Turbo manifold Log or Tube: Pros and Cons

[Jimbo]

Ok i have just bought a turbo and i'm about to buy a manifold for my TB42.

I have been quoted around $700 for a custom log style manifold made from steam pipe and also been quoted $1000 for an extractor style manifold.

My question is what are the differences (besides looks) between the 2.

The guy that quoted the log manifold only makes manifolds and says that unless i'm chasing that last bit of top end power a log style is better as the turbo will spool up earlier and giver better low down torque.

Can anyone verify this?????

What are ppls experiences? Pro and cons of both.

Thank ppl


Jimmy

[dumbdunce]

Ok i have just bought a turbo and i'm about to buy a manifold for my TB42.

I have been quoted around $700 for a custom log style manifold made from steam pipe and also been quoted $1000 for an extractor style manifold.

My question is what are the differences (besides looks) between the 2.

The guy that quoted the log manifold only makes manifolds and says that unless i'm chasing that last bit of top end power a log style is better as the turbo will spool up earlier and giver better low down torque.

Can anyone verify this?????

What are ppls experiences? Pro and cons of both.

Thank ppl


Jimmy

the log man is pretty much on the money - extractor style is cool for six million rpm and squeezing every last kW out of your junk, but a log style will do the job pretty nicely on a low revving diesel. All that said, $700 is a lot of money, and if you have any interest in doing it yourself, you could buy a welder, some pipe, a turbo flange and a header flange for less.

[Jimbo]

Ok but mine is a petrol.

Yeah i know $700 is a bit but some of the cast manifolds are more than that.

[dumbdunce]

Ok but mine is a petrol.

Yeah i know $700 is a bit but some of the cast manifolds are more than that.

same goes - it's not a high revving race motor, so a log will do fine. I think $700 is fair. in fact I think $1000 for an extractor type is a bargain.

Have you looked at an adaptor pipe from your existing manifold to the turbo? not as efficient but probably a LOT cheaper (in the $200 range)

[Jimbo]

I ahve extractors on at the moment and asked a few places if they could do anything with them but so far no.

Thanks fo rthe help though!

[HotFourOk]

Can you make a manifold out of the stock headers?
They are basically a log shape on most cars.. I'm not sure about the TB42 tho.


Just found this also...

Apparently the manifolds for a turbo diesel will bolt straight on though

http://outerlimits4x4.com/viewtopic.php ... 816e524dd2

Also, Quadcamshorty uses one:

Setup includes:
Front mount 600x300x75 intercooler
hi flow t3 turbo
diesel exhaust manifold
gq efi inlet manifold, with gtr skyline injectors
gtr fuel pump
Autronic smc ecu.
custom hall effect dissy etc
3inch exhaust

[-Scott-]

To maximise throttle response you want maximum energy transfer from exhaust pulses to turbine - at any revs.

A log type manifold has far from efficient flow characteristics, so energy from your exhaust flow will be lost in the manifold before it reaches the turbine.

You will have higher engine backpressure, higher manifold temperatures and longer spool times.

But there's no denying log manifolds are easier (and therefore cheaper) to manufacture.

I suggest your log man is afraid that if he quotes for extractor style, and somebody else talks you into log style, then he'll lose your business. He's more interested in gaining your business than providing you with the best advice.

My 2c,

Scott

[fatassgq]

from the guys I have spoken to that actually have turbo 4.2's and 4.5's they all say that once they put a tube manifold on the turbo spooled quicker than the log/diesel style ones. Not to mention better power
These are all pretty full on set ups though and I know of several others that have used the diesel style ones and are more than happy with the result.

I think you would be fine to go with the diesel style manifold. the difference in a mild set up just woudn't justify the extra expense. You will easily get over 200 rwhp with a diesel manifold and a reasonably simple set up.

Or you could make your own!!!

[punk_180]

i have just come out of modifying alot of turbo cars and the extra style manifolds are alot better than the standard (log) style manifolds.
The extracta style manifolds do allow for faster spooling, which is what you want on a low reving motor. On the last car i built it was spooling from 2500 with the extracta style it was boosting from 1900. it doesnt sound like much but once on the car it makes a lot of difference.

it also makes a big difference on the size of the turbo. aswell where you want it to spool from. if you want something for low down torque. go for a turbo that has a large intake housing and smaller exhaust housing this allows for revs through more of the rev range. Or if all you want is power then go for a big turbo, but keep in mind you will hit boost very close to redline.

i know you have probably thought all this through but if you havent there you go.

[Jimbo]

"i built it was spooling from 2500 with the extracta style it was boosting from 1900. it doesnt sound like much but once on the car it makes a lot of difference."

Cheers mate, those 600revs is a huge difference in my book and that is the response i was looking for.
I ahve got myself a hybrid turbo with a T3 exhaust and T4 compressor wheel (a/r = 0.5) Hopefully it will do the trick.

Ok hopefully off to see sandy and get my manifold made up next week!

[bazzle]

I ahve extractors on at the moment and asked a few places if they could do anything with them but so far no.

Thanks fo rthe help though!

2nd Sandy at aus 4wd.

Bazzle