[BigShow]

Following advice on another thread I'm going to be making a trip to Cool Louvres in Hampshire next week to get some bonnet louvres made to aid cooling of the engine bay.

The only decision I have to make is where I want them. The Mini on the enclosed pic has them both sides, however, so the vents on the right hand side don't interfere with the CAI sucking in cold air, I'm thinking of just having a set on the left so its sucks hot air away from the manifold area and the expelled hot air from the intercooler.

Not knowing much about this kind of thing I'd be interested to hear about where other people think I should place the louvres and why???

As some background, at Bedford Autodrome I'm seeing inlet temps of 51C and water temps of 93C when the ambient is 8C. I'm already talking to Paul at 1320 about charge coolers and a oil cooler will definitely be added shortly but the idea of bonnet louvres looks like a cost effective way to help in some small way the high temp situation as I don't believe from what I've heard that the upgrade to a GRS charge cooler will help that much on track over my current GRS set-up.

[alski]

its cost effective if you dont bother with a re-spray, howabout a 2nd hood with custom scoop as well, instead of your chav hat?,
also some primer and a custom graphic over vents might be cheaper than a respray

no idea on your question, but these ideas may help over-all
what you really need is u-tube wind tunnel or airflow over bonnet footage- can anyone help?

[Roofas]

Don't know if this helps but a have looky here

MINI COOPER :: North American Motoring - Venting the Bonnet - A Unique Design

[BigShow]

Quote: Originally Posted by Roofas (original)

Don't know if this helps but a have looky here

MINI COOPER :: North American Motoring - Venting the Bonnet - A Unique Design

This chaps gone to a lot of trouble but the results do look fantastic

[Paul Webster]

Yup Gnaster is a serious track / serial dyno dude and organiser of the RMW / dyno sessions in Texas this weekend.

He nearly writes as good as you Big Show

MINI COOPER :: North American Motoring - Latest DE Weekend

[Fisher]

Quote: Originally Posted by BigShow (original)

Following advice on another thread I'm going to be making a trip to Cool Louvres in Hampshire next week to get some bonnet louvres made to aid cooling of the engine bay.

The only decision I have to make is where I want them. The Mini on the enclosed pic has them both sides, however, so the vents on the right hand side don't interfere with the CAI sucking in cold air, I'm thinking of just having a set on the left so its sucks hot air away from the manifold area and the expelled hot air from the intercooler.

Not knowing much about this kind of thing I'd be interested to hear about where other people think I should place the louvres and why???

As some background, at Bedford Autodrome I'm seeing inlet temps of 51C and water temps of 93C when the ambient is 8C. I'm already talking to Paul at 1320 about charge coolers and a oil cooler will definitely be added shortly but the idea of bonnet louvres looks like a cost effective way to help in some small way the high temp situation as I don't believe from what I've heard that the upgrade to a GRS charge cooler will help that much on track over my current GRS set-up.

Hi,

I have goten a KMT water to air intercooler. After install I have removed the sponge on the plastic air diverter for intercooler.
After that I have removed the isolation on the bonet. For the final I have use the header wraps.

When I have open the bonnet on the original car the very hot air come out.
Now I must said it's much much better.

The heat goes throught the bonnet (no isolation), the air goes through the space under the bonnet and goes out where the header is. The header is isolate so here is less heat too.

Try, you will be happy with that setup.

[MINIMANIAUK]

The cheapest solution is simply to raise the rear of the bonnet by an inch -but this will not look good.
for vents to work they need to suck air out from the bonnet ,they do this by having a differential in air pressure beween the under bonnet and the bonnet surface
The surface pressure varies across the bonnet and the prime spot is likely to be around the area of the existing scoop (it is a curved surface before the bonnet flattens out) but it would not be the easiest position to actually fit due the curved nature, however the further forward the better,and following the airflow from inner to outer (again not the prettiest!)
If far enough forward it may also be possible to direct the radiator ,expelled ,heated air out the vents too.
a small vent just behind the intercooler would help too.
its all a case of form or function,and even if not the perfect windtunnel tested position they would still work.

[k-huevo]

The flow path under the bonnet is already designed well, once in motion temps drop close to ambient quickly. Temps in the airbox drop to within a few degrees Fahrenheit of ambient in seconds due to the snorkel’s inlet location. Heat generated by the SC is the biggest offender followed by conductive heat from the head/block; underhood ambient temps are insignificant in the overall performance scheme of things.

For street or show, make the choice based on aesthetic appeal, nothing wrong with that. For competition use, choices should be made on empirically obtained data. Place a thermal probe under the bonnet for one test and another in the air box and take notes, you’ll see things as they are instead of how it is perceived.

Engines make more power with hot oil than cool oil. The way to see if temps have exceeded the oil’s performance capacity is to have it analyzed; put good quality new synthetic oil in (Royal Purple XPR), thrash in the most demanding environment, drain and collect a sample, send for evaluation. If the oil has not sheered drastically, or the TAN is not excessive, no need for oil cooler.

[k-huevo]

A local race team has discovered the standard slats (grill) on the bonnet create flow diversion for the upper radiator portion at speeds above 85 mph, running open up front lowers coolant temps.

[alski]

i do worry about oil as when i see it climbing past mid point on chonopack acts as big hand brake, to any right foot fun, is their a max safe temp to run at?

how do i get my fluid analyzed? live 15miles from silverstone must be some local guys with all this f1 around, dealer oil change tomorrow so would be a good time

[BigShow]

Oil test and fluid analysis for motor vehicles

[MINIMANIAUK]

The under bonnet heat comes from different sources ,the engine,the exhaust and the radiator and intercooler
The radiator and intercooler add significant heat ,but they are related to speed -the faster you drive the cooler the outlet air becomes ,simply due the amount of air/second passing through the rad increases with speed -
over 40mphish the under bonnet temps will reduce ,louvres will help release hot air from stationary to this speed , it is still possible to have high boost and low speed.
The oil cooler is not only to keep the oil to a level of temperature for prolonged oil life --it is for removing heat from the engine
if your oil temp is increased by 10 degrees , then 5 liters oil have been heated ,that is a lot of heat energy . this heat energy has come from the piston top ,rings, combustion chamber,head,valves etc -this heat energy is a lot more that 10 degrees in those areas,but results in a 10 degree oil temp rise
if you are at a steady 90 mph you will get a certain oil temp an increase in speed to say 110 mph the oil temp will rise say 15degrees -this is due to the increase in power the engine is providing (to overcome wind resistance)and an increase in rpm
likewise the increase in boost pressure gives more power and more heat in the top end of the engine and that is why I suggest an oil cooler.
a little extra oil quantity wont harm either

[MINIMANIAUK]

For oil analysis try and get a sample from half way during draining and avoid the lowest oil in the sump and the last oil in the sump,
You can tell a lot by simply smelling the old oil for fuel in it or burnt smell ,and looking at its condition
Around 140 degrees C synthetic oil starts to have problems so a bit over the normal needle position should not be a worry oil condition wise