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Torsion bars and P1 gp.....

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ROSKO

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Discussion Starter · #1 ·
From the USCRA website as to the CB450:

"CB/CL/CR 450 (torsion bar valve spring type head)"

I would interpret that as meaning exacly what it says, 'torsion bar... type head' ....TYPE HEAD. It does'nt say restricted to using the original torsion set-up.

Anyone have any further info or comments?

BORN TO LURK, FORCED TO WORK.
 
U

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#2 ·
You freakin' people and you're looking for loopholes...

You can only use torsion bar valve springs on a CB450 in 500GP. If you move up to heavyweight supervintage, you can do whatever you want.

You can use larger valves and such, but you need to keep the stock torsion bar valve springs.

Did you know that you can swap the torsion bars to get a higher spring pressure? I think you swap them front/back, but I'm not sure.
 
ROSKO

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Discussion Starter · #4 ·
I love the verbal two step, if it's a 'loophole' whatever. 5 definitions of every word right? Well, it doesn't say 'must use torsion bars' and thats why I asked. Rules usually tell you what you CAN'T do.But, I'm no lawyer and argue mostly for the sake of it.
Just trying to figure it out. I've heard the torsion bars are no longer available NOS and honestly, the idea of running old sprung bars in a new engine is a little daunting.So, thats all. Any idea what sort of spring pressure a good torsion bar should produce?

I'm definitly interested to know the switch/trick for higher pressure, if you find any info hollah at me.


I've been in touch with Graeme at the site, super nice and very helpful. Sucks for me that he's in NZ....well, I'm rambling. Any info you have that'd be helpful is much appreciated.



BORN TO LURK, FORCED TO WORK.

Edited by - ROSKO on Dec 13 2005 9:16:54 PM
 
F

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#5 ·
Rosko,
Dude, I've been trying to find out if there's a measurable wear limit for the torsion bars, no luck so far. I've only heard back from KA Performance, who doesn't build stuff for the 450, only the 350 and 750. He turned me on to the WorldCycle dude, who used to race the 450 back in the day, but doesn't want anything to do with 'em now. (But he's cool anyway, 'cause he builds the coolest CB750s)
E-mailed the Henning/Harsh contact last week, haven't heard back...
From the research I've done so far, the swap of the torsion bars (flipping them from A to B) is not a reliable exercise, it's been done, but I guess not recommended for road racing. Don't know about the cost of the conversion to coil springs, I think I may have seen something at Megacycle's site. I'm not gonna bother, 'cause I'm not expecting miracles out of this thing anyway. Diminishing returns and all...
By the way, thanks for the offer on the CL wheel. Mine did show up, and it's in decent shape, so I'm good to go.

FR
 
ROSKO

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Discussion Starter · #6 ·
Call Terry @ Team Hansen. I talked with him a bit last year and the conversation wandered to his racing 450's. As I recall he actually recommended using the torsion bar set-up. Give him a ring. If anyone has acess to torsion bars and the know-how to make 'em fast it'd be him.

http://teamhansenhonda.com/contact.htm

BORN TO LURK, FORCED TO WORK.
 
U

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#8 ·
quote:
From the research I've done so far, the swap of the torsion bars (flipping them from A to B) is not a reliable exercise, it's been done, but I guess not recommended for road racing. Don't know about the cost of the conversion to coil springs, I think I may have seen something at Megacycle's site.
Click to expand...
$150 for the labor... http://www.intekra.com/ims/TermsPrices.htm
 
G

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#9 ·
Rosko,

From my expirence drag racing, it is better to just build the bike class legal and not worrying about engine modifications until later. Chances are you will not have enough skill to take advantage of anything more tha a stock motor at first anyway (this is not insult but you really have not been riding all that long). The stock engine is very forgiving to a newbie which helps keep costs down. Once you actually get into competition everything will accellerate, your skills will improve at twice the rate they are now (at first..it is a sliding scale once you become a veteran there is always room to improve but it gets harder), and the little tricks and expirmentation and mods will come a lot faster because you will be in the pits and see what everybody else is doing and will be talking and see what a lot of guys are doing. the competitive nature seems to make things go a lot faster.

Just build the goddamn thing and get racing already. You are really putting the cart before the horse thinking about internal engine mods at this stage, worry about finishing a race first. I wish bridgehampton was still open b/c that was an awsome motorcycle track. I'd say get keith code's book, and go over and practice your corner entrances and exits (way more important in road racing than straight line speed). Being smooth is way more important than being fast.
 
ROSKO

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Discussion Starter · #14 ·
Geeto-It may be putting 'the cart before the horse' and all but, while I have the engine apart I may as well ponder these things. Maybe it's a bit dangerous having the carcass of an engine sitting next to the computer. Break out that damn media blaster!

Tex- Don't worry, ghosts or not it's getting built.






BORN TO LURK, FORCED TO WORK.
 
I

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#15 ·
Johnny, make the banquet please, I want you and mary to get your trophies.

Rosko, I gotta agree . . . just get the engine together and play. Take care of all that other mod shit later. You'll agree with us after you run a lap and then sit the rest of the day out. Been there, done that.

scott

ps if you want that side cover, send me your address.
 
G

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#18 ·
quote:
Geeto-It may be putting 'the cart before the horse' and all but, while I have the engine apart I may as well ponder these things. Maybe it's a bit dangerous having the carcass of an engine sitting next to the computer. Break out that damn media blaster!

Tex- Don't worry, ghosts or not it's getting built.

BORN TO LURK, FORCED TO WORK.
Click to expand...
It's good to consider these things while the motor is apart but a reliable consistent motor is always better than a hot rod motor you are always tuning. Keep a Log book of the engine. Right now as the motor is apart take good notes on how it works and potential changes. Then when you go to the track take a good look at the mods others are running and their lap times (plus barometric conditions and your own carb tuning). Then when you are ready to make changes you aren't taking people's words for it but actually doing a sceintific expirement. everything you do write down its conditions and effects so when it's 95 degrees and 80 percent humidity and you are wondering how to rejet the carbs you can look up what you did last time in the same conditions and know where you are at.

When I used to drag race I failed tech twice and broke twice. The least fun you have at the track is having driven all the way to watch others race while your rig is out in the parking lot. Conversely, one time I finished second in a bracket class with a 17 sec. Chevy Tahoe (2door, 1999) borrowed from my mother, against some really heavy 12 and 11 second cars. Racing is more about the rider than the bike.

A stock motor will almost always be allowed to race and will 9 times out of 10 get you to the finish line. If you are naturally talented you are probably still two years away from your first win, more if you are not, so why not enjoy the trip while you are there and get the fast improvements out of the way.
 
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FR
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