GR Yaris Balance of tuning and durability limits

[Onehp]

Soon it has been three years this car is running about. And with that more knowledge emerges on the strengths and weakness of the G16E-GTS

We already know about the valve springs and the flaws in the valvetrain. In another thread this vid (thanks @yuri1312 )

emerged with a shattered piston and in the comments there are more witnessing about pistons cracked or similar engine damage.

Now roughly there are three things that kill and engine (except outright bad tuning):
Too much torque (mid range)
Too much heat (too high power)
Detonation of sorts

The first too are factors in metal fatique and don't necessarily show in the beginnings. The latter seems to be a factor in JP failures as it seems they aren't using the correct spec oils and may be getting LSPI which is worst at low speeds. This is excluding other factors of bad tuning, oil and fuel starvation etc that can also cause issues.

It seems the pistons aren't the engines strongest part, not incidentally then that these were upgraded for the GR Corolla which has to pass tough durability dyno testing before released to market.

In the end it is all compound, most know the rules of the game, pay to play. And this engine isn't bombproof we are understanding more and more. But what engine is, especially at this performance and price point.

Feel free to discuss expectations of durability with different tuning levels, and sharing experience of where the limits seem to go, more or less...

 

[Onehp]

One thing I noticed, there is no EGT sensor on this car, rather it is calculated by the ECU afaik. Meaning that piggyback, incomplete ECU remapping will invalidate any inbuilt ecu temp limits there. If anything this knackers turbos...

Also wonder how aftermarket ecu's deal with this, a vid of someone using antilag too much blowing the turbo out, also here maybe there was no applicable temp limit in place?

 

[Michael Knight]

Lots of speculation on the table, but interesting topic!
Hope there will be more such videos where they analyse the issues, and also show the facts what caused the issue. Problem is that for example from bad (or overoptimistic tuning) they seldom surface because its bad rep for the tuning company.

My theory is that there has been overoptimistic tuning, and with not optimal HW (unequal runner lengths) + maybe with wrong spec oil used (Non LSPI / SN+ spec).
I would bet that Toyota has done extensive testing to avoid the issue with stock car.

For tuned cars maybe the staying in moderate tuning targets for low/mid rpm's, use the correct grade oil is the way to go.
Or then just avoid driving sub 2.5k, at least with high engine torque demand.

Proper build would be to use stronger pistons (if that's an issue) but not the easy way to go.
Do we have any detail on P/N what GRC has for the pistons and will they fit to GRY? (Are the pins the same etc).

 

[MRA3]

90% of tuners (if not 99%) just don’t have the means to understand what this (new) engine is capable of with certain safety margins. Therefore, engines will blow out. Plus, afaik the ECU hasn’t been or at least all the tables and safety systems haven’t been fully understood/decoded 100%, so doing a remap on standard ECU has its risks.

This doesn’t mean at all is not at strong engine. On the contrary, I’d say, but engines have to blown in order to understand design limits (if you haven’t designed the engine yourself, of course). But I rather let others be the guinea pigs for all that testing, thanks.

 

[GRunt]

The engine is prooven to be safely capable of about 350 HP with stock internals. For such a light, compact open deck aluminium block with only 3 cylinders and such a low displacement, I'd say that's pretty damn good. With upgraded valves, piston rods und some other adjustments like cams it can produce 500 HP before gasket is blown. What can be fixed as well with stronger bolts. The block itself is quite strong, I'd say.

 

[Michael Knight]

Have just logged both map sensors during driving and Throttle body seems to flow well enough as there is normally only 0.2-0.3Psi drop of pressure between charge pipe and manifold. I do have different pipework to stock but still the pressure delta is small. Maybe it starts limiting at some point but at least not near stock boost.

 

[Onehp]

The engine is prooven to be safely capable of about 350 HP with stock internals. For such a light, compact open deck aluminium block with only 3 cylinders and such a low displacement, I'd say that's pretty damn good. With upgraded valves, piston rods und some other adjustments like cams it can produce 500 HP before gasket is blown. What can be fixed as well with stronger bolts. The block itself is quite strong, I'd say.

Proven in which manner? And with what hardware exactly? Valve springs necessary at least...

65000 track kilometers on the ring? Seriously, I'd like to know how long and hard 350hp has been pushed, and on how many cars. Roughly...

Edit: block is strong indeed, more talking about different reliability levels, all stock hardware, FBO, FBO+Valve springs, FVO+Valve+Hybrid etc.

 

[Michael Knight]

Low oil level and track driving don't go well together. so better to overfill little if spending lots of time on track. Know at least one broken engine at least due to that fact.

 

[Onehp]

The block itself is quite strong, I'd say.

The sub-10 drag have modified the block to closed deck I read somewhere....

 

[Michael Knight]

Low oil level and track driving don't go well together. so better to overfill little if spending lots of time on track. Know at least one broken engine at least due to that fact.

Given this is known issue, yet there is not a solution like baffled oil pan available. Would likely upgrade to such, just to be more safe on track. Fensport had their car with modified oil pan.

 

[MRA3]

Proven in which manner? And with what hardware exactly? Valve springs necessary at least...

65000 track kilometers on the ring? Seriously, I'd like to know how long and hard 350hp has been pushed, and on how many cars. Roughly...

Edit: block is strong indeed, more talking about different reliability levels, all stock hardware, FBO, FBO+Valve springs, FVO+Valve+Hybrid etc.

Agreed.

If any tuner can state this car on 350 hp can do 50.000 proper miles on the Ring, I’m all ears. I’m not saying it isn’t possible but it isn’t proven properly just yet imo.

Time will tell…

 

[micsub]

Thanks for the video Yuri1312. Looking at it (and the two others that follow) on the same subject, if I understood well (Youtube translation is what it is) it appears that the piston shattered due to 3 things :
- Pre-Ignition at high load
- High pressure built up in that cylinder at that moment
- Restriction of the OEM catalyser not helping to evacuate heat and partly the peak pressure when the exhaust valve opened.
All that due to ECU mod / Motec.

However, and as White Rabbit said, there may be a clue in the areas that have been strengthened in the GR Corolla engine...

Now I'm convinced about the benefit of the HJS downpipe catalyser !

 

[Onehp]

- Pre-Ignition at high load

Looks like he had just switched to an oil that wasn't formulated to prevent LSPI? If correct, a clear indication to always have the correct oil spec...

 

[Max]

Very interesting topic. I'm also planning a Stage 1(+) at 320ps/430nm in the near future. I've also found a good garage that takes its time and logs properly before and after.

The car should primarily be thermally stable. In the process, there will be a HJS DP added.

 

[GRunt]

Very interesting topic. I'm also planning a Stage 1(+) at 320ps/430nm in the near future. I've also found a good garage that takes its time and logs properly before and after.

The car should primarily be thermally stable. In the process, there will be a HJS DP added.

MPS engineering for example is doing 320 and 350 HP upgrades. Both require a downpipe and sport exhaust and sport induction kit. Namely they use HJS downpipe, milltek exhaust and eventuri intake afaik. The 350 HP variant is with GPF delete. They use stock internals and remap stock ECU.

300 HP on stock parts. Just remap.

 

[ruddy1975]

The sub-10 drag have modified the block to closed deck I read somewhere....

Absolutely will have and more...
Being on aftermarket ecu, they will be monitoring everything to include EGT/ coolant pressure/and all other temps..

 

[ruddy1975]

Agreed.

If any tuner can state this car on 350 hp can do 50.000 proper miles on the Ring, I’m all ears. I’m not saying it isn’t possible but it isn’t proven properly just yet imo.

Time will tell…

No tuner will ever do that I fear... how could they as too many things to factor in that would be outside of there control.

If you want a 100% reliable car backed by warranties etc, then we have to keep modifications to a n air freshener hanging on your rear view mirror. ..

Pays ya money and take your chances and all that jazz i imagine

 

[Onehp]

No tuner will ever do that I fear... how could they as too many things to factor in that would be outside of there control.

If you want a 100% reliable car backed by warranties etc, then we have to keep modifications to a n air freshener hanging on your rear view mirror. ..

Pays ya money and take your chances and all that jazz i imagine

Exactly, and why 'reliable 350hp' isn't worth much without a warranty or at least some data/history to back it up.

 

[MarcoB]

If you want a 100% reliable car backed by warranties etc, then we have to keep modifications to a n air freshener hanging on your rear view mirror. ..

yep

 

[ruddy1975]

Exactly, and why 'reliable 350hp' isn't worth much without a warranty or at least some data/history to back it up.

Completely agree.

But I don't believe there is ever a 'reliable ' number when it comes to tuning cars- we have numbers where maybe we feel the risk vs reward is worth it, but too many factors for a guaranteed any sort..

Coming from a Vauxhall background(please don't all block me at once ) the Corsa Vxr used to suffer from piston failures, always to the same cylinder and thought to be a thermal issue..

Vauxhall would take cars back in and as long as your ecu wasn't flashed(remap) they would fix under warranty.

But... they would never officially admit a problem, as I imagine the amount of warranty cases vs cars sold were minimal- so I don't think we will see a recall sometime soon on this.

I guess the simple answer as we touched before is that you most likely will never face this issue with a near std engine and all should take warning that once you go down that tuning road, the risk and what comes with it are yours.

At present, engine wise for me it is air freshener time, until I can give the car the hardware it needs to match the demand I will ask if it.