Pure acceleration

[gav]

I had a collegue that hotted up a cibby 900 back in the early 90s - took it to 1080cc and fitted various bits to it. Was clocked at 215mph on bruntingthorpe (a place in the uk where people do speed runs). I'm sure in the nearly fourteen years since they have managed to make bikes go faster with not much more effort.

Shame he didnt do a back to back run as he would have had a record! As at 2001 the record stood at 213mph
Jack Frost from Holeshot Racing (one of the links I provided) broke this record in July 2001 on a highly modded 440 hp turbo 'busa
source Performance Bikes Sept 2001

If you read back maybe 5 years or so worth PB issues you'll see an article where they did a run on fast bikes at bruntingthorpe - from memory quite a few of them did +200 - I believe the record for a tuned up shop bike might be in the nature of the 230 mark, and I know quite a few did 220 odd.
OK then Perf Bikes Jan 2001 "The 200mph Club" proclaims the cover, must be the one then! 9 bikes tested, only 2 broke 200mph and only just. A turboed nitros 300hp Bandit 1200 did 201.3 mph and a similar spec 245hp GSXR1100 did the same speed 201.3 mph.

Recently I'm told that the best production bike for tuning is the old suzi buss, and not much needs to be done to get them over the 200 mark. I know turbo kits are easy to install on them and they have plentry of room for extra tuning.
Well no, seeing they are not far off 200mph standard, certainly the early ones were, some later models are restricted to 186mph

Sounds like you are still living in the 80s if you believe production bikes cant be made to go fast or have to be specially tuned 'dragsters' that people use to make videos. You'll find in other countries, there are quit a few enthusiasts that build specials in their spare time so its not uncommon to see a bunch of nutters down the local d-strip on a saturday afternoon.

So do I keep looking?
Interestingly no one was racing a blade, maybe they should have been.
You said early 90's right? So we're talking before 95, the CBR900RR was originally designed as a 750 as a possible World Superbike contender, it was pretty highly tuned when it was released and I seem to recall that most consensus was there wasnt much left to squeeze more power out of it, all the heads were pretty well flowed and ported and it didnt usually respond to all the general blueprinting tricks that most tuners turned to.
Are you from the UK? certainly cibby isnt slang over here for the CBR range. What have you got planned for your F2? You looking at suspension mods as well as engine?

[onearmedbandit]

Oh dear...

[speedpro]

shit aye... a rail will only do 334mph... with about 2500hp... now i dunno if you guys have been near one wif the engine out, but 2 people can pick it up....

Even a Rodec block engine would need more than 2 normal size people to pick it up, the cranks are huge. Blown methanol motors make 2500hp. The newest nitro motors are doing well over 5000hp, more like 7000hp.

[speedpro]

"aiming" for 200+

http://www.bigccracing.com/welcome.asp?page=67


348bhp with gas 238bhp without. 9.2 second quarter @159mph
http://www.bigccracing.com/welcome.asp?page=73

makes a 215mph road bike look a little harder

You're confusing speeds attained in the quarter with speeds able to be attained on a good long straight. My mates car has done 203mph in the quarter, the datalogger said he was still accelerating real hard. Absolute top end with higher gearing would be lots higher.

[onearmedbandit]

Holy shit, just what is your mates car?? I love the sound of a blown alcohol/nitro V8, sounds like the earth is being ripped apart!

[speedpro]

If this was the case, you would not be able to cleanly rev out with full traction in the lower gears (ie 4th and 5th) as the 'thrust' is higher.

It's all to do with force vectors and stuff. In lower gears most of the power goes into accelerating the bike. The force to accelerate is generated at the contact patch of the rear tyre and is applied through the centre-of-gravity. This gives the force a reasonable vertical component which is what lifts the front. At higher speeds the acceleration is not so great and most of the power is used to overcome air resistance which results in different force vectors, ones which at 200mph or so are less likely to lift the front. At higher speeds the height of the centre of pressure results in vertical forces eventually high enough to lift the front again. As a consequence more weight is transferred to the rear wheel which would assist traction. Whether that would increase fast enough to keep up with rising demands . . . .
This theory ignores aerodynamics, like on the Hayabusa.

Sounds like it could be true, maybe.

[speedpro]

Dave's car is a tubular framed Corvette replica with a 530ci alloy big block, EPD heads, 14/71 blower, lenco transmission, slipper clutch, etc etc. I agree on the sound, when we fire it up in the pits to check it over, , oh boy - westie heaven. Sitting in the tow car by the finish line with them screaming towards you is pretty impressive as well. The scream from the blower belt and then the explosion of sound as they go past 15' away at 200mph followed by silence as they shut down and pop the chutes(hopefully).

The nitro motors sound different again, probably due to the burn characteristics, real hard with more of a popping sort of sound. Anyone going to the drags this weekend has to check out the nitro Harley, that is one HARD sounding machine. Ross Buchanan has got balls, he has to wear a bullet-proof vest in case it turns to shit and one boot gets destroyed every run by the exhaust.

I remember a V6 rail at Thunderpark which they used to start on Methanol and then switch to nitro. You could definitely hear the exhaust change. Way cooool

[gav]

sounds pretty good....for a car....

[TwoSeven]

No where did I say that '420 is only good for 213mph', what I did say is that in that particular example 420 was only good for 213. That particular example. Got it? Although one does not make a pattern, if I wanted I could have pulled up many examples of 215mph'ish bikes, none of which would produce under 250hp+ (and I'm being conservative with that figure).Now pray tell, what hp did your friends CBR make, surely if he big-bored it and had other various parts on it that helped it acheive 215mph then he put it on a dyno as well. I would just like to know how he acheived this monumental speed. Think about it, because there are no production bikes capable of this speed, even with the right gearing, currently available. And we have litre class and above bikes puting out 175bhp that are only reaching speeds between 175-185mph. The power required to take these machines to 215mph, a 30-40mph increase would take at least another 100hp. Tonight I'll do a search on this subject, and show you how power required to gain further speed is not linear.

Sorry but I still dont agree with you. First of all you did say that 420 is good for 213 (thats how I read your first post). Now you say that only that particular bike needed 420 for it.

The busa puts out about 160hp (approx) and is speed limited to 189mph by convention. The gixer 1k is also speed limited to 184 by convention and produces similar power. The busa was suzi's first bike to do over 200mph - ok a technicality it only did it by .5 mph (the test I saw) but it proved that it could be done.

So now you are telling me you require 250hp to do 200mph even tho its been done on bikes with nearly 100hp less. And you are thereby implying that it requires somewhere between 270 and 400 hp more to do just 15mph depending which of your posts I read.

Now I am aware that resistance increases more the faster you go, but bike have a pretty low drag factor as it is. And I am aware that driving force drops off quite considerably because of the gear ratios.

But if I want to gear my cibby 600 to do 215mph I'd just need to change the sprockets to a 17/42 and viola, it would be capable of that speed (ok, it would require a very still day and about a 10mile long track because its acceleration would be almost nil). But the fact is, it has the capability to do it.

Now to actually make it do that speed, all I do is increase the power, its just a matter of doing so until the driving force is greater than the resistance - so if I up the power from 100bhp to 160bhp (similar to the busa) I get 1.22kN of driving force, which I know is 30% higher than stock but equal to the busa which is also 1.23kN (my rough calculations - using the 1999 busa stats).

The sad fact is, my particular machine is only capable of 120bhp and would require a turbo, which they currently only custom make for a bloomin large price tag which only crazy people would shell out for.

If it were possible to fit a turbo to a cibby 600 i'd be a very happy chap indeed and would have a busa beating machine .. But out of interest there is a 205mph cibby 900 on the mr turbo site running a stock engine with just the turbo (if you are looking for an example).

Having just shown you that a 600 is capable of doing it in theory (although not physically capable), you should be able to see how easy it would be to make a 900 do it (and I've even given you the basline machine on the mr turbo site as an example).

So take a cibby 900, take it out to 1080cc (which you claimed couldnt be done until I told you how), and add a turbo, and viola, you have a machine that can do 215mph fairly easily.

[gav]

Mate, what colour is the sky in your world?
Reread my post #46, where I replied to some of your points.
Jack Frost from Holeshot Racing is one of the UK's premier motor builders, his 440 hp 'busa averaged 220 mph.
Having just shown you that a 600 is capable of doing it in theory (although not physically capable), you should be able to see how easy it would be to make a 900 do it (and I've even given you the basline machine on the mr turbo site as an example).
And what the hell does this mean? (although not physically capable) exactly. You could gear your CBR for whatever but it aint gonna pull that gearing.
In fact it would probably burn out the clutch to get mobile. Its gonna need hp to do it and lots of it
As for the Mr Turbo CBR I saw that too, however why don't they list a mr turbo kit for a CBR900? And the motor isnt stock it has a piston kit and different rods (as it would need I guess to lower the comp ratio)
But heres the link http://www.mrturbo.com/kit2.html
Wheres the Honda kit???????
So again, what spec was your mates CBR? You still havent answered.....

[Blakamin]

So take a cibby 900, take it out to 1080cc (which you claimed couldnt be done until I told you how), and add a turbo, and viola, you have a machine that can do 215mph fairly easily.

farqin bullshit!!!!!!
there is an outfit that runs a 175 CUBIC INCH bike in the states that cant get over 220....
farqin 215 "easily"... no fuckin such thing... if there was, why is the current record for a drag bike 235mph??????
you take 200 miles to wind it up to speed????

[onearmedbandit]

I just can't stop laughing, I'm trying so very hard not too, but it's damn hard.

BTW, it wasn't moi who implied that you can't get 1080cc kits for the 'cibby', maybe you should check who is posting what you think you are reading!!

But if I want to gear my cibby 600 to do 215mph I'd just need to change the sprockets to a 17/42 and viola, it would be capable of that speed (ok, it would require a very still day and about a 10mile long track because its acceleration would be almost nil). But the fact is, it has the capability to do it.

Now to actually make it do that speed, all I do is increase the power, its just a matter of

Clear something up for me here please. Are you saying that your cbr600 could do 215mph with the right gearing, as you say it would require a very still day and a 10 mile long track, as it is now? Because you then talk about upping the hp to get it to do that speed, which if you did wouldn't require 'a very still day and a 10 mile long track. I have to assume you made a mistake there, please tell me thats a typo.

[onearmedbandit]

Oh yeah, got those spec's yet, it would help sort out this debacle.

[Edit] Point to ponder.

Initially you claimed your mates CBR900 with a big-bore kit and various bits clocked 215mph at Bruntingthorpe. Now you're making a point of mentioning a CBR900 Turbo that does 205mph. So your mates bike, obviously non-turbo and non-nos as you haven't specifically mentioned these additions (which one would if that was the case) will convincingly beat this turbo example. But it seems the emphasise has gone off your earlier claim to defending the ability of a turbo'ed blade to top 200mph.

What we all want to know is, what spec was your mates bike?

Oh yeah, and you have forgotten to address the issues that gav posted, you know the points that cast doubt on your claims, I'm sure Jack Frost would love to know some guy had already established his record in the early nineties.

[dangerous]

The busa puts out about 160hp (approx) and is speed limited to 189mph by convention. The gixer 1k is also speed limited to 184 by convention and produces similar power. The busa was suzi's first bike to do over 200mph - ok a technicality it only did it by .5 mph (the test I saw) but it proved that it could be done.

Have you ever riden a Busa? its aerodynamics that gets the Busa doing over 300k (dont understand you lot talking in Miles) at about 200kph the bike kinda squates down as the fairings do as they were designed as regardless of HP at at certian speed a bike will hit a wall and regardles on HP it will not pull any harder.... so using the Busa is not a fair comperason, ever wounder why GR has no fairing on his turb Busa.... it wouldent pull whellies at 300k if it did and as he dosent have a fairing he needs 400+hp to get 300kph.

[scumdog]

As has already been mentioned, I'm sure you guys are tangled up with terminal speed at the drags vs total top speed, ya need to sort it out.