Twin Front Nostril VS Single

Powershift1038 · #1 (**permalink**) 06-24-2008, 05:55 AM

Is there any advantage/disadvantage to either?

mikiec · #2 (**permalink**) 06-24-2008, 09:51 AM

I have no idea. I do like the look of the twin over the single.

Mike

Jim Holden · #3 (**permalink**) 06-24-2008, 01:58 PM

The only diifference might be that the wide open "nostril" will be less restrictive to air going through the radiator. Too, there is a vent at the base of the windshield that feeds air to the cockpit. If you have the wide single nostril, hot air from the radiator flows up and in to the vent. Whereas, the twin nostril setup (in theory) directs air to either side and cooler air gets to the vent. That may be why the MKIIs deleted the cockpit vent, because they too had a single (albeit slightly different shaped) nostril.

Jim

JCoop · #4 (**permalink**) 06-24-2008, 06:39 PM

Aside from a probable aerodynamic advantage due to the smoother airflow over the windshield,
it definitely passes more air through a larger radiator for much better cooling.

Powershift1038 · #5 (**permalink**) 06-25-2008, 12:18 AM

WOW... that is a beautiful GT40, JCoop.

PatBuckley · #6 (**permalink**) 06-25-2008, 07:08 AM

...or perhaps that center section acts like a venturi and causes much more air to flow through which makes for way better cooling?

Seems that most cars used the twin opening set-up and I am sure if the single opening one was better that wouldn't be the case?

edit: The radiators are the same size.

Jim Holden · #7 (**permalink**) 06-25-2008, 07:14 AM

Just an observation: The twin nostrils were on the early cars. The late JW cars (see 1075) had the single wide open nostril. Hard to beleive that they would have gone "backwards" if the twin nostril setup was more efficient.

Jim

mreid · #8 (**permalink**) 06-27-2008, 07:46 PM

I also like the look of the twin better. Here's mine:

Fact is that at speed the twin causes the nose to lift.

GlynMeek · #9 (**permalink**) 06-27-2008, 08:58 PM

hmmm...on a more modern note, Porsche just went to 'twin' side intakes on the new 997 Turbo, as opposed to the single side intakes on the 996 Turbo! Interesting question!

Surely their is a 'fluid dynamics' expert out there who can answer this 'flow' issue!!!!!

Glyn

BT SNAKE · #10 (**permalink**) 06-27-2008, 09:16 PM

I don't believe any of us that own a GT40 Replica will ever drive one fast enough to find out which is more effective.
You should pick the one you like or buy both and switch off once in awhile. I personally have the twin nostril and never an overheating problem in 7yrs.

Hersh

Jac Mac · #11 (**permalink**) 06-27-2008, 09:23 PM

The large single outlet gives wayward pedestrians somewhere warm to recover while they await the ambulance!

BT SNAKE · #12 (**permalink**) 06-27-2008, 09:31 PM

Hersh

Powershift1038 · #13 (**permalink**) 06-28-2008, 12:46 AM

The front panel that houses the nostril seems to be removable. How difficult would it be to switch from one to the other? I know matching the paint would be an issue.

Jac Mac · #14 (**permalink**) 06-28-2008, 01:02 AM

As long as it has the same curvature & dimensions, yes the panels can be interchanged, problem is not all body/kit manufacturers use exactly the same dimensions for this part. Many make both versions available & therefore if you have a CAV, RCR etc you will have a choice, but dont necessarily expect the RCR to fit the CAV or vice versa.---- not picking on these two makes, just using them as examples--- add to this I have observed detail changes that mean there may be three or four versions of both single & dual types, stuff like bumps to clear the spare tyre when it was fitted to some early cars along with very deep versions like the one on J Coops car above. My own set of mold patterns has a shallower single nostril version that is only about 6" deep. I think Jay Cushman has several versions of both variants as well.

Powershift1038 · #15 (**permalink**) 06-28-2008, 02:46 AM

So... assuming you had a CAV GT40, and you purchased the different panel from CAV, it would probably be a fairly easy swap.

Jac Mac · #16 (**permalink**) 06-28-2008, 03:06 AM

I think that would be the case, but check with them (CAV) direct to confirm it. There is a Zip File with manufacturers & agents contact details further down the page on the -GT40 Talk- forum . Sorry Im a computer dummy

& dont have the necessary magic wand to transfer details like that from one place to another!

ENTDOC · #17 (**permalink**) 06-28-2008, 05:50 AM

Quote:

Originally Posted by Powershift1038

So... assuming you had a CAV GT40, and you purchased the different panel from CAV, it would probably be a fairly easy swap.

2 minutes tops

Powershift1038 · #18 (**permalink**) 06-28-2008, 07:27 AM

Quote:

Originally Posted by ENTDOC

2 minutes tops

That is what I was hoping to hear. I'm actaully looking at CAV which is very similar to the one in your avatar.

PatBuckley · #19 (**permalink**) 06-28-2008, 09:31 AM

Or you could find someone who has the twin nostril cover in the same color and trade him.

Tell him all about how much cooler the car runs with the single opening.

tvolfan · #20 (**permalink**) 08-23-2008, 09:26 PM

Not that it responds to the original question, but I think that the original twin nostrils resulted from the spare tire required by FIA when the original GT was designed. The tire was layed flat under the front bodywork and the two outlets exhausted the radiator air from around it. Early plastic models of the original car in the '60's demonstrated this. (shows how old I am)

The nostril shapes changed and were ducted as the car was developed and were finally changed to the single nostril for better cooling when either the tire was moved to a more vertical orientation or removed entirely from the front when allowed by a rule change (I don't know which).

Thought this might be interesting.