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  #81  
Old 26-11-2018
bowser bowser is offline
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besides altering the comp a good head also changes the timing (burn rate of flame, probably has some technical name to describe it) and the TPI ignition can't be changed - I lie, the map switch will retard it slightly which is what i had to do to help the rk heads run.

The TPI bikes just aren't ready for mods, you can't compensate them for extra fuel, extra oil, timing.
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  #82  
Old 27-11-2018
Nutty Nutty is offline
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Quote:
Originally Posted by ggg View Post
you would think dave could mod the head with a better squish band and shape keep the cc and comp ratios very similar and it should not run leaner than stock
Nope, increasing squish efficiency generally utilises more of the fuel charge and causes richer running...but...with squishless heads the entire fuel load burns creating cleaner running but less low rpm torque. The controller isn't capable of coping with anything other than the stock spec. Most good gains with the TPI motor come from getting closer to the stock blueprint.

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Originally Posted by bowser View Post
besides altering the comp a good head also changes the timing (burn rate of flame, probably has some technical name to describe it)...
Two separate things. Timing is when the plug fires, FFP is how long the fuel burn takes to get to the edge of the cylinder. Faster FFP allows for less timing. You can't bump up compression too much with squishless heads because you slow down the fuel burn on a head that already takes ages for the flame front to propagate to the cylinder edge.

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The TPI bikes just aren't ready for mods, you can't compensate for the mods with extra fuel, extra oil, timing.
The bike is fine, it's just the module holding things up.

'13 head, VF4 reed set and a Kokusan 2 channel module would be my starting point for tuning a '19. 3-4 hours in the workshop and it'd be done. The Kokusan module that Ossa used on their double-injected 2T 300Enduro is the essentially the same part that Kawasaki use on the dual-injector KX250F. Tuners will get hold of the TPI pretty soon. Hell, if I had one I'd be all over it like an octopus rooting a rabbit.

I much prefer tuning Yamahas, now...where's my phone.
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  #83  
Old 03-12-2018
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gedsar gedsar is offline
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So on Nuttys advice i chopped 100mm off the end of the silencer, rode all the same tracks as two weeks before and found a noticeable increase in torque. Wouldnt pull 2nd up some hills before mod and did it easily after it.
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  #84  
Old 19-12-2018
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>moto< >moto< is offline
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Originally Posted by gedsar View Post
So on Nuttys advice i chopped 100mm off the end of the silencer, rode all the same tracks as two weeks before and found a noticeable increase in torque. Wouldnt pull 2nd up some hills before mod and did it easily after it.
I thought a shorter muffler just increased throttle response on a 2 banger...where’s my grinder
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  #85  
Old 19-12-2018
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Gypsy501 Gypsy501 is online now
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[QUOTE=>moto
Like, lol


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  #86  
Old 19-12-2018
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ggg ggg is offline
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Originally Posted by >moto< View Post
I thought a shorter muffler just increased throttle response on a 2 banger...where’s my grinder
it does... i did that mod 100mm off the stcok muffler on my 300 and i lost heaps of top end, but i have a Arko muffler on mine.
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  #87  
Old 20-12-2018
axel axel is offline
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Lost top end? I always understood longer muffler would increase bottom end and shorter would increase top end (at the expense of each end). I went from 300 (08) stock with red spring, to HP FMF pipe, then cut the muffler 100mm, then had to go to the yellow spring to try and bring it back from being too SX for my liking.
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  #88  
Old 20-12-2018
Nutty Nutty is offline
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Originally Posted by axel View Post
Lost top end? I always understood longer muffler would increase bottom end and shorter would increase top end (at the expense of each end). I went from 300 (08) stock with red spring, to HP FMF pipe, then cut the muffler 100mm, then had to go to the yellow spring to try and bring it back from being too SX for my liking.
Apples and oranges. You can't compare tuned lengths of OEM and FMF mufflers because they have massively different core diameters.

You're thinking 4T Axel. Longer mufflers lean off 2Ts at higher revs and thereby bring more top end to motors that were slightly rich.

Everything you knew about tuning 2Ts is now redundant. With 2019s we are mechanically setting up the bike to suit a FIXED jetting spec.
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  #89  
Old 20-12-2018
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Okay so I got all keen today and decided to install the Slavens idle screw. I'll start by saying it's a rort for what it is and if I wasn't such a lazy bastard I would have sorted it myself for like $2.

However, the results have been quite positive so I won't complain. I started at the recommended setting (after restoring the fuel tuner to stock settings for idle) and it fired up much faster than normal but it was idling high, I turned the air screw all the way in and it was still high so I played with the idle screw until I got it where I wanted it.

End result is that is starts almost instantly every time now, idle is a set a bit lower than before (I always thought it was slightly high) and importantly the bottom end feels smoother and stronger. It pretty much eliminated the off idle bog when blipping the throttle too.

I then used the tuner to add a little more at idle only and the off idle bog has completely gone, praise the lord!

I have only ridden around the streets so far but it is noticeably better. I'm taking my bike to the high country with with me over Xmas/New Year so will report back later.
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