Slower?

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Mɐʇʇ
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Slower?

Post by Mɐʇʇ » Mon Jul 19, 2021 1:08 pm

Anyone else in the UK notice their car is a bit slower now the ambient temps are higher?
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simonmcc
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Re: Slower?

Post by simonmcc » Mon Jul 19, 2021 1:19 pm

Warmer temperature, less oxygen density?
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Re: Slower?

Post by Mɐʇʇ » Mon Jul 19, 2021 1:28 pm

Absolutely. The book by Corky Bell describes it well. Basically, on turbo cars, power is heavily governed by heat management.
So in the hot ambient temps, even with intercoolers, you have less power because the intake air temp is still higher.
Without intercoolers, you basically waste energy - pretty much all modern cars have intercoolers for that reason.

I'm convinced it was quite noticeable on mine yesterday - the old 3rd gear surge just felt a little more subdued in the midday sun.

(Well designed) powerboats love forced induction - they run raw water cooled intercoolers which means they end up with compressed air entering the engine below ambient temperature.
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steve2003rs6
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Re: Slower?

Post by steve2003rs6 » Tue Jul 20, 2021 11:06 am

Hi Matt. Cannot say that I have noticed any difference.
Even though the science says I should
Cold air bigger bang etc.
Ps. I thought these cars were limited to 150 mph
That is way out. Or my car has been de limited.
As I found on a recent track day.
Last edited by steve2003rs6 on Tue Jul 20, 2021 2:11 pm, edited 3 times in total.

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Weiß-sechs
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Re: Slower?

Post by Weiß-sechs » Tue Jul 20, 2021 12:56 pm

steve2003rs6 wrote:
Tue Jul 20, 2021 11:06 am
Ps. I thought these cars were limited to 150 mph
That is way out. Or my car has been de limited.
As I found on a “track day “of course.
What figures did you see Steve? Along the straight on your "track day" obviously....
Still feel planted?

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Re: Slower?

Post by steve2003rs6 » Tue Jul 20, 2021 1:15 pm

Just under 170. And I backed off as a bend was approaching.
It was a really good track day
Won’t be doing that again.
Last edited by steve2003rs6 on Tue Jul 20, 2021 2:54 pm, edited 3 times in total.

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Weiß-sechs
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Re: Slower?

Post by Weiß-sechs » Tue Jul 20, 2021 1:22 pm

"If in doubt, flat out" :smile_smoking:

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Re: Slower?

Post by steve2003rs6 » Tue Jul 20, 2021 1:33 pm

To be fair I think I need to get my Speedo checked.
As the M5 was neck and neck in the straights on the track.
And yes she did feel really planted.
Thankfully only two cars had booked the track on that day. It was early and conditions were dry and very favourable
5 MPG according to the instruments. But I get that anyway under hard acceleration.
As I say. Won’t be doing that again.
However a good friend of mine is a regular at the Ring and he keeps inviting me to go.
Last edited by steve2003rs6 on Tue Jul 20, 2021 4:56 pm, edited 4 times in total.

airtite
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Re: Slower?

Post by airtite » Tue Jul 20, 2021 2:46 pm

what are the average summer temps there?

steve2003rs6
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Re: Slower?

Post by steve2003rs6 » Tue Jul 20, 2021 2:49 pm

Changes day to day. At the moment in the UK mid to high twenties.

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Re: Slower?

Post by Mɐʇʇ » Tue Jul 20, 2021 3:00 pm

Yeah, we're rocking 28.5 indoors right now.
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Re: Slower?

Post by steve2003rs6 » Tue Jul 20, 2021 4:57 pm

Turn the central heating down Matt.
Or grab a cold one.

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Re: Slower?

Post by airtite » Wed Jul 21, 2021 8:24 am

laugh our winters here in Durban South Africa are like 18degrees on a cold day... I wasnt sure weather I should keep my aux rads on my car, it just seems strange to have them radiating heat onto the intercoolers but maybe the germans had a reason.

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Re: Slower?

Post by steve2003rs6 » Wed Jul 21, 2021 10:10 am

:jump:
Had some lovely times in S A.
I struggled with your summers. Winter time is just right for me. However walking about in a tee shirt when everyone else was wearing overcoats with woolly hats and gloves did make me look a bit strange.

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Re: Slower?

Post by steve2003rs6 » Wed Jul 21, 2021 3:30 pm

Temps in the UK countryside on the east coast hit 31.5 today.
It’s uncomfortable and thankfully air con in the car is working perfectly.
Years ago I was based at a oil gathering station in the desert whilst the Iran/Iraq ceasefire was on.
Italian station snamprogetti iirc.
Now that was bloody hot.
Used to work 6-10 am
Then 4-8 pm and I can still recall the intense heat.
Don’t know how we got any work done.
But we did. Probably because we were a lot younger in those days.

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