ESE's works engine tuner

[senso]

Too much air is sucked by the engine and because there is no re-jetting the engine is lean, maybe..

[Yow Ling]

Hi,

The following I'm unable to understand. The subject in speak is the air box for the Aprilia RS 125 streetbike. Reliable sources has reported several times about loss of power when the 'snorkel' is removed. I'd like to understand why. Understanding why, would be valuable when trying to figure out if the std design can be improved upon. Attached is an exploded view of the box, which I've tested holds 2,4 liter of water. And a back to back test in the dyno from the internet with and without the snorkel.

http://en.wikipedia.org/wiki/Helmholtz_resonance

[F5 Dave]

lean if no rejet of course.

& the entry to the box without the snorkel is horrible flat edges.

[lodgernz]

I have got R7376 several times for around 35USD, about 1/3 of the cost of the shorty Honda style.
And I would never use an Iridium plug again in a real race engine.
They seemed like a great alternative till we lost several engines in a row, including dropping an earth electrode on
the last corner of the last lap - to take a 125 kart title 3 in a row.
The Iridium centre ceramic will crack and fall off the instant you see even the smallest amount of deto, and the reason the R 7376 style plugs are expensive is that the rare
earth ground strap is laser welded to the body - I have never seen or heard of one failing, and the ceramic can crack occasionally, but again I have never seen one drop out.
Its one of those things, just accept that you pay for what you get, and buy the best when it really matters.

Wobbly, I'm a little confused by your post above. You are critical of Iridium plugs, and advocate the use of the R7376.
Now I see, in the NGK plug specification chart at http://www.ngksparkplugs.com/docs/RacingSpecs2013.pdf
that R7376 has an Iridium centre electrode.

When you criticised the Iridium plugs, were you talking about the sales name of that range, rather than the electrode metal?

[RAW]

Maybe you swapped the DEA and VM captions?

No Frits, definetly not. The DEA cylinder is an early one without the dimples, the VM is a copy of DEAs later model cylinder.

Posting incorrectly on purpose would be poor form

[wobbly]

Plain old Iridium plugs are a brand name, and yes they have Iridium fine wire centre electrodes.
As I said, these will drop the ceramic at the slightest provocation.
The R7376 has the Iridium centre, but also has a Platinum earth fine wire strap.
The construction is completely different, and is dead reliable.

So whats the go with Dutch Fisher then.
Coming on here and slinging shit at Frits over historical issues that i then expand on somewhat,with facts I know are accurate as I was actually there at the time, and he goes deathly silent on the subject.
Frits ignores it completely, that probably gives the posting the recognition it deserves.

[lodgernz]

Plain old Iridium plugs are a brand name, and yes they have Iridium fine wire centre electrodes.
As I said, these will drop the ceramic at the slightest provocation.
The R7376 has the Iridium centre, but also has a Platinum earth fine wire strap.
The construction is completely different, and is dead reliable.

Thanks Wobbly.

[ken seeber]

So whats the go with Dutch Fisher then.
Coming on here and slinging shit at Frits over historical issues that i then expand on somewhat,with facts I know are accurate as I was actually there at the time, and he goes deathly silent on the subject.
Frits ignores it completely, that probably gives the posting the recognition it deserves.

Good one, was wondering what was going to happen with this. I, like many others I am sure, read his post with amazement and confusion as to what he was on about. He was certainly serious and pointed and fucking unnecessary. I am a relative newcomer to this forum, and like everyone else, am good at some things and dumb in other things. One thing I am good at is knowing what is unnecessary. That post on this thread was unnecessary to the point of being disgusting.
If DF hasn't realized it yet, this ESE thread, with all its incredible history, is primarily about engines and associated technologies, with a big share of it towards 2 strokes. It is supported, been contributed to and read by a very large group of like minded and interested people. Some or a lot of these people have incredible related knowledge and experience and, for the huge benefit of many, willing to freely to share it. This thing is a gem.

To come up with some form of amateur political crap like he did is total wank. So, DF, learn from your absolutely stupid mistake, one that could affect many, and if you dare to continue with this crap then I for one will be asking the administrators to tell you to fuck off forever

[2T Institute]

Hi,

The following I'm unable to understand. The subject in speak is the air box for the Aprilia RS 125 streetbike. Reliable sources has reported several times about loss of power when the 'snorkel' is removed. I'd like to understand why. Understanding why, would be valuable when trying to figure out if the std design can be improved upon. Attached is an exploded view of the box, which I've tested holds 2,4 liter of water. And a back to back test in the dyno from the internet with and without the snorkel.

That was on a friends RS and if I wasn't there at the time looking at the dyno read out (had a EGT on and there was NO increase in temp) I probably wouldn't believe it. Power came back with the snorkel reinstalled. The airbox seems to be a Rotax designed part common with the MAX kart and the RS, they are on the small side and I'm wondering if the snorkel makes the airbox seem bigger or just makes it do a better job.Sounds better without the snorkel but noise isn't hp. In the end we give up wondering and built a long rod stroker engine

[monkeyfumi]

I was under the impression that any snorkel or duct contributed to the overall airbox volume.
Given the RS125 airbox seems quite small, the volume of the snorkel might add a considerable % amount.

[F5 Dave]

and did anyone measure the lid in the volume? filter isn't effectively there. . . .actually, maybe it is part there.. ahh heck I struggle to care enough atm.

I'd still be pointing fingers at the nasty intake of a hole in a flat surface. A carb in the breeze draws air from all around it.

[ac3_snow]

Long time listener (lurker?) first time caller....

Thanks to the lads at the house of speed I finally got my AM6 (50mm malossi mhr replica barrel) powered TZ 80 onto the dyno tonight.....

First dyno chart below (red) came as a bit of a shock - 10HP!. A bit of fiddling with the ignition (PVL Go Kart analog) and leaning up the main pushed us out to 15HP pretty easily but as you can see the graph is horrid......

So, I hear there has been progress....
Very keen to see the results and know what the changes were.

[koba]

So, I hear there has been progress....
Very keen to see the results and know what the changes were.

Me too!

[lodgernz]

and did anyone measure the lid in the volume? filter isn't effectively there. . . .actually, maybe it is part there.. ahh heck I struggle to care enough atm.

I'd still be pointing fingers at the nasty intake of a hole in a flat surface. A carb in the breeze draws air from all around it.

I agree with Dave, it looks like the hole faces forward, on a 45* face. Air will tend to go right over the hole rather than through it.

[husaberg]

Plain old Iridium plugs are a brand name, and yes they have Iridium fine wire centre electrodes.
As I said, these will drop the ceramic at the slightest provocation.
The R7376 has the Iridium centre, but also has a Platinum earth fine wire strap.
The construction is completely different, and is dead reliable.

So whats the go with Dutch Fisher then.
Coming on here and slinging shit at Frits over historical issues that i then expand on somewhat,with facts I know are accurate as I was actually there at the time, and he goes deathly silent on the subject.
Frits ignores it completely, that probably gives the posting the recognition it deserves.

I think the dutch fisher may have been referring to this Jan Thiel quote. (which has been translated by google)

Yamaha was later returned to 5 transfer ports. Or rather they have the Honda cylinders copied!
Cees van Dongen was thus the first, he has a casting mold to make for Yamaha 125 of his son Jos with Honda flushing ducts and exhaust.
The casting mold was later sold Bartol, who then worked for Yamaha.
So therefore, in a roundabout way the Honda copy with Yamaha ended, They are there, in 2000, it became world champion.
So Bartol for Yamaha Honda copied, and later for Derbi KTM and done the same.

I think it the Dutch fisher was in more in jest maybe somewhat lost in translation.