letting the hot air out

[badger1980]

Hi all ive seen some of the cars with the bonnet raised at the windscreen end and in previous post it was a recommended mod to do so how do i go about adjusting it to sit higher at the wind screen end cheers all

[volvokid]

I never heard of this one b4 lol would the car not look a bit stuppid by doing this?

[badger1980]

It makes the bonnet look quiet aggressive here's the link there's a pic about half way down the page with the raised bonnet

http://www.vpcuk.org/forums/showthre...t=17613&page=2

[volvokid]

That’s not my cup of tea, I think if you track raced your car all the time it may have some effect (minimal I would have thought) but for normal road driving is there any point?

[badger1980]

It allows the hot air to escape faster keeping the temps lower in the engine bay

[volvokid]

It allows the hot air to escape faster keeping the temps lower in the engine bay

Yeah but unless you track drive your car is there any point?

[badger1980]

Just to be different the cooler the engine bay the less stress on the engine components and proberley with the engine been slightly cooler and the hot air escaping quicker a slight mpg gain but wouldn't be much

[volvokid]

True it would be different lol and you will probably get flashed allot from oncoming drivers cuz they think you have left you bonnet open

[Justin]

I think, if memory serves me (less frequent these days) Pedro did something like this, although i believe (correct me Pedro) that he cut away the bonnet seal and plastic at the screen end of the bonnet instead of raising. Worth a PM i would say

[p fandango]

I think, if memory serves me (less frequent these days) Pedro did something like this, although i believe (correct me Pedro) that he cut away the bonnet seal and plastic at the screen end of the bonnet instead of raising. Worth a PM i would say

you are correct


altho you couldn't feel any difference when stopped in traffic you could see the heat haze coming from the gap so it was doing something


ditched the scuttle panel altogether now (it was to heavy lol)

[Wobbly Dave]

Just to be different the cooler the engine bay the less stress on the engine components and proberley with the engine been slightly cooler and the hot air escaping quicker a slight mpg gain but wouldn't be much

Unless you were in a traffic jam on an august bank holiday (or at a track/drag meet) -The ambient temp under the bonnet will only affect the engine performance if you choose to have hot air induction as shown by the picture above.

Basically pedro - gawd bless him - has created an engineering problem by sticking an unsheilded air intake next to the block.

altho you couldn't feel any difference when stopped in traffic you could see the heat haze coming from the gap so it was doing something

- hot air rises - its less dense than cold air - sadly that cannot be said of some owners.

Just to be different the cooler the engine bay the less stress on the engine components and proberley with the engine been slightly cooler and the hot air escaping quicker a slight mpg gain but wouldn't be much

Not as much as stress - reading this drivel.

I admit heat soak is a problem - but only in extreme conditions. As for gaining horse power through "having a gap" - I think opening a gap on the drivers window to let this particular hot air out would be a better bet.

[p fandango]

Unless you were in a traffic jam on an august bank holiday (or at a track/drag meet) -The ambient temp under the bonnet will only affect the engine performance if you choose to have hot air induction as shown by the picture above.

Basically pedro - gawd bless him - has created an engineering problem by sticking an unsheilded air intake next to the block.

oh Dave mate the pic is an old one & was posted to show the scuttle panel which is what the topic was about (yes its changed & it is still an open cone). Both being old-timers you should know i've never been one to work by the book. I know the theory "hot air bad, cold air good". Over the years i've gone thru many (& many) different intake designs both sealed & open, & for some reason an open cone design has ran faster 1/4mile times.

I know you've always said the standard airbox is good enough but i can't see it, the pipes are small, the MAF screen does nothing but block air, the corrugated section disturbs the air & their are too many bends. The standard intake position is next to the radiator which also gives off heat if i'm correct?

[p fandango]

- hot air rises - its less dense than cold air - sadly that cannot be said of some owners

i hope that wasn't intended to me Dave, especially after some of your own past experiences

(sorry i would of included it in my original reply, but only just re-read it & noticed it was me you were quoting)

[Wobbly Dave]

I know you've always said the standard airbox is good enough but i can't see it, the pipes are small, the MAF screen does nothing but block air, the corrugated section disturbs the air & their are too many bends. The standard intake position is next to the radiator which also gives off heat if i'm correct?

I may only be the stupid son of physics teacher - but as far as I know there are only 3 ways heat energy can 'move about' - for want of a better phrase
Conduction
Radiation
and
Convection.

Are you now contending that the position of the plastic tube into the standard airbox - is a poor design, due to conducted heat from the radiator?? It can't be convected (its a closed system) - radiation is equally unlikely and conduction (plastic is not a good conductor of heat).

The air passes through the water and convects away the heat from the hot water in the rad. First thing that air hits, after the rad pack is the engine block. So by unenclosing your air filter - at best all you can hope for is warm air??

I have seen the video on IPDs web site about the Short Air Ram. There may be some merit is smoothing the laminar flow of air into the turbo but again we are fighting over tenths of HP if that??

Look at the air intake for the BTCC car!! High EGT are the enemy of forced induction - so surely raising it by inducting air warmed by both the radiator and the block is just DAFT

My other comment was tongue in cheek - but I still think this skuttle panel removal smarts of desperation

[p fandango]

I may only be the stupid son of physics teacher - but as far as I know there are only 3 ways heat energy can 'move about' - for want of a better phrase
Conduction
Radiation
and
Convection.

i'm the son of a HGV driver, give me 100foot of truck with 14gears doesn't mean i'll be able to drive it

Are you now contending that the position of the plastic tube into the standard airbox - is a poor design, due to conducted heat from the radiator?? It can't be convected (its a closed system) - radiation is equally unlikely and conduction (plastic is not a good conductor of heat).

The air passes through the water and convects away the heat from the hot water in the rad. First thing that air hits, after the rad pack is the engine block. So by unenclosing your air filter - at best all you can hope for is warm air??

as you said in your first post "sat in a traffic jam on an august bank holiday (or at a track/drag meet)" the standard air box would still suffer from a degree of heat soak from the radiated hot air from the radiator because of the opening being there (not forgetting the other faults/flaws i mentioned in the standard airbox design)

I have seen the video on IPDs web site about the Short Air Ram. There may be some merit is smoothing the laminar flow of air into the turbo but again we are fighting over tenths of HP if that??

Look at the air intake for the BTCC car!! High EGT are the enemy of forced induction - so surely raising it by inducting air warmed by both the radiator and the block is just DAFT

we all know the theory side & hot air isn't as good, i was also told you'll lose power by fitting a decat & that was wrong. Whether the hot air intake isn't sucking in as much hot air as being tried to make out, or the straighter pipes counteract heat loses i don't know. But instead of just going by the book or ignoring an idea becuase someone says "it won't work becuase" i've tried it, & an open cone has given me a quicker 1/4mile time & i like it how it is so i'm sticking with it (until i try something else lol)

[Wobbly Dave]

But sat in a traffic jam - you are not going anywhere and how many times a day do you find yourself on a track day or drag strip?

So my point still stands and your arguement about the downpipe adds no more credulity to the hot air induction/unshielded cone.

I'd happily stick my car on a dyno with and without shielding to prove the point.

[p fandango]

But sat in a traffic jam - you are not going anywhere and how many times a day do you find yourself on a track day or drag strip?

i'm lost, wasn't that what i quoted you as saying. Have you just questioned yourself there? (HELP ME I@M CONFUSED)

So my point still stands and your arguement about the downpipe adds no more credulity to the hot air induction/unshielded cone.

the downpipe was used as an example of "don't take everything written as gospel", as i said i've tried many different intakes & the open cone (so far) has proved to be better on my car, as i'm using 1/4mile times for my judgement 9 times out of 10 the engine bay would of been nice & warm after sitting in the warm-up lane waiting to stage

I'd happily stick my car on a dyno with and without shielding to prove the point.

i'd be pretty impressed if you can do 2 runs with a car in the same spec that runs consistant to several bhp of each run, let alone being that accurate to record a reliable bhp difference between filters (but lets not go down the rolling road argument)

[Wobbly Dave]

What I meant was - the only time heat soak occurs is in extraordinary circumstances. In a traffic jam - you can't move anyway and second the track day/drag strip, is so seldom to make it a null point.

At the end of the day the original question - letting the hot air out - has so little influence on the outcome when compared to that of hot air induction/higher EGTs that I believe it is an excercise in futility to remove the scuttle or jack up the hinges.

You'd be far better of sorting out the induction with proper sheilding or sticking with the stock box?

[p fandango]

At the end of the day the original question - letting the hot air out - has so little influence on the outcome when compared to that of hot air induction/higher EGTs that I believe it is an excercise in futility to remove the scuttle or jack up the hinges.

i did actually say in my first post in this thread "i didn't notice any difference by removing the seal"

You'd be far better of sorting out the induction with proper sheilding or sticking with the stock box?

as for sticking with the stock airbox, we'll have to disagree on that one because i feel like i'm going round in circles. We all know the theory, i know what i've tried

[Wobbly Dave]

No you didnt Pedro - this is what you said

altho you couldn't feel any difference when stopped in traffic you could see the heat haze coming from the gap so it was doing something

However - I think the net result of the arguement for this thread remains the same. There is no point to elevating the rear edge of the bonnet. Can we agree on that?

My final clarification on the stock air box would be I meant to include the words "with a performance panel filter"
Unshielded cones filters can only be worse than the stock + filter for points I have previously eluded to, namely hot air intake.

...and indeed you may yet still disagree.