ESE's works engine tuner

[TZ350]

The Wobbly Piranha is finished, we are keen to try it out on the dyno, but because the ignition map will need to be changed and that takes time, its maybe next week after Te Puke.



A big thanks to Wobbly for his design and kitset pipe and Darren for his work putting it together, because without his help this would not have got finished. There is no way I could have done it myself, making a good job of pipes is a real art.

[Grumph]

Salvaging grooved shafts was indeed my main thought, any increase in seal life and/or reduced friction could be a side benefit.

Currently putting sleeves on the seal rubbing areas of an X7 road resto. Pretty common fix on those things.
The crank expert in ChCh - Barry Lynch, tends to hard chrome worn areas on race motors and grind, but sleeves road stuff. Horses for courses.

[Bert]

Look good TZ. looking forward to the dyno results.

or maybe not as it likely to have far more get up and go than mine...

[sonic_v]

The Wobbly Piranha is finished, we are keen to try it out on the dyno, but because the ignition map will need to be changed and that takes time, its maybe next week after Te Puke.



A big thanks to Wobbly for his design and kitset pipe and Darren for his work putting it together, because without his help this would not have got finished. There is no way I could have done it myself, making a good job of pipes is a real art.

I like to create my curves within the computer before I even go to the dyno, then it is possible to run through tests very quickly. Usually with a new pipe it can be very informative to run 3 or 4 straight line curves first as this can direct you to which curves to choose.

[TZ350]

Good idea, I will do that, I will set up some straights and good guess curves first. I have a good idea where things probably should be but just moved up the scale a bit. The good thing about the IgniTech is that the ignition curve can be re programed on the fly.

[breezy]

tz350,has this exhaust been designed to increase the power spread? you said you d hoped to get to around 4k usable power. noticed the belly setion has gone, is this the way to go now? does this pipe rely heavily on the ignition set up to work to its best? could this be the end of your excellent thread in pursuit of 30+rwhp suzuki gp125...i would sincerly hope not...

[wobbly]

The pipe was designed to give a wider range but at a slightly higher rpm again.
This may in fact not be possible with the transfer geometry it has, and it may need to be lengthened a little to put it back in synch with the porting.
The timings are spot on, but for sure the scavenging regime isnt a RSA copy.
The belly starts at 66% of TL, but has 3 sections of bend within it - and another at the junction of the rear cone - that is why it looks that way, I was copying the centreline shape of a pressed pipe..
Every pipe is timing critical, this design is no more or less sensitive in that it will need the retard slope moving to the right if it forces the peak power up a few rpm.

[TZ350]

tz350,has this exhaust been designed to increase the power spread? you said you d hoped to get to around 4k usable power, could this be the end of your excellent thread in pursuit of 30+rwhp suzuki gp125...i would sincerly hope not...

No, not the end yet, there are quite a few other people contributing interesting stuff to the thread and there is a way to go yet in developing this motor, both for max power and probably more importaintly, power spread.

The pipe should (hopfully) extend the top a bit and I hope a VTEC valve will plump up the bottom, then there are the 50's, and Wob is working on one for Giggles that will hopefully be 18 or so hp so plenty to do yet.

[Farmaken]

Will we see you at Te Puke TZ ??
Be nice to see the Wobbly Piranha feasting on fourstrokes !!

[TZ350]

Will we see you at Te Puke TZ ??
Be nice to see the Wobbly Piranha feasting on fourstrokes !!

Yes I will be at Te Puke as Kel's pit crew, but if its wet he may elect to run his FXR as trying out a new bike for the first time on a very tight wet slippery track might be a bit much.

But if its dry enough it would be good to get a few laps just to settle it in before the GP at Taupo.

I am looking forward to catching up with you when we get there, probably arrive mid morning Sat.

[koba]

Yes I will be at Te Puke as Kel's pit crew, but if its wet he may elect to run his FXR as trying out a new bike for the first time on a very tight wet slippery track might be a bit much.

But if its dry enough it would be good to get a few laps just to settle it in before the GP at Taupo.

I am looking forward to catching up with you when we get there, probably arrive mid morning Sat.

Cool, it will be good to see you there

I think it looks like a bit of a power track as far as kart tracks go, I always feel the disadvantage when pulling out of very slow corners and onto straights.

[husaberg]

TZ now has 30 or so HP a an impressive powerspread and he has achieved it but without a Electric PJ so far.
Will the expected performance gains in over rev potential (thus powerspread) you would expect from having one be hindered by the fact his carb is rather small (24mm because of the rules)
Also would the extra heat produced in the pipe from the high speed lean of effect his bike differently being air cooled. rather than being liquid cooled.

I also keep tripping over stuff done in the 70's and 60's that suggests something along the lines of a 10-20% greater power loss mid race compared to a liquid cooled as well.
Not that it matters, his engine still makes 30 HP more than mine does at the moment.

Has anyone ever ran the bike on the dyno long enough to get an idea of the performance loss you would expect from a AC bike compared to a Liquid cooled.

On the subject of bearings and seals and so forth.
Something Dave said about if worse comes to worse with his need for a suitable little end bearing he would use a crowded set up. Wobbly said something about Bultaco days and i didn't twig, What he was meaning because something i never understood with Jennings writing that the Bultaco would last better at high revs if the little end was substituted for a crowded set up. Why? Were the standard cadged ones just crap?

One other bit i can remember reading something where someone claims the MV the little 125cc and 250cc ones race bikes had an odd big end that was uncrowded with two different diameter rollers bigger ones inside and smaller ones sort of between on the outer toward the outside of the rod.
I guess it would allow smaller diameter rollers anyone have any ideas on that?

[Yow Ling]

One other bit i can remember reading something where someone claims the MV the little 125cc and 250cc ones race bikes had an odd big end that was uncrowded with two different diameter rollers bigger ones inside and smaller ones sort of between on the outer toward the outside of the rod.
I guess it would allow smaller diameter rollers anyone have any ideas on that?

I cant imagine different diameter rollers, maybe different lengths. Any roller that was just a tiny cock smaller would carry no load, and the fat ones would be just greedy,

[bucketracer]

Has anyone ever ran the bike on the dyno long enough to get an idea of the performance loss you would expect from a AC bike compared to a Liquid cooled.

We have often done 10-15-20 runs at a time when setting up the ignitions with no more of a break between them than the time it takes to slow the dyno drum and there was no real power drop but we are expecting it will show up on the track, Taupo should tell more.

[husaberg]

I cant imagine different diameter rollers, maybe different lengths. Any roller that was just a tiny cock smaller would carry no load, and the fat ones would be just greedy,

I should draw a picture, but the larger ones and smaller ones both carry weight