SpeedTherapy
Howdy Folks!
A few weeks ago, I was looking at the new rules for the new Classic TT (previously the Manx Grand Prix for classics) - I saw "up to 1000cc 2 cylinder 4 stroke built before 31.12.1992" n the new Formula 1 class. I've only been into bikes since the late '90s so didn't really know Ducatis earlier than the 996... I had a look at what was around in 1992 and discovered 851/888s. One of the first places for info I found was this awesome forum :-)
So, the wheels in the head started turning... I've raced a Ducatis on the Isle of Man twice in the past with mixed results - a DNS (Did Not Start) and an uncompetitive slow finish. I want to do it again. One of the big issues racing around there is the bikes get an absolute hammering. The chassis get pounded over the bumps and jumps at over 100mph and the engines are held flat-out for long periods. Ducati have a very poor record around there. Looking back at the database, it looks like more than 50% of the Ducatis that start a race over there don't see the finish line.
Not encouraging... BUT... I recon a properly prepared 851/888 could be up to the task. It doesn't have to be super fast... but needs to be bullet-proof. I have a few ideas...
Any thoughts/experiences would be much appreciated.
Also, any ideas on what model to go for and preparation tips?
😄
Also, being an amateur racer, budget is also a factor... so the wildly expensive exotica would be out of the question... unless of course there is someone out there who has such machinery and would want to go racing on the Isle of Man against the likes of McGuiness and Dunlop 😄
Looking forward to your knowledgeable feedback.
Not much time left so need to pull my finger out if I'm going to do it...
Ciao!
Paul
SpeedTherapy
...
(learning how this forum works)
griff851
With 49 days to go, your going to buy an 851 and race prep it, with out spending much dosh, and finish competitively with out the bike self destructing in some way? Good luck with that one. How about more like next years TT.
SpeedTherapy
griff851 wroteWith 49 days to go...
Classic TT is from 17th to 26th August. About 130 days. Have no illusions of finishing 'competitively' - there will be professional riders out there (McGuiness and co.) on ex-factory RC30s and the like. Just a finish will do nicely.
Still up against it though...
stafford
Either way I'll be there to cheer you on!
duc904red
Totally cheeky
Do you need race subframes etc?
Regards Steve B
rarebear
go for it
If i lived on 'you're side of the planet and had half a chance of pulling similar together i'd be there to. Go for it mate and good luck. I can't see why a properly prepped 851/888 in a mild state of tune, ridden at less than 105% can't go the distance. If you've got a reasonable amount of road race experience and some contacts put it all together and do what most talk/dream/knock you down about.
The ultimate fantasy i reckon-go for it.
griff851
Well then get your bike, pull it apart, turn it into a 926. Drill holes in everything. Get some one like Chris Steadman to do the heads. G cams inlet and A cams exh or 996 sps. Set compression to around 12.5. Corello rods. DP flywheel maybe. Nichols may be a bit light. If your keen you might want to change primaries, and sprocket final drive ratios.Clean injectors. Fast throttle as recently mentioned. Remove airbox cover. Ducati alloy basket and plates. Change clutch slave to aftermarket different ratio. Put an Ohlins du440 on the rear, gold valve forks. Replace hoop eye ends, lube up everything. Change any suspect bearings, attention wheel bearings and swing arm head stock.Replace frt and rear subframes with alloy. Stainless discs and sintered pads. Get powercomander, put on dyno. Buy seat unit and nose cone from Germany. ST4 headers, what ever cans. Set bike geometry to longest wheel base. Turn key push start go. Pray it holds together. Go f***ing fast and be scared.
Or you could just buy one, change the belts and see how it goes.
Anybody got anything to add?
Mr.R
I'm 100% sure that I could build a big bore or bored and stroked 851/888* that would kick out 135 rwbhp with complete reliability for a 6 lap TTand all of the practice week...
Short of any premature failures of any engine componants.
This motor would pull/grunt well from the midrange and not rev past "The Kiss of Death" (for a Desmoquatro motor) of 10,000 rpm.
Setting the rev limit on the map/chip at 10.5K would stop the motor self destructing over the bumpy parts of the circuit.
Troy Bayliss's BSB Championship winning 996cc motor was kicking out 169 rwbhp, but IMHO there's no way a motor in that state of tune would last possibly just the race let alone the fortnight.
The reason that I'd use 135 rwbhp, (an easily achievable target power figure) is that the factory 888/926's Corse machines had around this power and had found the limits of the chassis by then...
Even the 888/955cc bikes campaigned in the AMA Championships by FBF only made 136 rwbhp.
*To either 926,955 or 984c, top end power would be pretty much the same, but the bigger the capacity the more torque/grunt throughout the rev range = a wider spread of power.
After that it's down to getting the bike as light as you can without weakening it in any way.
If you're going to use magnesium wheels? I'd make sure all of them were new ones if I were you.
Well that's laid out my store, who's got the cash to see if I'm full of wind and piss, or can deliver what I'm confident of doing????
A big twin isn't going to beat the Fours, as to get anywhere near the power that they can produce, it's going to have lost any kind of reliability.
Before anyone mentions Hailwood's win, his bike expired as it crossed the line and the 4's back then didn't have the power that the more modern ones have/can achieve.
You can of course add the fact that S.M.B.Hailwood was a genius and the best motorcycle racer of all time...
edit...I'd never consider myself a top flight tuner*, but have had some experience preparing bikes for endurance racing up to World Championship level and built the 1st non works bike home in the Senior TT.
The real one not the MGP Classic one...
*If I was feeling pumped up and really big headed I'd possibly 😏 own up to being a slightly talented amateur.
Steve R
851 tricolore
rarebear wroteIf i lived on 'you're side of the planet and had half a chance of pulling similar together i'd be there to. Go for it mate and good luck. I can't see why a properly prepped 851/888 in a mild state of tune, ridden at less than 105% can't go the distance. If you've got a reasonable amount of road race experience and some contacts put it all together and do what most talk/dream/knock you down about.
The ultimate fantasy i reckon-go for it.
I'll second that,
I like the idea of an 851 'team' doing the 'ultimate test'
go for it Paul
good luck to you
sounds like you're up for some help from Steve too . . .
Ian
Pompey
Hi speed therapy, I take it you have already raced at the tt or Manx before? I heard they are tightening the rules at tt classic to cut out the club level racers from entering?
SpeedTherapy
Thanks for the support guys!
Steve B - don't know if the budget will stretch as far a race subframes. I'm thinking to do a bare minimum to the bike. Just make it Isle-proof. If things look promising, then improve it for next year. I'll keep you in mind for subframes, thanks.
Mr R - Would love to have 135 rwbhp :-) But will settle for 105 rwbhp this year - reliability is key (and budget is tight!)
Pompey - Yes, done 6 Manx GPs. Don't think I'll have a problem getting in this year - but good point with the new Classic TT. Might give the organizers a call to feel the waters.
Looking at a few options at the moment. A Strada and spend cash on building it up to spec. Or an SP3/SP4 which is already half-way there (and just do bare minimum on it - budget)?
I know with the later Ohlins (around 1999 onwards) one can get standard forks working much better with a good kit in them. One pays for bling factor. Are the Ohlins forks on the SP3/SP4 really that much better than the standard Strada stuff?
Another question - Are Good shocks readily available for 888/851s?
If so, what manufacturer would be a good match?
Thanks
Ciao
Paul
Mr.R
Out of the box the period Ohlins FG9050 forks (OEM on the SP2,3,4 and 90/possibly '91 851/888 Corse) are better, K Tech modified Showa's fitted to the Strada's from '91 are pretty good but weigh more.
Ohlins*, Nitron or Maxton shocks are about as good as it gets, the American's like Penske kit but we don't see them over here.
*Maxton modified Ohlins are very good, I use this shock on my '92 Strada based 851/916.
A good SP2,3 or 4 will kick out 110-114 rwbhp, but it'll cost quite a bit to buy one of them.
You could spend less on a decent Strada and then lighten, tune it and end up with a better bike with more power.
...and as I've posted I reckon I can get a bigger and wider spread of power than a standard SP, even a '92 SP(4)S and SP5.
My own '92 based 851/916c motor kicks out more power than a 926cc JHP tuned SP(4)S or a well sorted SP5 and it does it at much lower revs/peak power at 9,2-300 rpm.
128 rwbhp with a power band that starts from 3,500 rpm.
More power than any 996cc or base model 999cc road bike sold by Ducati to the public...
Steve R
griff851
Just a pity Steve your on the other side trapped on your wind swept rock. It would be good to match our bikes against one another. Battle of the shed el cheapo twins😄 although because of your Ti addiction yours probably cost more.😄
Mr.R
griff851 wroteJust a pity Steve your on the other side trapped on your wind swept rock. It would be good to match our bikes against one another. Battle of the shed el cheapo twins😄 although because of your Ti addiction yours probably cost more.😄
I reckon that my shed built old nail would give yours a run for it's money mate.
Like you I built mine on a shoestring budget, but I've got all the parts to build the next motor just that one step farther, only last week I ordered up a full set of 36/31 valves. 😉
To go with the 96mm barrels, Pistal Corse pistons, Carrillo rods, Corse alloy selector drum etc...
I've got a pair of 916SPS heads here at the moment to overhaul and shim for a fellow enthusiasts, of course I've had the verniers out...
TBH I think the 916SP I'm using heads fitted with 95/30 valves are better, (gas speed,cylinder filling for the rev range) we'll just have to see how well the bigger valved heads perform.
Steve R
brad black
what i think you should do, keep in mind i have pretty much no race bike prep experience.
don't waste your money with an sp, they're a collector bike now. and power wise they're quite crap (apart from sp5) compared to what people would expect, an 853 kitted 748 strada makes as much power ime.
i'd strip the motor, replace the rod bolts and big end bearings, check the big end plug or replace with steel and check/replace everything else as required.
if you want a close ratio box fit a 748 one (will need 5mm offset inwards on front sprocket).
shim the crank and gearbox without centre gasket and goop it all up.
if you want to get serious recase it in late model (01 on) s4/st4 cases, as they are stronger and have a better oiling set up, inc pump, etc, so get all that if you go that way.
if it stays 851 or 888cc i'd fit some 748 heads with the chambers modified, you'll get a lot more comp with std pistons without any extra effort and the 748 ports seem to work very well at that cc. i wouldn't bother touching the ports.
std cams with reset timing will give you a nice power curve ending around 10 or 10,500 which will be good for the cases. you can fit sps cams and get a similar curve, just with more everywhere.
st4/4s headers work well with mods at the swingarm point, but you might need to take note that the exits out of the collector are tucked in so they don't scrape at race lean angles. not sure on that point. if budget is good then a proper spaghetti system will work maybe a little better, but i'd not spend extra money there first (wheels and suspension). std headers will definitely cost you power, they're too small.
slipper clutch. most people i deal with say it's one of the best track based mods they've made.
get it tuned properly. if it's an 851 with a p7 ecu find a p8, run an 888 eprom to start with and have it mapped for each cylinder. regardless of engine set up, there will be benefits in tuning whatever you run properly.
for any of the ohlins forks you need different triple clamps. just fix the showas if you buy a 91 on bike. if you buy a pre 91 bike replace the m1r with showas. in that case you could get some ima triples to fit sbk (748, 916, 996, 998) forks to the 851 chassis if you really wanted to spend more money as they have the better style internals.
there's a few threads on the ducati ms supersport forum about fitting 04-05 gsxr 750 fork internals into the 41mm showa. apparantly quite straight forward, gives a much better cartridge like a 916, etc or k-tech kitted showa.
steve likes the maxton shocks, probably an easy tick off the list depending on delivery time.
put lighter wheels in it.
get rid of any weight possible, the easy-ish part i guess restricted only by $.
there might be a similar bike coming over from aust too i think for this class. similar, pretty std motor basis with chassis mods.
griff851
Mr.R wroteI reckon that my shed built old nail would give yours a run for it's money mate.
Like you I built mine on a shoestring budget, but I've got all the parts to build the next motor just that one step farther, only last week I ordered up a full set of 36/31 valves. 😉
To go with the 96mm barrels, Pistal Corse pistons, Carrillo rods, Corse alloy selector drum etc...
I've got a pair of 916SPS heads here at the moment to overhaul and shim for a fellow enthusiasts, of course I've had the verniers out...
TBH I think the 916SP I'm using heads fitted with 95/30 valves are better, (gas speed,cylinder filling for the rev range) we'll just have to see how well the bigger valved heads perform.
Steve R
You'd have to something special to get your lardy arse moving, as I'm a fly weight at 73 kg wringing wet:😁
griff851
brad black wrotewhat i think you should do, keep in mind i have pretty much no race bike prep experience.
don't waste your money with an sp, they're a collector bike now. and power wise they're quite crap (apart from sp5) compared to what people would expect, an 853 kitted 748 strada makes as much power ime.
i'd strip the motor, replace the rod bolts and big end bearings, check the big end plug or replace with steel and check/replace everything else as required.
if you want a close ratio box fit a 748 one (will need 5mm offset inwards on front sprocket).
shim the crank and gearbox without centre gasket and goop it all up.
if you want to get serious recase it in late model (01 on) s4/st4 cases, as they are stronger and have a better oiling set up, inc pump, etc, so get all that if you go that way.
if it stays 851 or 888cc i'd fit some 748 heads with the chambers modified, you'll get a lot more comp with std pistons without any extra effort and the 748 ports seem to work very well at that cc. i wouldn't bother touching the ports.
std cams with reset timing will give you a nice power curve ending around 10 or 10,500 which will be good for the cases. you can fit sps cams and get a similar curve, just with more everywhere.
st4/4s headers work well with mods at the swingarm point, but you might need to take note that the exits out of the collector are tucked in so they don't scrape at race lean angles. not sure on that point. if budget is good then a proper spaghetti system will work maybe a little better, but i'd not spend extra money there first (wheels and suspension). std headers will definitely cost you power, they're too small.
slipper clutch. most people i deal with say it's one of the best track based mods they've made.
get it tuned properly. if it's an 851 with a p7 ecu find a p8, run an 888 eprom to start with and have it mapped for each cylinder. regardless of engine set up, there will be benefits in tuning whatever you run properly.
for any of the ohlins forks you need different triple clamps. just fix the showas if you buy a 91 on bike. if you buy a pre 91 bike replace the m1r with showas. in that case you could get some ima triples to fit sbk (748, 916, 996, 998) forks to the 851 chassis if you really wanted to spend more money as they have the better style internals.
there's a few threads on the ducati ms supersport forum about fitting 04-05 gsxr 750 fork internals into the 41mm showa. apparantly quite straight forward, gives a much better cartridge like a 916, etc or k-tech kitted showa.
steve likes the maxton shocks, probably an easy tick off the list depending on delivery time.
put lighter wheels in it.
get rid of any weight possible, the easy-ish part i guess restricted only by $.
there might be a similar bike coming over from aust too i think for this class. similar, pretty std motor basis with chassis mods.
The boys from D-Moto are building a bike for some bloke for the race. I believe it will be for sale after the race.
The drop cam 748 heads with ST4 cams kicks butt. However the factory port work on mine was pretty average. A quick clean and port match was nessesary.
brad black
griff851 wroteThe boys from D-Moto are building a bike for some bloke for the race. I believe it will be for sale after the race.
yes, the 'for sale after' bit concerned me after shaun asked if he could borrow stuff from me to use on it.
Pompey
Thought so, I went last year to watch Rob Knoyles misses Shelly race in the juniors and on an r6. One of the last practice sessions went out really late in bad weather due to cloud on the mountain, my hat goes off to you!
I would get a good quality strada as cheap as you can then spend the money on suspension and making it as light as possible. It will have enough power to pull thru the gearing you will need and be strong enough to survive the miles. Then after you can spend the next year prepping the engine for what you need for next year after this years experience on it. If only I wasn't working I would be there to help!
