hi
i just want to keep the same torque curve but i want to scale it up a bit.
is changing the max_power value in the bike.ini enough or does that only change the bike info?
also i noticed the rgv750 has "230 hp" in the ini, yet gp bikes shows it as "230 kW" in the bike info window.
that's it? cool.
but does the value have to be in hp or kW?
Are you referring to the GP750?
What the .ini says doesn't actually affect how the bike rides, it's all in the .enge
yes i am.
it's hp in the ini but kW in GP Bikes.
ok, so how can i scale up the engine curve?
Quote from: vin97 on July 31, 2016, 08:38:47 PM
yes i am.
it's hp in the ini but kW in GP Bikes.
ok, so how can i scale up the engine curve?
Using engned
There is a scale tool in there (set to 1 by default)
Can i ask what you are doing with the bike.
doing some experiments with manu's moto2 chassis.
of course i would ask before "releasing"/showing anything.
Quote from: vin97 on July 31, 2016, 09:12:19 PM
doing some experiments with manu's moto2 chassis.
of course i would ask before "releasing"/showing anything.
Feel free to experiment :)
cool, thanks.
so, it's the "Scaled Throttle" parameter?
Quote from: vin97 on July 31, 2016, 09:33:53 PM
cool, thanks.
so, it's the "Scaled Throttle" parameter?
I believe so. Try it, nothing to lose. Just keep a backup of the original.
ok, will do.
one more thing: is it power at the crank, clutch, output shaft or rear wheel?
Quote from: vin97 on July 31, 2016, 09:36:13 PM
ok, will do.
one more thing: is it power at the crank, clutch, output shaft or rear wheel?
Pass :P
I believe crank. But without proper documentation, only Piboso will be able to tell us.
hmm, ok.
ah now that i think a bit more about it, is it maybe also possible to scale the curve along the rpm-axis?
i want to make the max power rpm fit approximately a hypothetical v5 750cc version of the aprilia rsa 125 engine, which would be around 12.2k.
edit: the "scaled throttle" only scales throttle input not engine power, so not what i'm looking for.
i noticed that the varese's max power rpm is already at 12.1k which would be close enough so maybe i'll that engine file.
ohh
Sorry, but i don't know of a way to do this
You might be able to do it in the .engn file using notepad and increasing the number values by a certain percentage. That should active the same outcome but it's a lot of work. Just make sure to only edit the vertical value and not the horizontal value as that would ruin the file.
I'll have a go tomorrow if you'd like. I'm interested to see if this can work.
Matty :D
Quote from: matty0l215 on July 31, 2016, 10:12:10 PMI'll have a go tomorrow if you'd like. I'm interested to see if this can work.
cool. it actually looks really promising. i'm using the motogp carbon brakes for the experiment.
it could be a realistic bike, too. if suter fits a 580cc v4 into a moto2 bike than a 750cc v5 should fit into the kalex chassis because there are no width limitations for the bottom cylinder row.
the 137kg of manu's kalex would also be a realistic weight for the bike. a slight change would be that a 2-stroke v5 is more compact (top cylinders could sit below the seat in between the frame), so you would have to move the CoG a bit up and back. ...haven't messed with that yet, though.
on manu's bike, the only part you see of the engine is the clutch, so in order to have the matching visuals you just have to remove the bottom of the seat and put 5 exhaust pipes on the bike (and possibly remove the clutch cover).
i was thinking of 300hp at the crank (rsa125 did 55) :D
Okay i'll have a look.
...in the meantime, i'm going to try using the varese engn file and scaling all the values up manually in notepad.
using the varese engn file worked nicely.
300bhp @ 12.4k rpm.
...and the bike still handles great.
had to make the crankshaft counter-rotating, though :D
Quote from: vin97 on July 31, 2016, 08:12:36 PM
i just want to keep the same torque curve but i want to scale it up a bit.
What do you mean exactly ? Raise the curve (i.e. move it vertically, up) ?
Edit the .engn and give it more torque at each point. For example, multiply the torque at each point by 1.1 to increase it of 10%.
You can use engned to visualize the curve (or Excel or whatever).
Quote from: vin97 on July 31, 2016, 09:36:13 PM
one more thing: is it power at the crank, clutch, output shaft or rear wheel?
Crank. There's a parameter in the bike.cfg file that gives the transmission losses (out of memory, it may be named efficiency, in the transmission section, and it's something like 0.92).
Quote from: vin97 on July 31, 2016, 08:12:36 PM
is changing the max_power value in the bike.ini enough or does that only change the bike info?
That changes only the bike info, no effect on physics.
Quote from: vin97 on July 31, 2016, 08:12:36 PM
also i noticed the rgv750 has "230 hp" in the ini, yet gp bikes shows it as "230 kW" in the bike info window.
Conversion needed :)
Try this. I've applied my throery and gradually increased the percentage of increase (over 14 points, from 0 to 100%) and the engine curve looks good but it is brutal.
https://mega.nz/#!jRYl0JhS!Mj2i7-ISqE5QxYLWPhdrlk_ptYTf_Ou31tJ8fILXew8
thanks but it already worked great with the varese engine. i simply edited the .engn file manually with notepad like you suggested and scaled every value by 1.6.
going to try your engine curve as well.
if you make the crankshaft counter-rotating, it's definitely controllable and probably right at the limit of reasonable (300hp@137kg). any more power and you would get wheelie right up to the braking point on every straight :D
Quote from: vin97 on August 01, 2016, 10:21:30 PM
probably right at the limit of reasonable (300hp@137kg). any more power and you would get wheelie right up to the braking point on every straight :D
300hp @ 137kg is well past the limit of reasonable, especially as I suspect that you folks want no electronic at all :)
Quote from: HornetMaX on August 01, 2016, 10:28:36 PM
Quote from: vin97 on August 01, 2016, 10:21:30 PM
probably right at the limit of reasonable (300hp@137kg). any more power and you would get wheelie right up to the braking point on every straight :D
300hp @ 137kg is well past the limit of reasonable, especially as I suspect that you folks want no electronic at all :)
This isn't the same project me and Matty are working on Max. We are working on a bike totally from scratch and not one based on another bike which I presume in this case is the Verase? ;)
Hawk.
nah, it's still ridable. see the video.
plus ~140kg is possible for a 2t v5 in a moto2 chassis. a two stroke v4 weighs ~15kg less than a moto2 engine. the suter mmx 580 weighs 127kg.
300hp at the crank is also possible for a modern 750cc v5. 125cc kart cylinders today are capable of 55hp. swissauto/suter already got 52.5 in 1995 with their v4.
Quote from: Hawk on August 01, 2016, 10:52:09 PM
This isn't the same project me and Matty are working on Max. We are working on a bike totally from scratch and not one based on another bike which I presume in this case is the Verase? ;)
That was understood :)
Quote from: vin97 on August 01, 2016, 10:55:02 PM
nah, it's still ridable. see the video.
Yeah, in GPB maybe ...
Quote from: vin97 on August 01, 2016, 10:55:02 PM
plus ~140kg is possible for a 2t v5 in a moto2 chassis. a two stroke v4 weighs ~15kg less than a moto2 engine. the suter mmx 580 weighs 127kg.
300hp at the crank is also possible for a modern 750cc v5. 125cc kart cylinders today are capable of 55hp. swissauto/suter already got 52.5 in 1995 with their v4.
The Ryger was possible too, right ? :)
no the ryger is not delivering what's promised because the conrod length is too long. still cool that they got hcci (no burning 2-stroke oil, and 99% combustion) working, though.
i'm talking about real engines here. like superkart engines of today or the 125cc and 250cc championship bikes (or modern replica versions of those).
(http://i.imgur.com/IY9EvGi.jpg)
http://www.swissauto.com/e/motor/projekt_techdata.jsp?ID_Display=20000D
..a 750 v5 would have 150cc cylinders.
Quote from: HornetMaX on August 01, 2016, 11:17:58 PMQuote from: vin97 on August 01, 2016, 10:55:02 PM
nah, it's still ridable. see the video.
Yeah, in GPB maybe ...
In real life it would obviously only work with electronics but given how advanced they are in MotoGP (or at least were last year on the Honda), there is no reason such a bike would be unridable.
..AW would practically make it a monocycle on the straights :D
Quote from: vin97 on August 01, 2016, 11:23:42 PM
no the ryger is not delivering what's promised
No, really ?! ;D
Didn't they show a dyno/engine test bench run what .. 3 years ago with incredible power, mileage and emissions ? :)
Quote from: vin97 on August 01, 2016, 11:23:42 PM
..a 750 v5 would have 150cc cylinders.
It's not because you can make one 150cc cylinder giving Xhp that you can make a v5 engine with 5 150cc cylinders outputting 5*X hp and fitting into a bike that is not a goldwing (no offence to ddcc, he loves these trucks).
those are real power values for real engines that have been raced successfully in championships.
"oldschool", dirty two-strokes, no direct injection or hcci experiments that don't quite work correctly.
if you check the math, you would get 330hp if you would just scale it up like 5*55*150/125.
plus, 2Ts seem to scale quite well, as suter proved by building a 500 V4 that produced 210hp in 1995. lightweight moving parts are definitely part of the reason.
a 580cc V4 fits into a moto2 chassis. since the bottom row does not have to sit between the frame, half a cylinder more of width on each side is no problem.
also, three tightly packaged square 150cc 2t cylinders are not much wider than, let's say the M1 engine (if at all), quite possibly even a Moto2 engine.
For a large 2s (you were talking about 750cc), what may be problematic is the size of the exhaust pipes needed after the collector (sort of resonant chambers needed to help the scavenging), not the size of the engine of course. 500cc ones were already fairly big (eating up all the space under the "tank").
it will probably be right at the limit of possible/reasonable again. but i'm sure one more pipe would fit under the suter mmx 580.
this right here is a harris 500 V4 chassis with a six cylinder RG750 engine + six pipes:
https://www.flickr.com/photos/teamheronsuzuki/sets/72157623652460096/
the bike has four expansion pipes under the bike, only three would be needed for a V5.
the difference between 150cc and 125cc 2T expansion chambers is close to insignificant. you could make it 0 by using slightly larger bore-stroke ratio.
330BHP does sound like an absolute untamed beast for any road racing bike never mind a 2 stroke. I doubt even with modern electronics and tyres it would allow for the full practical use of that power without major technical problems never mind a riders ability to be able to handle that power sensibly and safely? What's possible on paper doesn't always transfer onto the track. :)
Even Rossi had the BHP of his last Honda NSR 2 stroke 500 dumbed down from 210 down to 198BHP if I remember rightly.... It was just too much power for the bikes of the time. I've no doubt with modern tyres and electronics it would be feasible to handle the same BHP that the 4 stroke MotoGP bikes have nowadays, but to be honest I think they have found there sensible limits today for todays technology, otherwise I'm sure the factories could easily increase the BHP on todays MotoGP bikes, yet they have not done so.... So what does that tell you? :)
Hawk.
330hp would be the "theoretical"/impossible value.
300hp is only 25-30hp more than current MotoGP bikes. I don't think that difference will make the bike untamable.
True but back then they had to find a compromise between power and ridability, which is not necessary when you have AW and TC.
...I'm pretty sure the factories would increase the power if they could. Honda and Yamaha most probably do not like seeing the Duc pull away on every straight. ~68hp for one 250cc 4T cylinder is already pretty crazy. F1 only managed to get ~10hp more in the V10 days which of course is unattainable for an extremely compact 4 cylinder motorcycle.
Quote from: vin97 on August 02, 2016, 12:28:42 PM
330hp would be the "theoretical"/impossible value.
300hp is only 25-30hp more than current MotoGP bikes. I don't think that difference will make the bike untamable.
That just depends on how close they are to current technology limits. 25 - 30hp is a pretty big jump. You'd certainly notice the extra power in a big way put it that way. ;D
Quote from: vin97 on August 02, 2016, 12:28:42 PM
True but back then they had to find a compromise between power and ridability, which is not necessary when you have AW and TC.
Very true too.... and thank you for pointing out that modern MotoGP bikes are a lot easier to ride now than the old school 500GP bikes.... Totally agree with you on that. ;)
Quote from: vin97 on August 02, 2016, 12:28:42 PM
...I'm pretty sure the factories would increase the power if they could. Honda and Yamaha most probably do not like seeing the Duc pull away on every straight. ~68hp for one 250cc 4T cylinder is already pretty crazy. F1 only managed to get ~10hp more in the V10 days which of course is unattainable for an extremely compact 4 cylinder motorcycle.
Yes.... the other factories were caught with their pants down on that one for sure. Lol
Will be interesting to see Honda, Yamaha, and Suzuki's response for next year. ;D
But overall I'll be interested to see what you can come-up with this bike your creating. ;) 8)
Hawk.
Quote from: vin97 on August 02, 2016, 12:28:42 PM
...I'm pretty sure the factories would increase the power if they could. Honda and Yamaha most probably do not like seeing the Duc pull away on every straight.
As far as they (duc) finish behind in all the races (which is the case at the moment), I don't think Honda and Yam will bother too much: champagne and pretty girl are for the one that finishes 1st, not the one that is fastest on the straight :)
true but that's just because the bike turns like shit (lacks apex speed) due to the inferior chassis (that does not give enough flex and feedback) not because the Duc has "too much power".
if that were the case they would have trouble getting the power down out of corners (inferior acceleration) which is definitely not the case, compared to the other bikes.
plus, don't forget that the electronics also manage to tame the bikes enough to make them ridable in the wet!
Never said they have too much power. Just that raw power is not everything that matters, there's plenty more that matters, including, as pointed out by Hawk, rideability.
of course.
it would take a lot of testing and tweaking of the chassis to get the bike to compete with MotoGP bikes in terms of handling, specifically the swingarm.
those are just details, though, the potential is there. less (rotating and overall) mass and better weight distribution than a 4T inline-4 should mean better handling in theory. given enough time and money, it should be possible to modify the chassis so that it can utilize that potential.
edit: in real life, a gp800 chassis might be the best choice.
Amazing what you find looking st used bike ads. 8)
(http://i.ebayimg.com/images/g/RGYAAOSwZ1BXfNES/s-l1600.jpg)
http://www.ebay.co.uk/itm/Yamaha-TZ1500-V8-TZ750-Dragster-racing-motorcycle-SUPER-sprint-Bike-race-Vintage-/112081316143?hash=item1a1891292f:g:RGYAAOSwZ1BXfNES (http://www.ebay.co.uk/itm/Yamaha-TZ1500-V8-TZ750-Dragster-racing-motorcycle-SUPER-sprint-Bike-race-Vintage-/112081316143?hash=item1a1891292f:g:RGYAAOSwZ1BXfNES)
TZ1500 V8 - for a tuned 2T drag build it surprisingly only generates 280BHP and needs nitrous to get 520BHP
As Max noted - the exhaust requirement even for 4 cylinders is huge
£28,500 and only just down the road - do you think they are up for test rides? ;)
I suspect that scaling a 2T piston ported cylinder may be a case of diminishing returns due to port heights/stroke and available cylinder wall area - has anybody plotted cylinder capacity vs HP ?You may end up going down the Honda route of numerous tiny cylinders to build a large capacity 300bhp engine
lol nice find!
Quote from: h106frp on August 04, 2016, 09:19:29 AMTZ1500 V8 - for a tuned 2T drag build it surprisingly only generates 280BHP and needs nitrous to get 520BHP
As Max noted - the exhaust requirement even for 4 cylinders is huge
£28,500 and only just down the road - do you think they are up for test rides? ;)
I suspect that scaling a 2T piston ported cylinder may be a case of diminishing returns due to port heights/stroke and available cylinder wall area - has anybody plotted cylinder capacity vs HP ?You may end up going down the Honda route of numerous tiny cylinders to build a large capacity 300bhp engine
Yes, I have done plenty of research on this kind of stuff (got most of this information from the Aprilia RSA 125 builder himself) and scaling a two-stroke cylinder from 125 to 150cc still works quite well (again, I already took into account the losses, 55*150/125 would be 66hp per cylinder).
I'm not ignoring that two-stroke exhausts require much more space (note: not much more weight) but five would definitely fit if that one guy fit six on a GP500 V4 chassis (and Suter had no problems fitting the regular four on a Moto2 chassis).
The engine in that drag bike consists of two
40 years old Yamaha TZ750 engines welded together. It makes no sense to compare this to modern two-strokes. Even if you were to put 55hp kart cylinders on the engine, you would not get more power out of it because the crankcase is simply not capable of getting enough air to the combustion chamber. It's the same problem RGV500 replica builders have with the RG500 engine (even worse is the Yamaha RD500 crankcase with it's tiny transfer and intake ports).
Quote from: vin97 on August 04, 2016, 04:32:55 PM
I'm not ignoring that two-stroke exhausts require much more space (note: not much more weight) but five would definitely fit if that one guy fit six on a GP500 V4 chassis (and Suter had no problems fitting the regular four on a Moto2 chassis).
The problem is not really the number of cylinders but the total displacement: your 750cc is 50% more of a 500cc.
yeah, which means one more pipe, so three under the bottom of the bike instead of the traditional two. it's possible to fit four under a regular 500 V4 chassis with some clever intertwining as the "RG750 Delta" proves. as i wrote earlier, the size difference between 125cc and 150cc exhaust pipes is negligible (a comparison between the Suter MMX in the 500cc and 580cc version would show this nicely) and if this was actually the deciding factor, you could increase the bore slightly and end up with no increase in exhaust pipe size at all.
Well yes, if you say you can fit one more pipe piece of cake and 125->150 makes no difference then ok, everything is possible. Why not make it a 900cc v6 then ? Just increase the bore, fit an extra pipe, job done :)
come on max, you obviously can fit one more pipe, otherwise that guy would not have been able to fit SIX into a V4 chassis.
and if you tune the engine/exhaust to a different rpm you can keep the exact same 125cc exhaust pipes.
You can fit 4 more if you can make them smaller.
then you would need extreme overbore ratio which would kill the efficiency (power per capacity) of a 2T.
So what ? Take the usual approach and increase capacity. Everything seems so possible when one discusses 2 strokes :)
Nope, scaling up two strokes becomes very inefficient for larger engines (>200-250cc per cylinder) and the pipes required become quite large. big 2T MX bikes demonstrate this nicely.
300hp is also approximately the predicated horsepower if you calculate it based off of the "energy per combustion" value of MotoGP engines (2*4T-hp*2T-rpm/4T-rpm).
It sounds all so nice and easy and obvious I wonder why we don't have some nutter making this ...
$$$$$
and because there would be no racing series / application for the bike.
also, it would probably be useless without MotoGP-grade electronic aids (and a factory team doing R&D on the chassis).