Log vs tubular manifolds for turbo application

[jvanzyl]

Dear all,
As per the title can anyone succinctly tell me what the benefit of tubular vs log manifolds is?

There is a significant cost implication with the tubular so in effect I'm trying to figure out "is it worth it" for our cars.

Please note that the manifold creator will be a well known individual who has made other things for us and so I respect their design, I just want to know is it extra bhp we're talking here, better responsiveness etc.

Many thanks!
Ps please the below pic of what they are suggesting:
You cannot view this attachment.

[thetyrant]

Tubular like that will generally give best performance, however the price is going to be a lot more than a simple log or cast type which will often give enough performance for what people are doing with these cars on stock engines at least, will be interested to know what sort of ball park ££ they are thinking but i would except it to be getting on a grand maybe a bit more for low volume production of this tubular type ?

[shnazzle]

Tubular =
- more fragile (not sure this applies to the pitiful little engine it's going on in this case haha)
- longer spool I would imagine as it takes longer for the exhaust to reach the turbo. Maybe even lag?
- I would imagine overall better flow with tubular. Probably would work well with a bigger turbo because the pre-boost areas wouldn't be so dreadful as they'd be with a log mani.

Log =
- cheap
- strong
- small
- does the trick on our cars

[m1tch]

What size turbo/power levels are you going for? I think the log manifolds can cause a bit of a restriction at higher power levels but would be fine for most applications. I will be running a log manifold on mine - I have a T3 manifold on the shelf but might buy a cast T25 sized manifold when I go turbo.

[jvanzyl]

What size turbo/power levels are you going for? I think the log manifolds can cause a bit of a restriction at higher power levels but would be fine for most applications. I will be running a log manifold on mine - I have a T3 manifold on the shelf but might buy a cast T25 sized manifold when I go turbo.

The idea is for stock engines, and a GT2554R.. figured that would reach the "masses"

So pretty much expecting a ceiling of 240hp, and in that domain is it justified going with tubular?

[m1tch]

What size turbo/power levels are you going for? I think the log manifolds can cause a bit of a restriction at higher power levels but would be fine for most applications. I will be running a log manifold on mine - I have a T3 manifold on the shelf but might buy a cast T25 sized manifold when I go turbo.

The idea is for stock engines, and a GT2554R.. figured that would reach the "masses"

So pretty much expecting a ceiling of 240hp, and in that domain is it justified going with tubular?

A normal log manifold should be fine, think they only start to get restrictive from mid 300s upwards for the ones you can buy off the shelf at the moment.

[thetyrant]

I think if someone could make a improved version of the Malian as my below mock up picture at decent price (sub 400-500) it should sell pretty well, ive basically added 2 x 02/Lambda bungs for those wanting to use with piggyback ecu and a better angle into turbo collector would be nice as well

You cannot view this attachment.

There isnt many wanting to push big numbers on forged engines in these cars (at least this side of pond)  so making a good reliable/affordable solution capable of flowing 250-300hp is the key i think.

[Joesson]

A product that I am aware of from my early years in engineering is:
https://www.dpluk.co.uk/home
https://www.dairytube.ie/

This is good quality stainless, weldable steel used for food grade machinery. Whether the wall thickness is great enough for turbo pressures I know not but it is a readily available source of preformed material.

PS Amended .
Dairypipelines is more likely the company I remember . Dairytube has a more aggressive web site and came up first in my search.

[tets]

http://turbomotor.dk/contents/da/d28.html

This guy is cheap (and in Denmark). I wouldn't hesitate trying one for that money though - the tubular one is £85 and £130 for the cast + I guess shipping!!

[thetyrant]

http://turbomotor.dk/contents/da/d28.html

This guy is cheap (and in Denmark). I wouldn't hesitate trying one for that money though - the tubular one is £85 and £130 for the cast + I guess shipping!!

Interesting but prices look too cheap to be any good and suspect cheap far east made very low quality 

[jvanzyl]

http://turbomotor.dk/contents/da/d28.html

This guy is cheap (and in Denmark). I wouldn't hesitate trying one for that money though - the tubular one is £85 and £130 for the cast + I guess shipping!!

Interesting but prices look too cheap to be any good and suspect cheap far east made very low quality 

You guys actually tried ordering one?
It's impossible, and they don't reply to emails..

[tets]

I found him when I was looking to start assembling bits for mine - He came on recommendation from someone (can't remember who mind)
Until I got my kit on a car, I was going to take a chance on the tubular one and give it good inspection prior to using it. I'm still tempted to get hold of one just to satisfy my curiosity.
Like you say, it could be cheap and nasty Far East stuff but at that price it's got to be worth a look

[jvanzyl]

I've tried on multiple platforms to order one. You basically can't get it delivered to any where other than Denmark. I have lots of danish colleagues.. could maybe try and get them to forward one to me..

[Joesson]

I've tried on multiple platforms to order one. You basically can't get it delivered to any where other than Denmark. I have lots of danish colleagues.. could maybe try and get them to forward one to me..

A good test of how cooperative/ friendly your Danish colleagues are.

[tets]

I haven't but I think if you have colleagues in Denmark it would make it easier by the sounds of it!!

Or a roadtrip of course - Been years since I had to go to meetings in Aarhus and really liked the place.