supercharging your truck for cheap

[89_3&3]

I'm sure most of us know about those. I'm sure most of us also know they are geared to turn the RPMs required, which you aren't going to get with a direct drive and maybe a 1:3 ratio from your pulleys if you are lucky. There is a HUGE difference between a proper centrifugal supercharger (Rotrex, Paxton, etc) and driving a turbocharger with a belt.

Im not trying to make 3000 hp with 50 pounds of boost like some of these things are capable of

 

[89_3&3]

https://www.youtube.com/watch?v=sVem3i00rWQ&feature=youtube_gdata_player

 

[89_3&3]

Its bolts belts and parts wow
Even 3:1 at 4500 rmp x 3 is 13500 rpm
100.000 rpm = 20 pounds of boost with a diesel truck turbo
So if I push even 2.7 pounds of boost at max rpm there is an increase in hp and fuel economy

 

[89_3&3]

http://www.youtube.com/watch?v=d-DGeJOc6ko&feature=youtube_gdata_player

 

[89_3&3]

See I was just watching WWE and nascar on split screen and it just came to me

 

[89_3&3]

https://www.youtube.com/watch?v=SQMSSKfs4m4&feature=youtube_gdata_player
Ok so if you want to really get complicated this is how the pro models get there out put drive to max out there turbo's
But thats to much work for me I just want 3 through 6 psi

 

[89_3&3]

Ok so here do your own math and quit with the it wont work bs

 

[89_3&3]

Ok so here do your own math and quit with the it wont work bs

Well that pic sucked

 

[89_3&3]

http://www.procharger.com/models.shtml

 

[89_3&3]

So wait a minute there making a 250hp increase a 60,000 rpm empeler speed and i keep being told that 3:1 at 13500 rpm wont build enough pressure to make any boost hmm thanks for your expert opinion but I think ill continue anyway

 

[foamypirate]

You are leaving out one VERY important detail. They have an inside multiplier, in ADDITION to the outside ratio.

So, they are running a 5:1 or so inside the unit, multiplied by the maybe 2 or 3:1 driven pulley, which is still a lot more than just a STRAIGHT 2.5:1 drive (for examples sake).

6000rpm * 2.5 = 18,000RPM

(6000rpm *2.5) * 5 = 75,000RPM

So you're running about 1/4th to 1/5th the impeller speed...and that's at redline.

And yes, impellers are inherently very inefficient at low speeds, which is why you won't make boost with exhaust driven turbo when it's not under load. The load drives the impeller speeds up and THEN you make boost. You might be lucky to make 1psi with the setup you are planning, which likely will barely equal out with the power consumed to drive the turbo.

But whatever, have fun with your idea, I'm tired of trying to present the issues that will need addressing the make this work. You clearly know better than the rest of us, oh holy one...

 

[89_3&3]

Im not building a drag car look at there power gains its a work truck its a low boost system to increase hp and fuel economy

 

[89_3&3]

From what my calculator says 2.7 pounds of boost minimum at my max rpm thats lots
And look at some dives most look 1:1 and the gear box a the highest 7:1 from some of the ones I've looked at so 3:1 at the least wont suit my needs ?
the specs on the turbo said
150,000 rpm = 30 psi
At 100,000 rpm = 20 psi
So do the math at 13500 rpm thats 2.7 psi at 3:1 and ill try to squeeze a little more than 3:1

 

[89_3&3]

And if you want more out of it go pull a civic tranny and get the planetary gears and fab up a box

 

[foamypirate]

From what my calculator says 2.7 pounds of boost minimum at my max rpm thats lots
And look at some dives most look 1:1 and the gear box a the highest 7:1 from some of the ones I've looked at so 3:1 at the least wont suit my needs ?
the specs on the turbo said
150,000 rpm = 30 psi
At 100,000 rpm = 20 psi
So do the math at 13500 rpm thats 2.7 psi at 3:1 and ill try to squeeze a little more than 3:1

The equation isn't a linear relationship. Just because 100,000rpm = 20 psi, doesn't mean you'll have 2.7psi at 13,500. It's also not a question of PSI, but of CFM. PSI means nothing, that's just a resistance to flow. CFM is how much actual air you are moving.