Bump up the VFR’s horsepower?

Yes, it's called a 7th gen.

 

The fuel pressure regulator mod is free.

 

Thanks for the suggestion. Toyed with the idea of buying one last year, took it for a couple of test rides. It has power but is big and heavy, even for a VFR. It's not quite what I want.

 

What mod is that?

 

you mean that 600 pound shaft driver that sounds like a chainsaw? lol
just kidding.... kinda lol

 

People have been putting in higher psi fuel pressure regulators, or smashing down the stock one to increase the fuel pressure.
Pretty decent idea if you are on a budget. Should bring the air fuel ratios to where they need to be on the bottom end, but you will be rich up top if you basically richen it up across the board. The vfr needs no extra fuel up top, so this could kill top end. I am not really sure, just a theory.

 

Thanks! yeah I searched it and it came up om google in some old posts. Ehh...yeah it would help bottom end for sure but you would lose up top. Overall much better off with a PC I think....

 

yup just one setting. cant possibly fix everything. win some bottom. lose some top. no bueno.

 

Plus I was out for a 7.5 hour ride in 90 degree weather and my fan didn't come on. Once.
Even sitting at red lights. Highest temp at a red light was 203. Bike was b/w 180-190 all day.
Got 47mpg on that trip. The day I smashed that FPR was a great day.

 

I looked up the Shorai Lithium Iron battery and it came up with this:
LFX18A1-BS12

5.83 lbs lighter than stock. $189.95 suggested retail
Amazon has it for $167.50 and that was the cheapest of 4 places I checked. Other brands might be cheaper. Sears wants almost $300.
The factory battery goes for $63.72 from Service Honda and you can probably get a cheaper one than that.
If Mohawk is right you could save $50+ building one yourself. Details Mohawk?

If you already need a battery it might make sense to spend the extra $ but if you don't... not so much.

 

I found threads that mention the mod but no details of how to do it. Any links you can provide?

 

I haven't tried that yet. Do I drink it or bathe in it?

 

A gallon of gas weighs ~6lbs.

You can shed 12lbs by never filling the tank more than halfway. :wink:

Bike weighs 550, you weigh 200 in gear, total weight is 750. If you manage to trim 20 lbs off the bike, that's less than 2%.

If you're bracket racing, there's no benefit. If you're racing heads up, every lb counts but you're also on the wrong bike. :biggrin:

 

550? I thought curb weight was around 525. Don't be making my big fat pig fatter than it already is!

<edit>
I haven't weighed under 200 in gear since high school. Big guys just weren't meant for racing I guess.

 

I wonder if curb weight includes 5 gallons gas? Honestly, I don't know. :biggrin:

When I was racing a busa in the street class at Douglas WY, there was a 250+ guy on a ZX12. He was damn fast. Moral - if the belt size goes up, buy more cc's. :biggrin:

 

I'd like to weigh mine street ready for giggles. You can research, but everybody seems to have a different opinion on what it weighs. That way, after I do all the tail modification and go for the light battery I can compare to find out how much I managed to shed.

-Drew

 

Here's a pic, it's built from 4 x 10Amp/Hr Headway cells, so has more power than the standard Lead Acid 12Amp/Hr battery & saves nearly 3Kg.

Here's a US site that sells these, don't know the site, just did a search for the cells & it was the first that came up.
DIY HEADWAY Battery Cells-Elifebike Online Store

 

If I remember right, the full Two Brothers exhaust shed around 11 lbs. So I not only gained hp at the dyno, the weight loss was worth at least 1 more hp.
I think with the Powercommander, pipe, K&N, and snorkel removal put the hp close to 110 hp but it's been a long time and I didn't get a custom dyno to verify that.
I'll probably try the fuel pressure regulator mod since that's cheap and I'm going to have the bike apart anyway.


Now... for those interested in ram-air, here is an R6 forum thread on the topic. As far as I can tell, you can gain 3-6 hp from it but gains didn't really start until 85 mph so it doesn't do much at highway speeds... but that could be the design:
Ram Air Effect : Yamaha R6 : R6 Forum

There was a Hyabusa thread on the topic and at top speeds the gains were lost due to disruption of the air flow due to engine noise (?), but it gained something around 5 hp at 180 mph and nothing below 100 mph. The busa design reduced performance of ram-air above 150 unless you add air scoops. The ram-air scoops also reduce aerodynamics and negated gains due to the ram-air. But the thread I read it in didn't reference anything to back up the claims.

Ram-air adds 8 hp to the ZX-9R at 150 mph and 11.5 hp at top speed however, given the busa comments it may be less than that at the top end since this article is estimating the boost/hp:
Sport Rider-RAM AIR: More power for the Kawasaki ZX-9R through forced air induction


Based on that, I think the nose of the bike probably needs to be designed for ram-air to get the most out of it but you could get 5 hp or more but only at higher speeds. Below 100 mph it sounds like you are only talking about a single horsepower or so though.

An add on for the VFR is probably going to require sealed duct work to the front and a scoop to gain much pressure on the airbox. You would have to go over or under the frame from the front. Over would require a different tank and under... aren't the front cylinders in the way to do much? I suppose you could put scoops at the front sides and run duct work in from the sides but I really don't see a clean way to do it. I seem to remember the RC45 race bikes running duct work down from scoops on the upper corners of the fairing. Not exactly attractive. Clearly something like the RC51 frame and front fairing would have been the way to go from the factory. A look at the new Moto GP bikes shows an intake at the snout on most bikes but they seem more aerodynamic than the RC51.

 

$15.80 x 4 = 63.20 + $.80 for holders + shipping.
3.65 v x 4 (wired in series) = 14.6 volts

If I go this route I'll probably order enough for two and build one for my friend's 919 as well.

This is likely a Hong Kong site btw but it wouldn't be the first thing I've ordered from Hong Kong though.
<edit>
I forgot the connectors between batteries but those are only 50 cents. So add $1.50
Holders need to be on both ends I guess so $1.60 for those.

$30 over the price of a regular battery (estimate) isn't bad for 1/2 hp.

 

As stated earlier, I don't know that site. Here's the one i used in the UK for any UK readers Headway LifePo4 38120S 10AH

I added Ram-Air to my VFR via a duct under the headstock, above the oil cooler & below the cross radiator pipe ! Check out my 10year refresh projects for details, but here's a pic of the MK2 version.