Heatsoak

[noone]

After a week of hot days on the Eastcoast, I'm wondering how those with stock inter-coolers and aftermarket inter-coolers held up. From what i've read, the SMIC is ok with the stock tune, but after chipping the heatsoak takes the fun out of the equation pretty quick.

Any experiences?

[break]

Running GIAC/SMIC I had a noticeable decrease in performance yesterday driving during the middle of the day even though I was doing highway driving with no stop/start for the bulk of the drive (~35.5c outside according to my cars temp sensor... and I'd tend to agree with it)

The car was still hitting the boost levels it normally does (hitting 20psi, then tapering down to ~15psi by redline), but it definitely didn't feel as strong.

This morning on the drive to work it felt much better even though it was in heavy stop/start (~27c when I left, ~31c when I arrived at work)

Seems like the extra ~5c of extra ambient temp was the killer, not the heatsoak per se.

[gtimonkey]

heatsoak

I heard somewhere a while ago that every 4oC air temp increases costs 1% thermal efficiency. Not sure how accurate that is for the polo 1.8t but certainly is consistent with lots of the work I have done on power stations.

I figure that this is a big reason for the differences in dyno results about the place.

For anything that turns heat into work the theoretical efficiency is limited by the difference in the maximum and miminimum temperatures in the cycle. Petrol more or less burns at the same temperature so increased air temperature just robs you.

The best drive I have had in my pog was when it was -2oC !

[pomme]

I have a picture of 41.5 on the onboard temp for last tuesday. Car was definately not as happy as it normally is... neither was I, aircon couldn't keep up.

Don't think it was quite that hot but def 36+.. i think it always a few degs over.

[Blitzen]

Hey guys, this topic about heatsoak has been covered a number of times in the Polo forum.
Please do a search in the future.

http://www.vwwatercooled.org.au/newforum/upload/showthread.php?t=21585&highlight=forge+FMIC

http://www.vwwatercooled.org.au/newforum/upload/showthread.php?t=14559&highlight=heatsoak+polo

http://www.vwwatercooled.org.au/newforum/upload/showthread.php?t=24560&highlight=heatsoak+polo

http://www.vwwatercooled.org.au/newforum/upload/showthread.php?t=24619&highlight=heatsoak+polo

[danish]

I have a picture of 41.5 on the onboard temp for last tuesday. Car was definately not as happy as it normally is... neither was I, aircon couldn't keep up.

Don't think it was quite that hot but def 36+.. i think it always a few degs over.

Mine was showing 43 degrees driving through cronulla at around 3pm on yesterday.

Highest temp recorded in sydney was 42.5 or so at the airport so no doubt the temp gauges read a little hot. However, that could also be caused by heat rising from the road.

Anyone know where the temp sensor is housed in the polos?

[noone]

Hey guys, this topic about heatsoak has been covered a number of times in the Polo forum.

Thanks, but I'm not asking about dyno figures, I'm asking if people have noticed a difference in street driving.

I can sometimes feel what I assume to be heatsoak when blatting around the suburbs, just trying to gauge what people have noticed during the heat.

[Buller_Scott]

absolutely, noone.

this hot weather (last week in melbourne) basically kills 'performance' or get-up-and-go, if you will.

i live in the inner city and it takes quite a few clicks for the diesel to warm up- i usually try to warm it up over 7-10km's distance. by the time it's warm and ready to go, the stock side cooler is so badly heat soaked that many sensory perceptions fail to produce themselves when i put my foot down, e.g. backward body roll is reduced, less shove in the back, less urge etc etc.

it's going to be really really painful when melbourne has those glorious 40-50 degree weeks on end. i'll be switching back to stock map for sure during these periods.

[GoLfMan]

I certainly feel the effects of heat soak, especially in traffic, in my Polo TDI with SMIC. Anything 25+ I can start to feel a loss of shove

[vwthunder]

i live in the inner city

I might have seen you I am around Sth Melbourne, do you have a polo

Last week, with the hot weather here, I didnt realy notice a difference with the heat
I have the Forge intercooler

[mikepologti]

i noticed it a lil , but it didnt seem to affect performance that much.

[pixl]

Hmm. Well, stock tune here and aside from the air con not coping, I can't say I've noticed any degradation in performance. 20*C or 35*C and she drives the same -- however, less than 15*C (especially those cold winter nights) there's lots of fun to be had.

[DiZzY]

Guys you need to realise, any temperatures in the news or online is IN THE SHADE, not in direct sunlight.

So when your car says 42.5, mine did saturday and sunday, i truly believe it cause we are mostly in direct sunlight out on the roads.

[Blitzen]

Thanks, but I'm not asking about dyno figures, I'm asking if people have noticed a difference in street driving.

I can sometimes feel what I assume to be heatsoak when blatting around the suburbs, just trying to gauge what people have noticed during the heat.

I understand what you are saying, but I think Dyno readings more than show what hot weather will do to cause Heatsoak in a car.
It is akin from driving in a hot open road and then driving on a shady mountain road...The denser, cooler air of the shade providing better combustion conditions...

I think the original question answers itself really