sdminus

Im thinking of adjusting my ignition timing on my fd. ( i feal there is more to be had )

Are there any golden rules while adjusting. I currently get low knock levels
( more noise ) around 30 ish.

I was gonna take it by 1 deg at a time but am unsure how to do this regarding the split. .

What would be my peak torque knock level. I have only the open road to use at the mo and no egt gauge

Scott

papsmagu

iTrader: (19)

without setting up a map watch and logging your knock readings you are playing with fire. get a datalogit and start logging before you blow your engine.

sdminus

I have all this running. my knock is very low but i was wondering on the amount of timing the engine would take. I can refer to racing beats figures but i am told its a bit old skool and they speak nothing of the split really.

It seems like the car requires more fuel the closer the split. Is this correct. I am trying to learn this in detail for myself.

Scott

rynberg

The only way to safely play with timing is on a dyno with an EGT and wideband. Even then, it is relatively easy to blow stuff up.

sdminus

Thats really what i want to avoid. I was thinking that i would need a egt gauge. TBH the knock i get is quite low and doent change when the car is lean or rich really.

Scott

SlvrRexx

Err... I'm kinda at the same point at you sdminus. i'm looking to start upping my timing on pumpgas. umm... question why is the EGT very important? your exhust gets hotter under less and less timing right? <---i could be really misinformed. My knock levels are consistantly around 16 but i've seen one random spike to 40 once, hooked up my datalogit to log it but never got the 40 again. I'm planning on having my maps and logs up soon so you guys can make comments on it. also.. does changing timing change afr? not split but timing. cuz from what I read on rx7 tuning at top of single turbo forum it made it seem like the afrs do not change.

sdminus

From what i have seen it would suggest that the afr will alter when you make large timing changes. I am unsure about the egt. I get knock about 28 at peak tq ish. I got a big foot up on this with the timing map i got. I have experimented with a close tuned but over rich fuel map. I swaped between differant ign maps. The map with the closest split give the best drive and the best performance. This makes me wanna bring the split closer but i dont know how to do this in a controlled way and with safty.

Scott

twokrx7

iTrader: (1)

I don't understand why you need to know if changing timing affects AFR, if you are doing this experimentation you had better be logging with a wideband anyway. If you are talking small changes I don't expect you will see anything significant or consistent. Even with no changes the AFR can change a bit from run to run, crappy IAT sensor design and location makes sure of that.

You can tune ignition advance (meaning combo of leading and split, reducing split is like advancing the leading timing) to the threshold of safe knock and then back off a degree or two but you will not know how safe or optimal you are without more data (EGT & hp). I'm not saying not to do this because it's what I did for years, you better have a good believable and consistent knock sensor. My next rotary turbo will have EGTs in each runner setup for datalogging and I'll do final tuning on a decent dyno that can load up the car.