Why not 200hp ??

Folks,

I've read somewhere that the SBK 2002 version had more that 200hp. Does any one of you experts knows what kind of tunning has been done to achieve so much power in this V60 rotax engine?

200 hp is actually easier to do than it sounds. the problem is the reliability...

im sure i found somewhere that made supercharger kits for the rotax lump.. think someone in america did it

but as stress pointed out when you tune an engine so much reliability becames a major factor, and then there is stupid insurance costs to go with your increased maintenance cost lol not to mention the initial cost of getting the work done & the parts...

200bhp will be a crank figure, deffo not rear wheel.

The 06 onwards Mille with a 1060cc kit and gas flowed heads etc will put out about 150 at the rear, that would be more than enough for most TBH:biggrin

I didnt think gas flowed heads made such a difference on more modern bikes? as its just perfecting poor manufacturing tolerances which are better today. Or not?

Can you detail what should have to be done to easy achieve such power?

i said it's easier than it sounds, not that it's easy as in "ok, i can do it in a day" kind of way. i'm preety sure 200 bhp at the wheel can be achieved with a supercharger/turbo combo.

Yeh for sure, me and a mate were gonna try it on my RF900 streetfighter thing. Apparently the supercharger off a merc slk is a good fit, but nothing ever come of it

NOS it, HMmmmm

Found this mate,
http://www.apriliaforum.com/forums/showthread.php?t=174981
Originally Posted by BRG
Too much of a good thing?

Slightly off thread...

Just browsing around, I came across the Amann 73mm crankshaft.
As a ready reckoner, this would give:
1079cc with 97mm OEM pistons
1147cc with 100mm pistons
1193cc with 102mm pistons
It would also increase the max piston speed by just over 8% (35.3 to 38.2 m/s @10k)

A couple of German sources are reporting/positing crank-HP around the 175 mark.

Whilst at first very keen, I feel the third option would be too much for the internals of the Rotax motor, so will probably 'stick' with my 1103!

Opinions?

Ducati 1198 bore/stroke=106mm x 67,9mm
RSV 1000 bore/stroke= 97mm x 67,5 mm

i made the math few days ago about linear speed.

Vm[m/s]= ( 2 x C x N ) / 60
where:
C=stroke in meters
N= Engine RPM
60= Conversion factor.

So:

RSV at 9750rpm 21,93m/s
RSV at 11000rpm 24,75m/s
R6 at 14500rpm 20,5m/s
1198 at 11000rpm 24,89m/s
gsx-r 1000 at 13500rpm 19.1m/s

with 72,9mm stroke you'd have

RSV at 9750rpm 23,7m/s
RSV at 11000rpm 26,73m/s that means most probably EXPLOSION!!!!

running an engive over 24m/s is very dangerous for pistons and conrod , and an engine with over 24m/s linear speed won't last much.

This is what my bike may like as a xmas present, you know, just for the sake of it!!!! it would make the acceleration a little faster without changing the sprockets lol. And, its chaep and cheerful. Remember, a second 2002 engine is only about £300 quid so if it blows its easily replaced.

http://www.bigccracing.com/shop/product.asp?idproduct=239

I used to see a guy called roy up bury hill with a massive noz bottle like that, and a 99 R1. Had an arming switch like an F18 on the left fairing infill and the trigger button was hooked up to the horn so he could still be gripping the bar. Apparently it gave 50hp hits. He could only use it in 6th with the throttle full open, because any lower gear and it couldnt be sure it wouldnt flip ( the front would crest in 6th at 160), and if he didnt hold the throttle wide open it would blow the carbs off the engine

Funnliy enough not seen him in a long time :dunno

I once went on the back of a Gxer 100 slabside with NOS, went flat out on the dualer then pressed the button, it didnt accelerate like fast and furious but my god it did move, i have to say i ***** me pants LOL LOL

meant to say gixer 1100 slabside

I can imagine. I borrowed an old 1100 slabby once, that was tuned for drag racing from my boss. It went like the startship enterprise. Think it adds to it when you know that it doesnt really stop or turn very well either lol

LOL thats the one LOL scud missiles

Nice maths AND statement about piston speed, there, mate!

I like thinks like that....

As has already been stated, 200bhp isn't SO hard, but to make it for anything longer than 10 seconds is!! Lol. Piston speed IS a biggy, especially as peak BHP = revs. And then there's all teh acceleration / deceleration, heat, therefore coatings, squish size / space / area, air in / exhaust out / pulses, nevermind the honing / balancing / teeny tiny tolerances / balancing needed. And thats before any head work for size of valves / weight etc etc etc. Mind, if it was easy, everyone would be doing it!

"Cheap" bhp = F/I. But, as tis a Twin, its not gonna give big numbers peak, but it IS going to give good useable power where it's most needed.

Don't forget also that the SP motor in WSB is not the same internally as a stock rotax. Not even close. It was Cosworth built to a completely different spec. Even the homologation road based SP did not have race kit internals.

The Factory SP had a different bore, stroke, heads, crank etc etc. The stock Rotax bottom end would expire rather quickly with 200bhp. The Factory SP had Lots of Titanium internals, (Rods, valves etc) to allow higher revs (also hence the shorter stroke). Revs = power and you are unlikey to achieve race revs from a road motor without serious, serious work. A singe Ti NCR Ducati rod is about £1200 for instance.

The stock bottom end can expire with lots of track abuse on 130 bhp let alone 200.

Best things without Turbo or Sc..

2006-> Heads(The one with biggest valves).
Old Ecu(Or Motec Ecu) Advance ignition around +~10 degress.
Pc3/5 with map for front and rear cylinder.
Evo6 Exhaust or newest Smaltmoto 60mm.
57TB borred to 60TB
1127cc with steal barrel (http://www.spoonvalleyracing.se/page17.html)
Sloted cams(106/109)
Lighted flywheel

This will give around 155-165 Bhp

T Davidsso said:

Best things without Turbo or Sc..

2006-> Heads(The one with biggest valves).
Old Ecu(Or Motec Ecu) Advance ignition around +~10 degress.
Pc3/5 with map for front and rear cylinder.
Evo6 Exhaust or newest Smaltmoto 60mm.
57TB borred to 60TB
1127cc with steal barrel (http://www.spoonvalleyracing.se/page17.html)
Sloted cams(106/109)
Lighted flywheel

This will give around 155-165 Bhp

Click to expand...

Is that at the wheel? and how much £ for your extra hp?

Rob