ESE's works engine tuner

[Neal]

About the step on the flange - why does it work for the honda when a exhaust port match to round transition flange used ? Claims of 1.5hp on the RS125 .

[wobbly]

Frits is right as usual re the duct step.
I have done a huge amount of work testing the duct exit geometry, short answer is that smaller duct exit area is better, cutouts for promoting the Aux flow is better again, and remove the steps and you loose power.
But a CNC oval to round transition works best.
In a RS125 aftermarket cylinder design I beta tested ,it started with a 41 by 36 oval with steps.
I then reduced the size to 41 by 32 with a press in insert.
This made better power - then I added a CNC oval to round transition ( like all HRC A kit pipes have ) and the result was between 1.5 and 2.5 Hp increase everywhere.

Re the 4T steps.
This is a different scenario all together.
Steps in a 4T are trying to kill reversion, and due to the fact that flow velocity is compromised on the short turn radius, the reversion flow will be greater on the port floor.
Many race engines have no step at the top, and a big step at the bottom.
Many with a flat floor to increase port velocity and also create the big 1/2 moon floor step, at the flange face.

[Ocean1]

and i followed with Mr Honda's version
The removal of this step removes HP
From Memory Mr Bangs foul stroke also has one built in

Used to be a fairly common VW feature, the header tubes belled out at the joint to the manifold flange. Wasn't worth much, but apparently it did work IF the rest of the system was correct.

[TZ350]

More on the TPS thing.

This is an email I sent to Ignitec.

Hi
We have several bikes with Ignitec Sparker DC-CDI-P2 tunable two channel ignitions.
We want to use the TPS function.
We found that a 5K Ohm TPS unit worked OK but a 25K one gave us trouble.
Is a 25K resistance wrong?
What resistance TPS do you recommend?
Thanks

This is their reply.

Hello,
Standard automotive TPS has resistance about 5 kOhm.
25 kOhm is strange. Is it regular automotive TPS ?

We recommended to use automotive TPS.
Jiri Krejzl
IGNITECH

It Looks like a (nominal) 5k Ohm TPS is the unit of choice for the Ignitec.

[bucketracer]

Im not forgetting the rider at all there Rick, just continuing the idea that less is more as far as power goes. I really was certain that the bike Avalon was riding had 24HP, but it goes to show that the race wins for ESE have all come on the shoulders of the lower side of the maximum power, Am I correct in saying the fast 4T engines have around 24 HP at around 11,000 RPM?

Compairing hp with hp may not be the apples with apples comparison you imagine.

Rick and his low 20's light weight bike have a similar power to weight ratio as the 30hp Beast.

There have been a few suggestions that loosing a couple of hp from the Beast would make it a more competitive bike, but I don't think the idea was well thought through.

It become pretty obvious that the 27 and 30 hp options were both rideable in different ways and that reducing the Beasts power did not make it any faster ...... going fast seems to be more about the power to weight ratio.

Trimming the 30hp Beasts weight for a more competitive power to weight ratio looks like a much more rewarding way to go, than loosing a few hp.

TeeZee points out that a truer performance comparison would be the power to weight ratio of engine and bike with rider aboard.

Av and her bike probably have a better power to weight ratio than possibly any other bike and Ricks is pretty good too.

A lot of the fast 24 hp 4T's in lightweight chassis have a better power to weight than the 27hp Beast and a wider spread as well.

Talking about hp alone does not tell the whole story, its taken TeeZee to point it out.

[NOID]

pritty sure it was said ages ago, if you eat too meny pies etc you need to cut weight/add power to your bike. cut down weight and youll be amazed at the performance. cutdown on the pies also. WEIGHT LOSS is the best way to go faster cheaper (sometimes) aswell

[fixer]

Thanks for constructive comments on exhaust step. thanks also to Frits for the numbers. I have printed them out and they are now under lock and key guarded by deaf-mute Ninja warriors.

Another couple of sessions on the ESE dyno have yielded more interesting (and positive) results. First step was to finalise the jetting and then fiddle with the length of the adaptor between the barrel and the pipe. The length of the adaptor seemed a likely area to investigate since a roughly fitting but longer adaptor produced significantly better power than a good fitting but shorter adaptor.

These steps were taken yesterday.

Please forgive me if there are issues with the photos. I've never attached any before.

Photo 1 shows the long adaptor which is long (about 35mm) but fits only very roughly (it came with the pipe).
Photo 2 shows the short adaptor we made up which fits perfectly but is short (about 15mm).
Photo 3 shows the short adaptor with a hose clip added to extend its effective length to about 23-25mm.
Photo 4 compares the performance of the long adaptor (blue) and the short adaptor (red). The short adaptor makes very slightly more peak power but gets there later and drops off more.
Photo 5 compares the performance of the short adaptor (red) and the same adaptor with the hose clip added to increase its length. With the hose clip added, the peak power is the same but it comes in earlier and drops off less.
Photo 6 compares the performance of all three options. Merely adding the hose clip gets us from the peakier performance of the short adaptor almost back to the fatter and earlier power curve of the original long adaptor.

Woo hoo! Next step ... 2 hose clips! Alas, 2 won't fit, so a longer adaptor has to be made.

[bucketracer]

pritty sure it was said ages ago, if you eat too meny pies etc you need to cut weight/add power to your bike. cut down weight and youll be amazed at the performance. cutdown on the pies also. WEIGHT LOSS is the best way to go faster cheaper (sometimes) aswell

Actually I think your right, maybe I should have said "took TeeZee to remind us of it", looks like SS90 got a bit off track with his less hp is more idea.

[bucketracer]

Woo hoo! Next step ... 2 hose clips! Alas, 2 won't fit, so a longer adaptor has to be made.

Interesting pictures and graphs, looking forward to hearing how tuning by hose clips works out.

[husaberg]

Interesting pictures and graphs, looking forward to hearing how tuning by hose clips works out.

I seem to remember Wob used one to balance a stator.........

Useless or maybe interesting factoid/Question
What works bike ran a aluminum alloy RR77 crankpin with a hardened sleeve. that was reliable for 9500 hard racing miles with a future multiple world champion on it when he fitted one to his production racer model?

There could be two chocky fish's in this one for the correct answer

[Moooools]

More on the TPS thing.

This is an email I sent to Ignitec.

Hi
We have several bikes with Ignitec Sparker DC-CDI-P2 tunable two channel ignitions.
We want to use the TPS function.
We found that a 5K Ohm TPS unit worked OK but a 25K one gave us trouble.
Is a 25K resistance wrong?
What resistance TPS do you recommend?
Thanks

This is their reply.

Hello,
Standard automotive TPS has resistance about 5 kOhm.
25 kOhm is strange. Is it regular automotive TPS ?

We recommended to use automotive TPS.
Jiri Krejzl
IGNITECH

It Looks like a (nominal) 5k Ohm TPS is the unit of choice for the Ignitec.

Automotive TPS units tend to break down pretty frequently when subjected to vibration and heat. Might be worth getting a proper motor sport one. I just did an inventory of all our sensors and there were 12 broken TPS sensors in the box, collected over 6 years. We use a different model now but I can't remember what it is off of the top of my head.

[fixer]

Just before we gave up for the night yesterday, we thought we'd try out my fancy new NGK BR9EIX iridium spark plug ($29 from Scootling in Auckland). The BR9ES that was in the bike was of completely unknown vintage and might have been there since the bike was new (in 2002). The results suggest that I can save myself a few bob on spark plugs in future.

But notice I'm still smiling. This dyno business is fun!

Tim

[fixer]

Another day and a longer adaptor has been made up. About 5mm longer even than the original adaptor. Results very pleasing.

Photo 1 shows new long adaptor (or nozzle if you prefer) fitted.
Photo 2 shows the 3 adaptors we've used. From top to bottom:
- new long adaptor
- new short adaptor (with hose clip)
- old long adaptor (that came with the bike and doesn't fit into the barrel).
Photo 3 shows a comparison of the power curves of the new long adaptor (blue), the new short adaptor (green) and the new short adaptor with the hose clip fitted (red)
It would seem that size IS important. The new long adaptor makes the best peak power and at the lowest RPM. We have a winner!
Photo 4 shows the same comparison with the addition of the curve from the original pipe.

It may be rampant optimism talking, but I think the bike is going to be a lot more fun to ride at the track this weekend. The others may pass me but I don't think they'll have a bigger smile. Except maybe Cully - he'll definitely be smiling when he passes me! :-)

Tim

[Henk]

Used to run standard BR8ES plugs in the dirt bikes, three of those replaced regularly seemed to give better performance than a expensive plug changed less often. Wob will probably tell me I'm wrong but I'll stick with that approach for now.

[rgvbaz]

[QUOTE=Frits Overmars;1130484219] Just don't show it to the Poms; year after year they keep trying to beat those Dutch 50 cc bikes .
QUOTE]

To late Frits