Cockpit ventilation

[Jan 12]

Hi,

 

When driving my 69 Sportsoof the air pressure in the cockpit builds up. This is quite annoying and the only thing to do is to open the window a bit. This is acceptable at low speeds but quite noisy at highway speeds.

 

I believe the 70 model has a “vent†at the bottom of the b-post on each side to let air escape.

I was wondering if anyone has done this mod on a 69 and what the result was.

 

Thanks

 

[MikeStang 247]

Ha.. I never have pressure build up because the damn window to upper weather stripping seal is a constant leak haha.

 

Are you referring to the kick panel vents?

[Mach1 Driver 560]

huh, I've never seen it and a search didn't turn anything up- somebody got a picture?

[Grenadier116 24]

The '69 b-post looks to be the same as a '70, just without the opening. If originality is not a concern, you could probably make a template from a '70 and cut the opening in yours. Installing the grills might help relieve some of the pressure build-up. There must have been some factory provision for airflow in the '69's but I'm not sure how it works.

[Brian Conway 264]

Just open the kick panel vent ?  Brian

[Jan 12]

The problem is not getting the air in, it is getting it out.

 

There is actually no way air can escape.

 

I presume that's why the vent was introduced in 70.

 

[Jan 12]

I found this pic on the web, not too good but shows the opening.

 

Here's a link showing to the vent grill.

http://www.eddiemotorsports.com/product/interior-parts/1970-1973-mustang-door-vents-prmachined-finish/

 

so you know what I am refering to.

 

Thinking about making this opening to release pressure.

[MikeStang 247]

Aaahhh in the door sill area.

My car doesn't build pressure inside, despite everything being lizard skinned and Dynamatted LOL... Not sure why it don't tho

[RogerC 136]

I always noticed how well he kick panel vents flow with the windows open and not so good with the windows closed. I'm with Jan, ford probably added the B-pillar vents in 70 to help the airflow from the kick panel vents.

[barnett468 418]

The problem is not getting the air in, it is getting it out.

 

There is actually no way air can escape.

 

.

 

Sure there is, just open the rear vent windows.

[barnett468 418]

Just open the kick panel vent ?  Brian

 

That will increase pressure.

[Brian Conway 264]

Well I guess I need to admit that I haven't a clue what this ' pressure build up ' is you guys seem to be so familiar with.  

[Jan 12]

For me it feels like the pressure rise works like a parachute putting increased drag on the car.

I found a pic of Allan Moffats 69 Trans Am Mustang which has two openings just in front of the deck lid which I presume is to release pressure. Also note the two bars holding the rear window in place.

Anyway I think I will make the opening in the b-post as next winters project.

[Mach1 Driver 560]

Jan, I wonder if the "outside recirc door" in the heating system is stuck open? Look at this link: http://www.mustangandfords.com/how-to/interior-electrical/mump-0409-ac-repair/

 

Under Vacuum Actuated there is a diagram that shows the door

[fvike 173]

I always thought the '70 B-pillar vent was there to prevent rust in that area.

 

The vent would be on the other side of the door gasket, so I don't see how it will relive pressure in the cabin?

[RogerC 136]

FYI, I'm providing air exhaust at trunk drops via ducting to tube behind wheel well in pic below. A little elaborate maybe, but unique & functional.

[Jan 12]

This will definitely work, and at the same time prevent water entering the trunk.

 

I always thought the '70 B-pillar vent was there to prevent rust in that area.

 

The vent would be on the other side of the door gasket, so I don't see how it will relive pressure in the cabin?

Fvike, the trunk also gets pressurised which presses air forward over the rear wheel well towards the b-post and escaping outside of the rubber door gasket.

This location is fairly well protected from the elements and together with the “grill†prevents water entering.

 

Barnett468, opening the rear vent windows is the same thing as opening the door window = noise.

 

When you think about it the only provision Ford make for air escape in 69 was the rubber “check valve†on the trunk drops just under Roger’s pipe.

[Vicfreg 771]

 

The 1970 Mustang Sales Flyer for dealerships notes the changes for 1970 with the flow through ventilation.

 

 

 

[fvike 173]

Cool stuff. Never knew that. But where's the pressure-relief valve located?

[Rsmach1 71]

Nice find Vicfreg.

[Ridge Runner 1,112]

It is a plastic louverd vent in the b pillar with a rubber flapper in it if i remember corectly ,been a while since i worked on a 70 .It should be easy to fit to a 69 if you had the placement from a 70 to go by .

[fvike 173]

So the vent is the valve.

 

Come to think about it, you don't need a '70 to find the placement of the vent.

[Jan 12]

At last I found a good picture of the vent.

I have tried to find someone that sells these vents/grills without success.

NPD usually has everything but not this piece.

[Mach1 Driver 560]

D'oh, I finally looked at the door seal and figured this out. The door seal is inboard of the vent. Air comes out of this thing and exits from the crack around the door. Jeez I had it bassackwards.

[SWPruett 83]

I think Eddie Motorsports makes the only "replacement" to these vents and they are machined billet pieces.  I have always wondered why someone hasn't made decent repros of these after all these years.