ESE's works engine tuner

[bucketracer]

Found anything specific to a Two stroke there Bucketracer?

No, would be interesting though. General idea looks Ok, I am looking forward to seeing how TeeZee's plenum idea works out. Just getting it to run will be something.

BTW SS, good bit of detective work spotting Woodys catalytic converter.

[SS90]

The only thing I have found relates to forced induction two strokes and plenums, and none of it very conclusive (other than needing a reed valve).

It will work, by all accounts, but after a bit of development with volumes, lengths etc.

Mounting the carb there has big advantages anyway!

[Buckets4Me]

Mounting the carb there has big advantages anyway!

like it's harder to wipe off ????

[TZ350]

like it's harder to wipe off ????

It will also be easier to change the jets too.............not sure about it facing into the wind though?

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[richban]

It will also be easier to change the jets too.............not sure about it facing into the wind though?

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After you get it running you could try a U bend into a volume to keep everything out of the turbulence. I am sure it would have some tuning affect, good or bad don't know.

My own air box design is starting to look quite crude. Might have to read this end of the tread again.

[bucketracer]

More on Plenums from:- http://urbanracer.com/articles/anmvi...sp?a=3344&z=38

"The transition between the plenum and runner is the most critical aspect of an intake manifold. It needs to be smooth and harmonious. High-quality manifolds go so far as to have air horns incorporated inside the plenum chamber."

Interesting that TeeZee's plenum has features similar to these high performance plenums, like the internal bellmouth and a single throttle body with open runners to the cylinder.

[richban]

More on Plenums from:- http://urbanracer.com/articles/anmvi...sp?a=3344&z=38

"The transition between the plenum and runner is the most critical aspect of an intake manifold. It needs to be smooth and harmonious. High-quality manifolds go so far as to have air horns incorporated inside the plenum chamber."

The latest mods to my intake system is just that. Its is matched from the valve to the bell mouth of the carb. Overall length 170mm all I need to do now is create a 12mm long trumpet then putting that into a 1 litre airbox and that should give perfect length to match the exhaust. And 12000 rpm ish

[TZ350]

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Setting up the IgniTech ignition. This is a great unit, you can leave the LapTop connected while working on the bike and make adjustments on the fly.

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[speedpro]

You ought to pop the rivets and detach the flywheel. I love the revvy feel of a light crank and found a real advantage when hammering into a corner with being able to snap down the gears without the back wheel skidding. We took the flywheel off my brothers CB125T as well ages ago and I think it made a good difference.

[TZ350]

I love the revvy feel of a light crank and found a real advantage when hammering into a corner with being able to snap down the gears without the back wheel skidding.

Yes, I like the feel of a responsive motor too, but the GP's cranks are quite light compared to a TF or TM crank and we thought we would need some fly wheel effect to retain the phat lazy feel and drivability of the new motor that peaks at only 9,000 rpm for 21.5 rwhp. I will try your suggestion on a modified version of last years motor that peaks at 11,250 for 20 rwhp.

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[SS90]

Hey Teezee,

I was cc'ing a cylinder head today, and was thinking about the "basic" tunes you use on the GP's

Can you tell me what the compressson ratio's (corrected, and uncorrected) that you use on these engines (with 2mm removed from the top, and a standard cylinder head)

[k14]

You ought to pop the rivets and detach the flywheel. I love the revvy feel of a light crank and found a real advantage when hammering into a corner with being able to snap down the gears without the back wheel skidding. We took the flywheel off my brothers CB125T as well ages ago and I think it made a good difference.

How did you do that? I would like to modify the flywheel on my one but am unsure the best way to go about it. I could make another trigger altogether and that may work but it is a lot of work if it doesn't?

[TZ350]

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I have got the old GP motor out and started fitting the new motor with its plenum, should be good for a test run Friday then maybe off to the dyno next week.

I was looking at Chambers Yamaha SDR200 today and saw that it has a very large cast alloy air box with a snorkel. I think this must be setup as a resonant chamber for pulse charging the engine. In the pictures the grey piece with SDR on it is the cast alloy air box, it also forms part of the frame.

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[Brian d marge]

I have an article on the design of belmouths using CFD can try and post it if needed

I do love those Yamaha SDR frames ( cheap as here) , I think ( not sure that they are a bit flexy ,might be ok with the power of a bucket )

Just suspension then ,,,is there any internals that can be modded ?

Stephen

[TZ350]

Hey Teezee,

I was cc'ing a cylinder head today, and was thinking about the "basic" tunes you use on the GP's

Can you tell me what the compressson ratio's (corrected, and uncorrected) that you use on these engines (with 2mm removed from the top, and a standard cylinder head)

Hi SS, give me a few days, as I don't recall and will have to see if there is much in the note books about the measured compression ratios of the "basic" tuned engines.

Not much is left Std., around here any more. In tuned engines I prefer to use 7:1 or there about’s, on the other hand Chambers went to a lot of trouble getting things bang on 8:1 for his 100.

From memory my 7:1's usually finished up about 12 to 13:1 uncorrected, but its a balancing act centred around the exhaust opening point.

In my engines I am always inclined to give a bit away for the sake of reliability, but Chambers loves to take it all to the edge.

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