I have searched and have not been able to find pictures of pipes with a deto button(small deflector) welded into the header on the pipe. Does anyone know where to find these pics? They were pretty early in this thread.
Thanks,
DT
I have searched and have not been able to find pictures of pipes with a deto button(small deflector) welded into the header on the pipe. Does anyone know where to find these pics? They were pretty early in this thread.
Thanks,
DT
The good old Google "SITE:" search turned up this:.....
det button site:https://www.kiwibiker.co.nz/forums/s...-engine-tuner?
Update on my YZ, cylinder is now overbored from 250cc to 265cc, so I'm scaling then porting to suit, but also wanting to shift the powercurve up about 800rpm at peak, since I'm gearing limited already.
Stock cylinder transfers give STA of 0.000936 at 8500rpm. For the 265, I widened the ports so the % of bore width was the same as stock 250, then increased duration to the same STA as stock but at 9300rpm. Went from A: 116°, B: 116°, C: 121° stock, to a slightly staggered A: 122°, B: 121°, C: 119°. Relative power from 48hp to 55.6hp.
Stock exhaust gives STA of 0.000130 and 0.000168 with aux ports open. I widened the main exhaust to the full width of the PV blade, slightly reduced the radius on the upper corners, and increased duration from 185° to 190°. I'm reluctant to go much more duration as 190° is getting a bit much for 9300rpm. I left the aux ports at 185° to give them some stagger. I think this is about the limit of what I can do with the exhaust, but gives an STA of 0.000122 and 0.000157 with aux ports open. Power handling from 55.3hp to 58hp. So the transfers are still limiting.
Is this the right way to go about reaching my goal? Will having the exhaust smaller relative to the old arrangement make it more peaky? It's only 5 speed so I need to keep the power curve pretty wide...
Just need to get this laser cut to a thin sheet and start cutting!
Last edited by Nath88; 10th June 2018 at 14:12. Reason: Added pic
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More Dyno adventures .....
Had one of the very front running 4T's (Paul's EFI Yam 150) on the dyno today.
4T Blue Line 2T Red line.
When you look at the low end torque of the 4T and extremely wide curve you can see why mere mortals on 2T's get well and truly trounced by the 4T's drive out of the corners.
Had a chance to try the Arduino MAP simulator today.
RPM brown line, TPS blue and Arduino MAP simulation is the Yellow line.
The Arduino uses a MAP sensor to measure crankcase pressure and looks for the maximum and minimum pressure and outputs the difference as a simulated MAP value to the EFI's CPU.
Bike sounded good and was even starting to show signs of improved drivability.
I was rely starting to enjoy myself laying consistent runs and making little improvements with ignition/fuel and PV adjustments.
Things were going real well, on the home run I thought, then I heard the dreaded dyno death rattle......
Quick as a flash, in with the clutch and let the beast coast to a stop.
(&^%%$#$#^+_!!! could be the problem this time.
Turns out that it had drunk all its cooling water during 20-30 runs..... wasn't expecting that ....
Have not taken it apart yet but I suspect that small pressure drilling I put in a while back may be leaking or the head "O" ring. Not many other possibilities.
[QUOTE=TZ350;1131100765].
More Dyno adventures .....
Had one of the very front running 4T's (Paul's EFI Yam 150) on the dyno today.
4T Blue Line 2T Red line.
When you look at the low end torque of the 4T and extremely wide curve you can see why mere mortals on 2T's get well and truly trounced be the 4T's drive .
That's why you gotta use everytjing you can to your advantage. 3 stage baffles. Low and wide tranfers. Staggerd tranfers.
Longest pipe you can get away with. And good inner/outer radius. Radius on the right in pic, is absoulty terrible thru the whole curve.
I don't suffer corrosion on my stuff when I neglect them for a while either.
We do live in a rather dry climate though, especially in the winter time, that for sure helps.
In my case the 20% castor helps a lot too, but gives other problems than corrosion if left for too long.![]()
Too many ups and downs in the graphic. There are RPM's that are up, and RPM's that are down, close to each other, looks like a bandwith measurement problem. Try to get a datasheet of the MAP sensor, look at the response time and find out if you can take like 8-10 samples per revolution. Choose the 8-bit resolution ADC conversion off the Arduino to speed the software part up. Get rid of noise: sample deeper.
If I look at it filtered, I see the data increasing with rpm ,without significant spike.
Bandwith is just like: I want to look into this at let's say 12000 rpm, thats 200/sec, so you sample sort of valid at 2000/sec.
The dry climate is probably the biggest factor in preventing corrosion.
The worst customer carbs I ever had were those used on the West Coast of the South Island of NZ - Husaberg's home territory.
They'd regularly come back to me white with corrosion inside and out.
The 18 metres of annual rainfall may have had something to do with that.....wait for husa's response, LOL.
I have tested the Suzuki type deto cone, and the Yamaha type ( penny on a stick ) is better.
Piston and insert are ready to test the edge radius, will have some dyno results in a day or two.
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
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