So your saying 56mm TB might help my NA 1200?
My sled sometimes has a really bad bog off the line but this sled has been a real disappointment to me. My buddies stock 2010 800R will beat it on the top end across the lake. If I don't bog off the line I can beat him to say 600'-800' but then he catches me and pulls away...were both running the same gears...my sled is a 162 cut down to a 141.
He shouldn't be close, the bottom end bog is one issue and the top end is another, prob engine movement and clutching. Have you tried dumping fuel in on the bottom, what are you using for fuel control, what other mods do you have on the sled, ie who's BB, pipe, clutching etc...
I run higher fuel pressure than most and with the bdx intake it seems to be the ticket. With more air flow (in my mind) higher fuel pressure increases the atomization of the fuel and puts a little more in the cylinder to increase a rate of compression then lean it back out to get the snap feeling. With the right tuning I do think they would help on a 1200, but may help a lot more with the right porting.
On a 2 stroke, everything has to have a tuned flow, to much air will create a void, to small and it will restrict. Once you have achieved air speed it will help on every stroke to clear the cylinder. Look at it this way if the air is already moving from velocity when the ports open it will carry itself into the chamber helping the vacuum that is being created, if there is no air speed then the cylinder has to pull everything on the downstroke making it less efficient. You can make any of it work but mapping and clutching is key. The stock mapping is setup to run a restricted exhaust and intake. When you add more air you are still running the stock fuel map and timing. the little control boxes we use are no where near what we really need to make more power with these kind of mods, more like band-aids.
The new branix ecu boxes that are just starting to come out look promising (look at the m1100t thread about ecu's) this way you can remap the fuel and the timing, you should also be able to change the range and effect the stock sensors have ie the exhaust temp sensor that to me seems to effect timing and fuel, I'm not sure but because its a programmable ecu I would also hope we could change PV functions and other things. I would even contend we could change timing per cylinder so if the throw is off 2* on one cylinder you could match up the timing. I don't know how detailed it gets but its headed in the right direction.
As for the turbo's, when you have force induction and the ports open it will clear the cylinder and create a better burn, so with the 56mm when everything is open it will feed more air to clear. My question is those that see the gain from the 56mm what kit are you running. I would contend that most are running a 3071 turbo, thats how most of them came a few years ago. But many have found bigger turbos flow more air more efficient making way more power on lower boost. Same goes for changing the port timing, charge tube, no intercooler vs air to air vs water to air. To me these upgrades or changes are a far better bang for your buck and after they are done then yes you may see a difference with the 56mm as you should but I would be surprised if it made more difference than the bigger turbo. This is all assuming its tuned right
and is pure speculation on my part, just going off the best of my knowledge, but I could be wrong I don't have the kind of money to test for fun, I would sure like to though.
The worst part is you could tell me it does and without being the one that tuned it before and after I wont believe you because its near impossible for so many people to actually tune a mod sled, most just get lucky. Not saying you cant, just saying what I have learned and from failures and success and even watching people that should know fail its a skill that is particular to every sled is different from another.
