ESE's works engine tuner

[adegnes]

Regarding airboxes - any advice on what I should do in this scenario, without adding too much to the width of the bike?
I'm not concerned about filtration, but about the "air brush effect" from air passing the carb at 90°...

[husaberg]

Regarding airboxes - any advice on what I should do in this scenario, without adding too much to the width of the bike?
I'm not concerned about filtration, but about the "air brush effect" from air passing the carb at 90°...

But ditch the ram air you won't need it at road speed and it will only serve to bugger the carburation
http://www.kiwibiker.co.nz/forums/at...4&d=1413875764
http://www.kiwibiker.co.nz/forums/at...3&d=1413875763
http://www.kiwibiker.co.nz/forums/at...1&d=1411374076
http://www.kiwibiker.co.nz/forums/at...2&d=1411374076
http://www.kiwibiker.co.nz/forums/at...3&d=1411374076
http://www.kiwibiker.co.nz/forums/at...4&d=1411374076
http://www.kiwibiker.co.nz/forums/at...5&d=1411374076
http://www.kiwibiker.co.nz/forums/at...6&d=1411374076
http://www.kiwibiker.co.nz/forums/at...2&d=1411373100

Intake Temperature and Horsepower Loss

Estimate power loss or gains due to air temperature changes



HP Output = +1% HP per 10 degree temperature decrease
-1% HP per 10 degree temperature increase
I have seen much higher figures used.............note the temp will be in degrees F

http://www.aemintakes.com/temperature_testing.htm

[peewee]

Re airbox - for bucket bikes if you can fit it in it will be about the right size, and having a duct from somewhere in front of the bike will keep the air cool.
As long as the inlet to the box doesnt have air flowing across the carb mouth turbulence wont be an issue, the entry air speed isnt high enough to cause any problems.
Have dyno tested this on a 100 bucket, the airbox and snorkel with no ram, was worth about 1 1/2 Hp in 28.6.

whats your thoughts for a drag racer in atv configuration. seems most people just use k&n pod filters attached to the carbs, no airbox. the chassis is completely open with no fairings. would it even be worth the trouble to try and make a airbox or just stay with pod filters ?

[Dodgy]

One of the 300 customers wants some 38PJs so maybe you can do the Lectron thing for no outlay.

I have a set of PJ38s that I purchased for my road NSR300 that I never used. I offset bored the standard carbs and although prob not perfect at 33.5mm, it is only a roadbike after all.

Interested in selling on the PJ38s.

[bucketracer]

Regarding airboxes - any advice on what I should do in this scenario, without adding too much to the width of the bike?
I'm not concerned about filtration, but about the "air brush effect" from air passing the carb at 90°...

Back several 100 pages are posts where at a Taupo race meet, TeeZee found that he needed to protect the carbs bell mouth from air blowing directly across it and upsetting the carburation so he fashioned this crude but effective wind break from an ice cream container. As an aside, he also posted dyno graphs of 29 rwhp with that pumper carb like it is, without a bell mouth, he said, in back to back tests bell mouths seemed to do nothing for it.



He later made a better job of it using stiff rubber sheet. He said he would like to try it the other way around so it scooped air into the carb but was worried that it would just as effectively scoop up road gravel in the event of a crash. The way he has it in the pictures he hoped the rubber would fold over and cover the carb if the bike fell over.

[adegnes]

Thanks, I think I'll go for something like what TeeZee did, that carbon airbox is sexy though!

[fatbastd]

Dont succumb to the 'varmint theory'..sexy is what works, not what looks good..granted though, they are often they are the same..

[Haufen]

Back several 100 pages are posts where at a Taupo race meet, TeeZee found that he needed to protect the carbs bell mouth from air blowing directly across it and upsetting the carburation so he fashioned this crude but effective wind break from an ice cream container. As an aside, he also posted dyno graphs of 29 rwhp with that pumper carb like it is, without a bell mouth, he said, in back to back tests bell mouths seemed to do nothing for it.



He later made a better job of it using stiff rubber sheet. He said he would like to try it the other way around so it scooped air into the carb but was worried that it would just as effectively scoop up road gravel in the event of a crash. The way he has it in the pictures he hoped the rubber would fold over and cover the carb if the bike fell over.

Do you recall what exactly happened to the carburetion? Did it become lean at higher speeds? Maybe the air blowing across the carb bellmouth blew the blowback away thus preventing it from re-entering the carb and thus effectively leaning the carburetion?

[lodgernz]

I vaguely remember that someone, a long time ago, maybe Frits, posted a method of mounting a carb using O-rings rather than a rubber manifold.
I can't remember if it was in this forum or the GP125 one on pit-lane.biz.
Can anyone tell me how to find this post?
I've tried the usual Google searches using the "site:" parameter, without success.

[F5 Dave]

try this, there are some words too. . .hmm, this is what I saved. Problem is all the reed engines I've tried would clash the carb to the case if this short.

. . . . : if the tract diameter has to be small for some reason (rules), you can diminish its negative effect by making it as short as possible. And because it's a lovely day, here is my solution of making it really short.
I slip a plate (P in the drawing) around the carb. The hole in this plate is about 2 mm larger than the carb's outer diameter. Then I slip a thick O-ring O around the carb. Then I slide this composition into a hole in the disk valve cover D and fasten it with two bolts B.
Plate P compresses O-ring O which centers the carb in the disk valve cover so there is no metallic contact anywhere. With this solution I manage to fit the carb at 2 millimeters from the disk valve. It works with reed valves too.

You can play with the O-ring size and the rate of compression to vary the flexibility of the carb mounting. You can also fit a second, smaller O-ring at the bevelled end of the carb, next to the disk valve, to keep the carb from sagging when applying a light rate of compression on the large O-ring.
The ideal would be an O-ring with a sleeve. Maybe you can produce something like that with 'liquid rubber'.

[wobbly]

You can achieve very similar result with using the KZ10B intake.
Here the end of the carb is 2mm from the reed face, as the manifold flange is recessed into the stuffer.

[lodgernz]

Thanks Dave, that's exactly what I was looking for.
Thanks also to Wobbly for further suggestions.

[husaberg]

I vaguely remember that someone, a long time ago, maybe Frits, posted a method of mounting a carb using O-rings rather than a rubber manifold.
I can't remember if it was in this forum or the GP125 one on pit-lane.biz.
Can anyone tell me how to find this post?
I've tried the usual Google searches using the "site:" parameter, without success.

try this, there are some words too. . .hmm, this is what I saved. Problem is all the reed engines I've tried would clash the carb to the case if this short.

. . . . : if the tract diameter has to be small for some reason (rules), you can diminish its negative effect by making it as short as possible. And because it's a lovely day, here is my solution of making it really short.
I slip a plate (P in the drawing) around the carb. The hole in this plate is about 2 mm larger than the carb's outer diameter. Then I slip a thick O-ring O around the carb. Then I slide this composition into a hole in the disk valve cover D and fasten it with two bolts B.
Plate P compresses O-ring O which centers the carb in the disk valve cover so there is no metallic contact anywhere. With this solution I manage to fit the carb at 2 millimeters from the disk valve. It works with reed valves too.

You can play with the O-ring size and the rate of compression to vary the flexibility of the carb mounting. You can also fit a second, smaller O-ring at the bevelled end of the carb, next to the disk valve, to keep the carb from sagging when applying a light rate of compression on the large O-ring.
The ideal would be an O-ring with a sleeve. Maybe you can produce something like that with 'liquid rubber'.

.......................

I vaguely remember that someone, a long time ago, maybe Frits, posted a method of mounting a carb using O-rings rather than a rubber manifold.
I can't remember if it was in this forum or the GP125 one on pit-lane.biz.
Can anyone tell me how to find this post?
I've tried the usual Google searches using the "site:" parameter, without success.

And I am sure I didn't. Quite the opposite in fact: if the tract diameter has to be small for some reason (rules), you can diminish its negative effect by making it as short as possible. And because it's a lovely day, here is my solution of making it really short.
I slip a plate (P in the drawing) around the carb. The hole in this plate is about 2 mm larger than the carb's outer diameter. Then I slip a thick O-ring O around the carb. Then I slide this composition into a hole in the disk valve cover D and fasten it with two bolts B.
Plate P compresses O-ring O which centers the carb in the disk valve cover so there is no metallic contact anywhere. With this solution I manage to fit the carb at 2 millimeters from the disk valve. It works with reed valves too.

You can play with the O-ring size and the rate of compression to vary the flexibility of the carb mounting. You can also fit a second, smaller O-ring at the bevelled end of the carb, next to the disk valve, to keep the carb from sagging when applying a light rate of compression on the large O-ring.
The ideal would be an O-ring with a sleeve. Maybe you can produce something like that with 'liquid rubber'.

Here's some more Helmholtz-encouragement:

Regarding induction systems: build a short induction tract and visit a test bench.
You can forget about calculations. The formulas you find in various books are all based on the Helmholtz resonator. It made me write a simple story, called:
Helmholtz blues
"A Helmholtz resonator consists of a volume connected to a duct". That is what Wikipedia tries to tell you.
But that is a Helmholtz resonator in its simplest form; one that you won't find anywhere in an engine.
What you do find in an engine is an intake tract with a variable cross-sectional area. This tract is from time to time connected to a variable volume (the crankcase) through a very variable window (the intake port / reed valve / rotary inlet).
The crankcase is connected to a number of transfer ducts with variable cross-sectional areas, which are from time to time connected to a very variable volume (the cylinder) through a number of very variable windows (the transfer ports).
The cylinder is from time to time, through a very variable window (the exhaust port), connected to an exhaust pipe with a very variable cross-sectional area who at the same time doubles as a volume. This pipe volume is constantly connected to a big volume (the outside world) through a tailpipe with a constant cross-sectional area and constant entry and exit windows (thank God, finally someting that's not variable).
We call this a compound Helmholtz resonator .
The various papers also tell us how to calculate the resonator's frequency:
" frequency = speed of sound / (2*pi)* Sqr ( cross-sectional area of the neck / ( volume of the resonator * effective neck length ) ) ".
O yes, the speed of sound... It is dependent on temperature, which is not really constant in the intake tract and the crankcase, rather variable in the transfer ducts and very variable in the cylinder and the exhaust pipe.
Now the above frequency formula is not exact; it is an approximation that is usable as long as the volume of 'the' tract is very small compared to the resonator's volume.
So when engines are concerned, that formula goes very far out the window.
Who said gas dynamics is simple dull?
PS:
It's a similar story with acoustics. That is a sub-branch of gas dynamics, simplified with a lot of assumptions that are acceptable as long as the sound pressure does not exceed a certain limit. The wave pressures in a two-stoke exhaust exceed that limit by a factor of thousand. Bye bye, acoustics...

Thanks, I think I'll go for something like what TeeZee did, that carbon airbox is sexy though!

Dont succumb to the 'varmint theory'..sexy is what works, not what looks good..granted though, they are often they are the same..

I found these while i was looking for a case pic. Plus a few more out of the album.

[TZ350]

I'm still 1/2 a hp down on the RG at its best but with no over rev. As I review, it's spookily close to the last run on the RG before I put in a new ring. Bah.

Different problem, but I feel your pain Dave. Been working my arse off on this EFI thing. 90% throttle consistently makes more power than a 100%, 80's pretty close to and 70 is not far behind.



I keep making more power but can't get it to come back onto the throttle properly.

I just want it to throttle properly so I can ride it , Bah humbug, and stamp my feet.

[speedpro]

I know it shouldn't, but, I don't suppose it's using or at least being influenced by the VE table? How is your setup being told to only use the TPS table?

I have mine around the opposite way at the moment, VE table up to 95% throttle and then swaps to TPS above that. 4T versus 2T of course and 2T should only be using TPS table. Simple test would be to enter LARGE values in the unused table in the appropriate cells and do a run. If it falls over . . . . .

I think Ecotrons bury it in the software on a system designated for a 2T whereas I have a crossover table I can play with.