Timing

[Mybowlcut]

Hey guys.

 

Just wondering in what cases you'd adjust the timing on a car? I've heard that you do after you put a Weber on, but what are other cases when you would change it (apart from when it's out from wear and tear)?

 

Cheers.

Edited December 23, 2008 by Mybowlcut

[Super Jamie]

change of compression, modifications to distributor, change of fuel octane, tuning to get quicker response down low but less top end or vice versa

[Mybowlcut]

change of compression, modifications to distributor, change of fuel octane, tuning to get quicker response down low but less top end or vice versa

Interesting...

 

1. A shaved head would affect compression, yeah? If so, what kinda of adjustment would I make to compensate for this? What about a porting job?
   
2. Would a change of fuel octane (ie between unleaded and ultimate/premium) require adjustment? Or do you mean like ethanol or crazy stuff?
   
3. I thought if your timing wasn't set to the standard timing (or adjusted to suit the things you listed minus the last one) that it would mean the engine won't run as well? Could you please explain this a bit more?
   

Cheers.

[SLO-030]

Interesting...

[*]I thought if your timing wasn't set to the standard timing (or adjusted to suit the things you listed minus the last one) that it would mean the engine won't run as well? Could you please explain this a bit more?

Cheers.

 

The stock timing setting is usually a bit of a compramise really, for diveability, power, idle etc as the average joe doesnt wanna have a crap low end just to have a few extra hp in the high top end.

 

upto a point you can mod the factory settings for that bit more power on a fully stock engine, but if you go too far you too begin to comprimise things (e.g scarificing low end driveability of more top end power).

 

but as soon as you go modifying things like compression, cam, carb you have to change settings accordingly.

 

Yep a shaved head will increase comp. not sure how much more advance would be nessacery as it depend on how much you get it shaved and what the final compression ratio is.

 

Also a change of fuel, say from regular ULP to premium. you can give it a bit more advance to take advantage of the extra octane.

 

My ute is tuned for about 95-98 octane but due to the expensive petty price and fuel consumption i was running regular (91) and you could tell it wasnt tuned for it because as soon as you opened the secondaries it would ping a little bit.