RednGold86Z

iTrader: (1)

I'm not sure if this will attach right, so bear with me.

Actually it probably won't, since it only will attach .txt files, which lose the formulas. If anyone knows how to attach it without screwing it up, please tell. Otherwise, email me at schmidtj86@hotmail.com and I'll send it to you.

I wrote an excel spreadsheet tonight that will supposedly find the rpm at which a certain length of runner will be tuned - both for 1) The rarefaction pulse of the intake opening, travelling up the runner, reversing and reaching the intake valve before it closes - 2) And one for the pulse from the intake closing (if there really is one), travelling up the runner as high pressure, reversing as rarefaction, hitting the closed intake valve, travelling back up the runner, reversing as a high pressure wave and reaching the intake valve just as it opens.
There is also an estimation of the average ram velocity in the runner.
These only use cylinder displacement, intake cam duration, engine rpm, runner length, and air temperature. (VE too if you want to - in the volume of air going in part.)

To use it just change the stuff highlighted in yellow - which may not have been saved when going to unicode - anyway, just the parameters listed above.

Reminder: 1) This may not be even close to accurate, as I wrote it very fast. 2) There are some other harmonics listed, which have decreasing effect. 3) These are just approximations. 4) I assume no responsibility for any innaccuracies. 5) Feel free to change it to suit your needs - assuming you know how to use excel. 6) There shouldn't be any viruses, but always be careful, and scan things.

Please write back with any corrections, gripes, compliments, advice, whatever.

The data in there already is for a 600cc engine that I'm making an aluminum intake manifold for. I'm also putting a Muzzy engine management system on it, and will be trying to write the ignition, and fuel map for it in the next week or so, so wish me luck.

Have fun with the program.
Later,
Jeremy
schmidtj86@hotmail.com

rx7speed

ok if this thing will work for a wankel you are my best friend man

I am trying to make "TPI" setup for my rotary with variable intake runners on it

so I am hoping
and I think I cna convert all this piston stuff from a 4 cyl at least over to my rotary

so I am hoping I can get osmething to work here

hotmail will allow you to attach a zip file so if you want do that and send it to rx7speed87@aol.com

Vader

Hey, Rx,

I'm only asking because I don't know with any certainty, but I thought Wankels were supposed to operate without the intake pulses that are common to reciprocating (Otto) engines. If this were the case, the lack of a sharp sonic intake "pulse" would mean there would be less of a charging effect from sonic waves, and all you'd have working for you would be a synchronization of successive "sucks" instead of the extra "push" from a pulse.

I can't imagine there would be a lot of extra charging due to this low energy air movement, but I could be mistaken, again. I'm overdue, since I haven't been wrong yet today, except for putting extra scoops of coffee in the pot (and that might not be a bad thing...)

rx7speed

as far as I have read up on them they still have the pulse in them

the pressure waves are caused by the air hitting a solid object or a space that is either smaller or larger then the intake runner right?

I am trying to think of a way to explain it but damn man I just got off work so my brain is fried

I know the series 5 (89-91) have the variable intake runners in there in what they call the VDI (variable dynamic intake)
and the one in my car has a dynamic chamber in there that is to help with the intake pulse to push more air into the motor