How many degrees of timing is ideal during WOT?

[PieEyedPiper]

I've made several runs on the logger and have found my peak timing at WOT to be anywhere from 19-24 depending on ambient temperature and boost levels.

What is ideal? is higher always better?
Thanks.

 

[andymoraitis]

So, after reading this thread, I'm wondering if there is an advantage in advancing my base timing a few degrees (3-5*?)

I have an E3 @ 15psi and stock injectors, 190LPH and rewire but no fuel tuning. I don't see any knock, and my idc's hit around 100% just barely at the top of 3rd.

Absolutely not. As it stands, you're maxing your IDC's and that's rough on the injectors. Adding more timing advance is optimal in the case of zero knock, but if you advanced it any more, you'd go over the edge. As of right now, you need to back the boost down until you add proper fuel mods to bring those IDC's down.

For the record, I run a maximum of 12 degrees advance on a built 2.3 stroker and 50 trim on pump gas at 24 psi. Since the motor runs 8.8:1 and it has enough displacement to drastically increase air velocity, more timing than that isn't needed. If you look at how SBR tests their built motors, most are set to 12-14 degrees advance and high boost. It's always boost over timing on pump gas and you'll even find them using low timing on race gas. Buschur confirms the same thing.: a conservative race gas A/F at 11.5:1, low timing and gobs of boost.

Since the 1G runs lower compression at 7.8:1, you'll find that the timing maps are much more aggressive as there's more tolerance for additional advance before triggering knock. The stock 2G map peaks at 16 degrees on the highest airflow table due to a higher compression ratio (8.5:1). It's already been stated, but it's worth repeating that every motor will tolerate somethiing a bit different and the best way to find out is to log airflow and monitor knock, or get it on a load bearing dyno and see which method makes the most reliable power.

Let me add a caveat here. Don't try to run low timing advance like mine on stock, cast, parts. It's a recipe for hurting the internals in a serious way.

Just my .02,

Andy

 

[PC5505]

thanks for setting me straight.