Something cool I found at a local offroad expo

[GPSMatt]

slightly more durable than stock!!

wonder which flows better?

HMMMMMMMMMMMMMMMMM that tubular manifold is prety bad ass that thing deff flows a lot better. And like you said get it jet coated and wrap it.

[DTanklage]

I have had the ported stocker, ported HTT/BD and stock ATS flow tested. The shops flow bench says 223 cfm for stock, 249 for the HTT and 262 for the ATS.

wonder how they flow an ex manifold? i dont have a clue. if the are only flowing one cyl at a time i wouldnt think the numbers would be accurate as compared to when its on a running motor. would you?

[Philip]

The shops flow bench says 223 cfm for stock, 249 for the HTT and 262 for the ATS.

Thank you for that info. I was getting ready to buy a HTT pulse manifold. But looks like the ATS now.

[greasemonkey]

the stock one flows best but only if the CA EGR bullitsh is hooked up

hmm, thought the sarcasm would be picked up there, I guess maybe not. I know the aftermarket logs outflow stock.
GLHS, thanks for that info, haven't seen that before. I've been looking for anymore info on the tube manifold and google has failed me

I'm interested to see some testing results...obviously it'll flow like crazy...since it's a substantially larger volume I'm thinking it's going to work well only at high power/rpm levels.

[Ace]

How do the joints seal where comes apart? Is it just a tight slip fit, or what?

[greasemonkey]

How do the joints seal where comes apart? Is it just a tight slip fit, or what?

yeah it's a straight slip fit, the male and female side of the joint are both machined. it takes some pretty intent effort to be able to move them as it's almost a press-fit tightness, so it takes some creative heating/cooling and a BFH to move it...Brown's diesel lined mine up for me so all I had to do was bolt it on. it definitely doesn't leak at the joints, I've never seen any soot marks there and have never heard any complaints.

[PToombs]

Greasemonkey, what's the extra port on your stock manifold? Trying to set it up for a hood stack?

[greasemonkey]

Greasemonkey, what's the extra port on your stock manifold? Trying to set it up for a hood stack?

No, it's an example of the infinite wisdom of the state of california. that port is special to CA 2nd gens (which for some reason mine happened to have a stainless steel block-off plate ) it's for the EGR system, it's a 1" pipe that runs from the exhaust manifold directly to the intake horn...apparently someone thought that running 1,000 degree soot into the intake would help the thing run cleaner. in the first picture, the flange on the left is where that pipe is plumbed in, through the EGR valve.

[GLHS]

Not sure how he tested.
Another thing he pointed out was the stocker flowed less on the middle ports than the end ports.
He said the HTT/BD and the ATS manifolds flowed very even but the noise from the HTT/BD sounded almost the same as stock.
Remember also the ATS was not ported yet. After the shop ported it he said it only picked up 4 more cfm, but spoolup was much better.

[KTA]

If you had a big enough flow bench you could flow one properly by pulling through the turbo flange, and modifying the ports and runners to obtain the maximum flow, then you would probably want to turn it over and work each port a bit to try to even out the flow numbers in each port. In reality its probably more cool factor than anything. It is very rare in most diesel guys setups I see to run more boost than drive pressure at full power. Since backpressure is greater than boost you have negative delta, therefore no scavenging and negligeable advantage to equal length primaries snce the whole manifold is under pressure that balances itself by the laws of path of least resistance, whichever way is the least pressure will be the path of the gas. Because of the increased volume you do get a lot more lag though!!

[GLHS]

I do remember him saying he pulled through the flange.

[ford69557ci]

that egr spot on the ex manifold looks like a good place for an external wastegate

[greasemonkey]

...therefore no scavenging and negligeable advantage to equal length primaries snce the whole manifold is under pressure that balances itself by the laws of path of least resistance...

I feel slightly retarded now, forgot about the not scavenging affect of being under pressure, even at idle there should be enough pressure to nullify scavenging.

[greasemonkey]

that egr spot on the ex manifold looks like a good place for an external wastegate

it's probably a great spot for a w/g until the stupid thing shrinks up and tries to break the head/bolts off

[PToombs]

GM, thanks. I never thought about commiefornia and the egr thing!