Near Stock v. OFT Stage 2 Dyno

[DarkSunrise]

Originally Posted by Shiv@Openflash

By the looks of it (high higher, soft fuel cut), you have a tune file loaded. So I don't think that is the culprit. That header may just require custom tuning. Do you know if you were running a 93oct map or a 91oct map? The 93oct map, on 93oct, will make a few hp more.

That was 93 octane map on 93 octane fuel.

Do you think it's worth trying another dyno (i.e., coolant might have been cold, ECU may need to adjust, etc.) or should I just go straight to custom tuning? The odd part to me are the losses before 3500 RPM. I'm not a tuner, but that makes me think the engine wasn't completely happy for those runs or things hadn't properly broken in yet.

[Shiv@Openflash]

Originally Posted by DarkSunrise

That was 93 octane map on 93 octane fuel.

Do you think it's worth trying another dyno (i.e., coolant might have been cold, ECU may need to adjust, etc.) or should I just go straight to custom tuning? The odd part to me are the losses before 3500 RPM. I'm not a tuner, but that makes me think the engine wasn't completely happy for those runs or things hadn't properly broken in yet.

I think the best thing would be to flash the stock file back into the ECU and then dyno on the same dyno. Just make sure the engine is warmed up and that you do a few runs to get the header up to temp. That will give you a good idea of what kind of changes to expect with the new mods. If you still see the same loss of torque below 3500rpm, then it's caused by the new modifications and it's very unlikely that a tune is going to recover that. Where the tune will help primarily is from the midrange dip area and up. Very little can be done to improve low end response as that is most influenced by engine pumping efficiency.

Once you have this data, realistic expectations can be set and you can begin the custom tuning process.

That's how I would do it at least

[drewbot]

Originally Posted by s2d4

Open Loop actually.

Crap, but you know what I meant

[Fast_Freddy]

Since the intake wasn't changed I don't see all the fuss about the ECU needing time to learn. When I had my Ecutek tune flashed and dyno tuned there was no ECU re-learning required and subsequent dyno testing showed no further gains attributable to ECU re-learning. IMO the OP's results demonstrate one of the problems with "one-size-fits-all" canned tunes.


My mods were Borla UEL, Tsudo HFC front pipe, K&N drop-in. Base whp un-tuned was 160, canned stage 2 tune made 170 and the final tune produced 177whp.

[s2d4]

Loss of power in close loop -> no learning required, no need to be up to temp.
Some stock cars need MAF scaling -> no learning required, no need to be up to temp.
177whp tuned warm vs 178whp tuned cold-> no learning required, no need to be up to temp.
160whp stock vs 177whp stock-> no need to care about different conditions, different engine, who cares if one is surprisingly high and one is surprisingly low.

[steve99]

Originally Posted by DarkSunrise

That was 93 octane map on 93 octane fuel.

Do you think it's worth trying another dyno (i.e., coolant might have been cold, ECU may need to adjust, etc.) or should I just go straight to custom tuning? The odd part to me are the losses before 3500 RPM. I'm not a tuner, but that makes me think the engine wasn't completely happy for those runs or things hadn't properly broken in yet.

I think it would be worth logging a couple of wot runs in 3rd 2000-7500 to see what it looks like.

you may have exhaust leak upsetting O2 readings causing high fuel trims or heaps of knock ect that is cause of power loss be interesting to see street log to make sure it all looks ok.

on oft log

afr
commanded afr
wideband afr this is second o2 sensor
knock correction
flkc
iam
ltft
stft
rpm
load

[wparsons]

My money is still on doing the pulls before VVT activated, especially with the losses down low.

[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)?

[DarkSunrise]

Originally Posted by s2d4

Loss of power in close loop -> no learning required, no need to be up to temp.
Some stock cars need MAF scaling -> no learning required, no need to be up to temp.
177whp tuned warm vs 178whp tuned cold-> no learning required, no need to be up to temp.
160whp stock vs 177whp stock-> no need to care about different conditions, different engine, who cares if one is surprisingly high and one is surprisingly low.

Could I ask what you mean when you say "no need to be up to temp?" I'm no expert, but I thought I read somewhere that low coolant temps could result in up to 20 hp less on the dyno with these engines.

Originally Posted by steve99

I think it would be worth logging a couple of wot runs in 3rd 2000-7500 to see what it looks like.

you may have exhaust leak upsetting O2 readings causing high fuel trims or heaps of knock ect that is cause of power loss be interesting to see street log to make sure it all looks ok.

on oft log

afr
commanded afr
wideband afr this is second o2 sensor
knock correction
flkc
iam
ltft
stft
rpm
load

Thanks for the suggestion, I will see if I can get some 3rd gear logs in a few days.

[s2d4]

Originally Posted by DarkSunrise

Could I ask what you mean when you say "no need to be up to temp?" I'm no expert, but I thought I read somewhere that low coolant temps could result in up to 20 hp less on the dyno with these engines.
.

All of that was sarcasm.

[DarkSunrise]

Originally Posted by s2d4

All of that was sarcasm.

Doh I skimmed over your post and that went completely over my head

[BuBlake]

My guess is that the AFR is pegged rich or your IAM is lower than 1. I would gladly take a look at your logs and let you know if I see any problems. Log KC learned, Adv multiplier, AFR, commanded AFR, Engine speed, Engine Load, and MAF voltage. After making a few small adjustments to my own OFT tune I went from sort of feeling like I had a faster car to not being sure if I need forced induction.

[DarkSunrise]

Originally Posted by BuBlake

My guess is that the AFR is pegged rich or your IAM is lower than 1. I would gladly take a look at your logs and let you know if I see any problems. Log KC learned, Adv multiplier, AFR, commanded AFR, Engine speed, Engine Load, and MAF voltage. After making a few small adjustments to my own OFT tune I went from sort of feeling like I had a faster car to not being sure if I need forced induction.

Awesome thanks man. I will try to get some logs in the next few days and post them up.

[wparsons]

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)?

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.