ESE's works engine tuner

[senso]

Good night bucketers, here I come with another odd question..
Does anyone know how fast should I read an EGT and CHT probe?
I'm aiming at 1Khz in my custom dash(call it a home made data-logger), is it too fast, as I'm aiming at about 5 samples per engine revolution, maybe a little to fast for the thermo-couple to react?

Best regards.

[wobbly]

10 Hz is plenty to read an exposed tip EGT.
You may be able to sample 5 times per rev, but at 12,000 you only need to sample at 200Hz to get every combustion event.
Then the dash will update so fast you wont be able to read it, and the downloaded data wont be any more accurate than that done at 10Hz.
CHT is very slow to react,10Hz would be fine also.

Be careful with the Elf fuel as there are strict limits on the octain and oxygenates - check the numbers in the MNZ fuel spec.

[kel]

Be careful with the Elf fuel as there are strict limits on the octain and oxygenates - check the numbers in the MNZ fuel spec.

The Elf MITS fuel complies.

[dinamik2t]

You may be able to sample 5 times per rev, but at 12,000 you only need to sample at 200Hz to get every combustion event.
Then the dash will update so fast you wont be able to read it, and the downloaded data wont be any more accurate than that done at 10Hz.

Hey Wob! You would actually need to sample at 400Hz min, if you were to read successfully one value per cycle at 12k, to avoid aliasing.
You said that 10Hz is already enough though, so it doesn't matter anyway.. Cheers!

[wobbly]

Yes I understand that technically you are supposed to sample at 3 times the data stream rate to maintain accuracy, but in this case the egt wont change with any significance over 3 cycles
so it matters not.

[dinamik2t]

Yes I understand that technically you are supposed to sample at 3 times the data stream rate to maintain accuracy, but in this case the egt wont change with any significance over 3 cycles
so it matters not.

Yeah, no need to say 'you're right' Wob; I know I could have skipped the post altogether..

Something irrelevant: would you happen to remember this pipe design and perhaps the engine specs/performance?

[husaberg]

S having recently read an article on the people behind the design.
It might be ugly, but I do like the two-stroke aspect

The Chaperal J2 Was so clever well executed it would squat to the ground (like the Brabham Fancar) when the throttle was blipped. But plagued by mechanical issues
Oh ugly doesn't fully describe it, it should have been banned on looks alone.

But one thing i did gain that i had never heard of was the wooden Planks the F1 cars run under the tub. if they are worn by a certain amount after the race the car is disqualified. Clever and simple.


Only beaten by Harada's droopy tail.
Sure it may have been faster but it was an abomination in the style department. Actually i remember it being uglier, is this MK2. Either that or time has been kind to it.

[Ocean1]

The Chaperal J2 Was so clever well executed it would squat to the ground (like the Brabham Fancar) when the throttle was blipped.

Now why would it do that? Or did you mean when the auxiliary two stroke was blipped?

What it could do, (and unfortunately never got the chance to) was drive around upside down on the ceiling. At high idle the fans generated a force equal to 1.5 times the vehicles' mass.

But plagued by mechanical issues.

If a new product is 100% reliable it doesn't have enough features yet.

[TZ350]

... doesn't have enough features yet.

Sounds like my bike .....

[husaberg]

Now why would it do that? Or did you mean when the auxiliary two stroke was blipped?

What it could do, (and unfortunately never got the chance to) was drive around upside down on the ceiling. At high idle the fans generated a force equal to 1.5 times the vehicles' mass.

It was in the Blub, but it the video they do seem to run at a constant speed (showmobile engines)

If a new product is 100% reliable it doesn't have enough features yet.

Aye, but insert Keith Duckworth quote here..lol

[RomeuPT]

Yeah, no need to say 'you're right' Wob; I know I could have skipped the post altogether..

Something irrelevant: would you happen to remember this pipe design and perhaps the engine specs/performance?

The first segment is 25, not 35. Honda exhaust duct lenght is 56.

I would be interested in that too

[Frits Overmars]

Aye, but insert Keith Duckworth quote here..lol

You mean "Development is nothing more than correcting what went wrong in Design"?
I'd have to agree with mr. Duckworth, but since we are all human.....
Here's one from a certain Albert Einstein I like too:
"The simplest solution that fulfills all requirements, is the best". I abbreviated it to KISS.

[dinamik2t]

(not your quote Frits, eh?)

[RomeuPT]

If we are back to exhaust dimensions.

I been thinking, the exhaust port volume is an important value for power production, has it works like a connection pipe from a pump (exhaust).

Now, why is the header of Honda 40 and 41mm if the cross area exit of the cilinder port is ~36mm, wouldn't a smaller change keep the flow velocity and assuming the header is a connection pipe too....

Regards

Romeu

[Frits Overmars]

I been thinking, the exhaust port volume is an important value for power production, has it works like a connection pipe from a pump (exhaust). Now, why is the header of Honda 40 and 41mm if the cross area exit of the cilinder port is ~36mm, wouldn't a smaller change keep the flow velocity and assuming the header is a connection pipe too....

This connection pipe, together with the cylinder and pipe volumes forms a Helmholtz system; its length and diameters determine the frequency of this system.
The header length is rather fixed by the desired wave actions, so the header diameters must have a certain value in order to arrive at the desired frequency.