January 25, 2014 at 1:01 pm #20270
Wow this could be a real game changer!January 25, 2014 at 7:42 pm #20294
So, will there be a class emerge which allows FI? I’m not up on the latest rules in the EU, but AFAIK, the classes are divided in part by carburetion. Here in the US, I’m not aware of any sanctioning organization which allows FI.January 26, 2014 at 7:54 pm #20374
So, is this new engine a 6 speed shifter in 125cc size?January 28, 2014 at 6:12 am #20451
So, is this new engine a 6 speed shifter in 125cc size?
Bill by definition a “KZ” motor is a max 125cc, max 6 speed…
BTW, 56hp sounds like a pretty good stretch, maybe on the dyno for a few seconds before it goes BOOM!!!
CRJanuary 28, 2014 at 1:54 pm #20520
I can understand how emissions and efficiency can be improved massively with this technology but I’m struggling to understand how output can be improved to such a degree over a properly jetted carb. Maybe 5/10% but 20% ?????
Maybe where the maps can be programmed a lot more effectively with fly by wire EFi you can just peak every last bit of performance out of the top end to give good readings on a dyno.
Anyway, it would be lovely to see two stroke GP bikes hitting the track again one day 🙂
"When In Doubt, Flat Out" - Colin McRaeJanuary 29, 2014 at 6:16 am #20568
The key here is that is makes 55hp with a 38mm carb. The best KZ’s with normal 30mm carbs make close to 50hp so 10% gain by going to 38mm and EFI is not that much of a big step upJanuary 29, 2014 at 7:54 am #20577
Uhhh….what does one of these cost?January 29, 2014 at 8:04 am #20580
Looks like a very sweet package.
If the demand were there maybe a direct injected two stroke in the future. The direct injected two stroke outboards and snowmobile engines form Rotax are simply amazing.January 29, 2014 at 9:10 am #20584
The key here is that is makes 55hp with a 38mm carb. The best KZ’s with normal 30mm carbs make close to 50hp so 10% gain by going to 38mm and EFI is not that much of a big step up
Even “IF” a legal KZ made 50hp, which is a stretch, 10% above that would be huge… And even if they added nitro and had secret dyno room, 100ft below sea level to make 55hp, it would be a light switch power band….January 30, 2014 at 12:12 pm #20675
55HP? Not buying it.
No way it’s making a legitimate 55HP in any way that’s useful or reliable on the track. TBH I think the 50HP number thrown around for KZ motors is a trophy pull anyway. With a 30mm carb, compression and exhaust timing limits I’m doubtful.
<span style=”line-height: 1.5em;”>One thing to add…if you think EFI on a racing two stroke means the end of motor </span>carburetor<span style=”line-height: 1.5em;”> tuning you are going to be very disappointed. It depends on the exact EFI you are looking at, and how its implemented, but on any kind of racing application it’s not going to be balls to the wall AND autotuning at the same time.</span>February 10, 2014 at 7:57 pm #21584
Fellas, it is totally possible. EFI is being developed by many at the moment. BRC has our own. We use a 43mm slide throttle body that we designed. EFI only gets difficult on the 2-stroke when you try to tune the EFI like a 4T…
The HP Modena is quoting is achievable.
If you want to see an early BRC EFI test, go here:February 17, 2014 at 9:09 am #22139
Are you sure that Dyno’s properly calibrated 73 HP at approx. 14K RPM is over a 50% increase in HP over a “tuned” KZ. DOH!!!!
Have you track tested it yet. Looks like it would be fun as hell. BTW is that on petrol or alcohol?
Mike G.February 17, 2014 at 6:03 pm #22154February 18, 2014 at 3:55 am #22162
Mike, you were watching the speed in mph not hp. I didn’t do a hp pull, was just showing it running and the rpm range. That package was running gas and a KF style of exhaust. Makes ~45 hp in that config.<br>
Exactly, 45hp, not 55hp.
45hp for a 125, is pretty much maxed out. If and when you could get 1hp more over that, would be a quantum leap. To get 10hp more than that, would be monumental if at all possible. Couple that with drivability, and it may not even be justified if it were possible…
But it makes for a good story…
CRFebruary 18, 2014 at 8:34 am #22196
And many more google search resuls on ‘max hp 125cc motorcycle GP’
This was 2007, 55hp with 125cc w/carburetor. We are 7 more years of development ahead and with EFI this looks totally possible.
Also there was a topic 1-2 years back about TecSav putting out 50hp with their KZ engines under KZ rules (30mm carb).
This forum seems to be a place where whatever you say people will argue with you just for arguing sake. The 55hp was not ‘made up’ by a EKN user, it was from a press article in a karting magazine.
Now let the flaming and arguing begin (again) 😛February 18, 2014 at 9:05 am #22199
I don’t think anybody said it was a made up number…. And if they already had a 55hp KZ, why would EFI be such a big deal? The point is, for a person that builds motors and understands what it would take to get 55hp, and what you would end up with, it’s not realistic…
Google is a great tool, but you have to be able to decipher what’s real, and what’s notFebruary 18, 2014 at 10:27 am #22203
Since that video I posted showing our EFI running, we have seen as much as 53HP. Modena’s claim of 55HP is entirely plausable. The interesting observation we are seeing is that even while making this much HP, the internals of the engine are actually showing less stress and evidence of superior lubrication.
I can post a dyno curve if required, but from what we are seeing, EFI is great and looks to be possible in the very near future.February 18, 2014 at 12:02 pm #22220
Chris, Since that video I posted showing our EFI running, we have seen as much as 53HP. Modena’s claim of 55HP is entirely plausable. The interesting observation we are seeing is that even while making this much HP, the internals of the engine are actually showing less stress and evidence of superior lubrication. I can post a dyno curve if required, but from what we are seeing, EFI is great and looks to be possible in the very near future.
I’ll have to agree to disagree with you about the numbers, but I do agree EFI is the way to go, my newest superkart is going to be an EFI….February 18, 2014 at 5:06 pm #22243
Look up numbers for 125 Gp bikes. They made 55 HP with carbs. Why would 55 HP on an injected ICC be not in your realm of belief?February 18, 2014 at 7:01 pm #22249
#1 Howie, if 55hp 125 was the norm in GP racing, then an EFI KZ making that would be no big whoop…. What I have taken out of the original story is that the 55hp mark in a KZ is and would be huge.
#2 Running a narrow powerband 125 two wheeler around a track, although not easy, the poweband is less of an issue because with that type of bike you carry speed through the corners.
In a kart on a tight sprint track, it would be difficult to keep it in the powerband…
CRFebruary 19, 2014 at 7:36 am #22259
#1 now contradicting yourself? earlier you said it was not possible and now it is and now your argument (for arguing’s sake) becomes ‘so why is it special’? Dude…
<span style=”line-height: 1.5em;”>#2 I think that’s the key. Using a karting engine with stock exhaust which is designed for a broad and driveable powerband. Having that engine make 55hp (vs. close to 50 with carb) is an achievement. </span>February 19, 2014 at 7:52 am #22260
CR: #1 now contradicting yourself? earlier you said it was not possible and now it is and now your argument (for arguing’s sake) becomes ‘so why is it special’? Dude… <span style=”line-height: 1.5em;”>#2 I think that’s the key. Using a karting engine with stock exhaust which is designed for a broad and driveable powerband. Having that engine make 55hp (vs. close to 50 with carb) is an achievement. </span>
” if 55hp 125 was the norm”
Put on your glasses and read it again… 🙂February 19, 2014 at 8:23 am #22263
I read that. My point is valid with the ‘if’. No glasses needed.February 19, 2014 at 10:27 am #22269February 19, 2014 at 1:05 pm #22282
Theres a big difference between what was allowed for a GP125 and what is currently allowed for KZ. I think its misleading to follow the peak HP numbers too much. Thats without even talking about the difference between a kart and motorcycle application
KZ restrictions….. (numbers may not be 100% accurate)
Exhaust port timing 190Deg max
Venturi size 30mm max
Inlet type reed only
Head volume cannot be under 11.5cc
Analogic ignition only (so no CDI and no programmable curves),
A driveable 50HP under these conditions seems optimistic to me, regardless of who claims it. The 53HP quote from Jan Thiel I’ve been trying to find the source for because its without context about what configuration was and under what circumstances. I would hazard a guess that this motor may not fair to great on a kart, but I could be wrong.
If Riley thinks 55HP is possible then I have some faith, but I can’t see it being done with existing KZ specs. 125open now that’s another matter.
How did the RS’ fair back in promoto days?
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