injectors?

[drdarthinvader]

hi everyone
whats the basic principle to adjusting the perameters to the ifr ?
and what else would it alter?
i thought id start the vehicle tune with the injecters. as per forum advice
sorry this thread should be in gen III

[joecar]

The IFR works together with the VE and/or MAF tables...

If you change one, then the other is out.

[drdarthinvader]

ok ill wait until i get my lc-1 to interpolate the ve table yes?
one more question optermising the ve table does what to the engine ?

[joecar]

Dialing in the VE table means that the wideband measure AFR matches the commanded AFR...

This means if you set your commanded AFR (see B3605 and B3618) to say 12.8, then the wideband sees exactly the same... i.e. you can directly set your AFR for best torque and power (determined empirically on dyno, at the 400m track, or by other people's experience) on the first attempt... i.e. no "guessing around to steer the AFR in the intended direction"... you set it and you get it.

A dialed in VE table may be thought of as being "correct" in that it allows the PCM to calculate the true actual cylinder airmass.

[joecar]

Remember that:
- Above B0120, PCM calculates airmass from MAF,
- Below B0120, PCM uses MAF (steady state conditions) and/or VE (transien conditions).

Also, in OL the PCM selects AFR from:
- B3605 if not in PE,
- richer of B3605 and B3618 if in PE.

[drdarthinvader]

while ive got your attention
a sequence you would do is 1>injectors b4001 2>dial in ve table b0101
3>dial in maf table b5001 4>spark ho table b5913+low table 5>mixtures.....?

[joecar]

Would do 5.mixtures concurrent with 2. or between 2. and 3.

Remember, you don't want to go lean at WOT or at load...
set your B3605/B3618 to be suitably rich when doing AutoVE;
enabling PE may allow tracking errors during transition to/from PE if B3618 is significantly different than B3605... you can either leave PE enabled and have B3618 match B3605 in that area, or leave PE disabled and set B3605 rich in that area... either way the AFR has to be rich at load.

Don't need 3.maf if you're going to run SD... otherwise dial MAF in the same way as AutoVE (enable MAF, set B0120 to zero, make BEN table to mirror MAF B5001 table).

4.spark maybe hard to do without a dyno... advance till you see peak torque (torque stops increasing, flattens out), back off to just before flattening... all while keeping an eye open for knock/ping... knock/ping is not allowed... also spark timing required may/will change as AFR changes.

Also, when doing AutoVE, don't just raise the VE B0101 by 15%... the tutorial assumes heads/cam and other mods... look at your mods, and increase the VE accordingly... examples (varies on each persons's specific case): headers 4%; heads 7%; mild cam 6%; heads, cam 11%; heads, big cam, big manifold, 4:1 LT extractors 15%... you get the idea. ;)

When doing AutoVE and/or AutoMAF, remember to apply filtering to BEN map... think about the filter you're applying, you must filter out transient conditions... when driving to take a BEN log, operate the throttle as smoothly as you can... good data in -> good data out.

Also make sure motor/car is in good shape before tuning... spark plugs/wires not worn out, no air leaks, no oil thru PCV, no coolant leaks, clean air filter/MAF, good tyres (balance weights not lost), regular maintenance, etc.

:cheers: