ESE's works engine tuner

[wobbly]

Im happy to do a pipe for anyone, yes as you say nothing worth having is free, so I would want to model everything in EngMod
and that needs alot of input time.
PM me and lets get it on.

[TZ350]

I would love to see some posts of the pipe development process as it unfolds.

[richban]

Hey Rich that head looks alot like Mr Thiels for his Aprilia, hope it works as well.
.

Ah yes well, I found this picture on the interweb and thought well that looks pretty maybe I should give it a bash. Yep it's a copy it really matched up well to what i wanted. Will let you know if it makes more power or runs cooler hotter.

[chrisc]

I would love to see some posts of the pipe development process as it unfolds.

You and many of us too! I visit the ESE thread more than facebook/gmail/instagram (which is saying a lot for a 24 year old in NZ), so super appreciate anything more I can learn here.

Really keen to see your results with that head Rich

[Frits Overmars]

Wouldn't it be better to put the cooling fins on the outside of the cylinder, instead of in the exhaust duct? Just a thought...

[TZ350]

PatAT Asymmetric Timing in Two-Strokes




http://www.homebuiltairplanes.com/fo...o-strokes.html

Asymmetric transfer timing, I have no idea if it works but its an interesting idea ....

[richban]

Really keen to see your results with that head Rich

Me 2. Hey if you are coming to manfield on the weekend come down Friday for the test day and bring your 125. Race it on Saturday. It would be a good track to get a feel for the bike. Lots of straight bits to relax on. There will be plenty of people keen to help you set it up me included.

[wobbly]

OK so if you guys want to learn,I am happy to detail the pipe design process for a specific end use, as long as the customer is fine with what he is paying for
being given away on a public forum.

[RomeuPT]

Wouldn't it be better to put the cooling fins on the outside of the cylinder, instead of in the exhaust duct? Just a thought...

it's suprisingly the most tuned/used cylinder in Portugal. Made by Italkit for maybe more then two decades, still sells very wheel here, so much that other brands copied the most of it and offer a similar kit for a little less money.

The sucess of the kit it's not that it's amazingly good in performance but it's that cost's about 200€ with cylinder, piston and gasket's. And is actually reliable in most cases.

Some other's tried fairly good to input better cylinder kit's for the Yamaha DT/TZR in the nacional market, but at twice the price did not helped to sell.

[TZ350]

OK so if you guys want to learn

I am keen.

[RomeuPT]

Im happy to do a pipe for anyone, yes as you say nothing worth having is free, so I would want to model everything in EngMod
and that needs alot of input time.
PM me and lets get it on.

I did until now, two pipes for scooters, but I am not sure what exacly fit's to this engines.

My guess is, scooters are better for acelaration, so I did the diffusor start a litlee later and ending later too to improve power before peak hp.
Also they don't have gears and they can keep the engine in the rpm of most power in a race condition so probably narrow pipes work better.
I had also opted to do the biggest angle of the difusor around bdc.

Would this be wrong?

[wobbly]

We are probably loosing something here in translation - what do you mean by narrow pipes.
And also what do you mean by having the steepest diffuser around BDC,the point of maximum bulk flow should be around BDC for sure -
but in reality as the pipe length is fixed, the actual point of maximum depression will move from before BDC to after BDC as the rpm rises.
The earlier this happens means less overev power and visa versa, so moving the diffuser out further will gain front side power, but loose just as much if
not more in the overev past peak.
Overev power is more important I believe in this application, as hiitting a brick wall with the power graph going to almost vertically downward, will limit the advantage from short gearing.

[RomeuPT]

We are probably loosing something here in translation - what do you mean by narrow pipes.
And also what do you mean by having the steepest diffuser around BDC,the point of maximum bulk flow should be around BDC for sure -
but in reality as the pipe length is fixed, the actual point of maximum depression will move from before BDC to after BDC as the rpm rises.
The earlier this happens means less overev power and visa versa, so moving the diffuser out further will gain front side power, but loose just as much if
not more in the overev past peak.
Overev power is more important I believe in this application, as hiitting a brick wall with the power graph going to almost vertically downward, will limit the advantage from short gearing.

By narrow I mean a pipe that make the engine to have a narrow power band, instead of being a broader pipe.
The steepest part of the diffuser I usually put it at 43/44% to 60/61%. That is what I mean, I though scooters might benefit more from front side power instead of overrev, but ok.

Most or all decent pipes seen here have the stepest angle righ before mid section.

Thanks Wob

[wobbly]

Having the steep diffuser at 40 - 60% is perfectly normal now for any high performance race engine.
It started years ago with the old VSK range of pipes designed for Rotax, and ended up in the final few " tubo 100+ " designs for Aprilia.
This technique does exactly what I mentioned above,the max depression starts to occur BBDC on the front side of the peak, then moves to ABDC in the overev rpm range.
Giving the maximum ,widest, depression for peak Hp centred at your chosen
max Hp rpm.
The real trick for tailoring the Hp curve is creating the conditions for resonance superposition of the outgoing Ex pressure ratio, early in the powerband for
front side power,or later, past peak if overev is your requirement.
Here is an example of extreme superposition in the overev of a WR200 racing quad.
The remnant pressure at EPO adds to the outgoing pressure ratio and the pulse going down the header is off the scale - the max depression in the cylinder occurs well after BDC, all designed
for max overev capability.

[RomeuPT]

Having the steep diffuser at 40 - 60% is perfectly normal now for any high performance race engine.
It started years ago with the old VSK range of pipes designed for Rotax, and ended up in the final few " tubo 100+ " designs for Aprilia.
This technique does exactly what I mentioned above,the max depression starts to occur BBDC on the front side of the peak, then moves to ABDC in the overev rpm range.
Giving the maximum ,widest, depression for peak Hp centred at your chosen
max Hp rpm.
The real trick for tailoring the Hp curve is creating the conditions for resonance superposition of the outgoing Ex pressure ratio, early in the powerband for
front side power,or later, past peak if overev is your requirement.
Here is an example of extreme superposition in the overev of a WR200 racing quad.
The remnant pressure at EPO adds to the outgoing pressure ratio and the pulse going down the header is off the scale - the max depression in the cylinder occurs well after BDC, all designed
for max overev capability.

Would not this still benefit from max depression around BDC?
both cylinders I am working with have 190º of exhaust timing, so I guess superposition is there