Rotrex C38-91 Power Expectations - Page 2 - K20A.org .:. The K Series Source . Honda / Acura K20a k24a Engine Forum
Reply
 
Thread Tools
Old 06-28-2014, 03:01 AM   #21
rsamd
K20a.org Basic User
 
Join Date: Mar 2006
Posts: 180
Default Re: Rotrex C38-91 Power Expectations

ditch your crappy ebay intercoolers.
rsamd is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 06-28-2014, 08:57 AM   #22
aztec1382
K20a.org Basic User
 
aztec1382's Avatar
 
Join Date: Aug 2012
Posts: 105
Default Re: Rotrex C38-91 Power Expectations

I'm going to look through my email I bought the intercooler a while back and can't remember of the top of my head.
However it was the biggest one I could fit.

The one in now is 100mm pulley currently in is made for 8,200 rpm
Using the rsx type s crank pulley.

I'm open to suggestions, going to give e85 a try

Next would be to build a motor with higher
aztec1382 is offline   Reply With Quote Quick reply to this message
Old 06-28-2014, 09:21 AM   #23
rsamd
K20a.org Basic User
 
Join Date: Mar 2006
Posts: 180
Default Re: Rotrex C38-91 Power Expectations

With 85k rpm on an k24 you should see 15-16psi boost with an -91, and at 90k about 19-20psi.
i'm reving my k24 to 7800 138mm cp, 95mm bp. i see about 16psi and 480hp fly with a new well flowing tts intercooler. my old intercooler with 148mm cp made 16psi and only 440hp.
rsamd is offline   Reply With Quote Quick reply to this message
 
Old 06-28-2014, 10:17 AM   #24
aztec1382
K20a.org Basic User
 
aztec1382's Avatar
 
Join Date: Aug 2012
Posts: 105
Default Re: Rotrex C38-91 Power Expectations

Which one if these are you using
Or are you using the stock k24a2 pulley

Do you have any pics of your set up
Attached Images
File Type: jpg image.jpg (119.3 KB, 20 views)
aztec1382 is offline   Reply With Quote Quick reply to this message
Old 06-28-2014, 11:10 AM   #25
rsamd
K20a.org Basic User
 
Join Date: Mar 2006
Posts: 180
Default Re: Rotrex C38-91 Power Expectations

stock k20a2 (rsx-s 02-04) 138mm.
rsamd is offline   Reply With Quote Quick reply to this message
Old 06-28-2014, 12:14 PM   #26
aztec1382
K20a.org Basic User
 
aztec1382's Avatar
 
Join Date: Aug 2012
Posts: 105
Default Re: Rotrex C38-91 Power Expectations

the intercooler im running is the
PWI5973
http://www.pwrradiators.com/barrel-intercooler/
heres a pic of the set up
Attached Images
File Type: jpg IMG_9365.jpg (781.0 KB, 45 views)
aztec1382 is offline   Reply With Quote Quick reply to this message
Old 06-28-2014, 12:51 PM   #27
rsamd
K20a.org Basic User
 
Join Date: Mar 2006
Posts: 180
Default Re: Rotrex C38-91 Power Expectations

that ic looks very restrictive. sometimes theres no room to fit a better one. just for interest, what boost are u seeing?

i know of tts-performance.co.uk. they are running a custom ic setup in their lotus exige rotrex track car. about 600bhp on a 2.2l kseries engine.
https://www.youtube.com/watch?v=58g0ubJzs5w
rsamd is offline   Reply With Quote Quick reply to this message
Old 06-28-2014, 01:12 PM   #28
aztec1382
K20a.org Basic User
 
aztec1382's Avatar
 
Join Date: Aug 2012
Posts: 105
Default Re: Rotrex C38-91 Power Expectations

It's about as straight a shot to the motor as possible

I used to run a bell air to water on my turbo set up
But the pwr seems just as good
Right now it's at 12psi at 7,900 rpm but going to retune due to changing the ecu
And running flex fuel
aztec1382 is offline   Reply With Quote Quick reply to this message
Old 06-28-2014, 01:17 PM   #29
Dansk20pug
K20a.org Basic User
 
Dansk20pug's Avatar
 
Join Date: Jul 2012
Posts: 497
Default Re: Rotrex C38-91 Power Expectations

Quote:
Originally Posted by aztec1382 View Post
It's about as straight a shot to the motor as possible

I used to run a bell air to water on my turbo set up
But the pwr seems just as good
Right now it's at 12psi at 7,900 rpm but going to retune due to changing the ecu
And running flex fuel
Running a direct route isn't as critical as it would need to be on a turbo car, however the quality of the core is very important! Also needs to be as big as possible.. Minimising pressure drop is essential. Take a look through Jaydee thread as he posts results showing this.

If you are only making 12psi then that's awesome power for that boost pressure.. Just think you have another 10psi missing somewhere ;)
Dansk20pug is offline   Reply With Quote Quick reply to this message
Old 06-28-2014, 01:22 PM   #30
aztec1382
K20a.org Basic User
 
aztec1382's Avatar
 
Join Date: Aug 2012
Posts: 105
Default Re: Rotrex C38-91 Power Expectations

According to the tts video
They are making 640bhp at 7,500 rpm

I wonder what fuel they are running
As well as what pulley combo
aztec1382 is offline   Reply With Quote Quick reply to this message
Old 06-28-2014, 02:11 PM   #31
rsamd
K20a.org Basic User
 
Join Date: Mar 2006
Posts: 180
Default Re: Rotrex C38-91 Power Expectations

i think it was 99ron unleaded pump fuel. 1,4bar boost, c38-91 maxed at 90k. pulley combo idk but do the math.
rsamd is offline   Reply With Quote Quick reply to this message
Old 06-28-2014, 04:05 PM   #32
ekjdmh22
Lifetime Member
 
Join Date: Mar 2004
Location: the woods
Posts: 1,046
Default Re: Rotrex C38-91 Power Expectations

12.5 k20 110 rotrex pulley types ck pulley sk2 stg3 cams and c38-81 made 480 on pump
__________________
iaint scurred i got a na setup with 12:5 with a leaf blower on it

Final drive racing on fb check it out
hybrid-racing k swap parts #1
R.I.P adam west aka batman
R.I.P NICK HAINES
ekjdmh22 is offline   Reply With Quote Quick reply to this message
Old 06-29-2014, 03:44 AM   #33
Benson03
K20a.org Basic User
 
Benson03's Avatar
 
Join Date: Jan 2008
Location: Australia
Posts: 399
Default Re: Rotrex C38-91 Power Expectations

Back from the dead...

We have done quite a bit of work with the Rotrex over the past 3 years and suffered a few snapped shafts as well

On E85 and basic K20/K24 engine combination, we are making 350-380kw's. Ive got some in-car video with the car acceleration that i can post up if you guys are interested
__________________
BYP Racing and Developments
Built. Tuned. Driven
Find us on facebook
Benson03 is offline   Reply With Quote Quick reply to this message
Old 06-29-2014, 04:11 AM   #34
Dansk20pug
K20a.org Basic User
 
Dansk20pug's Avatar
 
Join Date: Jul 2012
Posts: 497
Default Re: Rotrex C38-91 Power Expectations

Quote:
Originally Posted by Benson03 View Post
Back from the dead...

We have done quite a bit of work with the Rotrex over the past 3 years and suffered a few snapped shafts as well

On E85 and basic K20/K24 engine combination, we are making 350-380kw's. Ive got some in-car video with the car acceleration that i can post up if you guys are interested
If we are interested...... Of course we are interested ;) I follow BYP on FB and im impressed.

These snapped shafts are concerning me a lot! If I have any failures I'll convert to the car to turbo.. I cannot be changing a rotrex every year
Dansk20pug is offline   Reply With Quote Quick reply to this message
Old 06-29-2014, 10:09 AM   #35
aztec1382
K20a.org Basic User
 
aztec1382's Avatar
 
Join Date: Aug 2012
Posts: 105
Default Re: Rotrex C38-91 Power Expectations

Benson I'm running a c38-91 with a bone stock k24a2, skunk2 intake manifold, 70mm tb,
Is the math right on this
85mm pulley X 12600 max speed(5%). / 138 crank pulley= 7,760 rpm
Should I expect max power from the Rotrex at 7,760 rpm
And how much boost should I see.
I am currently running a 95mm pulley and revving to 7,900 but we are only seeing 12 psi



Sent from my iPhone using Tapatalk
aztec1382 is offline   Reply With Quote Quick reply to this message
Old 06-29-2014, 10:48 AM   #36
bertje
K20a.org Basic User
 
Join Date: Sep 2011
Location: belgium
Posts: 153
Default Re: Rotrex C38-91 Power Expectations

Quote:
Originally Posted by Benson03 View Post
Back from the dead...

We have done quite a bit of work with the Rotrex over the past 3 years and suffered a few snapped shafts as well

On E85 and basic K20/K24 engine combination, we are making 350-380kw's. Ive got some in-car video with the car acceleration that i can post up if you guys are interested
did you replaced the rotrex or just shaft?
http://www.superchargerrebuild.com/?page_id=69
bertje is offline   Reply With Quote Quick reply to this message
Old 06-29-2014, 03:09 PM   #37
Dansk20pug
K20a.org Basic User
 
Dansk20pug's Avatar
 
Join Date: Jul 2012
Posts: 497
Default Re: Rotrex C38-91 Power Expectations

It's a shame rotrex haven't done something about this problem... Maybe they are more than happy for people to keep buying new ones instead of protecting their reputation.

It's a wonder we can't get a titanium shaft made, maybe that would eradicate any shaft snapping issues.
Dansk20pug is offline   Reply With Quote Quick reply to this message
Old 06-30-2014, 04:05 PM   #38
Benson03
K20a.org Basic User
 
Benson03's Avatar
 
Join Date: Jan 2008
Location: Australia
Posts: 399
Default Re: Rotrex C38-91 Power Expectations

Quote:
Originally Posted by Dansk20pug View Post
If we are interested...... Of course we are interested ;) I follow BYP on FB and im impressed.

These snapped shafts are concerning me a lot! If I have any failures I'll convert to the car to turbo.. I cannot be changing a rotrex every year
People can keep up to date with our work on the fanpage - BYP Racing and Developments

We had a great weekend at the most recent Time Attack recorded new lap records in both the DC2R and S2000. However, we did have 2 Rotrex failed with snapped shafts. It is concerning breaking these Rotrex but given the efficiency of these chargers, its so hard to make a change to anything else. The power delivery is spot on for our record breaking cars.

I have looked at turbo and our competitors car is turbo and its quite average. Even though we can make more power with turbo, but whats the point when there is hardly any drive ability? If your thinking about turbo for your FWD, i would highly reconsider!

Quote:
Originally Posted by aztec1382 View Post
Benson I'm running a c38-91 with a bone stock k24a2, skunk2 intake manifold, 70mm tb,
Is the math right on this
85mm pulley X 12600 max speed(5%). / 138 crank pulley= 7,760 rpm
Should I expect max power from the Rotrex at 7,760 rpm
And how much boost should I see.
I am currently running a 95mm pulley and revving to 7,900 but we are only seeing 12 psi

Sent from my iPhone using Tapatalk
95mm pulley will give you about 15-16psi @ 8000rpms

At last year WTAC, we ran a stock bottom end and pumped 18psi through it with revs capped at 8400rpms. 130mm crank pulley and 88mm Rotrex pulley. Estimated power of around 330-350kws at the front wheels

The stock bottom end is quite strong and can take alot of punishment. Having said that, our DC2R is running a sleeved forged bottom end

Quote:
Originally Posted by Dansk20pug View Post
It's a shame rotrex haven't done something about this problem... Maybe they are more than happy for people to keep buying new ones instead of protecting their reputation.

It's a wonder we can't get a titanium shaft made, maybe that would eradicate any shaft snapping issues.
Hopefully Rotrex can come to the table and sort out their shaft issues. Apparently there is a prototype shaft being tested by a dealer in UK
__________________
BYP Racing and Developments
Built. Tuned. Driven
Find us on facebook
Benson03 is offline   Reply With Quote Quick reply to this message
Old 06-30-2014, 04:12 PM   #39
Dansk20pug
K20a.org Basic User
 
Dansk20pug's Avatar
 
Join Date: Jul 2012
Posts: 497
Default Re: Rotrex C38-91 Power Expectations

I agree with what your saying.. For a circuit car the rotrex setup is hard to beat (your proving just that) but can I justify (or most people infact) changing a charger ever so often? Me not really.. If rotrex offered an upgrade then I'm back on board. Or offered a re-build service at a sensible cost..

It's strange and it needs sorting.

Benson, have you put your concerns to rotrex? With the success your having in TA you would have more puch than a normal consumer like me and most people in this thread.
Dansk20pug is offline   Reply With Quote Quick reply to this message
Old 07-01-2014, 12:55 AM   #40
Accordk24
K20a.org Advanced User
 
Accordk24's Avatar
 
Join Date: Feb 2011
Location: Oxford, UK
Posts: 648
Default Re: Rotrex C38-91 Power Expectations

Quote:
Originally Posted by Dansk20pug View Post
It's a shame rotrex haven't done something about this problem... Maybe they are more than happy for people to keep buying new ones instead of protecting their reputation.

It's a wonder we can't get a titanium shaft made, maybe that would eradicate any shaft snapping issues.

This is the only thing that worries me too. I've noticed its only on track use this happens. What about if its just used as a daily and the occasional street race? ;-) They should be able to cope with that...
__________________
HOND-R
HYBRIDRACING
Accordk24 is offline   Reply With Quote Quick reply to this message
Reply

Bookmarks

Tags
k24, rotrex, s/c

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the K20A.org .:. The K Series Source . Honda / Acura K20a k24a Engine Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in


Thread Tools

Posting Rules
You may post new threads
You may 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

Forum Jump



All times are GMT -8. The time now is 12:06 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
 

Garage Plus vBulletin Plugins by Drive Thru Online, Inc.