Midrace - Racing Setup (Beta Ark LC)

Leo015

Well-Known Member
Hello guys, i have a Beta Ark Lc and my current setup is Stage6 Sport Pro MK2, Yasuni C16, Malossi Crank, Dellorto 21, Malossi Variator, Delta Clutch, Malossi Belt and Malossi Rollers of 4g. It's quite a good setup, although i have some problems setting up the C16, but i want more power. Does the Malossi MHR cylinder make a lot lf difference with my current setup? Also which exhaust should i use with the Mhr cylinder, the C16 or MHR Team? And is the Dellorto 21 good enough for it?
Thanks!
 
Advertisement - register to remove this

Bas

Administrator
Staff member
You can also switch to the Stage6 Racing MKII but the MHR Team is also a guarantee to increase power. I would suggest to use the Yasuni C20 or the MHR Team exhaust to cope with the higher rpm. The 21mm is sufficient.
 

Leo015

Well-Known Member
I am looking for a nice street-daily setup. The Sport Pro is a bit tame for the C16, i can tell because it bogs down if i don't open the throttle at 1/2 or 3/4 . If i use the MHR exhaust wouldn't the setup be more peaky, like on/off? I was thinking that the C16 would compliment the MHR cylinder nicely as it would be in power band most of the time.
 

TuningMatters

Well-Known Member
To be honest I would go with the Stage6 Racing MK2 and the Stage6R1200 exhaust. The R1200 exhaust is a great torque heavy exhaust and the Stage6 Racing cylinder is a sgood as it can get for that price. With Malossi you are always paying a bit for the name (and the made in Italy), but to be honest the Malossi molds are quite old and you see it. The Stage6 ones are brand new and the timing is great with lots of space for improvement.
Have you flowed your engine yet? If not I would really suggest to do so, as this means free power (probably 1-2 hp more over the whole powerband!)

Here's a little Dyno of the Racing Mk2
http://www.tuningmatters.com/news/news-stage6-sport-pro-mkii-and-stage6-racing-mkii/

Peace,
Daniel
 

Leo015

Well-Known Member
The reason im going to use the mhr is that i already have t lying at home :) a friend gave it to me, he also gave me the mhr exhaust!
 

TuningMatters

Well-Known Member
Haha, ok got you! Which MHR is it? The regular one? If so, I would try the C16 first. The MHR Standard is not soo powerful, so you might be ok with the C16.
 

Leo015

Well-Known Member
Yes it is the regular MHR, no modular head. What will be the differences of the setup between C16 and MHR Team? By 'not soo powerful' what do you mean? Which is compared to it and will it make quite a difference from my current Sport Pro?
Thanks
 

TuningMatters

Well-Known Member
To be honest i think the difference between the Sport Pro MK2 and the MHR will be marginal... The advantage of the MHR is the V Exhaust port which allows for porting. But the stock timings of the MHR aren't so aggressive. Let me try to track them down... I know I have them somewhere...
 

Leo015

Well-Known Member
Are they over advertised? Because scooter-attack says "the little brother of MHR TEAM 2. 20 hp can be achieved with relevant parts." Alright mate thanks!
 

TuningMatters

Well-Known Member
Here's the AC Portmap attached. 20hp is very optimistic. It is of course possible, but needs thorough flowing of the engine housing. I'd say realistic is about 16-18hp (and this also requires engine flowing). I estimate a current 10-12hp for your setup right now (assuming no engine flowing) and plug and play with the MHR you will probably loose torque and have about 2.5-3.5hp more at around 1000rpm higher than what you have currently. As a daily rider, you want a lot of torque, correct? I'd go with the C20 or the R1200 exhaust as they are known for their good amounts of torque. However, a Stage6 Racing Mk2 would have worked a bit better here as it has a wider power band. The MHR cylinder kits are quite peaky!
 

Attachments

  • Malossi-MHR-47.6mm-Minareli-AC.jpg
    Malossi-MHR-47.6mm-Minareli-AC.jpg
    76.5 KB · Views: 13

Leo015

Well-Known Member
This sounds quite dissapointing. Expected more from such a cylinder. What if i used the MHR TEAM Exhaust which supposedly has a lot of torque and does not rev that much?
 

TuningMatters

Well-Known Member
Who said the team doesn't rev much? Actually the Team's rev even higher! If you want to go lower on rev and higher on torque the BigBore are more suited...
 

Leo015

Well-Known Member
Well i dont want to spend any more money on parts. I'll just use what i have. So what would be the best combo for the road and increase in power and speed?
 

TuningMatters

Well-Known Member
What parts do you have right now? As far as I understand you have the Sport Pro and the MHR and a C16 exhaust? If you don't want to buy more parts I guess you only have two options: Go with the MHR Cylinder, or not?
 

TuningMatters

Well-Known Member
Oh, ok. Then I would go with the MHR and try both exhausts. If the Team is to revvy, try the C16. It should give you more torque, but it might not rev enough... Should be possible to find the right setup in an afternoon...
Also, if you are save with the dremel you can try porting the MHR cylinder. By widening the exhaust port (without increasing the height) you gain torque! You can also try to lower the exhaust port by removing the food gasket (and use liquid gasket), which will also increase the torque, but this is more difficult as you might end up having to mill the engine foot to lower it further...

Cheers,
D
 

Leo015

Well-Known Member
I have in my mind using really light rollers like 3-3.5g and stiffer clutch springs. I dont know about porting, i certainly wont do it myself, the mechanic will do it for me if i decide but i will need port maps, as he wont know how to do it freelance. By the way, wha's the powerband of the MHR cylinder? I really thought the C16 would be quite good at it, just make power at lower revs.
 
Last edited:

TuningMatters

Well-Known Member
The Malossi cylinders are usually very peaky with a narrow band. The 86cc bigbore is a surprise there as it has a quite wide band. Given the fact that a CVT engine always operates at a very narrow band, this is not a problem. It just makes it more difficult to find the right setup. And of course high rev also means low durability for the piston and rings.
It doesn't really work the way, that an exhaust, or other component creates power at some random rpm. What happens is that the power band is shifted, slightly that is and in the worst case, the exhaust works against the cylinder kit and does not allow it to rev highly enough to reach the cylinders power band. With the C16 you might be ok as it certainly shifts the powerband a bit lower. In order to figure out which exhaust works best however, you don't need to change the rollers etc. Just go with some relatively heavy rollers (about 5 grams) and try each exhaust. The acceleration from stand won't be good, but once the cylinder reaches it's target rpm, you will notice the right acceleration.
Then try the same with the other exhaust and see what works out better.
After that you slowly go down with the rollers weight until it accelerates out of the corners and you're done (keep in mind the main jet and check the spark plug whilst testing!)
About the springs: they only affect the acceleration from standing. Just set them somewhere with what you're comfortable with. For city riding it is indeed better to have some looser springs installed as the super hard ones get quite annoying when there's lots of traffic (stop and go)!
 

Leo015

Well-Known Member
The Sport Pro has a wider power band compared to the MHR? By the way why should i start with 5g rollers? Anw i prefer having a wider power band with torque and sacrificing some hp.
 

Bas

Administrator
Staff member
The Sport Pro has a wider power band compared to the MHR? By the way why should i start with 5g rollers? Anw i prefer having a wider power band with torque and sacrificing some hp.

As Tuningmatters explained, the only advantage of a wider powerband is it's easier to find the right setup. The operation of a CVT engine is based to keep your engine at the rpm where it delivers the most power. So if you have a really wide powerband, it doesn't effect riding the bike, only for setting it up. It's not like with a normal gearbox transmission where you want a wider powerband.

The question to start with 5gram rollers has been explained, to explore which exhaust preforms best. To test and try to find out which pipe accelerates best.
 
Advertisement - register to remove this

Similar threads

Top