Advanced timing - any suggestions?

[kaplar]

Factory recommended timing is 5 deg. Some people claim that advancing it a couple of degrees would slightly increase the power.

Does anyone have any experience with this? How many degrees would make a difference?

Thanks,

Milo.

[kick-fix]

ECU already does agressive advance.
5 is the static starting point.
go ahead, advance it and give us the results.
put in some High Octane fuel and advance it. then when it starts to ping, back off.

But keep in mind the ECU already has a huge timing table , it uses.
way smarter than any fly weight dizzy, ever was.

its tuned the best they can get. out of the box !

have friend with a dyno , we'd love ot see hard data.

first effect my be loss of idle controls.

[fordem]

How much advance you can use and what effect it will have will depend on the grade of fuel you're using or perhaps willing to pay for.

I live in a country where we get one grade of fuel - "super unleaded" (octane rating unknown), I have a Swift (G13B carburetted engine) that is at 19* advance (factory spec is 5*) and runs like the proverbial bat "out of hell" and a first generation Grand Vitara (J20A EFI engine) that is at 15* advance (factory spec is 5*) and that also runs well.

Like kick-fix says - advance the static ignition timing (turn the distributor or cam position sensor) until it pings when you accelerate and then back it off until it just stops pinging.

Now - I'm not disagreeing with kick-fix when he says that the ECU has timing tables that are way better than the old style distributors - BUT - those timing tables are conservative AND based on intended operation on regular fuel rather than high octane.

You have to decide whether you're willing to pay the extra for the better grade of fuel required for this to work - and in my case - since I don't have a choice, I might as well get the most out of what I pay for.

[kaplar]

The US has (unfortunately) standardized lower grade fuels compared to for example Europe. Back there I would constantly use unleaded Euro98, which is 5 octanes stronger than the US most commonly found high grade 93. Shell sells a 94 grade, but not every pump has it.
The 93 octane makes a huge difference in my other car (Audi A6) vs. the 87 grade. Besides increased power, my MPG is better, and the turbos seem to respond faster. The bottom line is - I actually pay less, even though the initial cost at the pump is more.

Coming back to my 16v 1.6L Suzuki engine, I would assume that the ECU is market specific. Our ECUs are probably tuned to the US fuel grades. Hence the difference between the cars sold in Asia and our counterparts. It makes sense that the factory settings are probably more on the conservative side, so I will give it a shot. This is a good reason to put my recently purchased stroboscope to work. However, it seems that outsmarting the ECU will end up being an exercise in futility

Thanks for the input guys!

Milo.

[tusong200]

Back in the 80's I drove many times back and forth between Los Angeles and Northern Illinois. Several different vehicles (2 different Honda Accords, Opel GT, and Jeep J10). The south route (thru AZ and NM) was not much of a problem but if I took the north route (thru NV, UT and WY) I would have to stop and advance my timing by ear when I reached the mountains or high desert/plains. It was easy to do going up, just advance until the engine idled smoothly. Coming back down usually required an actual timing light adjustment.

Kind of the 'flip side' of your problem/question.

(I always claim to hold the record for single-handed trip from Chicago to LA without going over the speed limit and no illegal drugs. Leave at 12 noon CDT Tuesday, arrive at 4 PM PDT Thursday, 2300 miles in 54 hours. Drive, drive, drive, get tired, pull over, sleep in the drivers seat, wake up, Go.)

[kick-fix]

all true.

i was saying and poorly.
based on EPA rules and low octane mandates...etc

the linear flyweights haven't a chance to compete against any ECU.
linear and dumb fly weights.

for a given rule set, and level playing field the ECU will put the timing exactly where
needed for your low octane fuel and lowest smog. Last is economy or power.
except WOT , where the rules change again.

you can , put on you own ECU and set it where ever you want.

load, rpm, speed. Volumetric Efficiency at Load point, coolant temp. , air temp.

the hard part is out guessing the stock ECU.

YOu can put a Dash knob timing adjuster on any dizzy base car ( and set it where ever, you wish.
I had one one in the 60s. on chev. PU. sold everywhere this kit.

we had wide range fuels then.

Keep in mind the engineer , of our motor, designed the combustion chamber and piston such that the ping POINT is over the hump of max torque.
you actually get less power by doing the ping point test , on most modern cars.

this was done on purpose. and is usually demarked by not have a knock sensors.
this missing sensor, is the reward that engineer gave us.
1 less sensor to fail. Mine is real hard to make ping.

need false lean and overload , HOT motor, and too much advance .
nice motor it is.

Salud

[kaplar]

Tusong200 that's one cool ride man....love the profile picture!

[deeznutts77]

also these are only maped for 87 oct so no matter what oct u put in no diff in mileage. i think it hurts it cause with higher oct it needs to b advanced more than fact, but cant. ill go drive mine and spin through the gears and write down tha timing advancement on paper from my obd2 tool

[fordem]

Originally Posted by deeznutts77

also these are only maped for 87 oct so no matter what oct u put in no diff in mileage. i think it hurts it cause with higher oct it needs to b advanced more than fact, but cant. ill go drive mine and spin through the gears and write down tha timing advancement on paper from my obd2 tool

First - I have to disagree - and I'll also take this opportunity to point out to you the following two things ...

1 - that the ECU has no clue as to what octane fuel you have in the tank
2 - the ECU advances the timing relative to the base timing which is determined by the physical position of the cam position sensor.

I'm disagreeing because I drive a vehicle with the timing advanced on a daily basis, the difference that 5* makes (moving from the factory 5* base to 10* base) is very noticeable - even to a lay person who does not know that the vehicle has been in some way adjusted.

Some basic engine tech and then I will specifically address the two points I raised ...

The amount of power delivered as each piston moves downwards on the power stroke is directly related to the point at which the mixture is ignited - light it too late and it is still burning when the exhaust valve opens, wasting power - light it too soon and detonation occurs - get it "just right" and you get maximum power.

"Just right" varies with the rotational speed of the engine, you need to light it earlier when the engine is turning faster - hence the need for an advance curve in the distributor (if you have an old style distributor with centrifigual weights - or as kick-fix calls them - fly weights) or an advance map if you have ECU controlled direct fire ignition.

"Just right" also varies with the quality of the fuel - lower octane fuel is more prone to detonation and needs to be lit later to avoid detonation - the reverse is also true, if you are using higher octane fuel, you can safely light it earlier and extract more power from each stroke.

There is no difference required in the "fuelling" maps in the ECU to use a higher octane fuel, but changing the ignition advance maps IS beneficial.

1 - that the ECU has no clue as to what octane fuel you have in the tank

The engine has NO way to know what octane fuel is in the tank - there is no sensor to provide it with this information.

If the engine has a knock sensor (which these engines lack), the ECU is capable of sensing detonation due to low octane fuel and "backing off" the ignition advance until it stops.

Please note the ECU does not know what octane is being used, it just knows that detonation or knocking is occuring and it does not retard the ignition when it senses knock, it uses less advance.

2 - the ECU advances the timing relative to the base timing which is determined by the physical position of the cam position sensor.

The ECU relies on a sensor to tell it where the crankshaft is relative to "top dead center" and uses that to determine how fast the engine is turning and when to fire the plugs - if you move the sensor physically the ECU does not know that it has been moved.

If the ECU says fire at 20* advanced assuming the base timing is at the factory's 5* setting for a total of 25* advanced and you (or I) have moved that sensor back by 5*, then the plug will actually fire at 20* and not 25* - if you (or I) have moved that sensor forward by 10*, then the plug will actually fire at 35*.

Your scan guage gets it's information from the ECU - it reports what the ECU "thinks" it is seeing.

Second - the only thing that gets hurt if you put in higher octane fuel without changing the timing is your wallet - you're paying for perfomance and not getting it. It doesn't NEED more advance, it allows more advance.

[kick-fix]

keep in mind 87 Octane buns faster than high octane.
[ keep in mind if i had a pulse detonation engine, my regular becomes performance fuel]\
few understand that. "activation energy"

High Octane. ( preformance has nothing to do with that)
(this reduces the detonation point. so you can use it in higher compression motors that can produce more power due to the CR )
See? , low octane is so hot ,it detonates so easy. ( despite TV BS)
I was discussing these old kicks 89 to 95 and from 99 up some may have knocksensors. ?I dont remember.? other forum,?ask.

we dont have knock sensors. on these old motors 89-98.
other cars do just like you said, including Jeeps.
3d knock sensing and diff, timing on EACH cylinder. (my 99 had it) (and still sucks fuel)

we dont have that , we have very old obd1 cars. and eary OBD2

so putting in high octane fuel only does nothing . (mill the head, ?)

keep in mind , the generations of ECU and motor. not all, are the same.

on the old cars the timing is based on the CMP , if you set it to 5 and max is 20 you get 25.
if you set it to 10 and max is 20 you get 30 (same as said above)
so all timings range up , exactly by your error. nothing new here.
same as old fashioned dizzy. with fly weights. (rpm based 100%) ECU based is 100% base + ECU tables. + base setting. A +B = C. no magic.

that is correct if you lie to motor and to the CMP and ECU , no surprise again.the OBD2 port will lie its booty off. and by your exact error. offset. + or -
There are no redundant sensors to inform the ECU of your meddling.

if you dont have a new car , you dont have a knock sensor.
so it is NOT adaptive, as some real new cars are.

this forum section ends at 98,so explaining this here is of no use? and will confuse many.
other than side dressing. not applicable here.
right?

btw there is a great 3d live engine demo on wiki. all parts demo'd.
all this is shown in great living color.

Yes, thin wallets. that is all you get. cheers.

best of the best. (as typ) OCTANE.
Octane rating - Wikipedia, the free encyclopedia
what was this post. ahh.

advanced timing. so we are ON topic.

Here is my answer guessing at askers , angle ?
free lunch, NO, not even with thinner wallet ( 10000 forums, all with this question 10000 times and same answer) so now here.

the correct question to make it vastly more interesting would be.
What must I do , to make advancing my timing helpful , in some way.
answer, raises , CR, and retune motor and ECU and timing.


or better yet
How can I cut a fat hog , power wise. (zippo) (fire the EPA and get HP)?
sure ( drive WOT full time, it has special 12.5:1 AFR power mode , use it all the time and stop crying, hehehehee , btw that is true)
or
how can I make more power , cheaply.? little.
or
how can i get better economy.

Spinning the dizzy will do nothing . nothing much.
cept make it harder to start. (advancement)
and my cause a loss of power at certain RPMs and loads.

One great post was:
put IN the motor , the lowest octane fuel you can burn at the highest CR you can stand.

as you raise CR, the fuel will self detonate.
destruction.
so you put in fuel that stops this and that is high octane fuel.

Low CR motors with HIGH octane fuel can run rich and misfire.
it has trouble spark igniting and dont burn completely. due to its nature.
so using the wrong fuel in your car is wrong.

the CAT conv. will stink like rotten eggs.

all this ,on 89-98 no other.

speed costs. how fast do you want to go.

better.
want higher top speed.?
want more torque for pulling stumps.
or just want more exhaust noise. , im guessing but others will chime in with wants.

all have different paths and solutions.

you never said what you really want.

how slightly is slightly?

1hp. 1/10 hp?
or 10?

quantify your desires.

I want 25 more HP at 3000 RPM/

or ?
cheers, mr. fat hog