Kraftwerks Rotrex Supercharger Discussion

[digital_assassin]

The c38 can likely boost up to 20 psi or greater. I imagine they are rolling out with a moderate sized pulley so there is room to grow.

[Zach3794]

The rotrex can, yes, but the S2000 kit they make with the C38 doesn't have that much boost as any of the options I'm aware of. I doubt they're going to make a 20psi or greater option available. Big risk to them.


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[Calum]

Originally Posted by Zach3794

Really? I mean the numbers look not that great for an upgraded blower to me. Considering low boost on the c38 is the 14 psi they stated. Don't get me wrong it's more power, but even KW said there's a long way to go with it. Maybe it's just since I make 333whp on e60 with the c30 at 9psi it just doesn't seem so impressive...also unfinished tune


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Ok, so your making about 60 whp over what their dyno is showing for the revised tune on the same kit you have. For ultra simplified math, add that 60 whp to the 333 they're making on 91 with the high boost c38 and you're at 393. A hair away from 400 whp on your car, on your fuel, and on your dyno. Seems pretty fucking impressive for a super charged two liter to me. Especially considering that's only revving to ~6800 rpm.

When you add in that the gains would increase as a percentage and not a straight addition, those gains will get even better. And than factor in that there's no way in hell they are able to tune for mean brake torque on 91 octane at that pressure, but you likely will be able to with e85 and all of a sudden that c38 seems insane.

Oh, and there's the off peak power...

[Model Citizen]

Is the r2 tune the one which requires the "red" map sensor previously posted?

Are these something separate

Originally Posted by mit_peid

Kraftwerks told me the reason why the new tune they sent me didn't idle was because I didn't have the right MAP sensor so they sent me this nice new red MAP sensor. It got to me the next day and just installed it with the new "factory" Skunk2 tune file they had previously sent.

I'm happy to say that it drives a lot smoother around town in the short test drive I took. Looking forward to see how it performs at WOT later on tonight. Very happy with how Kwaftwerks responded to my input here even though it took a little time. Attachment 72252

[Zach3794]

The 60 whp additional was on the infamous mustang comparing my own car to the 91 tune with the same components. I was just saying that at the numbers were seeing for the c81 right now, it's a pretty small gain considering it's several psi over the base c30 setup. That's just my take


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[gmsii]

Originally Posted by Zach3794

Really? I mean the numbers look not that great for an upgraded blower to me. Considering low boost on the c38 is the 14 psi they stated. Don't get me wrong it's more power, but even KW said there's a long way to go with it. Maybe it's just since I make 333whp on e60 with the c30 at 9psi it just doesn't seem so impressive...also unfinished tune


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bro...few things:
1) you cannot compare ethanol numbers to 91 octane gas numbers...obviously with the crappy 91 octane gas we get in cali, increased airflow has diminishing returns when you cant put enough timing into it
if you feed the c38 equipped engine with ethanol you'll see some BIG numbers for a supercharger...certainly much bigger than what is possible with the C30 charger.
2) the Rototest used by KW reads very low compared to other chassis dynos.
before you compare our development dyno numbers to your car, maybe you should arrange a time to come by and make few pulls on our dyno just see you have a true baseline. we would be more than happy to accomodate you
3) if i am not mistaken, the R2 tune is not the same tune as the delicious tune. we can discuss offline if you need further clarification.

[Zach3794]

I'm not trying to do a direct comparison really...I'm just figuring in my head that at 14psi on 91 that c38 has gotta be severely limited on the amount of timing you can utilize...which goes in line with what you just said. Also it looks like on the high boost pull you're getting clutch slip so I imagine those numbers would be much more impressive if she kept grabbing up to the top. With an upgraded clutch and ethanol in the c38, I can't even imagine what the limits are for this kit. I can easily see 400whp coming on any dyno.

Again...not bashing you guys or the kit. Just speculating on the limitations of the motor as far as knock threshold on shit 91 gas.

On the flip side, the c30 with the 70mm pulley shows solid gains either way and I'm really stoked about that upgrade.

I think the moral of the story is that if anyone is expecting truly glorious numbers on just about any kit out there, especially in California, it's gonna be on ethanol. 91 just doesn't make the grade.




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[DeliciousTuning]

Originally Posted by Zach3794

If the r2 is indeed the Delicious Tuning update, I have it We dialed it in over here on this one, and the increases over the base tune that Kraftwerks is displaying is valid.

Hi Zach and Everyone,

There must have been a communication error some where, potentially even on my end. The "R2" tune that Kraftwerks is speaking about is not the same as our Delicious tune. I know they have in house developers/tuners so I am sure they have their own version of the tune now that I am sure improves the low end, as that was a complaint on the original tune we did.

As for the our tune we are always developing, it is completely new and different from what we did with Kraftwerks. In the time since we left we have started from scratch about 4 more times to really dial in a true Speed Density MAP for this kit and many other kits. So the new release will be quite a bit different in a LOT of aspects but the power delivery will be nearly identical.

We are also working on finalizing a tune for a larger MAP sensor that reads well above 20 PSI, so the smaller pulley will work well on it. The best part is, it is an OEM piece and since since our tunes rely heavily on them it will be reliable.

Regards,
William Knose
Delicious Tuning

[mit_peid]

I believe I have both the original OTS "Delicious" map and the newer "r2" map from Kraftwerks/Skunk2 that has been calibrated & built on a 4-bar MAP sensor. I do think the "r2" is a very big improvement from the original, but I noticed that the original map's basemap is ZA1JA01C whereas the newer "r2" basemap is actually the older ZA1JA00C. I thought the reason why Toyota/Subaru revised the factory map to ZA1JA01C was to account for the DI seal failure, but I could be wrong since virtually everything on the internet on the issue is actually in these forums (nothing I can find officially from Toyota/Subaru). Wondering if KW made the modifications to their newer "r2" map to mitigate the DI seal failure situation (not sure if it'd make a difference for me since I don't shift aggressively near redline).

[KraftWerks]

Just to provide a little information to the discussion:

-The R2 tune is a Kraftwerks tune, not a Delicious tune.
-The c38 graphs were preliminary tunes that are still being worked on but the potential looks to be very good.
-The 70mm pulley upgrade with the c30-94 has shown great gains even with 91 octane (even better with e85)
-The “Red” map sensor is a 4 bar unit

[Freeman]

Any idea of an ETA for a C38 tuner kit?

[glamcem]

I wasn't sure if I need to ask this question here or the other but but here you go.


for those who have the drop/choppiness in power after 6500 rpm, Has anyone of you changed your spark plugs with a 1 step colder iridium ones and tuned for it?

This is what I am referring to


@gmsii has mentioned this in the "KW discussion thread" and it's also recommended in the installation manual (page 2, bullet point 5)

generally the high rpm choppiness is from the spark plug...these were stock plugs, we will try a step colder...should smooth it out

My kit is in the mail and I am wondering if I should go ahead and order my plugs too..How hard was the install? I know it's somewhat hard to reach on Subaru engines but never had to change it with my previous Subarus

[Calum]

Originally Posted by KraftWerks

No problem!
-High boost with the C30 was 13psi
-High boost with the C38 was over 14psi (we haven't finished that tune)

Do you have know how much extra the c38 kit will cost?

[KraftWerks]

We're feel'n jolly. FT86Club Group Buy has started, won't happen again for a while:
http://www.ft86club.com/forums/showthread.php?t=63478

It's been pretty cool seeing how many people have purchased the kit, figured it would be nice to offer a deal for a few days.