Noob, Rotrex SC options - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Supercharger Discussion For all you misguided souls.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 12-04-2017, 06:42 AM   #21
Newb
 
Join Date: Sep 2010
Location: Portugal
Posts: 36
Total Cats: 1
Default

On a stock vvt head, forged 9.5/1 pistons, 2.5” exhaust, smallest pulley for 120000rpm @ 7200rpm, we are seeing 270hp (crank, because that’s how we measure it in Europe) power delivery is so smooth, I would say. 74 is a waste of time. Looking for options to hybrid it to a 94.

BTW, from the original Kraftwerks kit, nothing is left from the kit, at this power level.
kamel6k is offline   Reply With Quote
Old 12-04-2017, 08:12 AM   #22
Junior Member
iTrader: (1)
 
Join Date: Oct 2015
Location: Metro Detroit, MI
Posts: 263
Total Cats: 19
Default

Quote:
Originally Posted by bschonman View Post
I'm personally trying to keep the car streetable and therefore have as much low end torque as a rotrex car can have. Any recommendations for pump gas? No e85 around here. And my want for low end torque rules out cams, right?
Use stock cams. Consider the TSE Turbo kit if you want torque. Personally I'm going with Rotrex for the ironic lack of torque, in hopes of keeping a motor alive for more than two seasons per rebuild.
Goingnowherefast is offline   Reply With Quote
Old 12-04-2017, 12:40 PM   #23
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,163
Total Cats: 2,573
Default

>wants low end torque
>considering hands down least low end torque providing f/I application

lol
18psi is offline   Reply With Quote
Old 12-04-2017, 01:48 PM   #24
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,809
Total Cats: 1,780
Default

Quote:
Originally Posted by 18psi View Post
>wants low end torque
>considering hands down least low end torque providing f/I application

lol
I don't see the problem. he can spool his rotrex with compressed air.
Braineack is offline   Reply With Quote
Old 12-04-2017, 01:49 PM   #25
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,809
Total Cats: 1,780
Default

Quote:
Originally Posted by Goingnowherefast View Post
Personally I'm going with Rotrex for the ironic lack of torque, in hopes of keeping a motor alive for more than two seasons per rebuild.
you know you can do this crazy thing called: tuning.
Braineack is offline   Reply With Quote
Old 12-05-2017, 07:20 PM   #26
Elite Member
 
DNMakinson's Avatar
 
Join Date: Jan 2013
Location: Seneca, SC
Posts: 2,695
Total Cats: 266
Default

Guys are keeping this entertaining

OP, what about your son’s set-up that you don’t like?

Exactly what problem are you trying to solve?
DNMakinson is offline   Reply With Quote
Old 12-05-2017, 07:28 PM   #27
Newb
 
Join Date: Jan 2017
Posts: 13
Total Cats: 0
Default

I enjoy rotrex for it's lack of torque as well. Notice how I said "as much torque as a rotrex can have". I'm not looking for the 300wtq a efr would easily give me. I find my rotrex infinitely easier to drive on track than my FM2 car making a similar amount of power. Every time I push the pedal, I immediately get the same response. Maybe it's because I'm a novice driver, but I just prefer that. 250whp is 250whp however you get there.
bschonman is offline   Reply With Quote
Old 12-05-2017, 07:31 PM   #28
Newb
 
Join Date: Jan 2017
Posts: 13
Total Cats: 0
Default

Quote:
Originally Posted by Braineack View Post
you know you can do this crazy thing called: tuning.
A motor making 220wtq will always have a longer lifespan than the same motor making 300wtq. Tuning fuckups can melt a rotrex car the same way they would a turbo car.
bschonman is offline   Reply With Quote
Old 12-05-2017, 07:39 PM   #29
Senior Member
iTrader: (8)
 
paNX2K&SE-R's Avatar
 
Join Date: Dec 2007
Location: Mocksville, NC
Posts: 675
Total Cats: 11
Default

This may be a silly question but why don't people ever run the C38 size units on Miatas?
paNX2K&SE-R is offline   Reply With Quote
Old 12-05-2017, 08:47 PM   #30
Senior Member
iTrader: (2)
 
Join Date: Oct 2011
Location: SE NM
Posts: 1,458
Total Cats: 48
Default

Heads don't flow, so no need. Plus weak transmissions are always an issue.
Chilicharger665 is offline   Reply With Quote
Old 12-07-2017, 12:16 PM   #31
Newb
Thread Starter
 
Join Date: Nov 2017
Posts: 7
Total Cats: 1
Default

Back to the injector question. I have the options of 750cc or 1000cc at the same price. Does it make sense to just run the 1000's and not look back? I'm not sure, but I've been told that idle can sometimes be a problem with the bigger injectors. Seems to me that with the ms2 less on time should be fine.
Bmiata40 is offline   Reply With Quote
Old 12-07-2017, 01:10 PM   #32
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,809
Total Cats: 1,780
Default

Quote:
Originally Posted by bschonman View Post
A motor making 220wtq will always have a longer lifespan than the same motor making 300wtq. Tuning fuckups can melt a rotrex car the same way they would a turbo car.
again: tuning

Braineack is offline   Reply With Quote
Old 12-07-2017, 05:07 PM   #33
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,624
Total Cats: 1,559
Default

If they are ev14 injectors the 1000cc will idle fine
Attached Thumbnails
Noob, Rotrex SC options-20171115_202919.jpg  
sixshooter is offline   Reply With Quote
Old 12-07-2017, 07:15 PM   #34
Newb
 
Join Date: Nov 2017
Posts: 2
Total Cats: 0
Default



Never followed though with a build thread, in fact I think this is my first post
essentially I have a nice churbo build. Lots of influence from previous builds i.e. 18psi style intercooler routing.

Quote:
Originally Posted by DNMakinson View Post
Does your son have a build thread here on MT.net?

I suppose the thought is that the Rotrex will have low enough torque at low RPM that it can boost up to 300 whp at high RPM without bending stock rods?
1.9Conekiller is offline   Reply With Quote
Old Yesterday, 09:35 AM   #35
Newb
 
Join Date: Jan 2017
Posts: 13
Total Cats: 0
Default

Quote:
Originally Posted by Braineack View Post
again: tuning

What are those graphs showing? Is that controlling boost so it builds gradually to redline? Why would that be preferable over a centrifugal supercharger? Wouldn't the torque still be as low?
bschonman is offline   Reply With Quote
Old Yesterday, 01:13 PM   #36
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,809
Total Cats: 1,780
Default

I'm just saying, if youre worried about tq, you can tune torque.
Braineack is offline   Reply With Quote
Old Yesterday, 07:38 PM   #37
Junior Member
 
Join Date: Dec 2010
Posts: 401
Total Cats: 3
Default

Brain,

Your plots show that the tune increased boost on a turbo'd car, which increased hp and torque. On a Rotrex equipped car, would a superior tune increase BOOST over an average tune?

Thanks,
poormxdad is offline   Reply With Quote
Old Yesterday, 08:28 PM   #38
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,809
Total Cats: 1,780
Default

a turbo doesnt have to run full boost at all times. If you have an EBC, you can tune the boost output. If you're worried about too much tq, dont let the turbo produce too much torque.
Braineack is offline   Reply With Quote
Old Yesterday, 11:13 PM   #39
Junior Member
iTrader: (1)
 
Join Date: Oct 2015
Location: Metro Detroit, MI
Posts: 263
Total Cats: 19
Default

Quote:
Originally Posted by poormxdad View Post
Brain,

Your plots show that the tune increased boost on a turbo'd car, which increased hp and torque. On a Rotrex equipped car, would a superior tune increase BOOST over an average tune?

Thanks,
No. The boost that a Rotrex unit produces is a direct relation to the engine speed (rpm) and pulley size (ratio). No tune will change the amount of boost you make on a Rotrex.

Quote:
Originally Posted by Braineack View Post
you know you can do this crazy thing called: tuning.
Can tuning change the laws of thermodynamics to fix the inherent massive heat issues that accompanies turbochargers? No doubt, I think turbocharging is better for the OP and anyone would plans to do more street stuff than track stuff. But between turbos falling off (fixed by inconel studs and better hardware), cracked manifolds, High CLT's and oil pressure, high IAT's, wastegate issues etc. you have to at least admit that the Rotrex systems have some appeal to the track only guys. People that want to just stick it on, tune it once, and never have to worry about anything at the track except for suspension/tire setup and driver mod. I was able to hop in a Rotrex car and go extremely fast within a lap, and I'm not the only one that has that same story. Rotrex cars are just easy to drive fast on track without issues.
Goingnowherefast is offline   Reply With Quote
Old Yesterday, 11:19 PM   #40
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,624
Total Cats: 1,559
Default

sixshooter is offline   Reply With Quote
 
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 08:36 PM.