The ultimate VFR400 F3 race bike - 98HP

[willytheekid]

"dear Santa

Please kidnap This Chris fulla, and force him to rebuild my VFR750 to his amazing HP shitting standards.

...that is all"

...so friggin tasty...98hp!

[Mental Trousers]

$45,000 US$, sounds cheap for an F3 bike to me.

The prices that yanks can buy parts etc at US$45k = about NZ$250k

[roadracingoldfart]

Very cool way to get rid of a LOT of dosh. Whats the go with the wear patterns on that rear tyre, suspension issues or pressure issues?

A banked track maybe , just saying.

[neil_cb125t]

Very cool way to get rid of a LOT of dosh. Whats the go with the wear patterns on that rear tyre, suspension issues or pressure issues?

sh*t tires - that is all

[Wally]

Hi guys,
I'm one of the people working on your triples over here in the states.
I had traded emails with Chris Osbourne before we ever built our first one. He's was really great about sharing information.

You may know Frosty on here, I met him a few years back and he's the one who led me onto them.

The bikes we are building follow his (Chris') recipe. We are leaving ours stock, except for degreeing the cams, exhaust and mapping the A/F. We chose to stay stock simply to prove (we get a lot of wonky looks with these here) it was an inexpensive, reliable and competitive bike. Had we built them up, I think it would have hurt out chances of getting them legal.

We've built 4 so far, one got binned and became a paperweight and we then built 3 more. RWHP ranges from 66-68 on pump gas, using a dynojet dyno belonging to Doug Chandler. He says it reads a bit conservative.

Mike Lohmeyer raced one for us last year. He won a couple of races handily, and finished in the top 4 the other rounds. Unfortunately, we were running on exhibition in 450 super bike class for no points. Another friend, John, raced a second triple for us as well and did nicely in the novice classes (he was a first year racer)

This year, they are legal in 450 SBK. So far, 3 others have built their own, and a few more threatening too. We just raced this past weekend, and there were 6 altogether.

Mike Norman at G-force is a friend of mine and I think we're drawing him into participating on trying out a yamaha or two pretty soon. (all of ours are suzukis).

[Mental Trousers]

.....

Wicked. Way to go Wally. I'm very happy to know the triples are being used elsewhere in the world. Around 70RWHP is about right for a bog standard triple. I hope you guys are going to build some monsters out of them. After all, they've got the potential to make a reliable 95 hp.

[crazy man]

....

think Chris is over 90hp with his ones

[quickbuck]

........

Great to hear some Kiwi cunning is being used in the goold ol U S of A.
Nice work.

Keep us updated with progress, either here or the Sub Catagory of Race Reports will be cool.

[Wally]

Thanks all!

right now we dont want to build anything monstrous. We feel that we'd scare away folks as then they'd feel that they would have to spend big $ in order to "keep up", so we are staying stock. We'd really like to see this catch on here and being budget minded, we think, will help.

You guys might already be doing something like this, but recently, we found that we could get a better tune out of them by putting a bit of PVC pipe with a cap on it, into the velocity stack. This effectively isolates the dead cylinder from the airbox, so you dont get the funky bumps in the A/F graph. Makes the graph way easier to read and easier to make tuning decisions. I was able to get 2 more rwhp out of one bike by doing this.
I did drill a small (8-10mm) hole in the cap just to help deal with air expansion with temp rises.

I know Chris had a solution for the injector, but what we did was just to take a spare OEM injector, and put about 8" of clear vinyl tubing from the inlet to the outlet and fill it with water. Then plugged that "dummy injector" into the harness and the trouble light went out and it revs out nicely.

Do any of you have experience with the R6? Next up looks to be a 2007. I hear they are finicky.

Thanks!

[Mental Trousers]

....

On my old 450 triple (the gearbox started playing up and it missed fifth gear, stretched and snapped the rod on the dead cylinder and is now propping up a wall) I removed the fourth throttle body and put some duct in that went to an air filter then cut the exhaust near the mid pipe, welded it up so it was sealed then put somemore ducting to an air filter on the exhaust side. For the airbox I plastic welded it closed. After I did both intake and exhaust the thing revved out really easily.

As for the injector for the fourth cylinder a 15ohm resister has sorted that out for me on my current bike.

There's a couple of R6 450cc triples down in the South Island. Neil Smith's is quite different. I believe he drilled the piston then welded weight back in to balance it, then sealed off the intake and exhaust.

[Wally]

Thanks Mental T,
we are putting a freeze plug in the exhaust header pipe, as close to the collector as possible, with the thought of using the empty pipe as a damper of sorts for the air that the piston is still pushing around.
The plug we use is a decent fit, then we "glue" it in with high temp rtv. So far, so good!


One guy has stock head pipes and he's cut and welded his fairly close to the cyl head.

Until recently, we were leaving the intake open to the airbox.

Bummer about grenading your con rod! Is the one you have now a honda ?

I'll contact Chris again and ask about the R6 and see if he can offer any insight.

[Mental Trousers]

Yeah, my current bike is the CBR. It's a 450 triple but I've done something a bit different on this one.

Another guy to talk to is Greg Percival. He's the only one I know of that removed the piston and conrod and replaced them with a weight on the crank. He's has some big hassles with it but it seems to be much better these days. Although early this year the bike cracked the cases but I've no idea if that's related to the setup of the triple.

When I win Lotto I'd do what Ducati did to make the Supermono - replace the piston with a lever (see image below)