbo?

 

[SRadke]

You can't get enough rpm through a belt to drive a turbo. Turbos can easily spool up over 100,000 rpm.



-Scott

 

[steveinaz]

turbo speed

I found a website www.gatorsuperchargers.com that spins up a small turbo using two belts and a jackshaft. i believe that they can reach 50,000 rpm.

At 2800 rpm and two 4:1 increases comes to 44,800 rpm at the turbo.

Do you think the after the turbo cooler or the hoses will collapse before the turbo catches up?

 

[SRadke]

Do you think the after the turbo cooler or the hoses will collapse before the turbo catches up?

Huh?



That site is very interesting but I still don't understand what you're trying to do? If you want a blower, get a blower. If you want a turbo, get a turbo. If you want to run both, do it. They do it on Detroits all the time.



The idea of using a centrifical compressor (turbo) as a direct drive off the engine I don't understand. A blower is more or less constant displacement. Air volume vs. rpm is somwhat linear. A turbo, not so. Also by driving the turbo with exhaust air it knows when load increases (based on increased exhaust flow) and spools up to create more boost. It's a conceptually simple system that we don't need to complicate.



One more thing:

On the other hand, modern superchargers using secondary belt drives (instead of gears) and sealed bearings like the Gator, Powerdyne's "Silent Drive", Wynjammer, Germann ZR01 run much cooler, eliminating the need for intercoolers at any achievable boost level.

This was on that Gator site. The reson for the intercooler is to cool the air after it is compressed. When you compress air it get hot, simple physics. I wonder if these guys know what they're talking about.



-Scott

 

[steveinaz]

I would install the blower on top of the intake down steam of the intercooler. I'm thinking that a vacuum would occur until the turbo started making boost. The Caterpillar supercharged turbo engine has no rubber hose between them. It's all hard piping, simular in construction to a 3 piece ats exhaust manifold. No chance of a collapse.

I am going to eliminate the turbo lag that all cummins engines are born with.

Since this has not been done yet , I'm simply grasping at ideas. If we simply left everything simple we would still be walking around try to hit each other with sticks.

 

[Greenleaf]

Yes, many Detroit Two Strokes use a blower in conjunction with a turbo (or two) The blower feeds the air to the engine at lower rpm. It has to cause a two stroke cant pull air in like a four. (There is virtually no combustion chamber scavenging in the Two Stroke Diesel). Then after the engine picks up speed and load the turbo(s) feed the engine air. There is a bypass to render the blower inop at this point. A Two Stroke will NOT run without a blower. Simple.



The blower is a must because it cant get air at low rpm's. It DOES NOT feed air to PREVENT TURBO LAG. I'm not sure what your worried about turbo lag for. It is overcomed by a few simple mods. Trust me, I know. A stock Dodge with a CTD will have difficulty performing a burn out. I tried it, even on wet pavement. No go. Now, I have no lag. Hit the throttle and the rear wheels will light up. Zero lag. No blower.



I think he means by keeping it simple, you only need to perform some simple mods to what you already have. No blower needed. If what you have done isn't working because you can't reach 60 mph with 16k lbs behind your truck in 15 seconds, ask more questions and perform the required mods. Don't reinvent the wheel, it's already been done.



I (we) are only trying to keep things simple for ya. If you feel you need to design a better system, GO FOR IT! It's pioneers like yourself that invent things to better our world. More power to ya. And good luck. If we can help, call on us.



Scott

 

[SRadke]

Ah, I see where your at with the vacuum thing. Generally the pipeing is steel and connected with rubber. The rubber provides flex and isolates vibration. Keep in mind ultimate vacuum is equal to less than 15 psi (negative). Does that make sense? To pull ultimate vacuume inside something is equal to putting it in a chamber and adding 15 psi to the outside. It's not much pressure. Add to that the fact that your Cummins will never pull anything close to ultimate vacuum and rubber coupling hoses will not be a problem. If they were they couldn't be used on an intercooler.



Scott is right on with my thinking. I'm not saying you can't do what you're trying to do, just that you can get around it. Obviously it can and has been done because Cat did it. I'm just weighing the relationship between usefullness and cost effeciveness.



I'm sorry if it appears I'm pulling you down on this but I spend way too much time in a science lab. Then I saw the quote I posted above from the Gator Supercharger site which is obviously wrong and I got a little turned off buy the idea.



-Scott

 

[steveinaz]

You can't pull me down. I built my own 20" rims 12 years ago. Every person I talked to said that it wouldn't, shouldn't and couldn't be done.

I've just bought a truck at auction to use as a test bed. its a 91 4x4. No intercooler yet , but i have one from a topkick. I also have one from a 79 mack truck that sits over the intake manifold. It's odd but very adaptable.

I'll get something together and show up at one of these dyno runs.

Anybody got an old B&M blower sittin' around?