B6 Exhaust Piping?

[drddan]

Also, you asked if a stock replacement gen 1 B6 (323) headpipe would fit on your car, right?

Yes I did.
I was curious if it would fit the Festiva okay enough to be able to get the rest of the piping to line up.

If it would have the bend in the right spot to go around the bottom of the motor and get to where the cat. should be?

[BigElCat]

Also, you asked if a stock replacement gen 1 B6 (323) headpipe would fit on your car, right?

[drddan]

Yes it does. I was just agreeing with everyone that suggested 1 3/4 pipe size.
So I would have 1.80" going into 1 3/4" pipe. (1.75")

It seems like if I wanted a bigger down pipe than the port, I would need 2.0" exhaust piping.

Now I gotta figure out which down pipe to get. The B6 is 3 1/2 longer than the B3 manifold. I will need a shorter down pipe than the B3 used.

Do you happen to know of a good site for figuring out down pipe length?

[Christ]

A port opening slightly smaller than the pipe it dumps into is a good thing. It prevents flow reversion at the manifold surface to some degree.

[drddan]

I have been comparing B3 vs B6 exhaust manifolds. Measured the port openings on both and here are the measurements I found.

B3 exhaust ports are roughly 1 3/16 inch or 30 mm

B6 exhaust ports are roughly 1 3/8 inch or 35 mm

These are the ports at the head.


Measured with digital calipers, and this is the average, as the ports are not completely round.

Measurements at the outlet or down pipe side are

B3 port is 1.58 or 40 mm

B6 port is 1.80 or 45 mm


Since the B3 ports open to 1 1/2 inch down pipe, I am thinking the 1 3/8 inch B6 ports will be perfect with the 1 3/4 inch down pipe and exhaust pipe size.

Would I do okay with using the Mazda 323 as an ordering guide to which down pipe I have made or should order?

The B6 exhaust manifold is also longer than the B3.

[sketchman]

Mandrel Exhaust Systems says they don't make Festiva parts(I knew that already but whatever) and don't plan to.

[drddan]

Hey Dan....I found some 304SS tubing at work...it's 1 3/4".

I have a B3 e manifold with the head pipe still attached, I can use this as a mock up to hit the original Festiva cat converter. I realize you won't want run the stock exhaust from there, but the location needs to be exact.

Post a pic of your B6 e manifold with the heat shield off. What year was your B6 made? I'll buy a gen 2 B6 e manifold, and make us some heavy duty head pipes.

I'll need to source a couple of 90* elbows in 304 SS. This rest is gratis from my job.

Pm'd

[BigElCat]

Yup. I see the efi on Dan's B6: the e manifold is going to be inferior to this one.



Bummer. My goal was to make a head pipe to fit between this style and the stock Festiva converter.

[TominMO]

Hey Dan....I found some 304SS tubing at work...it's 1 3/4".

I have a B3 e manifold with the head pipe still attached, I can use this as a mock up to hit the original Festiva cat converter. I realize you won't want run the stock exhaust from there, but the location needs to be exact.

Post a pic of your B6 e manifold with the heat shield off. What year was your B6 made? I'll buy a gen 2 B6 e manifold, and make us some heavy duty head pipes.

I'll need to source a couple of 90* elbows in 304 SS. This rest is gratis from my job.

Pretty sure Dan's B6 is a gen1 motor, based on the valve cover. So the gen2 exhaust manifold my not apply.

[BigElCat]

Hey Dan....I found some 304SS tubing at work...it's 1 3/4".

I have a B3 e manifold with the head pipe still attached, I can use this as a mock up to hit the original Festiva cat converter. I realize you won't want run the stock exhaust from there, but the location needs to be exact.

Post a pic of your B6 e manifold with the heat shield off. What year was your B6 made? I'll buy a gen 2 B6 e manifold, and make us some heavy duty head pipes.

I'll need to source a couple of 90* elbows in 304 SS. This rest is gratis from my job.

[drddan]

Coool link Zoom.

1.5" gives a max of 92bhp.

Dan's efi B6 8-valve is about in this range. (Am I right, or wrong?)

I'd say "stay as small as possible" for torque, throttle respose, longer radius bends. No cat, easy to replace stock oval/big core muffler.

Hee Hee! :p

Dan's B6 8-valve will be carbed!

Weber 32/36.

I will use 1 3/4 pipe on this: ( which I just picked up today)






It is nice that the yard protected it, by capping it, with all the red and blue caps and plugs.

[blkfordsedan]

BigElCat-

Here's a link to the exhaust manifold & downpipe comparison;

http://www.fordfestiva.com/forums/showthread.php?t=39104&page=3

[zoom zoom]

Since Zoomzoom's link to the calculator comes form a Cortina site, I bet it is configured to work primarily for non-turbo four cylinder applications. Probably SOHC, too.

So it might do just fine for NA SOHC engines like the B3 and B6.

On the other hand it doesn't take into account displacement. I wonder if that's important?

I might be wrong. Very wrong.

Karl

Should not matter if it's a turbo or NA, or if it's 4 cyl or 6 cyl, or 12... sohc/dohc is irrelevant, like displacement. A 4 cyl car that dyno's at 200 hp pumps the same amount of air as an 8 cyl car that dyno's 200 hp. Like it's already been explained here, you just need a pipe capable of flowing X amount of CFM/lbs per minute, without being so big velocity is lost, or so small it's restricting.

[blkfordsedan]

I looked for your build, wow, 500 pages of posts. How about a link, or a few hints. I'd like to see this. What was the title of your build?

Sorry. All I have is my Blackberry right now. Its Project Procrastination...should be 3 or 4 pages back in the Garage forum. I agree, 1.75" would be about right for a stock B6.

You can buy pre-bent (mandrel) elbows in 90 and 45 degree from Summit and Speedway. With a welder and chop saw, a nice system can be had for little money.

[Movin]

For a single input to base calculations from HP or KW would be most relevant.