Soft Rev Limiter - Honda RC51 Forum : RC51 Motorcycle Forums
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 19 (permalink) Old 06-15-2011, 02:01 PM Thread Starter
Senior Member
 
raleighp's Avatar
 
Join Date: Mar 2011
Location: Keller,Texas
Posts: 606
Mentioned: 0 Post(s)
Quoted: 3 Post(s)
Soft Rev Limiter

Hi Guy's, quick question for you. I read the Mod instruction at rc51.org but it refers to the PCIIr and not the PCIII USB that I am buying. I know on the PCIII EX - California version there was a mention of soft rev modification but I decided against that model after reading the boards here.

I went to the PCIII website and they do speak to a rev "X" feature, but they list that only for Harley's..."Additional Features for Harley Davidson
Details
The first new feature is "Rev X-tend". This will give you the ability to have an increased rev limit over stock without having to modify the bike's ECM. No longer will you need to take the bike to the dealer to have the ECM "re flashed" in order to have the higher rev limit your bike needs with modified cams, heads, etc.

Do I still need to splice into the ECU to do the Soft rev ?

Raleigh

2001 SP1 - Code Name F-Bomb - PCIII USB / D&D High Mount System / 42T / EK SRX 530X / CRG Levers / K&N Filters / Stomp Grip / Rev Limiter Mod / Flapper Mod / PAIR Mod / Undertail / Hugger / 6K HID Lights / Speigler lines / Wave Rotors / CF Airbox / Shorai Battery - More to come, as soon as my slush fund get's more "Slushy" !
raleighp is offline  
Sponsored Links
Advertisement
 
post #2 of 19 (permalink) Old 06-15-2011, 05:47 PM
Senior Member
 
cbrbear's Avatar
 
Join Date: Aug 2010
Location: San Diego
Posts: 728
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Check out scottsms.com he has the kit and instructions, its a jumper from your grey plug on your ECU to a black blug on your ECU. Nothing to do with PC2r or 3 as those plug into the injector harness.
cbrbear is offline  
post #3 of 19 (permalink) Old 06-15-2011, 06:15 PM
Lifetime Premium
 
madbuyer's Avatar
 
Join Date: Sep 2010
Location: Indy
Posts: 8,335
Mentioned: 17 Post(s)
Quoted: 226 Post(s)
^+1 Thats the exact way I did the mod with no issues.



The very first schoolbook that was written had God all over it. --Dave Mustaine
madbuyer is offline  
 
post #4 of 19 (permalink) Old 06-15-2011, 09:14 PM
Junior Member
 
pannetron's Avatar
 
Join Date: Jan 2009
Location: Colorado high country
Posts: 26
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
The soft rev limit defeat mod has nothing to do with a PowerCommander; it just changes the behavior of the stock ECU.
pannetron is offline  
post #5 of 19 (permalink) Old 06-16-2011, 08:38 AM Thread Starter
Senior Member
 
raleighp's Avatar
 
Join Date: Mar 2011
Location: Keller,Texas
Posts: 606
Mentioned: 0 Post(s)
Quoted: 3 Post(s)
Thanks, will place my order today !

2001 SP1 - Code Name F-Bomb - PCIII USB / D&D High Mount System / 42T / EK SRX 530X / CRG Levers / K&N Filters / Stomp Grip / Rev Limiter Mod / Flapper Mod / PAIR Mod / Undertail / Hugger / 6K HID Lights / Speigler lines / Wave Rotors / CF Airbox / Shorai Battery - More to come, as soon as my slush fund get's more "Slushy" !
raleighp is offline  
post #6 of 19 (permalink) Old 07-01-2011, 03:10 PM
Senior Member
 
sdimex's Avatar
 
Join Date: Oct 2009
Location: massapequa ny
Posts: 132
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
so on rc51.org they state that theres another reason for the mod but dont say what
since they will not say why does Any one here know?



Neither www.rc51.org or it's members make claims to the validity of this modification nor does anyone involved with this website take any responsibility in the event of damage to your motorcycle as a result of this modification.

If you make this mod you do so at your own risk.

Having said that, the soft-limiter was not placed on the motor of the US Spec RC51's for any reason that
you might associate with preventing harm to the motor. The real reason is known by a few, but I
cannot divulge the info without breaching the trust of those contacts I have in the industry so don't ask
sdimex is offline  
post #7 of 19 (permalink) Old 07-01-2011, 03:52 PM
Moderator
 
SubSailor's Avatar
 
Join Date: Oct 2008
Location: Sarasota, FL
Posts: 6,461
Mentioned: 24 Post(s)
Quoted: 88 Post(s)
The soft rev limiter retards the ignition at around 9200 RPM.
By removing the soft rev limiter, it allows full ignition advance up to the 10,200 RPM redline hard limit.

No idea why they did it. Probably legal reasons.
After all, many bike have ECU controlled ignition retardation.
Suzuki's for one.

The Hayabusa and TL1000R both had this in the lower gears.
Supposedly, on the 'Busa, only 5th gear had full advance as 1st through 4th were retarded, and 6th was retarded to hold the speed down the 186 MPH agreed upon max speed by the manufacturers.

The TRE (Timing Retard Eliminator) modules worked around this by tricking the bike into thinking it was always in 5th.

Last edited by SubSailor; 07-01-2011 at 03:57 PM.
SubSailor is offline  
post #8 of 19 (permalink) Old 07-01-2011, 06:12 PM
Member
 
twoeleven's Avatar
 
Join Date: Mar 2011
Location: Los Angeles
Posts: 96
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
I bet the US spec bikes have the SRL in order to comply with emissions standards, as EPA keeps comin up whenever someone won't or can't discuss this. To which I say "Pfffft.". So you know something but can't say it because the Honda Red Riders will come take you away to an underground ore mine where you will be chained and beaten into hard labor?

I say it was to pass EPA testing, and you can tell Honda that I said it, out loud even! Heaven forbid.

Griff
twoeleven
twoeleven is offline  
post #9 of 19 (permalink) Old 07-01-2011, 09:53 PM
Lifetime Premium
 
madbuyer's Avatar
 
Join Date: Sep 2010
Location: Indy
Posts: 8,335
Mentioned: 17 Post(s)
Quoted: 226 Post(s)
EPA and noise standards. The flapper and the rubber/foam skirts on the air box were mostly to kill noise.

I say open her up and let her eat....just the way God intended



The very first schoolbook that was written had God all over it. --Dave Mustaine
madbuyer is offline  
post #10 of 19 (permalink) Old 07-02-2011, 04:20 PM
Senior Member
 
Join Date: May 2009
Location: Prevezanian Riviera
Posts: 145
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
The way I heard it was that the US EPA states that sound should be measured at 1/2 rpm from maximum. The soft rev brings the max to 9200 hence the measurement in the US is taken at 4600 while without the soft rev limiter it would go up to 5100 which exceeds the sound limit. The flapper I believe is an other thing that also limits noise at around the same rpm range where the sound test is done, which also creates a hole on the powerband.
ZeroGara is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Honda RC51 Forum : RC51 Motorcycle Forums 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:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome