New Rotrex C38-91 Supercharger

[dracul]

Intense. What a monster Hombre! How many hundreds of ponies are you shooting for?

 

[hombre]

The ROTREX C38-91 blower will pump a maximum of .63 kg/sec air into the engine. That's 83 lbs/min of air. You cannot make more HP than the actual physical mass of air pumped into your engine allows with your fuel... PERIOD.

Maximum possible HP can easily be computed by the Garrett forced induction formula:




Where:

· Wa = Airflow (lb/min)
· HP = Horsepower (flywheel)

= Air/Fuel Ratio

= Brake Specific Fuel Consumption ( ) ÷ 60 (to convert from hours to minutes)

I use a BSFC of .55lb per HP per hour, and .81-.83 lambda. Let's call that an A/F of about 12 with gasoline. One can easily compute maximum possible crankshaft HP:

83 = HP x 12 x .55/60

or

HP = 754

Let me take this opportunity to point out that I don't use anything from Bob Carpenter/Imfasttoo/et al... and I never will.

 

[goodfellow]

black & blue

she looks like a stone cold killer, Walt...

I can't wait to see what lays ahead.


be careful and good luck.



greg

 

[garygene351]

supper charge

Injection is nice,rather be blown! that's gotta sound?/feel awesome. Whats up with Carp. Race Mods?, almost went that rout, but did not like reusing stock parts in some of the build. THANKS for the CF parts, man that chin spoiler was a pain.PM me if you want as I will be looking for high compression next

 

[garygene351]

The NEED

I now see why you sold the body,ARE those diff. length shocks? Any of the frame stock? will you be taking on sponsors?/donations?

 

[hombre]

Thanks for your comments, guys!

Let's apply the same formula to a properly prepared supercharged R3 engine using the smaller Rotrex C30-94 blower spinning at it's peak off 100,000 RPM, and assume the same tuning parameters. Maximum mass air flow for this blower is .37 kg/sec, or 49 lbs/min of air.

49 = HP x 12 x .55/60

or

HP = 445 (max @ crank) :bch:

This would be representative of TriRocket3's supercharged R3 engine, and is consistent with his use of 1000cc injectors.

Now look what happens if you spin the C30-94 at only 60,000 RPM, as recommended by Carpenter & Imfasttoo. The max mass airflow drops to .28 kg/sec... only 37 lbs/min of air.

37 = HP x 12 x .55/60

or

HP = 336 (max @ crank)

It should be obvious why I don't use anything from Carpenter.

 

[hombre]

Big C38-91 ROTREX a perfect fit with equal-length stepped headers.

 

[HansO]

Yeah I was going to get Sam to make mine equal length till we worked out they were going to stick out that far, would have been fairly uncomfortable in normal riding pos but with your setup your legs probally don't go any where near them. Man I was hoping you would show us this side, those headers do look the goods what OD pipe did you do them in they don't look that big which is something I learnt from Sam in our conversations and that to big can actually be a negative effect

 

[hombre]

My headers step from 1 5/8 to 1 3/4 to 1 7/8 ODs, all in equal length sections to the collector. Sam is correct, in that a smaller diameter will have higher velocity flow... scavenging the chamber faster and more efficiently. My header specs were specified by BURNS STAINLESS... where Sam developed his Predator system. They know a wee bit about building racing exhaust systems.

 

[HansO]

Big C38-91 ROTREX a perfect fit with equal-length stepped headers.

My headers step from 1 5/8 to 1 3/4 to 1 3/4 ODs, all in equal length sections to the collector. Sam is correct, in that a smaller diameter will have higher velocity flow... scavenging the chamber faster and more efficiently. My header specs were specified by BURNS STAINLESS... where Sam developed his Predator system. They know a wee bit about building racing exhaust systems.

Should call the bike "The Terminator" it looks like it wants to terminate
Something, I won't say it but I think you know what mean! Eh eh