GR86 Exhausts

[unrealpatrik]

Remark Axle-back owners!

I finally installed the Remark Axle-back. What I find strange though… I received an additional flange type gasket for between the OEM stock midpipe and the Remark Axle-back… first I thought that it’s a spare gasket for the axleback but the size is actually different and fits perfectly on the rear of the stock midpipe…

This gasket is not mentioned in any instructions provided by the seller nor on the official Remark page… all instructions manuals and videos say to install the axle-back using the stock OEM gasket ring.

Anyone had the same?

I just installed the axleback on the stock ring type gasket per instructions, just wanted to check if I am not missing something?

 

[KobayashiMaru86]

I had one too. I didn't use it.

 

[unrealpatrik]

I had one too. I didn't use it.

Thanks for letting me know.

I emailed Remark and it was included by mistake it seems…

 

[Bathroom_Security]

The chaps at Abbey were kindly entertaining me about upgrades and exhausts and there looks to be 3x sensors on the front pipe, mentioned ones a pressure sensor?

Apparently the UK cars are a bit of a pain because we have the GPF and no one knows about the additional sensors. Even HKS weren't aware of it apparently.

Fensport still haven't got round to mapping the 86 yet, distracted with another car currently.

I know there are people here that have removed the GPF/OPF. Can you let me know is it worth removing it? PM me if you'd rather ...

 

[GRistopher]

The chaps at Abbey were kindly entertaining me about upgrades and exhausts and there looks to be 3x sensors on the front pipe, mentioned ones a pressure sensor?

Apparently the UK cars are a bit of a pain because we have the GPF and no one knows about the additional sensors. Even HKS weren't aware of it apparently.

Fensport still haven't got round to mapping the 86 yet, distracted with another car currently.

I know there are people here that have removed the GPF/OPF. Can you let me know is it worth removing it? PM me if you'd rather ...

I'm also intrigued, but don't want to throw up a CEL. I've scoured the web for high-flow GPFs and can't seem to find any. When i asked Fensport, they said they were still in the developement process.

 

[ZN8]

The chaps at Abbey were kindly entertaining me about upgrades and exhausts and there looks to be 3x sensors on the front pipe, mentioned ones a pressure sensor?

Early on I thought it was temperature but pressure makes more sense since its a filter. I would imagine you would have a pre and post pressure sensor to measure the deltaP across the GPF to let you know if it gets clogged up. I don't suppose anyone knows as its still new. Tbh it should probably be left alone, it just seems morally wrong to start pulling out emissions equipment nowadays when we are all pushing forward with climate change, its a bit like pouring engine oil down the drain.

 

[GRistopher]

Early on I thought it was temperature but pressure makes more sense since its a filter. I would imagine you would have a pre and post pressure sensor to measure the deltaP across the GPF to let you know if it gets clogged up. I don't suppose anyone knows as its still new. Tbh it should probably be left alone, it just seems morally wrong to start pulling out emissions equipment nowadays when we are all pushing forward with climate change, its a bit like pouring engine oil down the drain.

I maybe have a bit of confirmation Bias here, but there's a lot of data "online" that suggests that GPFs don't make any meaningful difference to emissions on petrol engines. The introduction of them is more of a one-size-fits-all approach by the regulators for all combustion engines.

 

[Sonic]

it just seems morally wrong to start pulling out emissions equipment nowadays when we are all pushing forward with climate change, its a bit like pouring engine oil down the drain.

It's also illegal to tamper with, or remove, emissions equipment. Removing the GPF will result in an MOT failure, making a vehicle unfit for road use and voiding the insurance. That's not to say that a lot of folk don't do it though - it's all about 'risk' and 'chance' again. The risk of being in an accident and the chance of your car being inspected may be small. I've done it before but, had to find a petrol head friendly local garage to remove the GPF on my KonaN; many other places wouldn't touch it for fear of being prosecuted and losing their MOT status aso. In the end it made little to no difference against changing out the header, putting in a 400cel Sports Cat and upgrading the whole system to 3". I'd not want to do it again, especially on a car under warranty.

 

[ZN8]

I maybe have a bit of confirmation Bias here, but there's a lot of data "online" that suggests that GPFs don't make any meaningful difference to emissions on petrol engines. The introduction of them is more of a one-size-fits-all approach by the regulators for all combustion engines.

I'm sure there are instances where the difference they make is negligible but the tech works for this car in my experience...

GT86, 300 miles after last clean (The carbon build up was a lot worse when it had a Perrin exhaust on it.)

GR86 after 2,000 miles after last clean (don't judge me )

 

[GRistopher]

I'm sure there are instances where the difference they make is negligible but the tech works for this car in my experience...

Observationally there is a difference there, but with the modern engine having direct injection, higher pressure and various other changes it's not really a reliable way of testing the GPF.

I'm by no-means against having a GPF. I'm purely looking at it as something that could be better optimised when tuning or upgrading the engine.

For example in forced induction applications where a 3 inch exhaust is recommended for the FA24. How would someone go about implementing a higher flowing GPF? Larger high flow cats can be added to allow increased flow of exhaust gasses. Surely there has to be a similar solution for the GPF.

 

[ZN8]

I thought it was pretty compelling, given that the FA20 and FA24 are near enough identical and both having the tech you mentioned. Its an apples to apples comparison.

There are sports/high flow GPFs out there, just as there is with cats, so its definitely doable, but is it worth it? You are probably chasing 3-5bhp out of the front pipe. The best gains are going to be had out of a decat manifold and a remap, but even then you are snookered, you can't delete the cat because there isn't another one further down the exhaust, so you still need some sort of cat in the manifold which will be restrictive and it also places limitations on how aggressive the map is otherwise you will cook the cat (not uncommon with it being so close the engine), you could put a cat in the front pipe instead but then you won't have a GPF anymore either.

 

[Sonic]

BTW, did anyone hear anything more about the CTEC system for the GR86? It started to look promising but it all went quiet around November last year and there's been nothing since. Is their GR86 project no longer going ahead?

 

[ZN8]

I'm in semi regular contact with Nigel from CTEC regarding the GR86 system as I have one ordered with them. The project is still very much alive but they have other works happening too which is why it's taken as long as has. I'm hoping either Nigel or myself will be able to share more info on it soon.

 

[Alistair31]

BTW, did anyone hear anything more about the CTEC system for the GR86? It started to look promising but it all went quiet around November last year and there's been nothing since. Is their GR86 project no longer going ahead?

Thinking of changing the Cobra already?

 

[Alistair31]

I'm in semi regular contact with Nigel from CTEC regarding the GR86 system as I have one ordered with them. The project is still very much alive but they have other works happening too which is why it's taken as long as has. I'm hoping either Nigel or myself will be able to share more info on it soon.

May I ask, what is making you hold out for CTEC rather than one of the numerous other options?

 

[Sonic]

Thinking of changing the Cobra already?

I just had one of those moments when you think "I wonder what happened to .." but, in answer to your question, absolutely not! The Cobra non-resonated has turned out to be exactly what I was after; a lovely OEM+ sound in general driving with a sporty rasp in the high rev range when making good progress. The cold start is still a bit rude though, as is to be expected.

 

[ZN8]

May I ask, what is making you hold out for CTEC rather than one of the numerous other options?

With the exception of the ARK Grip nothing else tickled my fancy It's either I didn't like the sound, the style or construction method, I also fancied supporting a UK business.

 

[Hachi-roku]

The GPF situation also raises another question. Are Toyota specifying a low ash oil for EU GPF equipped cars or are we all focused on viscosity alone at 0w20. I’m aware that a number of manufacturers maintained their viscosity recommendations but switch to a low ash at the time GPF started getting installed citing possible blocking of GPF if incorrect oils were used.

 

[TorqueOfTheDevil]

The GPF situation also raises another question. Are Toyota specifying a low ash oil for EU GPF equipped cars or are we all focused on viscosity alone at 0w20. I’m aware that a number of manufacturers maintained their viscosity recommendations but switch to a low ash at the time GPF started getting installed citing possible blocking of GPF if incorrect oils were used.

No mention in the manual.

 

[unrealpatrik]

2022 model year has ILSAC GF5 recommendation and from the model year 2023 and on it is ILSAC GF6. Both of these standards are already low SAPS in the recommended viscosity ranges anyway. So there's no point pointing out the GPF I believe.

GPF is something to keep in mind for the DIYers, who want to go out of the OEM recommendations.