Dyno sheet Rotrex 15-60 SC & MS DIYPNP tables
 

This is on a 95 Miata. I finally finished installing and tuning (although you are never "really" finished) a Kraftwerks Rotrex 15-60 SC race Kit on a 95 Miata. This is the smaller Super charger (not the larger 30-74 supercharger).

I have some dyno #'s from my setup. I am using a MS DIYPNP ECU.

The car actually made 201HP & 157 ft-lbs. But I removed 1 or 2 degrees of timing to be on the safe side since I run the car in very hot climate. That's the reason you see 197HP & 156 ft-lbs. I am also running 12 plates on my Supertrapp (I am guessing that uncorking it would yield a few more HP & Torque).

I used an IC from a 2004 Audi A4 I had in my garage. It cools well considering the price (free). At WOT (~9PSI @ 7,000 RPM) intake temps only rise about 15 to 20 degrees. 15 degrees on the road and 20 at the dyno.

I am also running:

"yellow" RX-8 Injectors. 450cc/min @ 3bar/43.5psi...Denso 195500-4450
NGK BKR7EIX-11Spark Plugs
AEM UEGO wide-band gauge
the "smaller" 80mm pulley

I have a post on another non-turbo miata forum with more details but I do not know if including a link to another forum is against the rules.

very impressiive - prior to my going to the dark side I was running a 30-74 which dyno'ed at 225 on a mustang dyno - I was running 525's cc and recorded 13 psi

so you don't gain that much going larger, just delays the onset of the boost

That is partially incorrect. While the boost may be lower, the blower is bigger and pushing more CFM at the same PSI. There was a thread I read a long time ago where an S2000 guy ran the C30-94 and the C38 (smaller one) and overlayed the dyno sheets. The power was more everywhere including down low, and all at a lower PSI. As far as I can see, there is no downside to running a larger Rotrex.

Don't forget that I managed to make 297whp with a C30-94, so there is more to be had with going bigger. I doubt I would have been over 260whp with a C30-74.

I certainly do not have any data to back this up....I would imagine a smaller SC may be more responsive and "spool" , for lack of a better word, quicker.

Regardless, for me the biggest advantage was less HP....how is that an advantage you may ask....here is my theory (which I am sure can be debated);

It is just a matter of prospective...I was only looking for some extra power for track use...my car does not really see much street use. My car only weighs 1,977 lbs. So 200 rwhp gives it ~10:1 power to weigh ratio. Plenty fast for the track.

Less power should in theory increase reliability, decrease wear and generate less heat (big one). It should also be easier on my brakes and tires....all things you would like on a track car if you do not want to spend truck loads of cash.

So in essence, I chose to give up some HP, hoping to gain in the areas described above....time will tell I guess.

Superchargers are belt driven therefore "spool" is inappropriate. I'm guessing your thinking of "rev happy" due to the inertial weight...same effect as light weight flywheel and pulleys.

Bigger supercharger will flow more CFM and make same power at LESS boost and less heat.

Thanks...."rev happy" may be a better word.

Regarding heat, I was refering to generating more heat in the engine not the SC...Higher HP numbers will inevitably generate more engine heat to dissipate.

Okay well how about same hp with less boost? That's what people are referring to.

+1

For this reason I switched from the C30-74 to the C30-94 before the system is even installed. We're making 180whp N/A on CA91 pump gas with this engine already so I think 350whp on E85 should be attainable at <15psi.

OP's dyno is impressive. 90% of peak torque over 2500rpm.

There is no such thing as "spool" with a Rotrex. The air delivered relates solely to the engine RPM. The bigger the compressor the more air flow delivered at that RPM.

MMMmmm... Looking forward to seeing results! This was the same reason Oscar Jr. said to go with the 94. I wish we has E85 up here.

I am peaking around 16-16.5PSI at 8k. I have no doubts that you can hit 350whp on a motor with 200cc more displacement, a better head design and E85.