NITROUS OXIDE ( nos / n2o ) advice forum

Well it looks like I'll finally get a chance to put the mods we did to the bike to the test next weekend at the top speed (standing mile ) and wheelie records meeting at Elvington . I've only done a couple of quarter mile meetings so far this year so I'm really up for this one . There are a couple of guys off UK Busas who run big bore N/A bikes who reckon they're going to kick my Nitrous butt ,well we'll see about that . Whoever loses buys the burgers and will obviously get the piss taken out of them so there's a lot riding on this . I'll post the results of the best of three shoot out next week .
Regards Greg H .

Hello All , just a quick update as promised . I only did the Sunday which was a cracking day , and by all accounts so was the previous day . There was a reasonably large number of riders competing split roughly 50/50 between Top Speed and Wheelie guys . I think the world wheelie record went over the weekend , I believe that it now stands at 180 mph , a speed which has to be maintained over a Kilo to count as a record . I had a good day culminating in a best of 208.2 in the mile which made me the fastest Gas bike there ,I reckon I would have been faster still had I been able to gear the bike higher because the thing was on the limiter in 6th at about the 2/3 mile mark . There were only three bikes running gas on the day as most of the guys in this game seem to be choosing to go the Turbo or Big Bore N/A route, I'm not sure why . . Oh ! regarding the Burger Challenge well, I'm afraid the burgers were on me this time as although my bike was flying it wasn't flying quit fast enough to beat Bazz off UK Busas on his big bore N/A Busa, who ran 214 in the mile . Fair play to him , cos he hasn't got mega horsepower but he sure knows how to achieve high top speeds over the mile ( he must have his gearing right ) . I'm afraid I'll just have to content myself with dusting him over the quarter mile at the forthcoming Drag Race meetings for the time being . Regards Greg H

Hi Greg,

Sorry I missed your original post but congratulations on achieving the 208 mph.

Sounds to me like your gearing really let you down if a NA motor could pull 214 so that's a shame but at least you know what to do for next year.

208 mph on two wheels is really an achievement Greg, congratulations.

funny enough, some other guy with a nitroused 928 porker took his car out for a Sundayride and accidentally hit the throttle and nitrous switch. Can`t recal his result, but it was something like 20.8 mph or so.

Well done Greg

Shame you didnt quite get em but you were close! I know once over 200 every 0.1mph extra is hard to achieve - but I'm sure you will have the NA guys eating your dust!

Hi Greg

Congratulations

You beat my old Porsche by 0.1 mph lol

I had already increased my gearing for my attempts by diff gearing and oversized rear wheels and tyres.... mine in theory (only) because of the gearing is capable of over 250...

So if your revs / gears were maxing out you need to change your gearing as although I dont know much about bikes I suspect a larger rear wheel/tyre may not be possible...

VERY well done again

All the best Brett

That's one thing on bikes which is very easy to do - just swap sprockets.

The standard ZX12-R redlines in top a little under 200mph, swapping the rear sprocket from 46 teeth to 43 teeth soon sorted that (and with the help of a few old crossfires and a little gas, the GPS said 211 . . . . . )

Yes , but over what distance .

Cheers Trev , I use the stock 17t front sprocket and alter the gearing by swaping rear sprockets , 46 for quarters and last year I used a 38 for the mile . This year I figured that a 37 would be right but I also took a 36 with me . The 37 resulted in a couple of 206.6 runs , after fitting the 36 we ran the 208.2 . 36 is the smallest that can be fitted to the stock rear hub so I,m going to go for an 18 or 19 front which will give me the ability to run much higher gearing to take full advantage of prevailing conditions . If it had been a straight drag race over 1/2 mile I'm sure I would have beaten the N/A bike convincingly cos the way the bike ripped through the intermediate gears was awesome. On the day he deserved the win cos he was better prepared seeing as it was his third top speed meet of 2010 ,where as It was my first since 2009 . There's talk of another meeting in 2010 , if there is I won't make the same mistake twice

hi greg met you at elvington at the weekend
ive dropped you a pm if you could reply i have some questions

many thanks
johnny

As far as I'm concerned that doesn't make the blindest bit of difference, if the long tarmac is there, use it .

(To be honest, doubt I would have done it within a mile).

Hi

Now I know this will sound REALLY stupid, buy if I don`t ask I wont learn...

OK...I now understand changing the rear sprocket is the same as changing a car diff to alter the ratios...

What I don`t understand is why changing a FRONT sprocket would make a difference to ratios or speed ?

Is this a really silly question lol ?

All the best Brett

it is a bit silly but a fair question, the ratio is just that a ratio between the front and rear sprockets so larger on the front sprocket is the same as smaller on the rear sprocket. on a hayabusa the front sprocket is roughly half the number of teeth to the rear sprocket so one tooth more on the front is like 2 teeth less on the back

johnny

Hi Johnny

Hold on are you saying BOTH front and rear sprockets are ON the REAR wheel ?Or the front of the chain ?

I was assuming for my question that when someone said "front sprocket" they meant on the FRONT wheel?

The only way I could figure that worked was 2 wheel drive...both front and rear wheels being powered....

I am getting really confused now, probably my age lol...

All the best Brett

ok to be clear
the front sprocket is driven by the gearbox and then the chan takes the drive to the rear sprocket which is connected to the wheel, if you forget the chain is there at all then its like the gearbox sprcket driving the wheel sprocket and the difference in numbers of teeth is the final drive ratio as in a diff. the only difference is that theres a chin in between instead of one directly driving the other

hope this maes sense now

Johnny

Hi Johnny

Phew ...thanks, now I understand...like a crown wheel/pinion in a cars diff

All the best Brett

Exactly

Johnny

Sounds good to me.

Some questions for you;
What jet numbers were you running?
What size bottle/s
How many were you using?
What was the nitrous pressure at start and finish?
How long was the nitrous system activated?

With this info I can give you some useful advice for next time and if you contact me before you run again I can offer you products to assist achieve your goal and give you some tips to achieve optimum results.

Brett, it's just like a pushbike - front sprocket where the pedals are.

Nice thing is it's easy to work out gearing changes because you can see the number of teeth on each sprocket and change them accordingly (not so easy peering into the inside of a diff or gearbox casing) and it takes minutes to change sprockets.

Hi Trev , the answeres to your questions are as follows .

Jet size . 100
Bottle size 5lb
No of bottles 1
Bottle pressure at start of run 960
We're spraying for the full mile
Incidentaly , the bike is consuming 1 lb of gas per run .

Regards Greg H

Hi Guys , well its looking like there may be another standing mile meet later in the year at Honington . If it takes place it'll be on the 10th of Oct . So far there seems to have been a good response from UKLSRA members and I for one am really looking forward to making ammends for my gearing cock up at Elvington .