So I bumped the timing.....

[turbovanman²]

I agree with Simon about being careful. But then again I was running 18 + degrees of advance with a FWD stage 5 cal for my g-headed 2.5 and it still was a dog. That was my first and last cal I bought. After working with Rob's base cals and D-cal I will never go back. The CEL knock is a great thing.

I am running probably more than that on my TIII. For some reason, it LOVES it,

[Aries_Turbo]

I am running probably more than that on my TIII. For some reason, it LOVES it,

in vac, yes.... in boost, no....

Brian

[janus]

care to explain brian?
i hear too much spark advance (in boost, supposedly?) will hurt turbo spoolup, right?

[Aries_Turbo]

i was only commenting on simons van. it likes more timing out of boost. makes the van more responsive and smooth on the street. he still needs to take some timing out of the ecu in high boost levels.

too much advance in boost causes detonation and breaks stuff. it shouldnt affect spoolup once slightly into boost that much.

as far as timing advance killing spoolup in vacuum.... if the engine is more responsive out of boost, spoolup is going to be decent.

now, pulling LOTS of timing and dumping in extra fuel really decreases spoolup time cause there is gas igniting in the turbine housing.

Brian

[janus]

ah sounds well understandable. thanks for clearing things up. i didn't think the 'too much timing under boost' was due to stuff breakage also, as far as the 'anti-lag' raw fuel dump into the turbo goes, i guess that's not what most of us would use on a street driver

sounds like one could tune the timing in vac right away based on the resulting responsiveness then.

[Austrian Dodge]

it's not uncommon to have very low (even negative) timing somewere in the ignition map, to help spool the turbo.
ford cosworth have a dip in their timing map somewhere in the 2500rpm range...it drops to -3° and rises with the next RPM break point again.

[fastasleep]

now, pulling LOTS of timing and dumping in extra fuel really decreases spoolup time cause there is gas igniting in the turbine housing.

Brian

I thought this was how a two-step with retard helped spool up on the line. Of course, I am talking about 8* or a little less retard (roughtly 4* BTDC) with the two-step to get the turbo to spool, not 1*-2* ATDC. This would leave the fuel to ignite while the exhaust valve was still open (hence, the loud pops from the exhaust). This is what I was doing on the Pinto to get it to spool. Once I let off of the momentary button (hooked to the clutch pedal) that energized the 2-step and retard, the thing was already at 8-10 psi. and lanuched.

Also, I thought that was what I was seeing when I saw the rally cars shooting flames; they wanted to retard the timing to get the turbo re-spooled quickly after being out of throttle momentarily............don't know why I thought that..............

Am I way off here?

-Les

[turbo84voyager]

in vac, yes.... in boost, no....

Brian

On mine this was a fwd cal so I couldnt tweak the advance other than advancing the timing in the distributor so I had my distributor at 18+ degrees so I had 6 degrees more even under boost.