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Hey guys I'm not used to tuning ej20s at all so sorry if I sound dumb ,
The car has a forged motor unsure of cr but I would think it's around stock fitted with a td05 16g turbo with a apexi pfc
Cars only running 1bar of boost atm hoping to run 1.5 bar
I take it these engine take a lot of advance , at just over 1 bar I've around 17 degrees and no audible knock at all, I have a feeling I'm underadvanced ,I've no dyno I can use unfortunately, could any one help me with a ball park timing figure for 1 bar and 1.5 bar for reference
Thanks for any help
It's hard to give you a ballpark value for ignition timing that will be safe. There are too many factors that can effect what the engine can take. You're right though that the EJ20 does usually want quite a lot of ignition advance compared to say an SR20DET or 4G63.
Without the use of a dyno your only real option is to slowly advance the timing until you find the knock threshold and then back it off to provide a safety margin. I would do this using quality audio knock detection, although most of the time I find the knock detection in the Power FC actually is quite effective.
Depending on fuel, CR etc you may find you're not knock limited at 1.0 bar although with a TD05 16G you almost certainly will be at 1.5 bar on pump gas.
Sorry I can't help more but the correct advance needs to be found for each application. Relying on someone else to give you numbers can be dangerous.
Thanks for ur help I fully understand what your saying
Another software you can grab is Barnhill's Virtual Dyno software and on there you can also input a WOT log and see if you are making positive changes to the tune on the timing map. At the same time listening for KOcounts.
There are many variables as was mentioned earlier, fuel, efficiency of tmic or fmic, ambient temp changes, coolant and also iat conditions. All these will affect how the ECU puts timing in until it hears a KO event.
Thanks I've just downloaded it , looks great il give it a try later
Ended up we had the wrong injectors so had to keep boost around a bar and stick with the stock injectors , timing at the top end around 22 car felt good for only 1 bar boost , was very impressed with virtual dyno , funny the apexi never picked up in so light knock coming on boost but I could hear it pretty easy
Thanks again guys
I've found the knock detection system in the Power FC to be a little hit and miss. In 90% of the installations I've been involved with it's worked exceptionally well. The other 10% it has either detected false knock (admittedly this was usually on mechanically noisy engines), or worse still it has struggled to detect knock that i could audibly hear with knock detection gear - this is why I'm such a big advocate for quality knock detection equipment.
Is the EJ20 a 205 or an EJ207? The 207 has a semi closed deck where as the 205 is open deck, not much support there. For a 16G Sized turbo, you could reference timing off of a Cobb Accessport map for a Stage 2 STi ( software and maps are free ), would be pretty similar, at least to give you a ball park idea. 16G isn't too much bigger than what is on the STi from the factory, though a little.
While they may take more timing than other motors ( I am ignorant to any other motors for comparisons ) Timing at peak torque kills EJs. Dont over do it; especially if you're not using a quality fuel.
On most all wrx's that I have tuned, I have found peak timing to hardly ever be greater than 17 or 18 degrees at redline. Usually I keep it around 15 degrees at 4-6000rpm. I find the EJ20, is better suited with greater boost pressure than timing to produce proper power.
@r.spec the peak timing value you mention is still going to rely heavily on the actual boost pressure you're running too. For instance the timing the engine will accept at 15 psi is not going to be the same as what it will accept or want at 22 psi.
Anon, Here was my rough tune on a Ej20G with GTX3071. Good pump gas and pretty low compression engine. But from what I gather the older Ej20G take a bit more Ign than the Ej207/205.
Although looking at this now, it looks rather aggressive and messy!