GR Yaris Upgrades for High Heat Conditions

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Michael Knight said:
thanks for that yumbo-link, got few plastic parts with quite good price. let's see if they deliver!
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I have used Yumbo a few times without any issues.
Be aware they will order-in to their shop from Toyota and then send you a request for the freight cost.
 
In race and rally cars where a catalytic converter is required, it’s often mounted at the end of the exhaust. One of the main reasons for this is to reduce engine and engine bay temperatures. The GRY transfer case could benefit from this as well.

While reading the Revolution blog (revo-tune.jp), I noticed that downpipes with the catalytic converter positioned where European models have the GPF are selling like hotcakes. However, such products don’t seem to be as popular in the European GRY scene.

Has anyone come across a decent one available in Europe?
P1440492.webp
 
tonic said:
In race and rally cars where a catalytic converter is required, it’s often mounted at the end of the exhaust. One of the main reasons for this is to reduce engine and engine bay temperatures. The GRY transfer case could benefit from this as well.

While reading the Revolution blog (revo-tune.jp), I noticed that downpipes with the catalytic converter positioned where European models have the GPF are selling like hotcakes. However, such products don’t seem to be as popular in the European GRY scene.

Has anyone come across a decent one available in Europe?
View attachment 34493
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I think the problem with that on road cars is they will struggle to achieve/maintain light-off temperature so basically won’t work. Then they’ll get poisoned and really won’t work!

That’s why they are generally placed as close to the engine as possible.

Maybe in a competition car all that doesn’t matter. Perhaps because exhaust temps are consistently higher, but maybe just because the rules say ‘must have cat’ and they can tick that box and no one really cares if they’re actually doing anything or not.
 
Lots of downpipes and exhausts available now.
Have not seen that one piece design before. Who makes them?.
 
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Michael Knight said:
if you don't want to do permanent holes to the bonnet, just thought that cheap mod to improve bonnet air flow is to remove the plastic corner plates next to windshield. Might try on next track day. now with -5'C it makes no sense. :D

as the opening is in the very corner of the windscreen don't think there will be positive pressure from above. but that's easily tested with some thread and tape.
They come off in 10s/side.

View attachment 34032
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My crude design,

Vent.webp
 
Duke said:
I think the problem with that on road cars is they will struggle to achieve/maintain light-off temperature so basically won’t work. Then they’ll get poisoned and really won’t work!

That’s why they are generally placed as close to the engine as possible.
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Without turning this into a discussion on emissions, I have to disagree with that.

While catalytic converters have been moved closer to the cylinders to be more effective and reach light-off temperatures faster, since emission testing starts 20s after a cold start (with new regulations reducing this to 5s), they can still be effective when mounted farther from the exhaust ports. However, this requires more expensive catalytic chemistry.

Research from 2012 (The Effects of Catalytic Converter Location and Palladium Loading on Tailpipe Emissions, https://doi.org/10.4271/2012-01-1247) suggests that increasing the distance by 1cm adds about $1-1.30 in precious metals.
 
tonic said:
Without turning this into a discussion on emissions, I have to disagree with that.

While catalytic converters have been moved closer to the cylinders to be more effective and reach light-off temperatures faster, since emission testing starts 20s after a cold start (with new regulations reducing this to 5s), they can still be effective when mounted farther from the exhaust ports. However, this requires more expensive catalytic chemistry.

Research from 2012 (The Effects of Catalytic Converter Location and Palladium Loading on Tailpipe Emissions, https://doi.org/10.4271/2012-01-1247) suggests that increasing the distance by 1cm adds about $1-1.30 in precious metals.
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Thanks, that makes sense.
 
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