throttle body question - Honda RC51 Forum : RC51 Motorcycle Forums
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 18 (permalink) Old 04-21-2011, 04:33 PM Thread Starter
Senior Member
 
Join Date: Mar 2011
Location: Amsterdam,NY
Posts: 194
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
throttle body question

my friend has a 2001 rc51 an was wondering if its possible to swap to the 02 an up bigger throttle bodies an what all would be needed
rockintwisties2011 is offline  
Sponsored Links
Advertisement
 
post #2 of 18 (permalink) Old 04-21-2011, 05:09 PM
Lifetime Premium
 
madbuyer's Avatar
 
Join Date: Sep 2010
Location: Indy
Posts: 8,335
Mentioned: 17 Post(s)
Quoted: 226 Post(s)
You would have to tune your butt off. The '02 and up have a 12 stream injector throwing gas down the intake....

The smaller intake will need to be ported to help with the added gas. That is a tricky tune by mapping alone.

Your trying to replace a urinal with a toilet bowl....

If you are up for it, Hord racing offers port and polish jobs. ~$850 buck.



The very first schoolbook that was written had God all over it. --Dave Mustaine
madbuyer is offline  
post #3 of 18 (permalink) Old 04-21-2011, 05:13 PM Thread Starter
Senior Member
 
Join Date: Mar 2011
Location: Amsterdam,NY
Posts: 194
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
ok local shop here just told my buddy if he gets the bigger throttle bodies his power commander will work to correct for the bigger bodies
rockintwisties2011 is offline  
 
post #4 of 18 (permalink) Old 04-21-2011, 08:22 PM
Lifetime Premium
 
madbuyer's Avatar
 
Join Date: Sep 2010
Location: Indy
Posts: 8,335
Mentioned: 17 Post(s)
Quoted: 226 Post(s)
Yeah...what do I know....I've only worked for the manufacturer of the throttle bodies for 20 years. (And have built a few prototypes...)

Power Commander will fix the intake for you

The duty cycle of the first generation injector (6 stream) is different than the 2nd generation (12 stream).

I will agree that your fuel burn could get better but still not efficient air intake to get the performance you are seeking.

My mistake.



The very first schoolbook that was written had God all over it. --Dave Mustaine
madbuyer is offline  
post #5 of 18 (permalink) Old 04-21-2011, 08:34 PM Thread Starter
Senior Member
 
Join Date: Mar 2011
Location: Amsterdam,NY
Posts: 194
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by madbuyer View Post
Yeah...what do I know....I've only worked for the manufacturer of the throttle bodies for 20 years. (And have built a few prototypes...)

Power Commander will fix the intake for you

The duty cycle of the first generation injector (6 stream) is different than the 2nd generation (12 stream).

I will agree that your fuel burn could get better but still not efficient air intake to get the performance you are seeking.

My mistake.
wasn't doubting u. I told him I was gonna ask on this forum before we did anything to his bike
rockintwisties2011 is offline  
post #6 of 18 (permalink) Old 04-21-2011, 10:11 PM
Lifetime Premium
 
gts455's Avatar
 
Join Date: Oct 2009
Location: Deutschland/Colorado Springs
Posts: 3,169
Mentioned: 4 Post(s)
Quoted: 37 Post(s)
Nice, madbuyer....pretty cool knowing you have that insight into those throttle bodies. i may have a few questions for you in the future.

2001 Honda RC51 SP1
1996 Honda CBR 900RR
2003 Aprilia RSV Mille R
1999 Aprilia RS50
2012 Triumph Daytona 675R (Sold)
2010 BMW S1000RR (Sold)
2005 Yamaha R6 (Sold)
gts455 is offline  
post #7 of 18 (permalink) Old 04-27-2011, 04:06 PM
Lifetime Premium
 
VeteranRC51's Avatar
 
Join Date: Feb 2011
Location: North Florida
Posts: 29
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
So I have a question that in all my searching has not been asked yet or answered. In reference to using a Moroki/ Thorston/ or Turn One Airbox that is obviously lighter and adds more usable air to the engine to suck whenever or especially when you pin the throttle; what about taking the whole airbox out of the equation and just having the filters sitting directly over the throttle bodies? If you need to make an adapter out of hose or "intake tubing." Would this be a prob? The only thing that I can think of is that the there is no "Pressure" built up......but there is also no real restrictions either, Cause no matter how big the airbox is, its still limiting in size, thats why were wanting to replace the orig airbox with the carbon airbox. Just a question, know I'll get sht from the experts.....
VeteranRC51 is offline  
post #8 of 18 (permalink) Old 04-27-2011, 11:19 PM
Lifetime Premium
 
gts455's Avatar
 
Join Date: Oct 2009
Location: Deutschland/Colorado Springs
Posts: 3,169
Mentioned: 4 Post(s)
Quoted: 37 Post(s)
you have to have a seal to create in there, other wise you will have air leaking out from everywhere. A loss of airbox pressure is a loss in power....a significant loss. Even though many forum guys have he Thorsten/Turnone/SS open airbox style it still has a rubber seal to create that pressure and in fact its been debated that these open style airboxes are not ideal for factory works spec racers because extreme braking and cornering can cause frame flex and a break in that seal and loss of airbox pressure and power. That is why the Works bikes and Moriwaki bikes all utilized a modified airbox but it still maintained a cover ike the oem box.

2001 Honda RC51 SP1
1996 Honda CBR 900RR
2003 Aprilia RSV Mille R
1999 Aprilia RS50
2012 Triumph Daytona 675R (Sold)
2010 BMW S1000RR (Sold)
2005 Yamaha R6 (Sold)
gts455 is offline  
post #9 of 18 (permalink) Old 04-29-2011, 03:31 AM
Senior Member
 
Join Date: May 2009
Location: Prevezanian Riviera
Posts: 145
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
I have questions. If they are both the same displacement, intake exhaust have small differences, they make about the same power (delivery is different), they flow almost the same air, how can they be spraying do much more gas? Is the fuel flow of the one different than the other?
If they used so much more gas they would either use much more air and make more power or flood and not burn the gas.

I thought the increase in injector holes improved atomization not flow. The throttle size only improved throttle response not air flow. It is almost like a venturi where the butterfly is at a larger cross section having a more accurate range of throttle control of the flow than when in a smaller part of the venturi (velocity stack).

Air/Fuel ratio x flow rate x efficiency = hp

Quote:
Originally Posted by madbuyer View Post
You would have to tune your butt off. The '02 and up have a 12 stream injector throwing gas down the intake....

The smaller intake will need to be ported to help with the added gas. That is a tricky tune by mapping alone.

Your trying to replace a urinal with a toilet bowl....
ZeroGara is offline  
post #10 of 18 (permalink) Old 04-29-2011, 03:38 PM
Lifetime Premium
 
madbuyer's Avatar
 
Join Date: Sep 2010
Location: Indy
Posts: 8,335
Mentioned: 17 Post(s)
Quoted: 226 Post(s)
Quote:
Originally Posted by ZeroGara View Post
I have questions. If they are both the same displacement, intake exhaust have small differences, they make about the same power (delivery is different), they flow almost the same air, how can they be spraying do much more gas? Is the fuel flow of the one different than the other?
If they used so much more gas they would either use much more air and make more power or flood and not burn the gas.

I thought the increase in injector holes improved atomization not flow. The throttle size only improved throttle response not air flow. It is almost like a venturi where the butterfly is at a larger cross section having a more accurate range of throttle control of the flow than when in a smaller part of the venturi (velocity stack).

Air/Fuel ratio x flow rate x efficiency = hp
Yes, your term is much better. I put it in simple folk talk like.



I wasn't trying to turn this into a physics lesson either....



The very first schoolbook that was written had God all over it. --Dave Mustaine
madbuyer 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