Chip

iTrader: (3)

Just thought this might interest some people, its a correction factor used by many rolling roads as this is believed to be a reasonabley accurate conversion equation for different temperatures, its known as SAE J1349:



So on a 400bhp @25 degrees theoretical @990mb atmospheric pressure engine you would expect to see (assuming pressure stays the same):

396bhp @ 30 degrees intake temp (4bhp lost from theoretical on a good cooler)
381bhp @ 50 degrees intake temp (another 15bhp lost versus good cooler)
368bhp @ 70 degrees intake temp (another 28bhp lost versus good cooler)


And thats assuming that the different coolers flow air as freely as each other, if you start getting a flow restriction as well on the smaller/worse intercooler then this can easily be a far bigger difference.


Easy to see why most tuners bang on about the massive importance of a good intercooler!

Shonky

What's the general intake temp an intercooled YB engine would run when moving? The equation's 1:1 ratio is @ 25°C so keeping them below that will increase power would it not i.e. 4bhp increase @ 20°C?

Chip

iTrader: (3)

Shonky, yes if you can get the temp below 25 then the correction factor on the dyno will subtract power rather than add it (ie you are gaining an advantage from going colder)

40 degrees is about par for the course in general if you wanted to pluck a figure, but it really does depend on the ambient temp and the boost and the turbo and the intercooler etc.

chaffe

and if your in the north east of scotland today, its bloody snowing!

the mk1 kid

Indeed! I remember seeing a cruising ACT of minus 1 at 80mph a few years ago, but it was a bit parky out!!

Tom

chaffe

lol

Chip

iTrader: (3)

On cruise if you have a 500 sort of sized cooler you should really be more or less at ambient, certainly within a few degrees.

chaffe

which is minus 2 today

ECU Monitor Enthusiast

iTrader: (1)

Chip, while we are on the subject....

As you know, dyno's take an air correction measurement and this is always the ambient air temp of the dyno cell or air temperature going into the air entry point of the engine.

Now.. I have always thought this was ok for N/A cars as the air temperature actually going into the combustion process is about the same...but on turbo cars it isnt as the turbo upsets the air density into the engine by adding heat generated from compression.
Imagine the power levels if this sensor was placed after the turbo..LOL
Can you see what I am getting at ?

Chip

iTrader: (3)

Well yes of course that would send power up massively but falsely so as the probe needs to be reading the point at which it first enters the system, which is at the air filter not at the inlet manifold, would just be a total nonsense there, you may as well stick it in a cup of tea

ECU Monitor Enthusiast

iTrader: (1)

In a cup of tea...You hear of some tuners doing this

(Not intended at a dig at anyone or company on this thread)

Chip

iTrader: (3)

Indeed, at some rollers if you are down on power its cause you made the tea too milky

Alg1k

iTrader: (2)

LOL

bezo

-2.5 in blair atholl

phil_focus

its very simple, the cooler the air entering the engine (post turbo) the denser it is and therefore the more fuel you can inject and the more power the engine will make.

simples

though HUGE intercoolers can increase turbo lag as theres a greater volume to pressurize so as with everything in life its a compromise.

Char1ie

iTrader: (6)

Or water injection when the intercooler size is limited.

Charlie

Chip

iTrader: (3)

Well of course, everyone is aware that it makes a difference for those reasons, but its I thought it would just be interesting for people to see some figures showing how much rather than just knowing "some".


IME that doesnt really seem to be true to the extent you might think it would be, I guess the bottom line is that at even at low rpm like 3000rpm you are consuming 50 litres a second of air anyway, so a few litres difference in intercooler size really doesnt equate to anything very noticeable.

phil_focus

it is a nice calculation and i do agree with you its nice to see actual figures, will even shock some poeple and make them realise how important intercoolers are AND the effect heat soak can have when you badly possition an open cone filter. hence the reason i run a pannel filter with uprated cold air feed in my focus.

your prob right too with the lag vs intercooler size but i've not had the oportunity yet to play with different sized coolers so the differences are prob very minimal.

chaffe

what about methanol injection lol

Rsmat

iTrader: (2)

i love interesting stuff like this...cheers chip.

Danny @ Enhanced Performance

iTrader: (3)

It also proves that if your car has already made good power at a given act and you dont ever see it rise over this or atleast often then there isnt any need for a better cooler..


cheers danny

left hooker

so what do you think of the pro alloy 50mm intercooler chip

Danny @ Enhanced Performance

iTrader: (3)

What power do you run???and was the car set up with that cooler??


cheers danny

Chip

iTrader: (3)

Ive not personally tried one mate, but on other people's cars they seem to work quite well, although not as well as the latest spec-r ones.

jammerrs

you need to read a thread tabatha did a while ago about heat soak......very suprising results tbh

found it, https://passionford.com/forum/ford-s...teresting.html

phil_focus

i've read that before mate, definately interesting but it only proves that an open cone is fine so long as its well possitioned. i've got a 2l focus. the air box is behind the batery and is totally boxed in so an open cone there even with a heat shield is uterly useless as there no air flow. a cold air feed will help at speeds above 30mph but as has been proved with the focus an open cone sucks in too much hot air when standing.

if i was to go open cone i'd have to move the battery to where the air box is, not a big job, and fit the cone just bellow where the battery was and pipe it accordingly. cant be arsed to do that at the moment though.

jammerrs

i just re-read it and realised youd commented, ill slide away slowely back under my rock sorry mate.

left hooker

ive got 340 bhp and yes it was set up to it

Danny @ Enhanced Performance

iTrader: (3)

Then imo its the best cooler you can have!!!
Get an act gauge mate and if your always in the 30s when driving its spot on,if it goes in the 40s when driving then id say you need a better cooler but i can gaurantee you it will always be plenty good enough for the job..


cheers danny

phil_focus

haha dont worry mate its not a prob. if i moved the battery and routed a decent open cone i would gain a few bhp but i'm not sure what i'm doing induction wise. might be going throttle bodies. then i've got the heat soak issue to deal with even more

chaffe

methanol water injection is an effective way of reducing ACTs

foreigneRS

you are just talking about heat, not heak soak

Alg1k

iTrader: (2)

I was thinking the other day ( I know )
whilst looking at my new cooler which has the same core as rods
whilst he has painted his
I was wondering if it will make a difference in the efficency of the cooler
black tends to soak heat up with better efficency
so will it soak up radiated heat more than just leaving it
as it comes with no paint on at all
or will it dissapate heat better
or will there be no significant gains or losses ??

chaffe

what about the effects of an intercooler water spay to help conduct heat away from the cooler and the use of methanol injection?

phil_focus

no mate, i was talking about both. if you place your filter in a hot area of the engine bay it will suffer from heat soak meaning the intercooler has got to disipate more heat which it cat do so up go your temps. even more important on an n/a, such as mine, car as theres no cooler.

Mark_

may be a stupid question but ive always wanted to know,


whats more effective, a charge cooler of intercooler?

Alg1k

iTrader: (2)

I would say charge cooler if you have a big enough cooling rad
and decent head of water. And a decent size charge cooler
lot more plumbing and weight though

Staffi

iTrader: (1)

Daz,

Slightly off Topic, how,s the build coming along bud??

Rsmat

iTrader: (2)

thats the 3rd time you have asked mate and no one seems to be bothered.

Mark Shead

Not tested it to say it makes any diff but the paint needs to be thin, The other thought is to anadise it black this is also said to work.

Mark