ESE's works engine tuner

**Haufen** · 9th May 2012, 10:08

Originally Posted by SS90

Calm down schatzi!

I build small frames for a living.

Have you had the opportunity of tuning a 2 stroke with more than 4 available ratios? No matter how you shuffle the cards, that, and than alone, is what holds you back.

Even at Stokach, where blech roller quarter miles reach frightening speeds, or the once a year 2 laps of the Nurburgring, where the limit is pushed further still, if these engines had more available gear ratios, then we would be able to build engines with more power (just over a narrower RPm range)

Don't worry, I am calm. Although our conversation somehow reminds me of that saying about arguing on the internet and the olympics.

My hope was more that you live for building smallies.

Yes I have had that opportunity, more than 4 as well as cvt engines. But the number of gears is only one side of the coin. The other one, which is the key to making peaky engines drivable, is the ratio between the gears. And my point is, that even on a very peaky engine, you can get your 4 gears close enough to each other to stay within the powerband at any time and still go ridiculously fast on the straights.

Another point in this case is that a gear shift takes time. Time in which the engine otherwise would be accelerating. Looking at the Italian sprint scene (150m), most of the riders use only 3 of their 4 gears. That is not because they would not get their gear ratios close enough to each other to make use of all 4, but because they are faster using 3 and thus saving one shift.

Italian 50RWHp Smallie using only 2 gears for 150m:

**bucketracer** · 9th May 2012, 10:08

Originally Posted by bucketracer

Originally Posted by SS90

I also wonder if the Suzuki GP100 has a lower primary drive ratio that the GP125? And, if so, are they interchangeable? This could sort out some of those big gaps between upchanges (Oh and alter your power output on the dyno too)

I would be interested in seeing the maths that support your assertion that a change in the primary drive ratio alters the power output on the dyno.

Attachment 263363

A graph you posted of a multi gear run.

Three different overall gear ratios and pretty much the same power output from each.

Changing the primary gear ratio affects the overall gear ratio just like changing gears does. But as we can see from the graph there is no real change in rear wheel hp.

Maybe you missed it when I first asked you, but I was hoping someone who knows so much could explain their claim in terms that make sense.

SS if you know so much why can't you answer a simple straight forward question about one of your claims ????? Your not ducking the question are you ???? I would be dissapointed as I was very interested in the answer because gearing is something we take a keen interest in.

**F5 Dave** · 9th May 2012, 10:30

Originally Posted by SS90

. . . (as the fastest bucket in New Zealand is currently a 4 stroke 150, as races are won on lap times, not back straight speed)....

Whilst that might be true, - it isn't.

While I was making a good stab at keeping the young lads honest on my low-mid 20s MB100 & reckon I could have raced for the lead, given some more laps [blah blah old man wibbling on] after I'd made the drive of shame home young Nat was doing the buss on a low 20s Derbi 80. The fact he fell off doesn't make the 4 stroke fastest. DaveM on Mikes bike had it continued would have done pretty well & very likely won once he'd got used to pedalling said beast.

**SS90** · 9th May 2012, 10:31

Originally Posted by Haufen

My hope was more that you live for building smallies.

Yes I have had that opportunity, more than 4 as well as cvt engines. But the number of gears is only one side of the coin. The other one, which is the key to making peaky engines drivable, is the ratio between the gears. And my point is, that even on a very peaky engine, you can get your 4 gears close enough to each other to stay within the powerband at any time and still go ridiculously fast on the straights.

Another point in this case is that a gear shift takes time. Time in which the engine otherwise would be accelerating. Looking at the Italian sprint scene (150m), most of the riders use only 3 of their 4 gears. That is not because they would not get their gear ratios close enough to each other to make use of all 4, but because they are faster using 3 and thus saving one shift.

Italian 50RWHp Smallie using only 2 gears for 150m:

Yea, I have seen Italians and their 150m sprints, totally different kettle of fish really (wheelie bars on a scooter, never thought I would see that.) and scootermatics dealing to CBR600s on a quarter mile??????? Has to be seen to be believed!

But back to the primary ratios, sure this is why I suggested it a few pages back, simply because it will mask the problem that the Suzuki GP 125 has in terms of gearing (that it only has 5 ratios, and the last 2 are too bigger a jump for the power spread to be able to pull), but this assumes that the GP100 has both a shorter primary ratio, and that it would fit a 125, unlike a smallie, you don't have to split the engine to do it either! Lowering the blowdown time area and building an exhaust to suit will also help immensely. (at the cost of a few horses, but....Meh, who cares, just over 20 HP 4 strokes are winning these races anyway)

**Haufen** · 9th May 2012, 10:31

Originally Posted by bucketracer

Hi Haufen, welcome to the net where some posters substitute endless talk and bragardo for real substance and become snide if you chalange them, get that every where I expect, like pubs, and clubs where there is always a big noting talker.

TeeZees 30hp engine makes 20+hp at 10500rpm.

TeeZee diarys his work whatever the result, good and bad, if anyone doesn't wan't to build a 30hp Bucket then don't would be his opinion.

Some of the FXR's lining up on the grid make a bit more than 20hp.

And anyone wanting to set the world on fire with a 20-22hp 2-Stroke are more than welcome to post their progress and results here.

Thank's for the welcome!

Has it already been considered buying an Aprilia RS125 engine (off ebay for example), taking advantage of the powervalve and the better gearbox? Seems like a pretty good starting point for a bucket engine to me.

Originally Posted by bucketracer

gearing is something we take a keen interest in.

Years ago I found an excel sheet on the net that graphically outputs force at the rear wheel. You can compare different gearbox settings as well as find optimum shift rpm for each gear change. If you don't already have such a tool I will dig it up.

**SS90** · 9th May 2012, 10:38

Originally Posted by F5 Dave

Whilst that might be true, - it isn't.

While I was making a good stab at keeping the young lads honest on my low-mid 20s MB100 & reckon I could have raced for the lead, given some more laps [blah blah old man wibbling on] after I'd made the drive of shame home young Nat was doing the buss on a low 20s Derbi 80. The fact he fell off doesn't make the 4 stroke fastest. DaveM on Mikes bike had it continued would have done pretty well & very likely won once he'd got used to pedalling said beast.

Its gutting that Speedpros engine expired, the last year it was never reported to fail (bad luck I guess)
It occurred to me last night that just because 30 HP has been achieved (I am impressed, and Wobbly had been saying that it would happen for ages) it all of a sudden, has become "what you need to win", when, well, it isn't, because going by current affairs, what you need to win is an FXR on slicks.

I truly believe in the future it will be 30hp 2 strokes (reliable ones) though, but I am certain it won't be from engines with single exhaust ports, it's just pushing ring and piston life too far, and to get that power, serious blowdown is required, and therefore narrow power, requiring either a change in gearbox speed (primary ratio possibly) or somehow more, closer ratio gears.

**richban** · 9th May 2012, 10:54

Originally Posted by SS90

I truly believe in the future it will be 30hp 2 strokes (reliable ones) though,

Nah it will be 28hp high reving 4 strokes that go around corners fast.

**crazy man** · 9th May 2012, 10:54

if you had the same bike one with a 2 stroke in it the other with a 4 stroke . same hp . first thing is the 2 stroke would end up 5 kg's lighter , you can stop one qicker into the corner been lighter and a lot less engine com . on a bigger gp type track the 2 stroke power is prombly in a better place but the smaller tracks 4 strokes in general have a better speed of power and reliability but a 22hp stroke should last not to bad

**wobbly** · 9th May 2012, 10:57

Reread the recent post where I said that NoMates won 3 straight titles on a 28+ RWHp 2T and was unbeatable.
Because it had plenty of power, plenty of powerband with a PV ( pulls from 6000,spins to 13500 )
a fast chassis, and a mad rider.
Sure, with Av on a RS125 and only low 20 Hp its a winner, but bring out the 28 Hp in the same chassis , and a quick rider,and she would get blitzed as well.

**crazy man** · 9th May 2012, 11:00

Originally Posted by SS90

Terry Fitzgerald had mid 70s (GsxR400) Andy Bolwell, Bredan Gere and John Lowther (all ZXR400's) had something similar, Chis Huddlestone had 68 (ZXR 400) and Adrian Main had 71hp (GSxR400)

But yea, as I am sure you are aware, Steve Ward had the measure of them all (most of the time), as did Glenn Hayward (even on his NX4 framed fiddler special) Jason Easton, Cam Horgan and quite a few others.

That was after Methanol was banned (boo), and before the 450 rule came in, where 80hp was the number for a big bore 400.

my bike had 67hp and was every bit as fast as andy bolwell bike and terrys also. they were at lest 25kg lighter than me

**TZ350** · 9th May 2012, 11:03

Originally Posted by richban

Nah it will be 28hp high reving 4 strokes that go around corners fast.

Pay attention

, because there could be a clue here.

**SS90** · 9th May 2012, 11:04

Originally Posted by wobbly

Reread the recent post where I said that NoMates won 3 straight titles on a 28+ RWHp 2T and was unbeatable.
Because it had plenty of power, plenty of powerband with a PV ( pulls from 6000,spins to 13500 )
a fast chassis, and a mad rider.
Sure, with Av on a RS125 and only low 20 Hp its a winner, but bring out the 28 Hp in the same chassis , and a quick rider,and she would get blitzed as well.

Granted, I'm not saying that's not true, but like you say, both scenarios require special riders, as you know, 2 strokes can be made fast,easy to ride and reliable. Much like a 2 stroke enduro bike.