800 In A 4th Gen Frame

[monstar]

Hello everyone, I'm new to this forum. The guys from speedzilla RC51 forum suggested I check this site out. They were right, you guys have a lot of good info on vfr's!

So, I'm looking to get a vfr project bike and from my research I think the 5th generation 800 would be the best motor to go with. My idea is to make a more track worthy vfr which means trying to shed a bunch of weight. All unnecessary stuff go's including subframe, gauges, lights, possibly steel tank, etc.

What a realistic weight I might end up with?

My other concern is the 5th gen frame. I hear it may have too much flex and a 4th gen would be more rigid.

Can a 5th gen motor go into a 4th gen frame? If so, which swingarm would work?

I'm not set on SSS, so if I have to run DSS no big deal.

Really hope to get my project underway soon... thanks!

[vfrcapn]

Why the 5th gen motor? The 3rd & 4th gen had right about the same power output so if you stick with them, and don't mind the carbs, you'll save endless trouble adapting motors and frames. I'd stick with the swingarm originally with the frame you use, the 5th gen is too wide to fit the 3rd or 4th.

As far as weight, there was a great thread here by member vfroem which seems to have been lost, but google still has it:

http://209.85.173.104/search?q=cache:2kGbp...rdiscussion.com

I have taken off 150 Lbs (68KG), the bike is now 379Lbs (172KG). (the weight of a 2006 Fireblade is 459 Lbs (208KG) -Wet- )

The weight of a completely standard VFR750F (90-93) with centre stand is 529 Lbs / 240 KG (-Wet-; incl. fuel, battery, oil, water )

Weight decrease by:

-magnesium rims

-exhaust system

-front forks (Fireblade Upside down)

-fuel tank (alloy)

-alloy subframe

-hawker battery

-centre stand removed

-rearsets

-tensiongears in engine removed

-race alternator

-VFR400 hub

-carbon airbox

-race seat

-mechanical clutch

etc.

VFR750F Standard: 90HP (at the rear wheel) 240KG. Every HP has to carry 5.86 Lbs

My VFR837F: 125HP and 172KG. Every HP has to carry 3.04 Lbs

You might be better off adding Toro's supercharger to a 5th gen and attacking it to reduce weight. I'd guess you could knock of 50 lbs somewhat easily if you were focusing on track only.

[Guest]

What classes would you want to run it in? I wouldn't be very competitive with any other bikes in the cc range.

[monstar]

What classes would you want to run it in? I wouldn't be very competitive with any other bikes in the cc range.

I don't plan on racing competitively, just track days and back road fun.

vfrcapn,

Thanks for that link, exactly what I had in mind. I really want to stick w/ FI motor, the idea is to eventually run a supercharger on it. As for the frame, would the 5th gen be a problem? I would think that with proper USD forks, adjustable shock, and some good weight loss it could handle aggressive riding... and 140+ hp?

I've managed to knock 40 lbs. off my RC51 with just removing unnecessary components/wiring and running a carbon airbox. I think doing the same to a vfr plus light wheels, carbon airbox, custom exhaust and alloy underseat fuel tank would be a good 50 lbs. or more.

Anyone make good rearsets for the 5th gen bike?

[Baileyrock]

Hey monstar, welcome to VFRD! :fing02:

Many great modders here and your project sounds like fun, just keep searching through the site to see what else you can find and keep us informed w/pics if/when you start. :fing02:

[hawglet]

Anyone make good rearsets for the 5th gen bike?

Harris is the only true "rear set" as far as adjustablity goes, that I've heard of but good luck getting ahold of a set. When I bought mine from EMA they told me that it was the last NEW set available in the state. They aren't importing Harris products anymore as I understand it, but someone else is, although I haven't figured out who. I'm sure someone will chime in with time about who it is. good luck and looking forward to seeing what you come up with.

[vfrcapn]

Anyone make good rearsets for the 5th gen bike?

Harris is the only true "rear set" as far as adjustablity goes, that I've heard of but good luck getting ahold of a set. When I bought mine from EMA they told me that it was the last NEW set available in the state. They aren't importing Harris products anymore as I understand it, but someone else is, although I haven't figured out who. I'm sure someone will chime in with time about who it is. good luck and looking forward to seeing what you come up with.

I don't think they make the Harris anymore but they pop up on eBay once in awhile. :pissed:

I got these off eBay UK.

There were some others making rearsets for the 5th gen too, you'll need to google. It shouldn't be too hard to adapt other models to fit though.