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TDR Rotrex Update with Dyno Charts!

Old Nov 16, 2015 | 02:10 PM
  #81  
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Agreed, there's a lot more known now about how to do it right than there used to be, and the Greddy kit from days of yore is in a class of it's own in the "rudimentary crap" department.

Still, most turbos that go to the track these days still break things and go through a lengthy process of break/improve until reaching a decent level of reliability. The TSE kit will be the very first to solve all the issues directly off the shelf.

In my eyes, there's definitely a place for the Rotrex superchargers in the world of going fast with these cars. They have their own set of strengths and compromises, but one of their biggest strengths is one of the most important and that is reliability - not just of the unit itself but also in terms of impact on the rest of the system. You can't win anything if you're broken in the pits.
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Old Nov 16, 2015 | 03:25 PM
  #82  
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Is it worth bringing up the changes to ST3/TT3 that are being made this year that incorporate dyno curves into the mix when calculating power/weight? I think this potentially makes the Rotrex interesting in that space. Maybe not optimal, but less sub-optimal.

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Old Nov 19, 2015 | 01:26 AM
  #83  
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Originally Posted by aidandj
I don't see 300+hp on any of those rotrex dynos either though...
see Emilio's Rotrex dyno charts on Deviate, and he says there is more power to be had:

https://www.miataturbo.net/superchar...t-proto-80788/

Bill
Old Nov 20, 2015 | 08:13 PM
  #84  
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Coming from a lurker who has a bone stock NA8, it looks to me that we have hit a great place:

Go with a TSE for 5K. Get a 6 speed, clutch, and a Torsen or OGK or OBX. Get an MS3 and fuel and spark parts. And just be happy with a car that's about as fast as a decent bolt-ons C5 on the street on your stock rods, and depending on suspension and tire an absolute terror on track if you know what you are doing.

Go with a Rotrex. Maybe skip the 6 speed. Everything else is about the same. Your about as fast as (?) on the street, and an absolute terror on the track if you know what you are doing.

Cash comes out similar. The Rotrex will really want exhaust mods you don't think about with a badass TSE mani, but maybe skips some of the driveline breakage.

Either way you are kicking a fair amount of *** even against excellent modern hardware.

Personally, if I was going to be cool with building a shortblock, TSE. If I wanted to stay on stock rods, probably Rotrex. And yes, I do realize the TSE will not blow your bottom end (LOL) on low boost, but the truth is that you are going turn it up, don't kid yourself. I bet a solid 75% of TSE buyers end up doing rods one way or another in the end.

If I get actual money and start standing to go #1 someday, TSE for me.

My 20 cents.
Old Nov 23, 2015 | 02:29 PM
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Originally Posted by Sparetire
Go with a Rotrex. Maybe skip the 6 speed. Everything else is about the same. Your about as fast as (?) on the street, and an absolute terror on the track if you know what you are doing.

Cash comes out similar. The Rotrex will really want exhaust mods you don't think about with a badass TSE mani, but maybe skips some of the driveline breakage.
I am going to have to disagree with you on this one. I've been running a Rotrex this year, making about 240WHP, and I initially went with the 5 speed for improved shift feel and to make a little money selling my 6 speed. At autocross the taller second gear was fine and initial testing looked promising.

It took one weekend at the track to realize how crucial gearing is to maximize the potential of the Rotrex. Unlike the turbo, you are relying on your top end...the gearing of the 5 speed does not do you any favors keeping the motor spun up. At most tracks the 5 speed will force you to pick a gear which does not favor the power band and the car is much slower as a result.

I just got back from my first weekend with a NB2 6 speed I swapped in and now the car feels like it has over 200WHP. The 6 speed lets you keep the motor on boil and has vastly superior ratios to the 5 speed. Bottom line, the 6 speed is an essential item to making the Rotrex a true terror at the track.
Old Nov 23, 2015 | 02:36 PM
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6spd is mandatory with the Rotrex for entirely different reasons than a turbo, but mandatory all the same
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Old Nov 23, 2015 | 02:39 PM
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Originally Posted by Sparetire
Coming from a lurker who has a bone stock NA8, My 20 cents.
Your 20 cents are worth 2 because there is entirely too much wrong with that post.
Old Nov 23, 2015 | 02:46 PM
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@sparetire

You're in Colorado- you should come for a ride in my Rotrex car... It's underwhelming at best (in a straight line). 6 speed and LOTS of shifting required to keep it boiling on track.

But.... I built the car over time as an N/A track car, then simply tossed the intake and bolted on a Rotrex kit.

I'd like to do TSE's kit, but worry about rods and more heat issues. Rotrex car is plenty fast on track.
Old Nov 23, 2015 | 06:01 PM
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Originally Posted by Lincoln Logs
I am going to have to disagree with you on this one. I've been running a Rotrex this year, making about 240WHP, and I initially went with the 5 speed for improved shift feel and to make a little money selling my 6 speed. At autocross the taller second gear was fine and initial testing looked promising.

It took one weekend at the track to realize how crucial gearing is to maximize the potential of the Rotrex. Unlike the turbo, you are relying on your top end...the gearing of the 5 speed does not do you any favors keeping the motor spun up. At most tracks the 5 speed will force you to pick a gear which does not favor the power band and the car is much slower as a result.

I just got back from my first weekend with a NB2 6 speed I swapped in and now the car feels like it has over 200WHP. The 6 speed lets you keep the motor on boil and has vastly superior ratios to the 5 speed. Bottom line, the 6 speed is an essential item to making the Rotrex a true terror at the track.
What diff do you recommend with the 6 speed for a rotrex setup? I probably run similar tracks to what you typically do.
Old Nov 23, 2015 | 06:01 PM
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4.7
Old Nov 23, 2015 | 06:20 PM
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Originally Posted by cyotani
What diff do you recommend with the 6 speed for a rotrex setup? I probably run similar tracks to what you typically do.
With my current power levels I'm running a 4.10, it was a really good match at Chuckwalla this weekend. When I bump up the power to 300WHP later next year I'm guessing the 3.9 may be more ideal.
Old Nov 23, 2015 | 07:27 PM
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Originally Posted by aidandj
4.7


Hell yes. Gear your car just like a N/A build. I'm at 6800RPM in 6th in my car (4.10 Torsen) at the end of the straightaways on both the tracks that I frequent. It is dialed.
Old Nov 24, 2015 | 11:48 AM
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I am running a 6 speed/4.10 with my 300WHP Rotrex. Would not chance a thing. I think the gearing needs are less about power and more about how narrow of a powerband we have. The build motor with custom cams helped broaden the powerband but I still would not change a thing with gearing. If anything I do regret not going VVT.
Old Nov 24, 2015 | 11:53 AM
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^ That's exactly what I surmised.
You only have 300whp at the peak of the powerband. Given the choice of dropping to 230whp or 250whp with each gear shift, you're going to want the latter.
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Old Dec 1, 2015 | 11:51 AM
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I have zero regrets going Rotrex with an AEM FIC "Bandaid" (to pass emissions). My car is used for track use and back and forth. No issues or fiddling of any kind. In fact it has set for a month on the trickle charger. (tracks are closed, Chicago weather) Today I unhooked the battery charger and it fired instantly and I ran an errand. I have nothing against turbos at all. For me this was the right decision. I am always amazed at how closed minded the turbo guys are about the Rotrex. I can't imagine what causes them to get so angry about something that works so well and is still in it's infancy compared to turbo Miatas. Yes, turbo cars are faster in a drag race or on the street, but it is not as big a difference on a road course where you rarely drop below 4,500 RPM. When you are at the limit in a corner there is something to be said for the Rotrex's "weak", but smooth, torque delivery

reread this post from 6 years ago:

https://www.miataturbo.net/general-m...nwillow-42314/


"Can't we all just get along?"

Last edited by tomiboy; Dec 1, 2015 at 12:32 PM.
Old Dec 1, 2015 | 09:42 PM
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Originally Posted by tomiboy
I am always amazed at how closed minded the turbo guys are about the Rotrex.

"Can't we all just get along?"
I don't let it bother me. Not one of these "turbo" cars beat my lap times at Sonoma.
Old Dec 1, 2015 | 10:00 PM
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To quote that link posted.

"It's like you are preaching MLK at a Klan rally"

You guys are on Miataturbo.net not miatatrackhq.org. probably why people are arguing.
Old Dec 1, 2015 | 10:44 PM
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Originally Posted by k24madness
I don't let it bother me. Not one of these "turbo" cars beat my lap times at Sonoma.
Same here... most turbo miatas just overheat after a few laps and go in.
Old Dec 1, 2015 | 11:07 PM
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guys,

let's cry some moar

BAWWWWWWWWWWWWWWWWWWW

QQ
Old Dec 2, 2015 | 12:33 AM
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Originally Posted by tomiboy
I have zero regrets going Rotrex with an AEM FIC "Bandaid" (to pass emissions). My car is used for track use and back and forth. No issues or fiddling of any kind. In fact it has set for a month on the trickle charger. (tracks are closed, Chicago weather) Today I unhooked the battery charger and it fired instantly and I ran an errand. I have nothing against turbos at all. For me this was the right decision. I am always amazed at how closed minded the turbo guys are about the Rotrex. I can't imagine what causes them to get so angry about something that works so well and is still in it's infancy compared to turbo Miatas. Yes, turbo cars are faster in a drag race or on the street, but it is not as big a difference on a road course where you rarely drop below 4,500 RPM. When you are at the limit in a corner there is something to be said for the Rotrex's "weak", but smooth, torque delivery

reread this post from 6 years ago:

https://www.miataturbo.net/general-m...nwillow-42314/


"Can't we all just get along?"
Agreed. It makes no sense. Oh well, reasonable people can objectively see the pros/cons of the Rotrex or superchargers in general.

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