GR Yaris GPF del advice

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GRBadger

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Dec 6, 2021
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Hi folks! đŸ‘‹đŸ» I’m getting a GPF (res) delete pipe fitted tomorrow at a local tuner in addition to my already fitted HJS sports cat. Anyway
 the tuner has just rung me to warn that it’ll almost definitely through a fault unless they map it out with their own software. I was under the impression that nothing needs to be touched in this regard so can someone advise / reassure please?

I’m already running a Litchfield supplied ECUTek tune that’s been faultless so don’t want to mess around rewriting it tbh and was hoping to easily liberate some horses with just a GPF delete. Ta!
 
GRBadger said:
Hi folks! đŸ‘‹đŸ» I’m getting a GPF (res) delete pipe fitted tomorrow at a local tuner in addition to my already fitted HJS sports cat. Anyway
 the tuner has just rung me to warn that it’ll almost definitely through a fault unless they map it out with their own software. I was under the impression that nothing needs to be touched in this regard so can someone advise / reassure please?

I’m already running a Litchfield supplied ECUTek tune that’s been faultless so don’t want to mess around rewriting it tbh and was hoping to easily liberate some horses with just a GPF delete. Ta!
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It shouldn’t throw a fault but I would have thought you’d want to rewrite the tune due to the better flowing system.
 
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Ecsrobin said:
It shouldn’t throw a fault but I would have thought you’d want to rewrite the tune due to the better flowing system.
Click to expand...
Thanks. Yeah that’s what I’m planning to do anyway to optimise along with an IC hopefully next month but just want the car driveable in the meantime. I was of the impression that any sensors are turbo side of the GPF so that’s why it’s all golden when waving it goodbye?
 
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GRBadger said:
Hi folks! đŸ‘‹đŸ» I’m getting a GPF (res) delete pipe fitted tomorrow at a local tuner in addition to my already fitted HJS sports cat. Anyway
 the tuner has just rung me to warn that it’ll almost definitely through a fault unless they map it out with their own software. I was under the impression that nothing needs to be touched in this regard so can someone advise / reassure please?

I’m already running a Litchfield supplied ECUTek tune that’s been faultless so don’t want to mess around rewriting it tbh and was hoping to easily liberate some horses with just a GPF delete. Ta!
Click to expand...
There's a setting in the ecutek software for higher flowing cats/GPF, you likely already have it with your tune.

Call Litchfield to confirm.
 
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What did litchfield say? I am doing the opposite. Have the gpf resonated delete and am fitting the HJS tomorrow
 
Litchfield mapped my car with HJS and it recently had GPF delete fitted but I picked it up on a Sunday so Litchfield weren't available to tweak map.

It was a couple hundred miles home so I was a bit concerned, but hoped it would be okay what with being freer flowing than before. Other way round might not be good idea.

When Litchfield finally got around to looking at it I was just told "looks good and is hitting all targets so we'll just add a bit more timing at the top" so it seems I was worrying for nothing!

It recently passed MOT with both these fitted as well - bonus!
 
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Ok so running a bit more ignition advance. If they had to retard the ignition it would be an issue

maybe if really hammering it. Mine was done on the dyno with the gpf so no remote mapping option. Interestingly they never asked what mods it had.
 
Sent Iain Litchfield a message whilst I was waiting for my local garage to fit the GPF del pipe and he arranged for an updated stage 2 base file revision to be sent over there and then so flashed the ECU before I drove back home again 😊👍

Would love to report back that it’s more rorty on the way home but was stop start rush hour traffic all the way. Did seem slightly louder on start up but the rear seats were down anyway to accommodate the boxed up GPF.

Have got to do some data logging to tweak the map so hopefully get out tomorrow to do this and will report back.
 
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When I fitted the gpf resonated it was definitely a bit louder. A little drone at 2200-2400 but nothing much. It was easier to rev out at higher rpm. I think it flattened the torque curve because it did not feel like it had that surge of power, more a constant drive throughout
 
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Mine's lovely now, like OEM+, you can tell it was designed for Jap cars with no GPF! It's a little loud on startup but nothing that would upset neighbours. Sounds awesome when moving.

My mate wants same setup on his Yaris after hearing mine! Not too sure what he's got now but its a bit bloody loud for me.
 
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Hi all. This week I’ve mostly been data logging numerous revisions of Litchfield’s stage 2 map tweaked to accommodate my GPF and sports cat and can report back that after 3 revisions that the car has a nice deeper and richer tone and along with the ECU tweak is a lot more responsive than previously but very smooth delivery throughout the rev range. I don’t have access to a dyno but it feels very linear up to around 5k then just keeps pulling whereas before it felt a bit strangled and running out of puff.
 
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I would agree with that summary. I fitted the HJS last week and have the resonated gpf delete. It’s definitely both working together because before the HJS mine felt good up top and would really pull but it would come on strong at higher rpm. Before the HJS I felt it had lost some low to mid range torque with all the gain up top. I would not say it was worse than before the gpf delete just the power being delivered differently and higher up the power band. It was a linear power delivery and that actually makes it feel slower because you don’t get that surge that you used to in the mid range that then quickly faded as rpm climb. The HJS has really bought it all together with much improved turbo response and seemingly a power delivery that pulls strongly throughout the rpm range. When I drive it correctly it leaps out of a corner. Noise
..not a huge difference. Yes tone is a little lower and you can hear a little pop or burble on the over run but it passes the wife test in that she has not smirked and called me a dick yet. Other than syvecs which is hard to justify it completes the car for me.

Fitting
.great video on here which I used and it’s spot on. I did mine after 11,000 miles and did not have a single bolt cause an issue. You will need a 3/4” impact gun just to get the initial torque required for the prop shaft guard and bracket for the cat to gearbox, otherwise it’s all hand tools. It took me 4 hours or so but an hour of that was me looking at it and scratching my arse or elbow without knowing which was which. No issues with the pressure pipe set up.
 
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