ESE's works engine tuner

[aljaxon]

who or what is "it" ?

"out of breath rpm" = rpm after which your max torque will not rise anymore. so the predicted rpm of max torque.
your STA's say 10000 for the transfer's and 11200 for the Bd , not 8000. so your engine has too much A.area if you are shooting for 8BMEP (to protect the engine) ? or raise the BMEP ? or other things are not correct/entered right.

the figure on the exhaust new sheet in box 14 E is saying 8000 rpm. i thought because it was yellow it was working out this figure from my port maps.

i didnt realise it was the figure that i'd entered myself in the first Data sheet in box 20 E.

and this is why i am reluctant to invest in engmod 2t because i dont trust myself to enter all the info correctly.


i dont know what the actual hp or torque is or at what rpm. this is a different project on an identical bike to the first one i did a couple of years ago. that had 10.8bhp at 9470 so i just entered that. ill try having a better guess and enter updated figures.


as for the bmep if i enter 8 box 40 D on exhaust new it gives bhp of 13.9 which i think is too optimistic for my porting and pipe building skills.
ive just entered 7 and it gives a more realistic bhp of 12.2bhp which by the time it reaches the back wheel is probably 11 which im guessing this is the case in reality, although i am hoping for more.
if i enter 7 bmep and 9500 max torque and rpm power i get out of breath rpm as blowdown 13171 and transfer 10938.

should i be aiming to up the figures im entering in the data sheet for power and torque rpm so they bring down the out of breath rpm to a closer match?

edit if i enter 10000 as my peak rpm and torque and then i enter 8.1 as my bmep i get out of breath blowdown 11105 and transfer 9933. ive got a single ex port at 68% of bore so cant really go much bigger. maybe ive gone to big on the transfers?

[aljaxon]

That is not wat I was saying. You can make the power band a whole lot narrower if you wish, but it won't improve power; it will cost power, as I already told you. You don't have to take my word for it, but then you'd better stop asking and start building.
The other day you wrote: "i havent got enough time left on this planet....im an old git".
Well, I'm an old git too; do you think I fancy wasting my time over this?

i can sympathise you being a fellow member of the old git club and thats why instead of going to the trouble to reply in depth i was hoping you'd say i/we found a narrower belly or sharper rear cone gives a narrower power band. or a longer or shorter header etc. jennings and bell suggest sharper angles give narrower power bands. and the freely available calcs that ask you for what type power delivery usually 3 types, wide normal and gp bike suggest the same. i know those are old and out of date?
i built a 3 pipes last year thin normal and fat - same proportions and lengths and the fat one worked best even though it shouldnt have. i posted about it on here. very little over rev on any of them. i built a further 3 pipes but didnt really come to any clear conclusions as to what was doing what. i altered the rear cone of one to a 3 stage but the difference was minimal. i appreciate you dont want to waste any of your time on this frits. i am grateful of your design, ive built 4 of your pipes and im running one now. i just wanted to tweak it a bit and who better to ask than the man who's design it is.
i realise making pipes without testing them on a sim is hard work and time consuming. i should be using eng mod then making a straight pipe to test on a dyno and then road test. but im just an old bloke whos messing about with mopeds in his shed cos theyre cheap and im not gonna kill myself on them at breakneck speeds. i think ive finally realised im out of my depth on here. asking questions that probably cant be answered simply.

[aljaxon]

I feel comfortable in being Frits muscle on this one. He has never once stated it is the holy grail, final tuned pipe you will ever need. His concept literally says it is for getting beginner tuners on their way. I have made a few FOS pipes and they taught me a lot. To believe any of us can give you a perfect scenario pipe design is foolish. There are too many variables. Engmod still needs good inputs, and it is a design tool, not the sorcerers stone. You will be disappointed with engmod if you do not real world test along side of it, until you know you are feeding the correct information.

While on the topic, my personal belief with the simulation pipe challenge is that more than the top pipe design should to be dyno tested in conjunction with the sim results. Showing everyone how accurate reality replicates the sim on multiple designs would be beneficial to all parties. I would be happy to laser cut and build some of the pipes, but I would not be happy to ship them to NZ lol.

condyn i only wanted to know in which areas to tweak the FOS design to give a narrower power band. and when frits says it cant be tweaked for my desires then im trying to wonder why? surely any pipe desing can be tweaked to become better? possibly at the expense of power elsewhere? i havent got engmod2t. im only a diy tuner working on a shoestring budget playing with mopeds. i actually enjoy making pipes having taught myself to tig weld. but i know the time should be spent doing other stuff in my life. a bit like busying myslef on here when i should be doing the dishes or decorating......

[wobbly]

Aljaxon, I think you need a lot more in depth study on your knowledge base, and we need alot more info.
When you say "i enter 8.1 as my bmep i get out of breath blowdown 11105 and transfer 9933. ive got a single ex port at 68% of bore so cant really go much bigger. maybe I've gone to big on the transfers?".
You have the whole concept back to front , if the Blowdown rpm is 11105 that is way in excess of the Transfers at 9933 , so how the hell can the transfers be " too big ".
And regarding the pipe geometry , every section of the pipe has a specific area of influence on the powerband shape , and all of them can be mixed and matched to gain a specific characteristic.
As the rear cone is made steeper its reflected return wave is increased in amplitude, and reduced in bandwidth.
This has a corresponding identical effect on the resultant power , with reduced front side, increased peak power, and reduced overev.
But that's just one element , there are a dozen more , so me trying to help with so little detailed specifications, is a lost cause.

[JanBros]

Aljaxon, I think you need a lot more in depth study on your knowledge base
You have the whole concept back to front

this.
you do not design ports and than start playing with the BMEP end rpm's to get the numbers right.
You decide what (BMEP) you want from the engine at which rpm's, and only than you start to draw port's to match the STA numbers.

If you want to use a specific cylinder, you can try and play with BMEP and rpm's to figure out what it might be capable of, but don't expect it will always be able to match what you want from it.

[Flettner]

Off to NZ Cylinders for Nikasil.

[Wos]

hell of a welding job!

How will the power valve sildes be driven ?

[Flettner]

hell of a welding job!

How will the power valve sildes be driven ?

Like this, this is one is out of my Autogyro engine, I built it years ago and seems to work fine. Via the Ignitech ignition to control it.

[porttiming124]

Hello everyone.
Concerning the calibration of the dyno egts.
In my land and sea software I can reset the temperatures.
I would like to validate that the probes all read the same temperature at the top.
I thought about making a small box preheat to 600Celcius for example and I could fix all the probes.
Currently on a 2 cylinder engine I reverse the probes from one side to the other and I do the temperature differential but I would like them calibrated.
I'm curious to know how you did it? THANKS

[aljaxon]

this.
you do not design ports and than start playing with the BMEP end rpm's to get the numbers right.
You decide what (BMEP) you want from the engine at which rpm's, and only than you start to draw port's to match the STA numbers.

If you want to use a specific cylinder, you can try and play with BMEP and rpm's to figure out what it might be capable of, but don't expect it will always be able to match what you want from it.

i did an identical cylinder 176 124 2 yrs ago and entered it into your excel based on that guesed i wanted 190 130 to up the peak power rpm. so i ported it to 189 128 and made a port map and entered it into your excel to see what was what and to see what needed tweaking.
im not fussed what the bmep or hp or torque is. i just need to know the optimimum rpm my current porting has so as to make a pipe matched to the same rpm. if my ports need tweaking a tiny bit then im happy to do that but im not too sure on how to interpret the results on the excle. . is there any way i can upload the excel or would a screenshot do?

[aljaxon]

Aljaxon, I think you need a lot more in depth study on your knowledge base, and we need alot more info.
When you say "i enter 8.1 as my bmep i get out of breath blowdown 11105 and transfer 9933. ive got a single ex port at 68% of bore so cant really go much bigger. maybe I've gone to big on the transfers?".
You have the whole concept back to front , if the Blowdown rpm is 11105 that is way in excess of the Transfers at 9933 , so how the hell can the transfers be " too big ".
And regarding the pipe geometry , every section of the pipe has a specific area of influence on the powerband shape , and all of them can be mixed and matched to gain a specific characteristic.
As the rear cone is made steeper its reflected return wave is increased in amplitude, and reduced in bandwidth.
This has a corresponding identical effect on the resultant power , with reduced front side, increased peak power, and reduced overev.
But that's just one element , there are a dozen more , so me trying to help with so little detailed specifications, is a lost cause.

cheers for reply wobbly. i just wanted the narrowest powerband pipe ever made peaking around 10500. maybe max torque at 10000, i can sort the tuned length out myself.
ive made the FOS pipe (a few times) which is said to be a good starting point. so i now want to tweak it to suit my purposes but frits says it cant be tweaked unless it will produce less power.

maybe thats less peak power but if the narrower power band has MORE power at the start and finish then thats surely better. ie a better curve to suit my purposes.

to my mind i can visualise sharper angles on the diffuser and rear cone separated by a longer belly. i would love this to be confirmed before i waste loads more time building it to find out its a dud.

i dont know if ive worded the b;lowdown and out of breath rpm. its all taken off janbros excel sheet. im not bothered about power numbers. just the rpm my motor works best at so as to match a pipe to it.
at the moment the thing flies. so im not too far off.

[aljaxon]

this.
you do not design ports and than start playing with the BMEP end rpm's to get the numbers right.
You decide what (BMEP) you want from the engine at which rpm's, and only than you start to draw port's to match the STA numbers.

If you want to use a specific cylinder, you can try and play with BMEP and rpm's to figure out what it might be capable of, but don't expect it will always be able to match what you want from it.

yeah i dont expect any of the power figures to be achieved in reality. they are largely immaterial. im just interested in finding the rpm my motor works best at to build a pipe to it. and if your excel reports a major flaw in my porting then i will look at that.

[JanBros]

yeah i dont expect any of the power figures to be achieved in reality. they are largely immaterial. im just interested in finding the rpm my motor works best at to build a pipe to it. and if your excel reports a major flaw in my porting then i will look at that.

the excel only calculates the time-area's of the port's and says nothing else about for example the transfer ducts or other determining aspects of an engine's power.

without actual numbers, it's hard to determine any power figures or rpm's based on the excel. for example : if you know the rpm of max power and you enter all the data correct, you can "predict" the max power the ports can deliver by adjusting the BMEP till the STA-numbers match for the known rpm of max power (or, at least the lowest target of transfer or blowdown , because it will not be able to keep up for the higher one). but that tell's you nothing of the power the complete engine can deliver.

I feel like you want simple straight answers for question's that do not have simple straight answers.

[aljaxon]

the excel only calculates the time-area's of the port's and says nothing else about for example the transfer ducts or other determining aspects of an engine's power.

without actual numbers, it's hard to determine any power figures or rpm's based on the excel. for example : if you know the rpm of max power and you enter all the data correct, you can "predict" the max power the ports can deliver by adjusting the BMEP till the STA-numbers match for the known rpm of max power (or, at least the lowest target of transfer or blowdown , because it will not be able to keep up for the higher one). but that tell's you nothing of the power the complete engine can deliver.

I feel like you want simple straight answers for question's that do not have simple straight answers.

i just wanted to know what rpm my ports are currently best suited for. and i thought thats what your software is for? obvioustly as you say it cannot take into account transfer tunnels etc so at the end of the day its only going to be a rough guide. but a rough guide is better than nothing?

if i raise all the transfers by 0.3mm i get this


in the above pic the blowdown and the transfer sta's nearly match thats at 8 bmep if i lower the bmep figure the out of breath rpm goes up quicker for the blowdown than the transfer. do i need to input my actual bmep? if so then i need to put the bike on a dyno.

i thought this was a tool to help me work out whether my porting was good to go without using a dyno and just to make educated guesses.

so can i use the excel by adjusting the bmep and the offset of the transfers until i get the out of breath figures the same for the rpm that i want peak power for?

[Frits Overmars]

you do not design ports and than start playing with the BMEP end rpm's to get the numbers right.

so can i use the excel by adjusting the bmep and the offset of the transfers until i get the out of breath figures the same for the rpm that i want peak power for?

Al, do you read the answers to your questions?