MK1 dual Nostrils

Jack Houpe · 13th April 2009, 08:20 PM

For those of us that have the MK1 with the dual nostrils you will notice that only about 60% of the fan on each side exits through the nostrils. Last summer I was on a mission to find out how to cool the cab and took some IR readings while on the road. I drove the car hundreds of miles and took measurements on the way and shortly after refueling. As I thought the fans from the radiator reflected the remaining percentage of heat from the radiator to the foot well, my readings were if you can check my past posts on this issue over 100 degrees F down by your feet. Looking at the original MK1 cars you will notice that the diversion area is located so that most of the air passes through the nostrils. Ours does not. I got the nerve and with a air grinder, cut out the two boxed areas that where limiting the air to the nostrils. Formed up a scoop affair and then fiber glassed front and back sides. My wife and I took the car out for a ride the other night and she said "you know my feet are not hot anymore" she wears sandals. I think that that solved a lot of the heat sink into the foot well area and believe it or not we both noticed it was quieter. Crazy but seemed that way.

Jack · 13th April 2009, 08:51 PM

Good job Jack, I have always liked the two nostrils, but should I ever build a 40 had decided in favor of the single. Your solution appears to work very well.

Thanks for the input! Now back to work on my RCR SL-C.

Mike Drew · 17th April 2009, 02:07 PM

Jack,

Cushman makes what appears to be a very nice, and proper Mk 1 dual nostril front that is constructed much like your modification. I take it that this is the original, proper configuration of this piece.

I can't understand why Superformance got it wrong (if indeed that is the case).

Garry · 17th April 2009, 04:46 PM

Mike,
It was pointed out to me that SPF, most of the SA manufacturers, and others are using the old KVA molds for their bodies. This might explain some small differences in the body syles. That in no way makes these less than desirable bodies, just what I heard from a knowledgable source.
RCR is using molds from an actual MKI that was sourced from a US owner. Whether that makes them more correct is food for thought...and I am sure that there are some who will weigh in on my comments.

Just for the record, I don't know this for a fact so please be kind when you flame on this.
If anyone else has a different story, we would all like to know the scoop.
Garry

Bill Musarra · 17th April 2009, 06:25 PM

A lot of the manufacturers did the dual scoops. Most if not all used the short depth on the nostrils. Orignial? I don't know, nor do I care. I have to ride in it and I want it to be as pleasureable as I can for me and my passenger.
I have DRB #5 which was manufactured by Dennis Bedford before he sold to GT Forty Australia years ago. My car was manufactured somewhere close to 10 years ago. After I got it, I had my fiberglass guru to add the increased depth to the nostrils. He was going to do it as a straight shot, but I convinced him to make it a rounded afair as the potos show.

I was concerned with not only the heat, but the pressence of increased air pressure under the nostril itself. I believe there was an incident or two with the nostril clip becomming airborn at speed. That may have been due to poor securing, but the pressure contributed somewhat as well.
The other concern I had was that I didn't like the restriction that some of the fan mounting utilized. I wanted as much flow through the radiator as plossible. I still haven't secured my fans yet but will use some form of attachment that goes along with the securing of the A/C to the front of the radiator. It may be brackets welded to the top and bottom of the radiator or the plastic push throughs to hold them in place. Will have to work that out with the A/C guys next month.

Bill

Garry · 17th April 2009, 07:55 PM

Bill,
Very nice! I love that color combo. Thanks for posting. It looks like a terrific solution to the heat and pressure problem.
Garry

JimmyMac · 18th April 2009, 05:41 AM

Bill,
That's a nice job.

The original twin scoops also dropped quite low behind the radiator and the MkIII cars had bonnet hinges and stronger release catches fitted to the nostil panel.

Victors · 18th April 2009, 04:48 PM

Not sure about that, folks.

I think the original dual nostril did not go all the way down and the air flow was directed to the top out of the nose and down under the front nose.

Some pictures of 1063, 1017 and 1036 show this

Cheers!

Martin · 18th April 2009, 05:41 PM

The angles at which the photos are taken are key. The original MK1 twin nostrils that I have seen are quite a complex shape. The angle is steep just in front of the radiator and goes all the way down then gentle as it goes back towards the centre of the car. If you were to extend the gentle angle all the way to the front of the nostril it would end up about where most manufacturers seem to have them fabricated.

Martin

JimmyMac · 18th April 2009, 06:18 PM

An original unmolested car.
Note the inner spoiler at lower left of the photo.

Jack Houpe · 20th April 2009, 07:09 AM

Quote:

Originally Posted by Mike Drew

Jack,

Cushman makes what appears to be a very nice, and proper Mk 1 dual nostril front that is constructed much like your modification. I take it that this is the original, proper configuration of this piece.

I can't understand why Superformance got it wrong (if indeed that is the case).

Mike you are correct, Cushman makes the correct Nostril but he was not sure if it would fit or not. I hated to spend the money and it not, plus I would have had it painted to match. Matter of fact I think it was you who suggested him to me last time we were together in Little Rock. It took a lot of templets to get that curve on the opening correct, but I am very happy with the looks and the performance so far but its still cool here in NW Arkansas. I am leaving this morning for Big Bend Open Road Race, its going to be in the 90s in South West Texas all this week, I will let you know if this really is going to do the job after the race.

Mike Drew · 21st April 2009, 05:01 PM

Jack,

I just looked at your photos closely for the first time. It seems that you have introduced a shroud around your fan motors that requires all the air exiting the radiator area to pass through those two relatively small orifices. True, or no?

Several of my Pantera buddies tried similar setups and found that they worked great at low speeds, but were overly restrictive at higher speeds. There simply wasn't enough room for the air to get through the radiator and out the back side. The result was stagnation, and overheating when driving above 100 mph.

One friend fixed this problem by creating hanging flaps, which were hinged at the top, and under vacuum conditions, would seal against the shroud so the fan motors sucked air exclusively through the front of the core. At higher speeds, airflow would blow the flaps open and allow the air to escape.

(Coincidentally, that is the factory setup on my '81 VW Scirocco...)

Let us know how things work out for you, and if you experience any overheating at speed, consider busting out the hacksaw and removing some of your hard work.

Jack Houpe · 23rd April 2009, 08:38 AM

Quote:

Originally Posted by Mike Drew

Jack,

I just looked at your photos closely for the first time. It seems that you have introduced a shroud around your fan motors that requires all the air exiting the radiator area to pass through those two relatively small orifices. True, or no?

Several of my Pantera buddies tried similar setups and found that they worked great at low speeds, but were overly restrictive at higher speeds. There simply wasn't enough room for the air to get through the radiator and out the back side. The result was stagnation, and overheating when driving above 100 mph.

One friend fixed this problem by creating hanging flaps, which were hinged at the top, and under vacuum conditions, would seal against the shroud so the fan motors sucked air exclusively through the front of the core. At higher speeds, airflow would blow the flaps open and allow the air to escape.

(Coincidentally, that is the factory setup on my '81 VW Scirocco...)

Let us know how things work out for you, and if you experience any overheating at speed, consider busting out the hacksaw and removing some of your hard work.

Yes Mike, all the air from the radiator is going through those two nostrils. I am at the Big Bend Open Road Race now and its hot here, close to 100, I ran the practace 16 miles yesterday at 124 mph and with the ac on, never had an over heating problem even in the stop and go waiting in line. I will say I didnt have the ac on in line, seems like a waste with the doors open.

Mike Drew · 24th April 2009, 04:25 AM

Quote:

Originally Posted by P2164

Yes Mike, all the air from the radiator is going through those two nostrils. I am at the Big Bend Open Road Race now and its hot here, close to 100, I ran the practace 16 miles yesterday at 124 mph and with the ac on, never had an over heating problem even in the stop and go waiting in line. I will say I didnt have the ac on in line, seems like a waste with the doors open.

I would expect that you would have zero problems at low speed; in fact your shroud probably increases efficiency greatly when sitting still. I'd only be worried about high speed air stagnation?

Jack Houpe · 27th April 2009, 06:26 PM

Quote:

Originally Posted by Mike Drew

I would expect that you would have zero problems at low speed; in fact your shroud probably increases efficiency greatly when sitting still. I'd only be worried about high speed air stagnation?

Mike, as you know I have a time off relay that keeps the electric water pump on for two minutes after I turn the car off. During the stop and go process of the race the engine created enough heat (195+ F) to kick on the fan relays while the pump was running, (this is another mod I did so that they would come on with key off) and when I walked by the front of the car the air was not coming out straight as you would think but at almost a 90 angle. I believe that this is happening because of the cylindrical shape I made them. I do not know if this is good, bad or doesn't matter, all I know is my feet are no longer hot and thus the cab is less hot. When I used my IR gun at the area of the foot well that was 105 before, it was in the 89 F range. I have cured one problem but not sure about the effect. The one that Cushman sells looks to be the correct piece. If I had a choice when I purchased the car I would have ordered a single air exit like the MKII which I think is best all around.

Mike Drew · 28th April 2009, 12:50 PM

Quote:

Originally Posted by P2164

If I had a choice when I purchased the car I would have ordered a single air exit like the MKII which I think is best all around.

Functionally, I couldn't agree with you more there. But the aesthetics of the original setup like yours are so much more appealing to me.