How much timing for 98RON FI WOT

[chunkyvy]

Hey guys just going though a few tune logs that have ended up in my possesion, i no nothing about tuning but was wondering if 16-17 dg timing at WOT on 98ron running 14PSI seems excessive? Standard comp and stroke engine.... Thanks guys

[Tre-Cool]

with that engine combo & boost with that fuel octane level to me is a big YES.

Do you see any KR in the log?

[LuisS]

It's up there....

[chunkyvy]

No KR but some BS (block split) was evident, lol. Just trying to pin point what went wrong. Will post log sheets shortly for all to see.

[Delft Maloo]

12* is getting up there as being high on most setups but 16-17* is pushing well past the safe zone imo, unless your running some meth or other high octane additive.

[chunkyvy]

no additives at all.... just pump 98.....So obviously to SOME tuners out there this does seem excessive.... interesting....

[jca]

Hi, is that the actual timing or the conmanded timing?. regards Jason

[Delft Maloo]

Hi, is that the actual timing or the conmanded timing?. regards Jason

Good point, big difference. Iv seen a few boosted tunes that have high timing in the main tables but rely solely on adders/subtractors to keep everything in check.

[vuss383]

To SOME tuners ....... That little quotation has me wondering . If you think its ok to run that sort of timing on the combo mentioned you would want to have a good supply of blocks imo .

In saying that, on a built engine with the comp in the correct region you will get well over the safety of 12* on pump fuel.

Troy

[swingtan]

If you ran 1.5:1 rockers, the timing is probably fine......

16' would be pretty high considering you're pumping in twice as much air as normal. The cylinder pressures would be very high, making the chances of detonation also very high. I guess there is a remote chance that the engine running very rich to try and control that much spark, but it does seem very high. What were the logs taken with? Any chance of providing them for checking?

Simon.

[LuisS]

no additives at all.... just pump 98.....So obviously to SOME tuners out there this does seem excessive.... interesting....

Take the information anyway you like :)

From my end , if I was tuning a std comp & stroke engine running 14psi boost , I'd reckon I'd be somewhere between 10-15 deg max....

A camshaft may allow for extra timing , as will a nicely working intercooler....

As I said , in my opinion , 17 deg on that combo is getting up there..

[planetdavo]

Hey guys just going though a few tune logs that have ended up in my possesion, i no nothing about tuning...

Is it really worth playing, considering the risks involved with a fair few dollars of engine by the sound of it???
Sounds like tears if you get it wrong. :bawl:

[chunkyvy]

I am not playing with it, I am checking the screen shots taken from the tune after it went wrong. Everyone I have asked has said it was too much timing, just thought I would ask on here as I know there are some very good tuners on here. I will post up info shortly. Car went really well, for a very short time :bawl:.

[HYMEY]

I normally only run 12 degrees on 6 psi on pump fuel, as I have found any more timing doesnt really do much for gains in power, air-fuel ratio will somewhat under full boost, Keeping the afrs stable at 12.0:1 and 12 deg works nicely on LS3s/L98s with low boost, be f^&* if I would run that much. Some guys think more timing more fuel works with FI but I found correct afrs and moderate timing is the key to reliability and hp. Its all about safety of stock internals, don't push it a bit of heat soak and its all over. If you keep the timing moderate and afr stable hp will be more consistent and removes the need for adding/subtracting timing all the time which normally happens with more aggressive hi octane tables. Problem is turbo motors are heat soaked most of the time anyway. Keep the timing moderate and consistent and be happy with it.

[macca_779]

It's certainly may be up there. But without knowing dcr, afr, iat we are all just guessing.