How much power can you get from a 620?
 

I entered the DD series this year intially on a pretty stock 2002 620ie and have spent some money on personal riding development and slowly added a few performance extras to the bike.

As a result of these, my perfomances have improved and I intend to further invest in my bike and myself for next year's series.

I'm pretty sure about how I'll develop my riding next year, but as a hypothetical exercise, what can be achieved in terms of performance upgrade to a 620ie and at what cost?

With paddock talk of 70+ bhp bikes for next year, how realistic is this? What would deliver this kind of performance?

Whilst not expecting to get to these levels of performance, what can be achieved, how and at what cost?

My plan would be 6-speed box, custom exhaust and PC map, but what else? As engine work is extremely restricted, what can be done? Blueprinting? Suspension?

Tim

I'd concentrate on suspension Tim, I think this is where you'll find the biggest gains in laptimes. Sure you might find more power out of the engine but in terms of cost per reducing laptimes I didn't think it was worthwhile chasing.

IMO

Fair enough - but I know sod all about suspension!!! I wouldn't know a preload change from a compression change if it smacked me in the kisser!!!

The suspension on mine feels fine, its had reworked front forks and a S4 rear shock, but the only adjustments I've made to either was going 2 clicks harder on the rear shock (why? - because I could!!) I then subsequently had a big slide at Brands and I quickly moved it back. But I felt / noticed no difference.

I suppose I could get someone to work with me on this, maybe the suspension guy at 100% for example, but without knowing what's wrong (if anything) with my suspension now - how can this get better? Perhaps I shoudl ride someone's DD bike that has been setup? But in all likelyhood this would be setup for them and may feel worse to me?

Perhaps I should get myself to a track and get playing.
Tim

i think 70+ is realistic but as tony says outright power is not the be all and end all. you need to be able to use what you have effectively.

i dont think a few bhp makes chuff all difference to be honest. but most of the front runners either/have or will have a few mods such as pc's giving upwards of 65 bhp.

but the the talented rider with a well set up bike will prevail.

b.t.w im going down the same route as you. sssshhhhhh.....

Snot is currently 65.7 and the tango queen is 66.5

As you might remember tho, it has been a constant battle for AK to get increase of power on the 'Snot Mobile - here is the 'fight' for the increase this season for Snotty;

Cadwell woodland: 583 std, on 48hp - got good placings tho with a 5th & 6th
Castle C : 675 on 52.5 hp 5th & 7th
Snett: 675 on 54hp - smoking badly 10th
Donny: 620: on 62.5 - 2nd & 5th (after guest riders removed from points)
Brands 620: on 65.7 with PC fitted - novice rider out for first go, no results....


Snot also had the benefit of forks re-worked, and good rear susp, which was more important to us, than the higher HP at the start of racing.

We will be returning the snot to 583, and the tango queen MAY get an FIM chip for next season, IF all our 'garage sale' booty goes. We expect to then get approx another 2hp.... but then again, if Andy can ride like he did on Sunday, we might just leave as is, except getting the forks done:)

C

Better brakes so you can brake later, should save 10th in every corner + better suspension.

Tim why not visit someone like K-Tech etc, they're not that local but what they don't know isn't worth knowing, I guess you could give them a call and explain your needs, riding style, weight etc etc they might just have some base settings, or might go further, springs/revalve etc

I'd be dubious that you could get more than 70bhp without ram-air effect. It seems to me that there's a definite ceiling around the 65-66bhp mark before costs become absurd (unless you have free labour).

Far more importantly, I think the useability of the engine diminishes as you eek the last couple of bhp out of it. Off-idle fuelling and an asthmatic bottom end seem to be the results of overtuning.

Already got those, the brake setup is better than my 996R :o:o:o

Where's babel-fish when you need it :puzzled::puzzled::puzzled::puzzled::puzzled::puzz led:

If your 620 was making big power numbers - circa 68-70 then I'd be interested to look at your torque and power curves. They might have big final numbers but I think they might be at the expense of what drives you out of the corner. I'd be more interested in making sure I had that covered and having the suspension well sorted and some decent brakes.

Tim why don't you just take some measurements on your bike, put some oil on your forks and shock to see how much of your travel you are actually using when you're braking as hard as you can and cornering as fast as you can etc ... then you'll know if they need adjusting. You actually don't want to be using your full suspension travel because you're not giving your suspension it's best opportunity to deal with surface imperfections when your forks or shock are nearly fully compressed.

Do you feel like the front pushes at all, or that it's really difficult to turn - especially when the power is on? Part of this will be geometry as well. It's all a complex equation that the more I learn the more I realise I don't know - that's why I paid Neil to sort it out for me. If you're happy to pay a few hundred quid on chasing 2 or 3 horsepower I reckon you'd be MUCH better off spending £500 on suspension.

i dont agree......well i do to a degree...get the suspension set up and the brakes then if you can afford to get 70+ rwp why not.............sure 66 is easily acheivable as has been shown by most of the 620ies on the grid, if you can get 70rwp and you can afford it why not give your self every advantage you can........
Of course the rider has to be able to exploit the gains for them to be worthwhile otherwise they become redundant..........

Phil

ps..if i had the money i would eek every bit of BHP i could..........

Even to the point where you have sacrificed your midrange completely just to see a big top end number? You'd have to ride it like a two stroke just to have any power but you'd have the disadvantage of still having the engine braking meaning that while you're likely to lock up the rear a lot downshifting for corners in order to keep the revs so high.

You'd better possess the finesse of a very experienced racer or have a decent slipper clutch to be able to ride a bike setup like that I think.

I could be completely wrong of course, it wouldn't be the first time.

I'd be more happy to sacrifice a few bhp in the top end to make a bike that drives off the corners better and is generally easier to ride.

agreed....would not sacrfice power curves to the extent of a 2 stroke ...my bike spend most of its time in the upper reaches of the revs anyway
My point is if you can acheive high rwhp while maintaining power delivery acceptable to the ride why not.........
I dont think with 70rwhp that rear lock up would be an issue.?..and besides i would fit a slipper clutch to combat that if indeed it was a problem............

If you can afford too have it all...why not give yourself every chance you can buy.?

[Edited on 14-9-2005 by fil2]

Phil, this is exactly what we sacrificed financially for a good set up at the beginning of the season, as TP agrees with, mate.

Suspension first, first & first!

im not disagreeing with that at all CK or TP.....what im saying is if you can have BOTH and afford it..why not.? why not afford yourself every advantage you can if you have the funds to do so...?............

I reckon to get that sort of power and a decent slipper clutch you've just invested around £2k-£3k or more in the bike - depending on where you go to and your own tuning expertise. If you haven't sorted out the suspension then you still need to do that as well, plus brakes - now you have a very, very expensive bike.

Not worth it for DD IMO.

Excessive revving of duacti engines can result in oily unpleasantness! :lol:

75bhp at 11,000 rpm is very nice, but you'd better have a blueprinted engine including balanced pistons. There's always a good chance of bent valves, blown head gaskets, etc, when running an engine at its very limits, and rebuilds rarely come in at less than four figures. Is this series really at a stage where this is normal for the series leaders? Madness.

Thats all relative .!!.....if u can why not is all im saying...and if you want to give yourself the advantage that it may bring you on the track why not.!..the amount of money racers spend on their bikes in another classes is beyond compare....

If i had the money i would buy a new monnie 620ie roll it into BAINES and say build the fastest best handling monster you can.. "ring me " when its done or you want me into sort suspension etc.....:D..........



:ninja:

[Edited on 14-9-2005 by fil2]

yup.................and why not if they can afford it or want to put that effort in.?

I see what you are saying ... if money is no object then go for it! Fill your boots.

I don't really care to be honest, I could have spent more on power but chose not to because I didn't think the cost per bhp were worth it for my situation. If someone is in a money no object situation then good for them - rock on.

this was only a hypothetical question really. but the fact is if you had unlimited cash and wanted to spend it on a DD bike you could have a 70+ bike that handles the nuts and weighs stuff all. you still have to ride it though and in reality no one would bother spending that much on a DD bike.

How would you pare the bike down to 150kg without braking the rules? All the usual suspects (wheels, engine parts, etc) must be original. A Ti screw kit might save 1kg, and a carbon tank another 2kg, but the dry weight of a monster is 177kg, so I doubt anyone would get it much below 165kg regardless of budget.

Our rough estimate with Snotty was 170:(

be interesting to weigh them exactly tho....

I wonder if Scotty has some scales - or maybe berto (which he uses for his big 'hump' :lol::lol:)

Sorry Scotty!!!!:rolleye::o:alien:

C:saint:

Too much for me :lol:

Reliability over tuneability ? Handling over BHP ? ;)

Base dyno's etc from 620 here http://www.moto-one.com.au/performance/620sport.html

If weight = speed then speed = DIET and this cost nothing but will power ;)

It was a hypothetical question and should perhaps have been entiltled "how quick can you make a 620" .

As the points regarding suspension are well made.

I was kinda looking for an approx list of parts / price to see what effectively could be achieved on a particular buget.

ie
PC111 - £300
Dyno time - £40/hour
Custom exhaust - £500
Blueprinting - £400
Lightened flywheel - £80
etc, etc


Tim

My 620 sport makes 60.2 bhp at the rear wheel, please let me know where i can find 10 bhp more . I think that the over all set up of the bike is more important than bhp. But i may be wrong ?

What sort of results are you getting on track though?!?!?!?




...oh yeah ;) :D

By my interpretation of the rules a lightened flywheel is illegal - what does everyone else think? It's not specifically mentioned as an item you're allowed to change and the catch all statement about mods not specifically mentioned are not allowed seems to cover it?

I could be wrong ...

"Lightened flywheel - £80"-you'll not be doing that of course young Tim since it's outside the rules..............??

John

Surely 'blueprinting' is outside the rules too?

IN FACT - There is no reason to have an engine taken apart/re-built by anyone as you can't do anything to them according to the rules.

So it kind of begs the question, what are these tuners doing?

The rules allow you to fit an exhaust, air filter, PC3 or Dynojet kit and set the cam timing... nothing else.

How engines range from 58-68 is a bit confusing considering the lack of mods allowed.

Must be some good engines and some not so good engines I suppose.

Thanks John - you've just saved me £80 ;)

What about if you remove the flywheel all togeather?

That saves you 2 pounds :lol:

Not all dynos are equal. Not all are calibrated. Not all are calibrated or maintained to the same std and some tuners add "the bling factor" to the readings to gain business. I have personal experience of this myself.

As 600 Pantah racing engines in the early 80's were delivering 80+bhp then I suppose it's not beyond the means of some to attain more than 70 now...whether those means are legal or not is open to question.
If people are getting 65-68 now then they are in minitwin territory (most sv's are in the 65-69bhp bracket) which, for an old air-cooled 2 valve motor is pretty good going!

[Edited on 14-9-2005 by twpd]

Looks to me that its time to strip some engines at cadwell.How much does a protest cost ? X 20 = ?

Who's gunna check them and know what they're looking at?

Could be the most fun all year :D

...who's not coming to Cadwell now? :lol:

[Edited on 15-9-2005 by domski]

quote of the year imho.