ESE's works engine tuner

[richban]

Why???
We haven't even got to the stage of using the TPS and powerjet... I would have thought there was still a lot of love to be gained yet.

Yep. But to be honest I want the best simple option. I want the best carb for the job. The one that flows best and is most tuneable. Less dyno more racing.

[wobbly]

The Lectron 40HV flows alot more air than a 38mm SPJ but has a venturi behind the slide of 36mm.
Thus at part throttle it acts like the smaller carb.
Insanely easy to jet.
Just get a pair of 5-2 and 4-2 needles, then fine tune the high range with 40 to 70 powerjets - also makes equalising & fine tuning each side simple as well.
The TZ400 when it ran at PI had 4-2 with 85/90 on top, so I will now go to 5-2 and drop down to around 50 powerjets.
And when you want to go sex plus I have made some inline solenoid bodies that will switch the PJs from Ignitech.

[richban]

The Lectron 40HV flows alot more air than a 38mm SPJ but has a venturi behind the slide of 36mm.
Thus at part throttle it acts like the smaller carb.
Insanely easy to jet.
Just get a pair of 5-2 and 4-2 needles, then fine tune the high range with 40 to 70 powerjets - also makes equalising & fine tuning each side simple as well.
The TZ400 when it ran at PI had 4-2 with 85/90 on top, so I will now go to 5-2 and drop down to around 50 powerjets.
And when you want to go sex plus I have made some inline solenoid bodies that will switch the PJs from Ignitech.

Cheers. So what is the off throttle fuel feed like? I sort of like having the rich pilot when the brakes are on into a corner.

[F5 Dave]

So going off APT? I'd have bought one for my GG if I'd had the spare. Dumb single income. Wife lost her part time job today.

[wobbly]

Rich wants simple - APTs need alot of dicking around to get even close as they dont have a big matrix of needles with top end and mid
taper changes.Makes tuning a twin more than twice as hard.
Plus no fine tune powerjet.
The trick venturi shape is more suited to great throttle response for say buckets on a kart track, or MX.
They have apparently recently done some more needle combinations, but I havnt had time yet to look into this.

Re the Lectrons bottom end tuning on the overun Rich,simply turning the rod in 1/4 turn increments makes for super easy changes in off idle fuelling.
And as I said about the TZ400, it had 4-2 needles with big powerjets, so simple next step is a 5-2 with smaller PJs - will end up with same egt and better part throttle corner response.
No effect on the bottom or mid tuning, just rearranging the top end.
The 300 motors will end up making some more power than the old TZ based 400s - 86RWHp so that motor is a bit overcarbed, but the HV venturi helps the mid response a heap.
One of the 300 customers wants some 38PJs so maybe you can do the Lectron thing for no outlay.

[oktrg500]

Hi,

One subject which isn't discussed often here is the air intake system. In my book turbulent air = no good. Hot air = no good. For sure, designing a good air feed system isn't that easy, or is it?

I found one previous discussion about this topic starting here http://www.kiwibiker.co.nz/forums/sh...post1130747647

It seems to me most of the buckets are running open air carburation, with a few exceptions using KN filters.

Quoting Frits: "Is an airbox on a bucket worth bothering? Definitely, but not so much because of that 1% ram-air pressure; its main purpose should be to feed cold air to the carb."

With my 125cc engine I'm in the category where the main purpose is feeding the carb with cold air.

I'm wondering about e.g. what the inside of the air box should look like. Most of the pictures of custom air boxes I've seen is just a big box with the carb inside. Fed from the front of the bike, I guess the air will be rather turbulent inside the box.

Any advice, pics and experiences you can share will be very much appreciated.

Thank you.

[oktrg500]

This >> https://www.facebook.com/Techgp/phot...=photos_albums

[husaberg]

Airbox stuff is mixed in here
http://www.kiwibiker.co.nz/forums/al...p?albumid=4844

[husaberg]

No surprise that a 500ccm engine does not give more power than a 125ccm gp engine if the cylinder is mistreated like this. "The power valve ports are slightly smaller...." So why using a 500ccm engine if you don`t let it breathe? unbelievable...

http://www.2tprofessor.com/blog.html
This also has a thread on Pitlane plus I think he has occasionally posted on here.....

[Martin1981]

http://www.2tprofessor.com/blog.html
This also has a thread on Pitlane plus I think he has occasionally posted on here.....

yes husa. and the guy asked Jan Thiel how much hp is possible with a 500ccm single. jan told him that it can pump out up to 140hp!.....if everything is done right....if this is too much power then one shold reduce the engines cylinder volume, and not choke it!


same with 4 stroke engines....first engines with big volume or turbochargers are built and then they get choked by air restrictors

[senso]

Sweet two stroke jesus, would love to see even a 120hp 500cc single, staying on the bike would be a challenge.

[richban]

Re the Lectrons bottom end tuning on the overun Rich,simply turning the rod in 1/4 turn increments makes for super easy changes in off idle fuelling.
And as I said about the TZ400, it had 4-2 needles with big powerjets, so simple next step is a 5-2 with smaller PJs - will end up with same egt and better part throttle corner response.
No effect on the bottom or mid tuning, just rearranging the top end.
The 300 motors will end up making some more power than the old TZ based 400s - 86RWHp so that motor is a bit overcarbed, but the HV venturi helps the mid response a heap.
One of the 300 customers wants some 38PJs so maybe you can do the Lectron thing for no outlay.

This all sounds great. On the shopping list for sure.

Re the PJ38's. I don't have any but other Richard does. Not sure he would let them go. I am running the modified PWK power jet air strikers, YZ250 carbs TPS etc. They are working well but are running at the angle limit now and the last needle position. The bike thats running the PJ's is running some big jets to keep things together when the ram air is on song. But this has caused 3/4 throttle issues.

.

[senso]

Sharing another job in another cast iron cylinder.
What do you guys think about what I have done, any stupid mistake?
Original vs ported(never liked this word :/ )
The paper is not there to hide anything, its just so my very,very old camera can focus in the plane of the ducts.

[adegnes]

^looks great! Well done.

[wobbly]

Make the ball nose radius on the bore/duct edge way bigger - like this pic I have posted 20 times.

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.