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-   -   BEGI "Directed Pulse" vs non directed pulse manifold (https://www.miataturbo.net/diy-turbo-discussion-14/begi-directed-pulse-vs-non-directed-pulse-manifold-7147/)

miatamania 02-02-2007 09:35 AM

BEGI "Directed Pulse" vs non directed pulse manifold
 
I was looking on BEGIs website at the manifolds for the 1.6L T25 Manifolds reading about the new "directed pulse design" which is $439...but they have 2 older manifolds, still new of the "non directed pulse design" for $250?

What gives is the new one that much better?


also, it says they offer coolant reroute on their turbo kits, think they would offer just a kit?

Braineack 02-02-2007 09:51 AM

1. The new manifold cancels out exhaust pulses. Since 1-3 and 2-4 fire together, this way there is less turbilence or something silly like that. Talk to Markp about it, it was partly created from his suggestions.

2. Of course.

magnamx-5 02-02-2007 10:52 AM

makes sense that when you aim the oposing cylinders pulses at each other you will get abit of turbulance and in some cases reversion of exhaust flow. By flowing them on a parralel path the pulses intensify each other with their succesant momentum thus increasing exhaust velocity with a scavengeing effect. I believe it makes sense to me i am sure some one will try to debunk that theory and i will have more reading to do to figure out why they are right but from a pure physics thermo/fluiddynamics standpoint it makes sense. It would help to have a picture of said manifold to base my theory off of. With out that i can only speculate as to the most effective setup and what they did.

Braineack 02-02-2007 11:00 AM

http://www.rev2red.com/images/cars/b...nifold_006.jpg

magnamx-5 02-02-2007 11:07 AM

ok that helps looks to me as if with the casting they are trying to direct the exhaust into the turbine as straight on as possible. Notice the nice smooth and wide tapered divider this allows for a gradual change before the two exhaust pulses hit each other making them as parralel possible. The ridge seems to let one shot over the other. So that a bit of a swirl action is also possible if the other side of the manifold exit is made in a smiliar manner looks like i am right. Still it is a top notch peice but the little engineering details like that make it all the better.

Braineack 02-02-2007 11:11 AM

yeah the slightest little lip

http://www.bellengineering.net/Image...Manifold_2.JPG

magnamx-5 02-02-2007 11:12 AM

sWWEEET

TurboTim 02-02-2007 11:25 AM


Originally Posted by Braineack (Post 78166)
1. The new manifold cancels out exhaust pulses. Since 1-3 and 2-4 fire together, this way there is less turbilence or something silly like that. Talk to Markp about it, it was partly created from his suggestions.

2. Of course.

I don't understand what you mean by "1-3 and 2-4 fire together". Technically 1&4 and 2&3 should be paired based on the firing order. I guess "directed pulse" should be "directed flow"? :confused:

Is their coolant reroute like most other reroutes (out the back of the head) or what they call their modified heater core outlet, or something else?

Sorry you aren't the one to ask these things, but besides BEGI you know the most about their products I think.

magnamx-5 02-02-2007 11:29 AM


Originally Posted by TurboTim (Post 78226)
I don't understand what you mean by "1-3 and 2-4 fire together". Technically 1&4 and 2&3 should be paired based on the firing order. I guess "directed pulse" should be "directed flow"? :confused: .

True but at higher RPMS the gasses wont have time to escape fully to the turbine wheel hence they will hit each other at some point slowing down the flow, it might not be alot but it will still happen. think of two hoses spraying into a divider and out of another hose and hte divider is a simple T the dramatic change in flow and, the momentum of the other gasses will cancle out alot of Kenetic energy now think of it as a Y the flows will change abit more gradualy and the momentum of one charged section adds to the other creating more overall velocity and flow for the water out the other end. gasses are no different cept Gravity has a whole lot less of an effect on them.

Ben 02-02-2007 11:31 AM


Originally Posted by TurboTim (Post 78226)

Is their coolant reroute like most other reroutes (out the back of the head) or what they call their modified heater core outlet, or something else?

They are offering an actual reroute kit, reroute in the definition we think of it in, as an addition to the bypass kit that they have been offering.

Braineack 02-02-2007 12:01 PM


Originally Posted by TurboTim (Post 78226)
I don't understand what you mean by "1-3 and 2-4 fire together". Technically 1&4 and 2&3 should be paired based on the firing order. I guess "directed pulse" should be "directed flow"? :confused:

Is their coolant reroute like most other reroutes (out the back of the head) or what they call their modified heater core outlet, or something else?

Sorry you aren't the one to ask these things, but besides BEGI you know the most about their products I think.


I'm sleepy in the mornings....

What I meant to say was pulses from cylinders 1 & 2 don't interfer with pulses from cylinders 3 & 4. I dunno where I pulling firing order from...not even correct. I chalk it up to Friday morning syndrome.

From what I hear, both the water-bypass reroute and Coolant re-route are now standard on all turbo kits and they sell both seperatly.


A new feature that is now standard on our Turbo Systems is a Coolant Re-Route. This is in addition to the water by-pass. The heater lines from the firewall are routed back to the radiator inlet. Pictures to follow in a few days.
Stephanie

TurboTim 02-02-2007 12:05 PM


Originally Posted by Ben (Post 78232)
They are offering an actual reroute kit, reroute in the definition we think of it in, as an addition to the bypass kit that they have been offering.

Ahh nice! I wish this was available when I did mine. Thanks for the info guys.

miatamania 02-02-2007 12:13 PM

I kinda know what it is, I should ask more, is it that much better than the old style manifolds?

Because 250 vs 440...eh, it looks tempting.

y8s 02-02-2007 12:40 PM

maybe noticeable on a dyno but probably not noticeable with the butt dyno. should improve spool and if what people above said is true, better response at higher rpm too.

I recall markp describing it as "the #1 and #4 runner dont point at each other"

it's like a half step below equal length shorty tube manifold--those tend to have all the tubes in a collector pointing "in".

miatamania 02-02-2007 01:19 PM

So in peoples opinion...since everyone has one...w/ a GT2554r...and a their downpipe, worth it to get it?

Braineack 02-02-2007 01:35 PM

yes. are you looking to buy Neo's?

Arkmage 02-02-2007 01:49 PM

I think the reason the older ones are so cheap is because they are "sold as is"... they don't have any to offer as a replacement like the newer ones so they are selling them at a severe discount.

Stephanie Turner 02-02-2007 05:19 PM

They were on sale 'cuz that is all there was left of those. Came with mounting hardware and warranty. ALL manifolds are now directed pulse.

Ya'll are correct about the direct pulse feature. :)

And the coolant re-route can be done separately. I will have info and photos in a few days.
Stephanie

miatamania 02-02-2007 05:20 PM


Originally Posted by Braineack (Post 78289)
yes. are you looking to buy Neo's?

huh, whose, where?

Braineack 02-02-2007 05:22 PM

sorry... neogenesis2004 has talked about selling his almost new begi manifold/dp and gt2554R....n/m


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