"The 14 Car" Performance therapy project

Continuing to catch up on posting progress I'll move on to the front brake duct cooling system.

The Baer brakes are large by huge 14" rotors with 6 piston calipers. The rotors are the curved vane type which are designed to move air from the rotor hat through the hollow vanes in the rotor to cool the rotor as long as it's turning. I want to have additional cooling ducts ta aid cooling for several reasons.

A. The aero changes I'm making will reduce the air exchange in the wheel wells. So that might contribute to the rotors, pads and calipers heating more than without the aero changes.

B. I'm running 285 front tires on 18" X 10" wheels that just barely clear the calipers. So the calipers and rotors are kind of shrouded by the wheels which might reduce cooling.

C. With the Yokohama AO 48 DOT R sticky tires I can brake harder during threshold braking before lock up than I would be able to with higher tread wear tires so more heat is generated.

D. Keeping the rotors and pads cooler should extend their life.

E The car is is stock bodied with no lightweight fiberglass or carbon fiber and propelled by an iron headed Pontiac engine so at 3500 lbs + it's no featherweight race car, yet I'll treat it like one on track.

Here's the basics of what I've done.

1. Remove the speed sensor mount to open up more space for a 3" brake duct hose.

2. Make backing plate for the rotor hat that has minimal clearance with a tube to attach the hose.

3. To attach the backing plate I used a threaded boss in the spindle (supplied by Baer with their package) and drilled then tapped two bolt holes in the caliper abutment so the backing plate has three bolts holding it.

4. Modified a couple dashboard vent ducts from mid 80's GM trucks so the 3" brake duct hose would fit on them. They're slightly too big for the duct hose stock so a few V cuts and they can be squeezed just enough to get the hoses on.

5. Mounted the duct opening vents in the core support up high right next to the radiator on each side. This is a high pressure area behind the grills which isn't affected by the bow wave at the very front of the bumper or air dam. I'd originally planned on using the park/turn signal openings however a discussion with Ron Sutton about the bow wave influence and the reduction of pressure on the splitter just below the signal opening caused me to change plans.

6. I've built everything using 3" 300 degree brake duct tubing. It's a tight fit by the outer tie rods and sway bar ends snaking a 3" tube in there with such wide wheels/tires. I checked turning radius, suspension travel considerations, and such but I may find that I need to downsize to 2" tubing. So I'm going to test with the 3" and if all's good make a prettier set of backing plates welded instead of riveted. If there's clearance issues I'll move down to 2" ducts and add inline fans.

Here's the pics!

Spindle with speed sensor mount in pic below.



Speed sensor mount removed (but opposite spindle).



White line in pic below shows how much of the rotor hat is blocked by spindle arms, caliper brackets, and abutments.

















 
Very Kool Birdman.

Bringing back memories of Herb Adams own VSE Road Race Trans Am.
He used Hurst Airheart braking system parts.
I think NASCAR issue back then. Circa 1979.
 
Herb actually sold a brake duct kit through VSE. Tried to find info on it but didn't find much.

I bet Herb would really like my car. I've talked with his suspension guy from back in the day and incorporated some of the things they used back then in my project. Some of the VSE parts are being repopped now but Herbs concentrating on the Contessa.
 
Well off Baby Boomers stop in the shop often.
Many are into Road Racing at Route 66 Joliet.
I have been told its $30,000 to join the club.
No way Hosee' ? !
 
I have to spend more time on the Pontiac Forums.
One I think is based in Illinois .

Performance Years is the best by far.

Will google what Herb Adams is up to.
 
thats not only really good photographic skill, its rather interesting in that,
it shows well above average effort and the \thinking and in fabricating what should be a significant upgrade to the brake cooling efficiency
 
I wanted to seal off the openings on the top of the cowl where fresh air enters. This will increase air pressure on the top of the cowl so I'll get more down force in conjunction with a new hood to cowl seal which will be installed after final paint. I decided to use a reproduction screen I already had and modify it to seal off the openings. I used 3/32 EPDM rubber sheet and it's held in place with # 10 - 5/8"Phillips pan head screws and nylock nuts with 3/16" body washers to spread out the clamping force. The higher the air pressure, the tighter the seal will be. The car very rarely ever gets wet so I'm not concerned too much with drainage but if I'm on a trip and it rains I'll just pop the screen out.

Here's the pics!







 
Continuing my efforts to manage under hood airflow and pressure I wanted to seal off the inner fender wells above the frame. The stock inner fenders have a factory installed "splash shield" which helps separate the air in the inner fender from the engine compartment. I wanted to take that a step farther. So I made up some patterns and used 1/8" EPDM rubber sheet to more effective seals. I'm going to be running the modified stock upper control arms for a while after reassembly but plan on eventually switching to upper and lower arms that will allow more positive castor and negative camber so I'll need to reconfigure the seals. With that inn mind I'll be using threaded hardware to hold the seals during assembly after paint now but may use pop rivets to save a little weight when the tubular arms are installed.

Stock splash guard in pic below. Note the gaps to the inner fender well not only around the control arm but also where there was no stock shield between frame and inner fender.



Pics below show pattern making and the new seals in place.







 
The inner fender extensions on the 70-73 birds rusted out pretty easily and over the years I've seen a lot of cars missing them completely. It's a part some might just consider part of the crash protection crumple zone or be considered more of a splash guard. However it's also a part that affects aero. Without it the air coming under the front air dam collides with the air in the wheel well and seeks a place to go. I believe that the air will flow through the opening into the area behind the core support.

Twenty five years ago when I first built the car reproductions weren't available and I didn't really have a way to make replacements. I cut off the bottom of one of them because the rust had eaten it all up while the other had rust holes but wasn't as bad. Eventually I got a better (but not great) set off a parts car and planned on installing them.... Ya, never got around to that, and they disappeared along the way. Reproductions are available now, but I have the ability to make them so I did. If it was a customer car I'd have installed repros because of the fabrication labor time, but since it's my car I made them.





 
again, damn impressive photographic skills
and amazing restoration,
plus thinking outside strict restoration.
all very nice!
 
Thanks Grumpy!

The core support of the early 2nd gens had a lot of gaps on the sides and top as well as large openings for the bumper supports to pass through it. I wanted to seal these areas off to keep the air out which should reduce under hood air pressure and increase the difference in pressure in front/back of the radiator which will help the radiator be most efficient.

Now those of you with early 2nd's might go look at the car and think pffft there's only an inch gap here and there and the holes for the bumper supports. However even though they're not directly open to the front of the car the cavity between the core support and the bumper/splash pan is one of (if not the) highest air pressure areas on the car. So the air is trying to get past the core support through the gaps as fast as it can. This is the same principal of why the brake cooling duct openings are placed in the core support rather than on the splash pan.

So how big are the gaps really? I added them all up, then recalculated thinking I must be wrong but no.... Imagine a hole this big in the core support letting air in!



The bottom of the core support is bolted tight to the lower edge of the splash pan sealing it. So the sides, top, and bumper openings are where I needed seals. To seal the sides and bumper holes I used 3/32 EPDM rubber sheet and pop riveted it in place. 3/16" aluminum rivets with 3/16" body washers.









To seal the top of the core support I used the same rubber but with plastic push pin fasteners for a more finished factory look. All of the seals will become tighter as air pressure increases forward of the core support with speed.



 
I am the only other Early 2nd Gen Firebird Trans Am owner here Birdman.
Any 1970-1/2 Poncho Pontiac Firebird is Very Rare today.
Not many were built for entire run of 1970.
Production got off to a late start in 1970. May 1970 I recall.
1969 Birds were sold as 1970 Models prior.

Just interesting.
The Corvette Guys 1963- to present are always Crying & Whining about Hot running engines.

I kinda smile and laugh.........Pontiac's don't because of the Huge Twin front Grille openings.
My TA never had an issue holding 160 180 F even on a Red Hot 100 F summer day in the Midwest.
 
I have those special Fender Extensions also.
Cleaned them up at the last Job. Ultra Sonic cleaned. Then Glass beaded.
From a Rust free Texas Car.
Originals for mine .
 
the cars coming along so well... its amazing the amount of work youve done and theres stil sooo much left to do
 
the cars coming along so well... its amazing the amount of work youve done and theres stil sooo much left to do

that is almost an expected condition, we all deal with,
for almost the entire time spent during the restoration process,
of almost any musclecar,
well that, and finding your nearly out of cash,
you can,t find a tool you need,you know you own.
your missing several parts you were sure you already had,
your wife or girl friend thinks your spending FAR to much time working on the car!
and the guys that swore they would have the parts you need,
or swore they would be over to help out,
can,t find the parts and never show up to help,
some of the parts you do have,
won,t fit or need serious and extensive, repairs,
and of course the fact there's always more tools,
that you find are mandatory to complete the restoration process
 
I knew when I decided to "go all the way" and tear the car down to the shell plus do all the things I'd always said I'd do one day that this was a major undertaking. I'm fitting and massaging front end body parts now. Then they'll all come off so the subframe can come out for fitting the engine/trans that was never offered in the subframe I'm using. Once that's set then mock then install subframe with engine/trans to mock up new headers/side pipes. Then it comes apart again for frame paint, plating, jamb paint, etc. Once that's done then it gets assembled for body paint. After that the fun part of final assembly. Then testing and tuning.

You guys may wonder why I didn't mount the engine and trans already. It's because I wasn't sure any of the steering/suspension could be used because the late 2nd gen frame is different than the early ones and the steering pieces, core support, etc. are all different. So I figured better make sure I'l be able to use the frame before mounting the driveline and smoothing/painting frame.

Brian, you're the ONLY TA OWNER here... ahahaha cause,..... well ya, mines a fake!
 
There may be one early 1970- 73 F- body subframe around me still .
I would have to check with a friend that runs a salvage yard.
They don't show up on Craigslist here in Illinois Period.
Just in case .

The Subframe motor mount hoops are special for the 1970-71 Firebird Trans Am Cars as you recall Birdman.
Should transfer easy to the later subframe.
 
I've already done a lot of work to the 81 subframe so I'll keep trying to use it. It was made with better steel and the factory welds are better than the 70 was. I'm running original style modified engine mounts. The 81 subframe doesn't have the holes for the early 2nd gen Firebird engine frame mounts or the holes for the T-400 trans mount. So I've gotta set the engine/trans in place and mount up the side exit headers etc. so I get everything where I'd like before drilling holes.
 
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