Go Back   EcoModder Forum > EcoModding > Motorcycles / Scooters
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 04-23-2013, 09:47 AM   #1 (permalink)
Master EcoModder
 
mechman600's Avatar
 
Join Date: Jul 2008
Location: Langley, BC
Posts: 1,225

Colorado - '04 Chevrolet Colorado
90 day: 22.98 mpg (US)
Thanks: 190
Thanked 271 Times in 165 Posts
Trading the ZX-7R for a CBR929RR

Yeah, not exactly eco compared to most other bikes here....

But unlike the 7, the 929 has some technology like EFI and HTEV. HTEV is an exhaust valve built into the headers that varies the effective length to the collector and increases backpressure at lower revs. It is broken on this bike, but parts are ordered, so we will see how it works compared to the "old fashioned" ZX-7R. It sure is a lot quicker - 150 HP and 380 lbs dry.

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 04-23-2013, 04:06 PM   #2 (permalink)
Master EcoModder
 
Join Date: Feb 2009
Location: France - Paris
Posts: 762

la_voiture_de_courses - '03 Renault Megane Estate
OldContinents
90 day: 44.34 mpg (US)

xiao lan - '01 Audi A2
90 day: 38.88 mpg (US)

Brit iron - '92 Mini Mini
90 day: 45.5 mpg (US)

Prius - '09 Toyota PRIUS Lounge
90 day: 47.37 mpg (US)

Beemer - '06 BMW F800 ST
90 day: 53.06 mpg (US)
Thanks: 188
Thanked 33 Times in 30 Posts
So that is like Yamaha EXXUP system ?

It is just a matter of linking the exhaust flow with the inlet flow (AKA throttle) to get rid of a part of the camminess of those very high specific power engines.
I believe they can do the same with cam phasers these days but the trend might not have reached the bike world so far.
  Reply With Quote
Old 04-23-2013, 08:36 PM   #3 (permalink)
Master EcoModder
 
mechman600's Avatar
 
Join Date: Jul 2008
Location: Langley, BC
Posts: 1,225

Colorado - '04 Chevrolet Colorado
90 day: 22.98 mpg (US)
Thanks: 190
Thanked 271 Times in 165 Posts
Quote:
Originally Posted by renault_megane_dci View Post
So that is like Yamaha EXXUP system ?

It is just a matter of linking the exhaust flow with the inlet flow (AKA throttle) to get rid of a part of the camminess of those very high specific power engines.
I believe they can do the same with cam phasers these days but the trend might not have reached the bike world so far.
I believe the EXUP was simply a butterfly valve that created restriction at lower revs. This HTEV is more complex and, well, seems like it should work well.

IDLE to 3000 RPM:
Cylinders 1 & 2 are combined, cylinders 3 & 4 are combined in HTEV with only two outlets for back pressure:

3000 to 8000 RPM:
Flow straight through the HTEV. Cylinders 1 & 4 are combined, cylinders 2 & 3 are combined in the exhaust collector after HTEV (not pictured):

8000 RPM + (11500 RPM Redline):
Hard to tell by picture but it looks like all cylinders are combined in HTEV:


Honda has used actual for real VTEC in two bikes - the Japanese only CB400SF and VFR800F. Critics say the only thing it accomplished was added complexity. I rode a VFR800 version and it was kind of neat, but whether it was only the sound change at 6800 RPM that tricked my head or not I will never know. Not sure why it hasn't caught on - more expensive? Heavier? Higher chance of catastrophic failure if something goes off? Who knows.
  Reply With Quote
The Following User Says Thank You to mechman600 For This Useful Post:
renault_megane_dci (04-24-2013)
Old 05-24-2013, 03:55 AM   #4 (permalink)
Master EcoModder
 
mechman600's Avatar
 
Join Date: Jul 2008
Location: Langley, BC
Posts: 1,225

Colorado - '04 Chevrolet Colorado
90 day: 22.98 mpg (US)
Thanks: 190
Thanked 271 Times in 165 Posts
I finally got the HTEV system working. Turns out there was more than one problem with it. First off, the ECU had a bad driver, so there was no power to the HTEV servo motor. Secondly, there was a spread terminal at the ECU plug making poor contact on the +5 VDC HTEV position sensor wire.

It would have been mostly simple to fix, but my first used eBay ECU caused my bike to have no spark. I had to go through the resolution center to get a refund. The second used ECU caused my bike to run on three cylinders. I had to go through the resolution center again to get a refund on that one. Today I installed used ECU #3 and it works like a charm.

The engine definitely runs smoother under 3000 rpm. The EFI is calibrated to have some exhaust back pressure at low revs, so with my HTEV previously stuck in the 3000-8000 rpm position, the idle was much higher and hunted up and down, and the throttle was jerky under light loads.

It will be interesting to see how the FE is with this bike. I'm not expecting much with 929cc, but hey, you never know - it might be decent.

Here is a video of me testing the HTEV out:

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com