cast manifold vs. tubular vs. twin scroll tubular

[Drift247365]

Sorry been trying to get my head wrapped back around in the DSM game, but what is the pros and cons between all three manifolds and why is there a need for what looks to be dual WG bungs on a twin scroll. If there was already a post about this I apologize in advance. Just doing a lot of research and building at the same time.

 

[2gmitsueclipse]

1. Control + C the following:

dsm cast vs tubular site:www.dsmtuners.com

2. Click here:

Here

3. Paste the copied text

4. Many good threads to look through.

 

[Drift247365]

thanks....ive read up on most of them in here but didn't see too many on pros and cons of each manifold and what gains and demises can come from each.

 

[2gmitsueclipse]

thanks....ive read up on most of them in here but didn't see too many on pros and cons of each manifold and what gains and demises can come from each.

Interesting.......
In the very first thread that pops up, contains this information:

Yes and No

A cast manifold and an EQUAL LENGTH tubular manifold in theory should be able to achieve the same peak HP, with all other things being equal.

BUT, cast manifold and an EQUAL LENGTH tubular manifold DO NOT have the same HP curve. An equal length tubular manifold (ELTM) will shine in the spool up range, where the cast manifold will fall behind.

Reason...

- A cast manifold has uneven runners that will cause exhaust pulses to enter the turbo in a non-rhythmic pattern. Since the #2,#3 runners are a straight shot into the turbo, those exhaust pulses will reach the turbo sooner than the #1,#4 longer runners do.

- Firing order of the 4G63 is 4-1-2-3. You get exhaust pulses that looks like this

cyl#4 = Long exhaust pulse
cyl#1 = Long exhaust pulse
cyl#2 = Short
cyl#3 = Short

- So when you look at the rhythm above, it will be a

PULSE - wait - PULSE - PULSE - short wait - PULSE - long wait - PULSE (Cyl#4repeat)

On the other hand, an ELTM rhythm would look like this...

PULSE - wait - PULSE - wait - PULSE - wait - PULSE - wait - (Repeat)

Which manifold do you think will spool up faster and smoother?

But once the turbo is fully spooled both manifold should perform the same and achieve very similar peak HP levels, as long as the runners are not a restriction itself.

 

[YUPOK]

There really isn't a short answer here, what is your application?

 

[bastarddsm]

There is sooooooo much information out there. Most of it is theory though.

 

[Drift247365]

pretty much was looking at a twin scroll tubular but wasn't sure on why the manifold was made that way but also wanted to see what is the main use for it and why it is better or worse than the original cast manifold. quicker spool time? less lag? just some small things