advance ignition timing?

[neilwade2000]

i hear that mk2's can gain power from advancing ignition timing,if this is so could anyone tell me how far to advance on a n/a 2ltr 1990? CHEERS GUYS.

[Lauren]

You need to check the timing with a timing light, 'tis the only way.

Advancing the timing is not a brilliant idea, the best you could do is set the timing to stock with optimax in as this will help, though the difference will not be astounding. Though this will mean that the engine is liable to pinking if you run standard unleaded.

Advancing the timing by just guessing is not a good idea as you could easily melt your pistons if you are not careful.

[Leon.]

[JJ]

The mk2's have knock sensors to retard the igntion accordingly in the event of pinking occuring - very few NA's I've advanced have had increased levels of knock = responce improvement and ecu doing its job !

[BenF]

On a Friend's Rev1 NA GLimited , we advanced the timing a few degrees after a session on a rolling road when he was running optimax.

What we saw was a little more mid range torque (10ft/lbs) but peak power output remained the same as before, around 160bhp, even with an intake and exhaust. Top end power was probably limited due to the standard ECU overfueling.

A few days after this he found he was getting knocking at light throttle when cruising at 70mph (I can remember my 120bhp Mk2 coupe doing this too) and we had to set the timing back to standard 10 deb BTDC.

I'm fairly sure the early Mk2 NAs didn't get knock sensors though (especially given the problems he had) - all Mk2 turbos certainly do though.

[JJ]

I'm fairly sure the early Mk2 NAs didn't get knock sensors though (especially given the problems he had) - all Mk2 turbos certainly do though.

Perhaps - I've got two rev 2 NA blocks on the floor with knock sensors - havent had my mits on a rev 1 yet - will do soon though for knowledge.

To many factors involved from different engines / milage... ones that are using a little oil will create pinking / knocking earlier than a tight engine .... applies to those with increased levels of blow by around the rings - more positive crank gas = more recirculated into the intake - again, effectively diluting the mixture and causing knock.

Spark plugs, injectors etc etc... all contribute to it. The key is to have a nice combination of good parts, then the ignition timing can go forward to improve response and not provoke unsightly unharmonic combustion.

On a Friend's Rev1 NA GLimited

Again.. another note, another ecu to the equation japs spec difference to Uk destined - one that designed to run with 100 ron petrol = already aggresive ignition maps !

[BenF]

I'm fairly sure the early Mk2 NAs didn't get knock sensors though (especially given the problems he had) - all Mk2 turbos certainly do though.

Perhaps - I've got two rev 2 NA blocks on the floor with knock sensors - havent had my mits on a rev 1 yet - will do soon though for knowledge.

To many factors involved from different engines / milage... ones that are using a little oil will create pinking / knocking earlier than a tight engine .... applies to those with increased levels of blow by around the rings - more positive crank gas = more recirculated into the intake - again, effectively diluting the mixture and causing knock.

Spark plugs, injectors etc etc... all contribute to it. The key is to have a nice combination of good parts, then the ignition timing can go forward to improve response and not provoke unsightly unharmonic combustion.

'unsightly' - lol!

On a Friend's Rev1 NA GLimited

Again.. another note, another ecu to the equation japs spec difference to Uk destined - one that designed to run with 100 ron petrol = already aggresive ignition maps !

Yep, Jap fuel is 98 or 100 RON - I'm assuminng the NAs probably would have been setup to use 98 RON my MrT for the Japanese market.

He was only seeing 160s in power output - he may have needed new HT leads and plugs to improve the power figures ...

[JJ]

He was only seeing 160s in power output

Isn't that enough ???? considering no major mods ??? Might have been roller inaccuracy to peak higher too !

[ethan]

if you have induction and zorst i would also gut the tvis and grind out some grooves were the butterflys were you loose a big of low end but mid/high is alot better as the air velocity islower helping higher revs then i would advance a bit of timiing