Near Stock v. OFT Stage 2 Dyno

[DarkSunrise]

Originally Posted by ztan

Does it take a while for AVCS to get cam position registration initially sorted after flashing the ROM and doing a run?

I seem to remember a recommendation to let the car idle for at least 30s, if not more, after re-flashing.

OP and Fast_Freddy: was there any settling in time after reflashing between pulls, or did the pull get run straight away (i.e. was there any time for the cam timing to get settled)?

Hmm that's the first I've heard of that. We didn't let the car idle for 30 seconds after flash, so that might have been the issue too.

[Wepeel]

I believe the recommendation from Shiv is to let it idle for 60 seconds after a reflash without touching the throttle pedal.

[s2d4]

Originally Posted by wparsons

I don't remember what the reasoning is, but it definitely takes a while before VVT changes start happening.

I don't remember how long it normally takes, but I just watch the OFT until the valve timing starts changing and then drive away.

Might pay to wait a little longer if it is apparently still self calibrating.

[s2d4]

Originally Posted by DarkSunrise

Hmm that's the first I've heard of that. We didn't let the car idle for 30 seconds after flash, so that might have been the issue too.

Nah, must be the OTS tune since Freddy says so.

[Fast_Freddy]

Originally Posted by ztan

Does it take a while for AVCS to get cam position registration initially sorted after flashing the ROM and doing a run?

I seem to remember a recommendation to let the car idle for at least 30s, if not more, after re-flashing.

OP and Fast_Freddy: was there any settling in time after reflashing between pulls, or did the pull get run straight away (i.e. was there any time for the cam timing to get settled)?

In my case there was no settling in time between flashes and pulls but it's a moot point now that s2d4 has everything figured out, as usual.

[904FRSlow]

After flashing, isn't it 50 miles for the fuel trims to relearn?

[wparsons]

It can take A LOT longer than 50 miles for the trims to stabilize, depending on a lot of factors.

Plus, unless the tune was WAY off, it wouldn't drop power like this.

It's been confirmed that the car was flashed and basically run on the dyno immediately after startup, so I'm sticking with VVT being disabled.

[904FRSlow]

Originally Posted by wparsons

It can take A LOT longer than 50 miles for the trims to stabilize, depending on a lot of factors.

Plus, unless the tune was WAY off, it wouldn't drop power like this.

It's been confirmed that the car was flashed and basically run on the dyno immediately after startup, so I'm sticking with VVT being disabled.

I just reflashed my car last night. I got to 50 miles today and was told by my friend that 50 is fine.

[phrosty]

Originally Posted by 904FRSlow

I just reflashed my car last night. I got to 50 miles today and was told by my friend that 50 is fine.

When it comes to fuel trims, it's not so much miles as it is how much time you spend in each trim bucket.

[s2d4]

Originally Posted by wparsons

It can take A LOT longer than 50 miles for the trims to stabilize, depending on a lot of factors.

Plus, unless the tune was WAY off, it wouldn't drop power like this.

It's been confirmed that the car was flashed and basically run on the dyno immediately after startup, so I'm sticking with VVT being disabled.

Surprising to see it make 178whp up top with AVCS off.
Maybe people who knows about it can chime in.

[s2d4]

Originally Posted by Fast_Freddy

In my case there was no settling in time between flashes and pulls but it's a moot point now that s2d4 has everything figured out, as usual.

Easy, don't make statements until it's been confirmed.

[904FRSlow]

Originally Posted by phrosty

When it comes to fuel trims, it's not so much miles as it is how much time you spend in each trim bucket.

I drove 50 miles below 4k rpms. It feels pretty normal driving now so should I be good if I go WOT?

[DarkSunrise]

@steve99 @BuBlake

Did six 3rd-gear pulls tonight on the highway. Would love to know what you guys think:

http://www.datazap.me/u/darksunrise/...e?log=0&data=1

One thing I noticed upfront was that my IAM started off around 0.88, but quickly rose after that. Not sure how long it's been that way.

[Fast_Freddy]

Originally Posted by s2d4

Easy, don't make statements until it's been confirmed.

When has that ever stopped you?


No, I think you nailed it. His MAF needs to be re-scaled and the ECU needs a lot of time to learn those big fuel trim changes caused by the exhaust mods. Although the OP only questioned the possibility that his engine might have been too cold on the post-tune pulls, your assumption that it definitely was too cold must surely be correct since it is your assumption.


Bravo.