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On 5/5/2019 at 8:28 PM, Cezar B said:

Here’s a clip, mate 

Aftermarket exhaust... nothing else 

Jeeeezzz...sounds mean buddy...did you have that done around our area??

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17 minutes ago, N88RPT said:

Jeeeezzz...sounds mean buddy...did you have that done around our area??

Yes, Pete! Done it in Watford. But the exhaust is USA import

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  • 2 weeks later...

Its been proven and tested out that removing the cover is worse for the engine building heat up,  big write up on a USA site,

On 5/27/2019 at 12:13 AM, Yuss said:

Better cooling for those weekend blasts! 

DSC_0457.JPG

In May 2019, there was some debate on the Facebook group if this removal was a good idea or not.  The counterargument was that the small opening would create a Venturi, which would actually help draw air out of the engine bay.  I decided to run a test with a remote temperature sensor to get some data on this question.

I did five runs on a sunny spring morning on the East Coast US with the hood temperature sensor mounted just aft of the scoop opening (see image above).  The readout was then placed at the base of the driver's side A-pillar so I could observe the temperature as I was running.  In addition to this hood sensor, I also used the built-in ambient air sensor of the car, and a separate hand held temperature/humidity monitor.  

After letting all three sensors settle overnight in my garage, I first took baseline readings on all three.  I then drove for half hour to the test road to get all coolant and oil temps to the normal range.  I then did a run with my standard configuration (no cover), then with the hood scoop taped shut (so non-functional scoop), and then next the stock configuration.  I finally finished with two runs of the no cover configuration to see if conditions were consistent.  All runs were done in S+ mode (so no Atkinson cycle), and at a sustained speed of 70 mph.  The data is summarized below.
 

Ambient (car sensor) Under Hood (wired sensor) Ambient (hand held sensor) Delta T Comment
73 75.1 73.9 2.1 Morning baseline reading
75 128.3 75 53.3 No cover
78 123.5   45.5 Scoop taped shut
81 129.8   48.8 Stock config
81 134.8   53.8 No cover
83 138.0   55.0 No cover (60 mph)
All readings in F


As you can see above, and to my surprise, the best reading was with the scoop taped shut.  Now in full disclosure, there was a small opening as the tape pulled away from my paint (ceramic coated and waxed, so very slick).  While driving, I could see the tape bulging out and up, indicating either lift from the air flow above, or positive pressure below.  By the time I had stopped, there was a small opening pealed up.

But the second surprise is how much worse the no-cover configuration was.  It was a consistent 53F rise with the 70 mph runs and slightly worse at the lower 60mph speed run.  Presumably , in the case of the latter, the lower speed meant lower air flow.

In the light of this, I have put back my rain cover.  It is possible that at even higher speeds, the stock configuration would win out over the no-scoop configuration. This result reminds me of the RR-Racing find that the stock intake is already very good.  The only improvement they could justify was the intake diverter.  Lexus must have done testing on the design already.  As a final note, I have always liked seeing the blue intake runners when the hood is closed.  I guess I will now have to unfortunately do without that.

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15 hours ago, mr2lad said:

Its been proven and tested out that removing the cover is worse for the engine building heat up,  big write up on a USA site,

In May 2019, there was some debate on the Facebook group if this removal was a good idea or not.  The counterargument was that the small opening would create a Venturi, which would actually help draw air out of the engine bay.  I decided to run a test with a remote temperature sensor to get some data on this question.

I did five runs on a sunny spring morning on the East Coast US with the hood temperature sensor mounted just aft of the scoop opening (see image above).  The readout was then placed at the base of the driver's side A-pillar so I could observe the temperature as I was running.  In addition to this hood sensor, I also used the built-in ambient air sensor of the car, and a separate hand held temperature/humidity monitor.  

After letting all three sensors settle overnight in my garage, I first took baseline readings on all three.  I then drove for half hour to the test road to get all coolant and oil temps to the normal range.  I then did a run with my standard configuration (no cover), then with the hood scoop taped shut (so non-functional scoop), and then next the stock configuration.  I finally finished with two runs of the no cover configuration to see if conditions were consistent.  All runs were done in S+ mode (so no Atkinson cycle), and at a sustained speed of 70 mph.  The data is summarized below.
 

Ambient (car sensor) Under Hood (wired sensor) Ambient (hand held sensor) Delta T Comment
73 75.1 73.9 2.1 Morning baseline reading
75 128.3 75 53.3 No cover
78 123.5   45.5 Scoop taped shut
81 129.8   48.8 Stock config
81 134.8   53.8 No cover
83 138.0   55.0 No cover (60 mph)
All readings in F


As you can see above, and to my surprise, the best reading was with the scoop taped shut.  Now in full disclosure, there was a small opening as the tape pulled away from my paint (ceramic coated and waxed, so very slick).  While driving, I could see the tape bulging out and up, indicating either lift from the air flow above, or positive pressure below.  By the time I had stopped, there was a small opening pealed up.

But the second surprise is how much worse the no-cover configuration was.  It was a consistent 53F rise with the 70 mph runs and slightly worse at the lower 60mph speed run.  Presumably , in the case of the latter, the lower speed meant lower air flow.

In the light of this, I have put back my rain cover.  It is possible that at even higher speeds, the stock configuration would win out over the no-scoop configuration. This result reminds me of the RR-Racing find that the stock intake is already very good.  The only improvement they could justify was the intake diverter.  Lexus must have done testing on the design already.  As a final note, I have always liked seeing the blue intake runners when the hood is closed.  I guess I will now have to unfortunately do without that.

what a load of gash!!!

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20 hours ago, mr2lad said:

Its been proven and tested out that removing the cover is worse for the engine building heat up,  big write up on a USA site,

In May 2019, there was some debate on the Facebook group if this removal was a good idea or not.  The counterargument was that the small opening would create a Venturi, which would actually help draw air out of the engine bay.  I decided to run a test with a remote temperature sensor to get some data on this question.

I did five runs on a sunny spring morning on the East Coast US with the hood temperature sensor mounted just aft of the scoop opening (see image above).  The readout was then placed at the base of the driver's side A-pillar so I could observe the temperature as I was running.  In addition to this hood sensor, I also used the built-in ambient air sensor of the car, and a separate hand held temperature/humidity monitor.  

After letting all three sensors settle overnight in my garage, I first took baseline readings on all three.  I then drove for half hour to the test road to get all coolant and oil temps to the normal range.  I then did a run with my standard configuration (no cover), then with the hood scoop taped shut (so non-functional scoop), and then next the stock configuration.  I finally finished with two runs of the no cover configuration to see if conditions were consistent.  All runs were done in S+ mode (so no Atkinson cycle), and at a sustained speed of 70 mph.  The data is summarized below.
 

Ambient (car sensor) Under Hood (wired sensor) Ambient (hand held sensor) Delta T Comment
73 75.1 73.9 2.1 Morning baseline reading
75 128.3 75 53.3 No cover
78 123.5   45.5 Scoop taped shut
81 129.8   48.8 Stock config
81 134.8   53.8 No cover
83 138.0   55.0 No cover (60 mph)
All readings in F


As you can see above, and to my surprise, the best reading was with the scoop taped shut.  Now in full disclosure, there was a small opening as the tape pulled away from my paint (ceramic coated and waxed, so very slick).  While driving, I could see the tape bulging out and up, indicating either lift from the air flow above, or positive pressure below.  By the time I had stopped, there was a small opening pealed up.

But the second surprise is how much worse the no-cover configuration was.  It was a consistent 53F rise with the 70 mph runs and slightly worse at the lower 60mph speed run.  Presumably , in the case of the latter, the lower speed meant lower air flow.

In the light of this, I have put back my rain cover.  It is possible that at even higher speeds, the stock configuration would win out over the no-scoop configuration. This result reminds me of the RR-Racing find that the stock intake is already very good.  The only improvement they could justify was the intake diverter.  Lexus must have done testing on the design already.  As a final note, I have always liked seeing the blue intake runners when the hood is closed.  I guess I will now have to unfortunately do without that.

right, will keep it brief as it late and I am tired, but this test is in no way conclusive, firstly by blocking the bonnet vent and removing the engine cover you are changing how the air flows within the engine compartment, buy only having one sensor you do not get the picture of the total under bonnet temps, the temperature may reduce in this area but increase in others, secondly, for any test to be meaningful you need a baseline, this test has clearly been done with back to back runs, the ambieant temps have increased but also the latent heat within the engine has increased, first test you are cooling a moderately cool engine with cool air, last test you are testing a warm engine with warm air and cooling curves are not linear, we are comparing apples with eggs!!

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  • 2 weeks later...

Quick gran tour to the Scotish border via A696, A68 and A7. Great roads! 

The engine bay was definitely cooler with the rain cover removed, water temp was reading below half way mark most of the spirited drive.

DSC_0514.JPG

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3 hours ago, Yuss said:

Quick gran tour to the Scotish border via A696, A68 and A7. Great roads! 

The engine bay was definitely cooler with the rain cover removed, water temp was reading below half way mark most of the spirited drive.

DSC_0514.JPG

Great roads, in a previous job I used to have to travel up to the scottish borders every now and then. If you used the A697 from Morpeth to Coldstream you missed a treat, next time come off the A1 at Burtree Gate and follow the A68 all the way up to Jedburgh - fantastic drive 

 

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1 hour ago, bobmc said:

Great roads, in a previous job I used to have to travel up to the scottish borders every now and then. If you used the A697 from Morpeth to Coldstream you missed a treat, next time come off the A1 at Burtree Gate and follow the A68 all the way up to Jedburgh - fantastic drive 

 

I take those roads when delays on A1 but in a artic.... spend 3 days snowed in last year just a mile from Coldstream 

F7F39810-430C-4A94-9855-3C5F94C83799.jpeg

ED17B519-CDB8-4EB4-B73D-F846AD77F516.jpeg

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  • 2 weeks later...

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