Side window butterfly vents

[mogg]

Comments please as to the pros and cons of these vents. If you have a GTR with aircon but no vents, I believe it's not possible to get un-conditioned air into the cabin. Is this a problem or just personal preference. Personally, I would like the option of getting a good stream of fresh air into the cabin. Is this only possible if you have the vents fitted ?

Thanks

[steve_d]

They are called 'helicopter' vents.
They work well as they can be pointed forward to pull air in or backwards to pull air out.
There is no other air inlet unless you design your own as I have. This brings air into the footwell.

Steve

[peterpsg]

They work well, but can be quite noisy at speed if pointed into the wind...

[ultimarobert]

Aside from the aircon, unless you have built in an alternative method of natural air intake, I highly recommend these.

[G Man]

Yep I accidently tested my open to 195mph and they work fine !!

[bigmack]

You might look at ducting air into the cabin from the front brake duct slots or off the rad intake hole. I got a nice set of aluminum adapters to attach to the cockpit above the battery and brake reservoirs. I think its 3" ducting. I think you can even find a mechanical door so that you can block this off during winter months. Just a thought.
Cheers!
-Mack

[gdr]

I tried air ducted from a front brake cooling vent to below dash - partial success. Later fitted helicopter vents, and they are great. I would definitely recommend the heli-vents, cheap and easy to fit.

[steve_d]

I ran an air pipe from the front and through the bulkhead where it then goes into a valve I manufactured. The valve is controlled using a choke cable alongside the heater control.

A word of warning with the helicopter vents. Do not leave them closed and facing forward if you intend travelling at high speed. The air flow gets under the front edge and pops the vent open. To say 'pop' is somewhat of an understatement. If it happens you will think the world has come to a rather nasty end. The crash is deafening and scares the sh1t out of you so be warned.

Steve

[Graham-P]

I'm running ducting from the passenger brake duct into the cockpit above the battery, but I'm connecting this 3 inch pipe to a 4 inch tumble dryer hose into one side of the heater motor (blocked off the other side). Just need to make up some sort of butterfly valve to shut it off when the occasion requires.

Graham

[crafty]

This looks like another good topic for the revised forum.

On that note, there'd not be many builders out there who have not used this forum and/or someone else's website for inspiration/encouragement/ideas so I urge all of you guys who dont have websites to get with the program and get one so we can all see what you are doing and so you can attach photos with your ideas/modifications.

[steve_d]

Graham-P said:

I'm running ducting from the passenger brake duct into the cockpit above the battery, but I'm connecting this 3 inch pipe to a 4 inch tumble dryer hose into one side of the heater motor (blocked off the other side). Just need to make up some sort of butterfly valve to shut it off when the occasion requires. Graham

The problem with connecting it direct to the blower is that you can only run with incoming air and not recirculated. If you bring your duct round and point it at the blower you have the best of both.

I have a valve design that works in 3" pipe if anyone is interested.

Steve

[Graham-P]

steve_d said:

Graham-P said: I'm running ducting from the passenger brake duct into the cockpit above the battery, but I'm connecting this 3 inch pipe to a 4 inch tumble dryer hose into one side of the heater motor (blocked off the other side). Just need to make up some sort of butterfly valve to shut it off when the occasion requires. Graham The problem with connecting it direct to the blower is that you can only run with incoming air and not recirculated. If you bring your duct round and point it at the blower you have the best of both. I have a valve design that works in 3" pipe if anyone is interested. Steve

The main reason for connecting direct to the blower is that I have 8 air vents and wanted to get some form of 'forced' (incoming cool) air on the face, feet etc (via the heater box)........but take your point about recirculating as well, and I guess the valve would take care of that?
I could be talking complete bo####ks and over complicating things but that's how I was looking at it.
YHM!

Graham

[BigMack]

This is just an opinion, but I think it may be a good idea to allow the air to exit to increase the cooling effect in the cockpit. This is what GTRmannen from Spain did. He drilled exit holes at the rear of the side screens. Only problem is that this would leak water into the cockpit when it rained.
The light bulb turned on, when I was watching one of the videos on PH of a grey GTR running at high speed around an airfield somewhere. The camera was mounted at the back of the car at an angle so that you could see that the doors were actually lifting open at speed. Of course, this was probably at over 130mph, but it looks like the cabin is definitely pressurizing with air. Wouldn't give you much cooling at a standstill though. I thought it was pretty interesting.
Cheers!
-Mack

[pb3]

This discussion has occurred a few times in the past, do a search and I am sure you will find quite a few threads on the topic of ventilation. On my GTR I duct air from a front brake duct grill into the cockpit, but also duct and suck it out the other side to increase airflow and to reduce pressurisation issues. See http://pb3.mysite.wanadoo-members.co.uk for fresh air ducting for example.

[steve_d]

You do not need to provide an exit path for the ventilation as there is no seal along the whole length of the door bottom. Unless you have extremely tight shut lines plenty of air should escape.

Steve

[steve_d]

Graham is interested in the air valve I used on my GTR so I will post the design here for everyone.
It basically uses two of these drain pipe adaptors. 3” ducting fits onto the round end nicely.
The finished design consists of these 2 parts glued together along their square edges with a spindle through the bond line. An aluminium plate is bonded to the spindle to form a butterfly valve inside the square section and an actuating arm fixed to the end of the spindle. All the bits need to be fabricated and installed before the halves are glued together. The valve plate needs to be longer than the width of the square section so that when it is closed it is not at 90 degrees to the flow or it will jam in the housing.

Steve

[ezakimak]

if your after a valve, you might be able to use a throtle body of a fule injected engine, either cable operated or via a veriable resistor to control some of the newer electronic throtle bodys. the electronic circuit goes under the name of "servo" actuation IIRC, from robotics class. should be able to google it.

[craig-ultima]

Back to the original post - I have put the driver side helicopter vent in. It is very useful for cooling and just blowing fresh air into the cabin. I also have AC.

Not only that but it is surprisingly an incredible talking point. Last week I was out at a party and some people started talking about cars and there was a guy bragging about a Ferrari something or other that he had. A few of my friends started telling him that I had the exact opposite - a car that defined air conditioning as a hole in the window. He took the bait.

Given all that, it is nice to have fresh air blowing into the cabin. The footwell hoses might do the trick, and if I build another Ultima I'll do something like that - but I'll probably still do the helicopter vents. If nothing else - they say "hey, I'm a racing car".