So I drove a Rotrex on Sunday at Buttonwillow... - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

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Old 12-23-2009, 09:27 PM   #21
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It was a lame joke, I know.
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Old 12-23-2009, 09:30 PM   #22
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i kinda want one
don't understand the whole CARB EO thing
but i know i have to pass emissions
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Old 12-23-2009, 09:32 PM   #23
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Originally Posted by Savington View Post
Since you can throttle-rotate either car at track-out, they're the same. The Rotrex is just easier to control.
Since no one else has said it... I guess I will. What's the fun in that? Haha
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Old 12-23-2009, 09:32 PM   #24
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Originally Posted by hustler View Post
We need a special forum for members running under X-time on Y-track. Oh wait, thats track HQ. lulz
Heaven forbid someone on this forum should cop an elitist attitude
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Old 12-23-2009, 09:37 PM   #25
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I'm just still waiting on a dyno of an all out setup. I want to see what the ceiling for this thing is already. I hate waiting for stuff btw...
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Old 12-23-2009, 10:07 PM   #26
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I'm just still waiting on a dyno of an all out setup. I want to see what the ceiling for this thing is already. I hate waiting for stuff btw...
Ceiling on what specifically? I suppose if we put a C38-94 on a fully built stroker on E85 we could make about 500whp.

TrackDayHookey is making 300whp with a stock head, built bottom end 94 engine, Racing Beat header and 2.375 street exhaust on 100 race gas, with a homebuilt C30-94 based system. He's planning a built head 99 engine, bigger exhaust, cams and possibly E85. I suspect he'll be making about 350whp then.

The OGK will use a system similar to William's car (that Sav drove) only with a big cam, full-on 99 race engine. I suspect I'll see around 310whp on the same C30-74 blower that our 165whp base kits come with.

Last edited by emilio700; 12-23-2009 at 10:42 PM.
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Old 12-23-2009, 10:38 PM   #27
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In for chinarotrex...any idea when those will come out?

JK


I seriously should not be reading this thread. I really like Sav's review...and the plot is good enough for me.
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Old 12-23-2009, 10:39 PM   #28
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In for chinarotrex...any idea when those will come out?
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Old 12-23-2009, 10:45 PM   #29
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Originally Posted by emilio700 View Post
Ceiling on what specifically? I suppose if we put a C38-94 on a fully built stroker on E85 we could make about 500whp.

TrackDayHookey is making 300whp with a stock head, built bottom end 94 engine, Racing Beat header and 2.375 street exhaust on 100 race gas, with a homebuilt C30-94 based system. He's planning a built head 99 engine, bigger exhaust, cams and possibly E85. I suspect he'll be making about 350whp then.

The OGK will use a system similar to William's car (that Sav drove) only with a big cam, full-on 99 race engine. I suspect I'll see around 310whp on the same C30-74 blower that our 165whp base kits come with.
Emilio, there's a thread on m.net where the FFS zombies are declaring MP62 superiority because "their" kit makes 190 whp. So I ask you, what's mechanically involved in bringing the base kit up a tad, to get it to the ~200 whp level?
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Old 12-23-2009, 10:49 PM   #30
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I bet it's the same as a turbo - cool the intake charge, address the fueling, and be careful. Instead of a boost controller, you adjust boost on the Rotrex using an intake restrictor.

"Address the fueling and be careful" may as well be greek for the FFS folks, though.
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Old 12-23-2009, 10:50 PM   #31
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Heaven forbid someone on this forum should cop an elitist attitude
I am the most modest and soft spoken person on the internet. I also only speak the truth.
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Old 12-23-2009, 10:53 PM   #32
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Interesting, so mechanically, you simply use a less restrictive restrictor.
Intercooling is a great thing, but with the outlet temps, would it really be necessary at the ~200 whp level? If the MP62 can get away without charge cooling, I would expect the Rotrex to also get away without it.
Fueling is another story. There are times when I want to bash those morons' heads together.

Remember, a throttle body located fuel injector will bring your intake charge temps down from 300 to 100.
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Old 12-23-2009, 10:56 PM   #33
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Originally Posted by Savington View Post
I bet it's the same as a turbo - cool the intake charge, address the fueling, and be careful. Instead of a boost controller, you adjust boost on the Rotrex using an intake restrictor.

"Address the fueling and be careful" may as well be greek for the FFS folks, though.
Compressor outlet temps are 1800*.

3:30
Dramatic affect of cooling.
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Old 12-23-2009, 11:01 PM   #34
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I think TDH put it best - I asked him forever ago what was under the hood of his Miata and he replied: "It's the yo-yo guy's blower."
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Old 12-23-2009, 11:03 PM   #35
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Originally Posted by Ben View Post
Emilio, there's a thread on m.net where the FFS zombies are declaring MP62 superiority because "their" kit makes 190 whp. So I ask you, what's mechanically involved in bringing the base kit up a tad, to get it to the ~200 whp level?
Either making the engine more efficient with typical N/A mods like a header, porting etc. or more CFM from the Rotrex. The base Kraftwerks Rotrex is already set on "kill" as we like to say, meaning it's spun right up to it's max RPM then the top half of the boost line is capped with an inlet reducer. So it's the linear rise with a plateau wherever we choose. That means making moar boost is just a matter of using a different shape inlet reducer.

From the KW1, just add an I/C and pull maybe .75 AFR fuel, from around 11.0:1 average to maybe 11.75:1. That might be worth 15whp and essentially what we'll do for the KW2. Buy it from us without the ECU, and you have better control over the power delivery. Being able to run more timing down low and pull it back as boost builds.

The Rotrex runs cool enough to run 5psi non I/C without pulling timing. We find though that at about 7psi no I/C, you just have to add to much fuel to control knock in a stock Miata engine. It's just no longer efficient as you are dumping so much fuel in to douse things, even with the Rotrex. We could tune as aggressively as some of the MP62 kits, but we prefer a fail safe tune that will tolerate bad quality gas, dirty injectors, carbon fouled plugs that are hot spots etc. Wiliam has run as much as 9psi non-intercooled with stock timing during testing but that's a risky tune, similar to what you might see on some production MP62 kits with drastically reduced timing. I think we saw IAT's in the mid 200's when we did that. The base, KW1 kit on the NB runs between 170~190 post blower IAT's at full chat, back to back runs, fully heat soaked. One pull will see only like 145. The crossover pipe sheds a surprising amount of heat and the manifold soaks some up so we see maybe 10-15 less at the plenum.

Unless you had a strong reason to do so, I personally wouldn't choose to build a non I/C kit for anything more than about 175whp. Adding an I/C is easy, its make more midrange torque and noticeably more top end without changing anything else at all.

FWIW, we have invited several owners of unmodified MP62 kits on stock engines to run their cars on our dyno, including a "190whp" kit. We will have stethoscopes and headphones.

Last edited by emilio700; 12-23-2009 at 11:20 PM.
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Old 12-23-2009, 11:06 PM   #36
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The combination of factual data and satire in this thread is making my head spin.

On a serious note. I have like the possibiliy of the rotrex kit since you introduced it. My biggest gripe is the cost compared to other options. Make the price more competitive and I think you would see more widespread adoption.
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Old 12-23-2009, 11:14 PM   #37
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Most of us want to go fast for cheap. I agree with neo: if/when the costs dip down on these bad boys you'll get a whole lot more customers
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Old 12-23-2009, 11:25 PM   #38
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Quote:
Originally Posted by neogenesis2004 View Post
The combination of factual data and satire in this thread is making my head spin.

On a serious note. I have like the possibiliy of the rotrex kit since you introduced it. My biggest gripe is the cost compared to other options. Make the price more competitive and I think you would see more widespread adoption.
Yup. The Rotrex unit itself is expensive and the :$ ain't helping.

FWIW, the NA8 KW1 base kits will incorporate a significant added value over what is currently available with the KW1 NB kits. Can't tell you anymore yet.
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Old 12-23-2009, 11:38 PM   #39
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i kinda want one
don't understand the whole CARB EO thing
but i know i have to pass emissions
CARB = California Air Resources Board = Nothing to do with Georgia state emissions testing!

Last edited by r808; 12-23-2009 at 11:49 PM.
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Old 12-23-2009, 11:55 PM   #40
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When do the TR 15x9s come out?
Quote:
Originally Posted by gospeed81 View Post
In for chinarotrex...any idea when those will come out?
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