I threw my Bro's RX-1 car on the dyno ---- results inside!

[tarmacblack]

The gearbox is an 8.2:1 reduction so in order to get the car to shift out I had to load the dyno to 55%.  Just as a comparison on a diesel that makes over 600 lb/ft of torque with a 3.73:1 rear end any thing over 40% is most of the time too much for the truck to power through.  I guess that's the wonder of torque multiplication.

Here's the chart, pretty awesome what a good job the centrifugal clutch setup does holding peak power.



It was my first time dynoing a Centrifugal system, it got me excited seeing the results so I thought i'd share 

[fabr]

I'd like some details about that 275 HP RX-1. What was done to it to nearly double stock HP? Pretty impressive!

[tarmacblack]

A lot 

It's been converted to propane and turbo'd.  Stock crank, stock rods, arias forged 9.5:1 pistons, sleeved cylinders, and a whole lot of custom parts, too many to list off the top of my head.  The car runs really reliably at 20psi, this dyno run was on 16psi so it should go past 300whp on higher boost setting.  We'd have turned it up, but it was a new motor that was pretty much broke in on the dyno.

I'll have to try and dig up some pictures of the setup to share, it's really an innovative setup.  If any of you are into snowmobiling you may be familiar with Simmons Turbo systems (propane turbo conversion) and the names Brad Story/Val Simmons.  Brad is the car builder/owner.

If you want to know more detailed specifics ask away 

[borris]

Too many questions to ask.Why not you just start in and I'm pretty sure that'll bring in  a lot of discussion! I'm really intrigued about the propane setup.

[tarmacblack]

I need to dig up some photos of the car, i'm sure that will encourage more questions.

Most of the custom parts have to do with the turbo kit and the propane conversion.  All of the FI stuff is pretty much eliminated.  The fuel rail is replaced with a "vaccum" rail as Brad likes to call it.  Custom intake and exhaust manifolds are built, I think they've finally settled on this design, I believe it to be the 10th or 11th revision.

They have a pretty nice machine shop where they build most all of the parts, so there isn't a shortage of machined and engraved billet aluminum on the car.  The intake manifold, and all of the propane kit covers are machined and engraved with their logo (mixer, vaporizer, tank end caps on the sleds etc.)

Propane has proven to be a pretty awesome fuel for turboing the four strokes.  Despite the lower energy content, it makes really good power after adding forced induction.  The octane rating, anti knock characteristics, and the slow controllable burn rate make it an awesome fuel.  Plus it's quite a bit easier on the wallet than race fuel  .  Only real downsides are you lose the cooling effects of the gasoline (propane enters the engine as a vapor so it doesn't absorb the heat like gasoline).  Consequently the engine comes up to operating temps much faster, but will also run 15-30 degrees hotter.  We've combated this on my bro's car and my dad's car (2.49 hybrid subaru powered car) by adding really high capacity/flow oil coolers, and large radiators (typical upgrades for sandcars) which has pretty much solved the heating problems.

I'm not sure what exactly you all would like to know about it, but like I said before, i'm happy to answer any questions I can.  I was a pretty big skeptic at first, but after seeing how well it works i'll be converting my CBR engine to Propane this winter and turboing it  .

[lee1969GB]

What kind of cost $ would it cost to get the rxi motor up to that spec? Yes some pics would be great.

[Admin]

the motor alone would run in the neighborhood of 3500, i seen one pushing 500hp claimed to cost over 30k..

[tarmacblack]

Sorry it took so long, but here are some shots of the buggy/engine setup:





















I'm planning on doing the same engine with a different drive setup in my own car.  The CVT keeps the engine making peak power for so long that the car becomes a real riot to drive.  Not to mention it's easier for less experienced drivers as they don't have to worry about finding the right gear for the right situation (aka my wife).

If you can find a wrecked sled, generally you can pick them up for between $1500-$2000, you'll need clutch upgrades, head studs, head shim or lower comp pistons, and then all of the turbo kit hardware, and the fueling upgrades.  So to get it to these power levels you're going to need in the neighborhood of $5-6k if you can put it all together yourself, and you find a good deal on a sled/engine.

[fabr]

Very clean,nice setup!

[Engineer]

Very nice!  What kind of differential/gearbox is that being driven by the CVT?  Very impressive that it can handle the driven pulley cantilevered.

Curious why it is right hand drive?

[tarmacblack]

Very nice!  What kind of differential/gearbox is that being driven by the CVT?  Very impressive that it can handle the driven pulley cantilevered.

Curious why it is right hand drive?

It's a second generation Hymark trans, as far as I know Steve only built a handful of them.  I've only ever seen them on his car and on my brothers.

The car is RHD because his wife owns 3 USPS routes.  The theme for the car when it get's paint will be "haulin the mail."

If you look close you can see that the passenger grab bar and foot rest are tabbed identically to the pedal set and steering shaft so it can easily be changed from RHD to LHD if so desired.

[trojan]

That's awesome! got any more info on the turbo-propane conversion?

[VLADD]

That is BAD ASS...
Altho-, you might want to fab up a cover for the CVT they really don't like dust and sand, in them...Mud or water either

[tarmacblack]

That is BAD ASS...
Altho-, you might want to fab up a cover for the CVT they really don't like dust and sand, in them...Mud or water either

You're right, you can definitely feel (with your hand) the wear on the clutches from the sand, that set however is still going strong after it's 3rd season.

He had a cover he built with outerwear material and some aluminum frame work, but a shredded belt demolished it, since then he's just run them open. 

[tarmacblack]

That's awesome! got any more info on the turbo-propane conversion?

What kind of info are you looking for? 

You can purchase all of the components for that same setup from Simmons Turbo systems or any of HP3 dealers for that matter.

This is what the system was designed for originally: