agusto experts please advise

[Darrell Taylor]

on programmable ignitions ive not found it to work like that but they are on race engines ,i hold a static timing thru peak then rapidly retard back to around 3 degrees as the power curve falls off past pipe peak rpm

[camel]

so....with this ads 3 pipe on my dyno graph power kicks in nicely from 5k to 7k then falls off a cliff just after that...which i dont mind,it is how i wanted this motor to perform..
so....id like to reset the timing at given rpm settings.....so being an agusto 6000, what is the optimum timing to aim for at what rpm...eg 18 degrees at 6k?

[Adam_Winstone]

thats correct adam, but only when the fuelling is not readjusted to suit ,the guys with egt,s should be identifying the throttle positions and making the relevant changes to jetting, seems a shame having the tools but not using them ,almost every jap bike has a similar ignition curve but also have fueling to suit from the factory
with these boxes you identify the peak power rpm then retard back straight after so the setting should be based around a known peak rpm for the kit/pipe combo in use so a guy with an ads3 should be set much different to the guy with a franspeed race ,a flick thru the dyno pages on here should find rpm values to work to for anyone fitting a unit

the trick is to fuel the curve but is not commonly known most people fit a box and get a big wow from the results as its just leaned out the whole range up to 3/4 without making a single jetting change ,,at 5k a 35 pilot at 20 degrees is safer than a 20 pilot at 18 degrees
but ignition,compression, pipe dimension and fueling all play a role there like a combination lock to decifer on the dyno to find the best results

Thanks for the info. I've noticed what a massive difference auto retard ignition kits make to jetting requirements from trying to fit them (Varitronic and Agusto) to motors that were already set and jetted for static ignitions. Indeed, it is one of the times that I find most challenging to get setups right on the road, seat of the pants testing rather than dyno feedback, and know just how difficult it is to get the balance right.... then to make a timing change and throw the jetting out again . Dynoing really is the better way to do this. I'm sure there must be lots of people out there that simply buy the Agusto units and bolt them on, thinking that they are safer by doing so but little understanding how they work or how they might affect the other elements of set-up (e.g. jetting).

Whilst I am trying to get to grips with these kits and better understand the fine tuning that is required, I certainly do appreciate your informed feedback on the subject, thanks.

Right, now I need to find that link to pipes, kits and beneficial ignition curves.... ?

Adam

[ForemanBob]

I took the Agusto unit off my GP with the ADS3 pipe... 6k revs was what I found to be the maximum in practice on the road with that pipe, and pootling around with the pack I was nowhere near that in practice.

I have found better results with that pipe without....

[camel]

I took the Agusto unit off my GP with the ADS3 pipe... 6k revs was what I found to be the maximum in practice on the road with that pipe, and pootling around with the pack I was nowhere near that in practice.

I have found better results with that pipe without....

ok thanks....basically your saying with the agusto it wouldnt rev past 6k but without it was?

[fishi]

you know this unit?

http://www.sip-scootershop.com/main/bas ... anguage=EN

[ForemanBob]

I took the Agusto unit off my GP with the ADS3 pipe... 6k revs was what I found to be the maximum in practice on the road with that pipe, and pootling around with the pack I was nowhere near that in practice.

I have found better results with that pipe without....

ok thanks....basically your saying with the agusto it wouldnt rev past 6k but without it was?

No what I'm saying is that the ADS3 pipe in practice does not really want to go much above 6k, so therefore most of the time you are not at the end stop of the unit.

I set a fixed 18deg and my scooter is happy with it, with that pipe.

[nelson pk]

You could be playing into the demon's hands!

Too much ignition advance will make you pink, however, 'backing off' will result in the revs dropping off and the timing advancing again, which in turn can lead it to run hotter One of the commonly reports from people with EGTs and advance/retard ignitions is that they can't ride slowly with packs of standard machines or their revs drop off, ignition advances and temps creep up. In this case you either need to keep the revs up to retard the timing and bring temps down or rotate the stator so that the whole of the range is retarded a little.... or just cane it everywhere!

Adam

I heard you say this before about EGT temps going "up" with advancing the timing but this does not ring correct for me.
When i advance the timing on my scoot the EGT temp goes down and there is a logical reason for this..........
When you advance the timing you are putting more heat in the head and less out of the pipe because its firing earlier.
EGT's go up when you "retard the ignition" because the charge is burning hotter when it goes into the pipe because it has fired later in the cycle.
Try retarding your ignition with the same jetting and watch your EGT's go up significantly!
If you advance the timing your EGT should go down and CHT should go up. If you retard the timing your CHT should go down and EGT should go up.
I have mentioned this before but nobody seems to pick up on it.
EGT's generally dont go up with advanced timing they go down. Remember you are measuring exhaust gas and not head temperatures.
For exact EGT readings use an accurate probe (about £100's worth) and a digital readout otherwise its not very accurate. I've seen the cheap analogue ones that people go for because they are....well....cheap....... and i have to ask how you can read them accurately on a vibrating lambretta when the difference between 600 degrees and 650 degrees is so small on the gauge?

[nelson pk]

By the way i am not suggesting that anyone advances their ignition to get their EGT's to go down as that would not be very good for your engine

Just trying to clarify how an EGT reads and it is not as simple as hotter is bad and colder is good. Too cold on an EGT can be just as bad as too hot.

[drunkmunkey6969]

You could be playing into the demon's hands!

Too much ignition advance will make you pink, however, 'backing off' will result in the revs dropping off and the timing advancing again, which in turn can lead it to run hotter One of the commonly reports from people with EGTs and advance/retard ignitions is that they can't ride slowly with packs of standard machines or their revs drop off, ignition advances and temps creep up. In this case you either need to keep the revs up to retard the timing and bring temps down or rotate the stator so that the whole of the range is retarded a little.... or just cane it everywhere!

Adam

I heard you say this before about EGT temps going "up" with advancing the timing but this does not ring correct for me.
When i advance the timing on my scoot the EGT temp goes down and there is a logical reason for this..........
When you advance the timing you are putting more heat in the head and less out of the pipe because its firing earlier.
EGT's go up when you "retard the ignition" because the charge is burning hotter when it goes into the pipe because it has fired later in the cycle.
Try retarding your ignition with the same jetting and watch your EGT's go up significantly!
If you advance the timing your EGT should go down and CHT should go up. If you retard the timing your CHT should go down and EGT should go up.
I have mentioned this before but nobody seems to pick up on it.
EGT's generally dont go up with advanced timing they go down. Remember you are measuring exhaust gas and not head temperatures.
For exact EGT readings use an accurate probe (about £100's worth) and a digital readout otherwise its not very accurate. I've seen the cheap analogue ones that people go for because they are....well....cheap....... and i have to ask how you can read them accurately on a vibrating lambretta when the difference between 600 degrees and 650 degrees is so small on the gauge?

I'm guessing Adam was just generalising and trying to illustrate the scenario where the heat generated at low revs at say 21-23 deg BTDC can be potentially damaging to the engine, which it can be....compared to 17 deg etc. But that aside, I can also confirm Nelson PK is correct, when I was experimenting on the dyno with various ign curves/retard settings on an MTech a while back, I put the timing just past peak RPM very close to TDC to experiment with gearing and over-rev......and had the downpipe on an exhaust on a tuned RB glowing orange on one setting........lol......I decided not to run that setting in the end!! lol