ESE's works engine tuner

[Peljhan]

I build many complete pipes with hydroforming. But I just finished excel driven sheet for Solidworks and decided to make it that way. It will be faster as cnc laser company is close and I weld it up in a day or two and I never tried hydroforming on stainless. Additionally I have to send it to laser cut anyway as my forks and frame is welded up from sheet metal.

Local company that builds 4t pipes is Akrapovič
But they got only large diameters available, like 40mm+
Stainles steel stores have mostly 1,5mm wall thickness and nothing on stock.

I attach pipe dimensions. For now header is 0,7/1,4°. Cone angles are half angles as I am used to that. And rear cone is one piece.
Made to run 167°-170° of exhaust timing and around 6700rpm peak power. 128° transfer timing. Will se how that will fit as I never made so low rpm tuned engine. And rpm needs to be low as it will be used onl up to 30km/h. I have better ways to die.
Cylinder is dmp70, 4 transfers with rear side 2 booster transfers.



Would put it into EngMod but I want to drive around over the summer, so no time for that for now.

Polar inertia = moment of inertia around steering axis?
I made forks as you can se in a way that axle is a bit more forward and steering axis is quite inclined, so it tends to keep the direction of riding = harder to steer. But because mass is high I believed it will easen on turning the steering bar. We will see

[Haufen]

I dont know where to curve it anymore. I tried aiming it towards floor but forks are in the way. I try to keep it tidy.

If space and pipe length are an issue, looking into other types of exhaust pipes might also be an option, e.g. box type, perforated rear cone ones, a shorter pipe with an ATAC and so on.

[wobbly]

Any header down at 1.4* included will achieve nothing. Never has , never will , double it.
Why do weird , when weird doesnt work.
An enclosed perforated rear cone would work well in this application , but the " muffler " tube would end up longer than a normal pipe end point - less the stinger.
But an internal stinger would help anyway.

[Peljhan]

I don't want to go over 80mm on belly section because of size. 2,8° header would end with 43,6mm diameter. Wouldn't that weaken the difusor acting as it would need to be shallower to get length back?
These engines are old school design (small crankcase volume). Is in this case difusor action less expressed as it is can't pull from crankcase that much as modern design?

If I make perforated cone with enclosed chamber, I will put a hole in side of enclosure and make standalone muffler facing back. Or similar as on attached picture.

Wobbly, is that a design I should use? Should total exhaust length be changed or it should be same as with full (classic) cone?
I used a picture from Frits files.

[wobbly]

The header angle increase would have more beneficial effect than any down side from a shallow diffuser. Make the diffuser 2 cones , 2/3 - 1/3 lengths.
You are dealing with no bmep here.
The vevey was originally designed for an engine pulling more than twice your design rpm , an adaption of this would need to be twice as long.
So as I said the muffler tube ends up being longer than your " ordinary " pipe design.
And the later designs that I did of this type of pipe ended up with a 3* tapered header as well.

[Peljhan]

I had the rear cone and muffler design in mind from Vevey picture, not complete dimensions.
Will make a change. Anyway I must build it for this summer riding and make some development over winter.

If I understood, the perforated angle cone with enclosure should have smaller angle than same classic style cone?

[wobbly]

Well its going to be shallower by making the body only 80 Diameter anyway.

[philou]

how long should the lobe flywheel be for an ignitech?

does its length have a function? capacitor charging time or other ?

[Peljhan]

how long should the lobe flywheel be for an ignitech?

does its length have a function? capacitor charging time or other ?

I can tell you info only for Zeeltronic. It should be min 2mm height difference and about 25° of "length".
If you get spark at the end of step, but you want it at beginning, you need to interchange pickup wires. Signal is listening when step happens.

[wobbly]

The Ignitech lobe height works at anything from 1.5 , but length can be anything from about 8mm to 25mm.
I have split a 24mm lobe into 2 with an 8mm gap to enable twin fire on a 180* twin that originally ran wasted spark.
The ECU spits the dummy if the lobe is over about 25mm , it does have a " long lobe " option but I simply shortened a longer 50mm Chinese flywheel lobe in the mill due to misfiring.
It also differs in that its recommended you use the falling edge to fire, as this is a specific characteristic of lobe triggering - whereas noise can trigger the ECU with rising voltage spikes.
This is the default situation that occurs when the base timing is set with the falling edge past the trigger pole , with the piston at TDC.

EDIT - you must use a resistor plug and cap , and note that the trigger input and the coil output are on opposite ends of the connector.
Keep all other wires well away from the coil outputs - this is the biggest cause of misfire issues people have by insisting on bundling everything together in a " loom ".

[diesel pig]

Keep all other wires well away from the coil outputs - this is the biggest cause of misfire issues people have by insisting on bundling everything together in a " loom ".

Just to be clear the pick up coil(or coils) wires should be keep separate from all other wires from the pick up coil until they go into the CDI ? and if it is a multiple coil set up should the wires for each coil be keep separate from each other?

[wobbly]

In a word yes , the input trigger wires should be routed well away from the coil wires. I always have the trigger (s) on one side of the bike , the coil wires (s) on the other.
These are on opposite ends of the ECU connector for a reason.
And the grounds for the trigger inputs , and the power grounds , are separate as well , and should also be physically routed apart.
The white and orange coil drive wires can be side by side and this has no effect on the triggering accuracy.
But be aware though , the output wires ( such as a PV drive or PJ switching ) if routed in a loom with the trigger inputs will generate errors and misfires due to EMI crosstalk.

[diesel pig]

In a word yes , the input trigger wires should be routed well away from the coil wires. I always have the trigger (s) on one side of the bike , the coil wires (s) on the other.
These are on opposite ends of the ECU connector for a reason.
And the grounds for the trigger inputs , and the power grounds , are separate as well , and should also be physically routed apart.
The white and orange coil drive wires can be side by side and this has no effect on the triggering accuracy.
But be aware though , the output wires ( such as a PV drive or PJ switching ) if routed in a loom with the trigger inputs will generate errors and misfires due to EMI crosstalk.

Interesting stuff, I will be going over my wiring looms very carefully to make shore I have not done something bad by mistake.

[wobbly]

Its not really doing something bad by mistake , the real issue is Ignitech and others dont tell you this basic stuff , that more often than not prevents anything approaching a " plug and play " scenario.
The only solution is to spend years of tracking down the issues others have unknowingly created , and going grey and or bald in the process.
I really wish I had someone telling me how not to fuck it up 20 years ago.

[TZ350]

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The re balanced crank works a treat. Reeves to 10k now no problems. Smooth as. Now for a bit of serious tuning on the dyno.