So I drove a Rotrex on Sunday at Buttonwillow...
#1
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So I drove a Rotrex on Sunday at Buttonwillow...
..and I'm ashamed to say that it wasn't bad at all.
The setup:
'99 chassis, stripped/caged, ~2200lbs w/o driver, 6-speed, 3.909 Torsen
XIDA doubles, 15x9s, 225/45 NT-01s, Goodwin BBK
GTC-200 wing, custom endplates, front splitter
Rotrex blower
RC550s, Walbro 190lph, Adaptronic, E85, 230whp/212wtq@9.5psi (detuned from ~260 for stock longblock longevity)
This setup turned a 1:57.4, which is the 3rd fastest Miata at Buttonwillow, and the 2nd fastest car on NT-01s (Matt Andrews is 1st, my car is 3rd).
Throttle response was excellent, better than I am used to obviously. The car had a throttle body problem that made it a little sticky right as you cracked it open, but other than that it was really nice. No pre-application to spool a turbo like I do in my car - open the throttle and go.
Power delivery was, in a word, smooth. The best way to describe it is that it felt like the car had a straight 6 in it, very similar to my dad's E46 M3. No peaky rush, no thump of power, it was there right as you opened your foot and built smoothly to redline. I expected it to be a little peakier, a little more top-end oriented, and it didn't feel that way at all - just a nice strong pull from 5000rpm into the rev limiter. I was aware of the torque curve when I was driving it, so I consciously kept the revs as high as I could, but even then when the track required me to stay down a cog in order to avoid a shift in an awkward spot, I never felt like I was off the powerband.
To be honest, this is about as far as you can get from a turbo. There is NO rush of power, no drama, and it's almost hard to get excited about it, but there's something to be said about that. From a driveability standpoint, this is without a doubt more driveable than my car was, even with the T25, and it has the oomph, with 230whp from just 10psi. I got out thinking I had done a 59, and was very surprised to see the pair of mid 57s on the time sheet.
Anyway, thought I'd share my thoughts. It's a neat piece. Not neat enough to switch my track car over (I'm a fan of that big stupid rush of torque), but I could see owning a daily driver with one of these on it very easily.
The setup:
'99 chassis, stripped/caged, ~2200lbs w/o driver, 6-speed, 3.909 Torsen
XIDA doubles, 15x9s, 225/45 NT-01s, Goodwin BBK
GTC-200 wing, custom endplates, front splitter
Rotrex blower
RC550s, Walbro 190lph, Adaptronic, E85, 230whp/212wtq@9.5psi (detuned from ~260 for stock longblock longevity)
This setup turned a 1:57.4, which is the 3rd fastest Miata at Buttonwillow, and the 2nd fastest car on NT-01s (Matt Andrews is 1st, my car is 3rd).
Throttle response was excellent, better than I am used to obviously. The car had a throttle body problem that made it a little sticky right as you cracked it open, but other than that it was really nice. No pre-application to spool a turbo like I do in my car - open the throttle and go.
Power delivery was, in a word, smooth. The best way to describe it is that it felt like the car had a straight 6 in it, very similar to my dad's E46 M3. No peaky rush, no thump of power, it was there right as you opened your foot and built smoothly to redline. I expected it to be a little peakier, a little more top-end oriented, and it didn't feel that way at all - just a nice strong pull from 5000rpm into the rev limiter. I was aware of the torque curve when I was driving it, so I consciously kept the revs as high as I could, but even then when the track required me to stay down a cog in order to avoid a shift in an awkward spot, I never felt like I was off the powerband.
To be honest, this is about as far as you can get from a turbo. There is NO rush of power, no drama, and it's almost hard to get excited about it, but there's something to be said about that. From a driveability standpoint, this is without a doubt more driveable than my car was, even with the T25, and it has the oomph, with 230whp from just 10psi. I got out thinking I had done a 59, and was very surprised to see the pair of mid 57s on the time sheet.
Anyway, thought I'd share my thoughts. It's a neat piece. Not neat enough to switch my track car over (I'm a fan of that big stupid rush of torque), but I could see owning a daily driver with one of these on it very easily.
#5
In my experience, pretty good. Instant throttle is easy to manage.
Although a big roots blower might be a little simpler to drive, as the "full torque everywhere, at any time" curve will eliminate any chance of being stuck between gears. On William's car (and my car) you usually have more torque than you can put down at 4K at autocross speeds, so the loud pedal is used to flatten the Rotrex' rising torque curve.
Although a big roots blower might be a little simpler to drive, as the "full torque everywhere, at any time" curve will eliminate any chance of being stuck between gears. On William's car (and my car) you usually have more torque than you can put down at 4K at autocross speeds, so the loud pedal is used to flatten the Rotrex' rising torque curve.
#6
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I'm not arguing that it's better or worse than a turbo - it's not. It's extremely different - the only comparison I can come up with is the 6-cylinder one. It feels like that.
I think it would be pretty good. I've autocrossed my 2871 and it's not fun - even the 2554 was a handfull. I could see it being pretty good for an autocross car - throttle response, instant torque on pedal application, no lump of power to deal with.
#7
Tour de Franzia
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I've never had this "uncontrollable torque 'lump' terror" from a turbocharger which makes the car burst into flames and crash.
Why is this car so fast with no torque?!?!?! How??? Why????
Why is this car so fast with no torque?!?!?! How??? Why????
#8
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I autocrossed my 2871R at ACS in August, and I would spend a lot of time bouncing off the rev limiter in 2nd gear. Someone asked me why I didn't just shift, and I had to explain that it would just spin the tires in 3rd too, and I was using the limiter in 2nd as a traction control device.
#9
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I'd need to feel what the Throttle does, i really dunno what it's like. I just know I drive like that one the street DDing or in the rain, even autoxing, I only run full boost when I have a reason for it, car is much more manageable I agree.
#14
that's my car Andrew drove. when Andrew got out of the car, I could tell he thought he got beat (this was Miata Challenge, and he had to be sub 2 minutes to clinch the title). Car was not setup yet (just threw on the hard top, coilover few days prior, were chasing down some ground issue all day, didn't have time to dial the suspension nor aero), it had turn in understeer, exit oversteer, and high speed understeer. When Andrew found out he did a couple of mid 1:57s, jaw dropped. He didn't think it was any faster than his own car. I think the word he used was "deceptively fast"
if I had more time to dial the suspension in, fixed the aero, replace 2 flat spotted NT01, more seat time (he did 1:57 by 4th lap in black group). I am sure Andrew would of done a 1:55s.
if I had more time to dial the suspension in, fixed the aero, replace 2 flat spotted NT01, more seat time (he did 1:57 by 4th lap in black group). I am sure Andrew would of done a 1:55s.
#15
dyno plotwars
Forget that the cars are stinking fast, stone reliable, fun and easy to drive. That's not the issue at hand. The issue is that they are not turbo's and don't produce a dyno plot like Braineacks.
Jeezuz, how many times have I seen that particular dyno plot? Like it proves once and for all that, um, actually I'm not sure what it proves because it seems he doesn't actually compete with his car. It also seems he has never driven a Rotrex powered car.
One might conclude that his often stated opinion must therefore be based entirely on what he has read in this and other forums. Not, as it might be assumed, on any empirical first hand knowledge. My dyno plots kicks your dyno plots ***!
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