750 liner

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ROSS BROWN
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Re: 750 liner

Post by ROSS BROWN » Sun Oct 14, 2012 11:21 am

Greg
Yep 'your right about the dry sump.." FIX IT ONCE AND FIX IT PROPERLY ".
The gearbox bearings will have a rating well above 7500rpm.. the gearset I don't now.
Chain temperatures have shown to be a proplem..
Check out the pictures of the half finished job on page 1 and 3 on of my build diary. It looks like you have the room
for a similar set up.. 2 or 3 teeth greater on the driven idler sprocket will help you no end.
But a push truck will be a must..
Mike Acitiff has a pretty trick parralell bar system to push Rocky up to speed . there are pictures on the net somewhere.
Sorry "Tiny" but finding the link to this picture would be like trying to find BSF bolts in this workshop.. Mon :)
IT IS ALL A RACE AGAINST TIME.
TIME WAITS FOR NO ONE.

HOW FAST CAN YOU GO ?

S/UF 925

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Greg Watters
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Re: 750 liner

Post by Greg Watters » Sun Oct 14, 2012 1:24 pm

Torque multiplication in the lower gears transfering to the second box will have to be taken into account too
std input shaft runs to 7100 rpm , secondary box will have an input of up to 3500 in primary first gear, it may not like that much , although the hp levels are stepped by gear so first will have only a few psi boost, but 6-8th gears will be at max hp with a secondary input speed of 8325 rpm

Looking at the gearing chart i made this morning i can't see how i can do anything but run 8 or more gears, a push truck would have trouble getting me up to speed to put it in first otherwise
a jackshaft may help, with final sprocket selection , give me a better range of gearing than just a pair of sprockets with not much difference in size
but i was being lazy in that area and wanting to fit a busa swingarm complete with suspension , as i need the area the current horizontal rear shock is in for other stuff
the requirements for top and bottom suspension brackets are quite simple , and the system works

momec3
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Re: 750 liner

Post by momec3 » Mon Oct 15, 2012 6:25 pm

The year Lucky Kaiser put the hot 351 in his bike liner his old Kingswood wagon wouldn't tow him fast enough because of the big cam in the 351.
The previous year it was OK cause the motor he got for a carton of beer was stock and would pull from down low. It ran 201mph

So I had driven the XP ute there in street trim so he inlisted me for a bit more speed.
Lloyd hopped in the back to hold the looped rope and we towed him up to about 120mph to release him.
Lloyd who was sitting facing back said his cheeks were wobbling like a skydiver.
The clutch in the Ute suffered a little but not as much as Luckys. He only ran 160mph odd and fried the clutch.

I don't think we would sneek the above method of release past the officials these days.
I don't think Lloyd will hop in the back with me anymore anyway cause I then speed up on the way back to the pits.
Put the wind up him so to speak.

Chris
Chris

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Greg Watters
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Re: 750 liner

Post by Greg Watters » Tue Oct 16, 2012 8:10 am

Chris i was about one tooth in the rear sprocket from doing the same thing this yr
new combo with bigger cams and the low compression made for a very lazy start
every pass Kim made had all the startline officals and ourselves holding our breath untill the bike slowly crept up to enough rpm to get positive manifold pressure and get down to business , usually about 4-500m out

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AuotonomousRX
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Re: 750 liner

Post by AuotonomousRX » Tue Oct 16, 2012 4:28 pm

Greg is it possible to get gear Ratios changed to a wider Turbo Friendly spread? Including Primaries as well?
Would the torque in the lower wider spaced gears provide enough acceleration to get into needed ratios for target speed if the spread was suited to a Turbo Engine, with maybe a 1:1 25/25 6th gear?
What sort of Torque spread does the 750/Turbo have?

I found this, seem Ratios have changed over the years in GSX R 750s.

2006 -2011 1.761 (74/42) Primary Drive
Low: 2,785 (39/14)
2nd: 2,052 (39/19)
3rd: 1,714 (36/21)
4th: 1.500 (36/24)
5th: 1,347 (31/23)
High: 1.208 (29/24)


2000 model 1.857 (78/42) Primary Drive
Low: 2.785 (39/14)
2nd: 2.052 (39/19)
3rd: 1.681 (37/22)
4th: 1,450 (29/20)
5th: 1.304 (30/23)
High: 1.181 (26/22)


1998 Model 1.756 (72/41) Primary Drive
Low: 2,866 (43/15)
2nd: 2,058 (35/17)
3rd: 1,650 (33/20)
4th: 1,428 (30/21)
5th: 1,260 (29/23)
High: 1,120 (28/25)

It's a challenge. :?

Pete
#866
(I have used a RGV specfic Gear Calculator, to help me work out Ratios, I found this as well http://gearingcommander.com/ as well as.)
Metric Target 250 on a 250 on a Red Bike

Pete :shock:
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Greg Watters
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Re: 750 liner

Post by Greg Watters » Tue Oct 16, 2012 4:50 pm

Pete the 96-99 750 we use is quite different to the later motors, it was more like a scaled down busa ,
later ones have different distance between gearbox shafts and just about everything is built lighter
our power spread is mainly between 10 and 13000rpm , not been an easy bike to ride as it goes from 80 to 300hp in a few hunderd rpm
bit like a manic 2 stroke , short shift or miss a gear and you have to downshift 2 to find the power again
Been talking a bit with Derek Mcleish , he runs a couple of vehicles in the US including a very nice little liner
and has done some interesting stuff with gearboxes , he thinks and i agree now that a car type gearbox may be needed as a secondary to cope with the torque
start in 4th and drive it backwards to get 3 od gears (but i suspect the gear spread will be too much :( )
local wreckers are keen to help

Your 98 model ratios differ from mine, could they be from a 600, which is one option to lower first , mine is 2.625:1 42/16 yours : 2,866 (43/15)
I have several 600 and 750 gear sets available to choose best combinations

I have gearing commander in my favorites , and use it so often i am thinking about subscribing so i can get it offline

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AuotonomousRX
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Re: 750 liner

Post by AuotonomousRX » Tue Oct 16, 2012 6:48 pm

Greg

I see what you mean, that is a a narrow power band, but with a big hit of power once it's on boost.
So, yeah, you need a XXXstrong Transmission to handle that type of Torque curve when multiplied by the Ratios.

I got the info from http://www.suzukigsxr.org/category/suzuki-gsx-r-750/

Not familiar with the GSX-Rs, might be like RGVs different countries have different specs for the same model/year.

Like I keep finding out this Land Speed thing is a world unto itself 8)

Pete
#866
Metric Target 250 on a 250 on a Red Bike

Pete :shock:
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Greg Watters
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Re: 750 liner

Post by Greg Watters » Sat Dec 29, 2012 11:28 am

Long time with nothing much happening
but while on the harvester been able to plan more and organise at least one bit i could not do
decided to run the mechanical fuel pump from the crank
have the drive made up ,
Image
Image
Image
bearing and seal unit screws into the crank access plug , shaft locates on the starter clutch unit and all held together by the crank end bolt
and testing the plan to fit a secondary gearbox
a holden 3 speed is just about too long, but if i make a swingarm from scratch i can make it fit
Image
Image
Bit of tooing and froing with Jon B over ratios and how this may work,
Jon has a spreadsheet that pretty much confirms my feeling that i need about 8 gears

potentially getting gears cut and shafts modified to get exactly what i want , and from there its a small step to make the box too
and save complications with swingarms etc ... going to depend on costs,
a friend Joe has a gear cutting engineering business ,has been to Gairdiner with us and understands what i am trying to do,
he runs a twin turbo 27 litre meteor motor in a pulling tractor , has converted it to quad cam , efi etc
so this is tame in comparison :lol:

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Greg Watters
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Re: 750 liner

Post by Greg Watters » Sat Dec 29, 2012 11:43 am

Dry sump pump will mount in the current water pump position , there readily available to bolt in from kit car use
http://www.novaracing.co.uk/nova-dry-su ... e-pump.htm
talked at length with these guys about transmission stuff too, liked what they could offer, just my pockets were not deep enough

now the workshop is clear of harvesters etc i can make a jig and modify the roll cage and driver area so i fit better, tapers in too much for me at the moment

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ROSS BROWN
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Re: 750 liner

Post by ROSS BROWN » Sat Dec 29, 2012 12:28 pm

Interesting to see that you have changed the driven side of the gearbox into the drive !
Can't quite remember the internals of those old holden gearboxes.. and the way the gears are cut...

FOOD FOR THOUGHT...... Have you improved the chances of it jumping out of gear... :?
IT IS ALL A RACE AGAINST TIME.
TIME WAITS FOR NO ONE.

HOW FAST CAN YOU GO ?

S/UF 925

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JonB
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Re: 750 liner

Post by JonB » Sat Dec 29, 2012 2:32 pm

Fuel pump drive looks the goods.

Innards of an Aussie 3 speed.
Image
Gears are helical cut but shift gear is all straight cut so the shift mecanism shouldn't get too upset by counter rotating.

Cheers
jon
DLRA#1115
Underhouse Engineering

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Greg Watters
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Re: 750 liner

Post by Greg Watters » Sat Dec 29, 2012 2:39 pm

Looking at the direction of the drive and wondering how hard it would be to shove the whole lot out through the side if i reversed the running direction of the box

i am looking for a 1:1 drive then several overdrives
this seems to fit both issues

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RGV
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Re: 750 liner

Post by RGV » Sat Dec 29, 2012 8:02 pm

That's going to put a hell of a lot of side load on the input and output shafts that weren't designed for it?

Could you use a small shot of NOS to get you off the line, say 50 HP?

Dave

Last Minute Racing "its a 2-stroke ya twit - Its supposed to smoke"
DLRA #928
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2010 MPS/G 250 118 MPH:)
2011 Washed Out:(
2012 Washed Out:(
2013 MPS/G 250 131 MPH (RECORD):)
2014 MPS/G 250 140 MPH (RECORD):)
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ROSS BROWN
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Re: 750 liner

Post by ROSS BROWN » Sat Dec 29, 2012 8:56 pm

let me get this straight... I know you's are both at it..
Jon you want to run yours backwards... :shock:...... sort of feasable.... thrust issues maybe ...?
Greg you want to run yours in the right direction but have it work backwards ... :shock: ...... that just does my head in .....

Another option.... I don't think they are that expensive ...I'm going to use a push truck so no need for me to ask the price..
.......................BENTEC 2 SPEED.........................air operated TOP FUEL bike gearbox , works in a similar fashion to the LENCO car gearbox,
planetary gear sets , almost unbreakable ..and take up minimal room..

Image
IT IS ALL A RACE AGAINST TIME.
TIME WAITS FOR NO ONE.

HOW FAST CAN YOU GO ?

S/UF 925

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Greg Watters
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Re: 750 liner

Post by Greg Watters » Sat Dec 29, 2012 11:03 pm

doing my head in too. went back to the shed to look again and both of us have the thrust in the same direction anyway
but as Jon mentioned to me earlier today, the bearings , angles, thrust plates etc are the same at both ends so it does not realy make all that much difference
and mine could end up with straightcut gears with bike type dogs , i'll see what Joe suggests

But i do like the sound of the Bentec

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