I will be designing and building my turbo manifold shortly but would like to get some peoples opinions on what would be the best and most practical to build.

Ideally I'd like an equal length tubular manifold leading to a normal 4-1 collector however these are more difficult to design and build due to the space I have to fit it in. I've read that these promote better running and smoother power delivery.




The other option is the Log style manifold, easier to make, smaller size however poorer flow characteristics.



I have little room to make the manifold fit between the block and the chassis rails and also the manifold cannot dip too far down otherwise it will foul the area for the steering column.



I think I will be positioning the turbo changer above the chassis rail and close to the engine, I will need a bulge in the bonnet as it will not fit with the standard bonnet due to its location and size.

Ideas are welcome

how far are you going with the tuning?

If your sticking with a mild increase in power, then id go for the log manifold. Very easy to make, and the most similar in design to most stock OEM manifolds. It takes up the least space too

min runner length is 400mm sprouted from the swedish contingent .

if space is tight a properly designed log manifold will still allow upwards of 300hp.

ill try burning that flange of tomorrow .

Volvorsport if you could get those flanges made tomorrow and send them before chirstmas, I may be able to make it during my 2 week break

I think more than 300bhp in this would be mental, think Ill be sticking to between 200-250bhp, so have been thinking about the log type as its very easy to make and cheap as I dont need as many mandrel bended tubes. I can always change at a later date to something a little more curvy I suppose.

i think ive got some weldable bends left aswell .

What size are the bends? Im looking at 38.1mm diameter and ideally a 1D bend radius but can only find 1.5D, if I could get 1D I might make a tubular manidold.

Let me know if you get the flanges made up, that will be AWESOME!!!

here are examples of some of the ones we sell for peugeot/ citroen engines.. may give you some inspiration.

http://atspeedracing.co.uk/products/index.php?main_page=index&cPa th=4_6






custom fabrications available

www.DP-Engineering.nl
contact: Pieter
info@dp-engineering.nl


- colin.

art

when do you find its better to use an external wastgate on your setups atspeed?

generally accepted if running over 400hp. only really needed if running high boost pressures where you may overpower the actuator spring and boost be limited by this. also most large high power turbos do not accomodate internal wastegate.
running external wastegate can also provide better turbo efficiency and more power. also will have finer boost control at high boost, high power levels when combined with an Electronic Boost Controller

and also they sound cool

The sound cool i would say,actually am addicted to it

worth while making my gt2871r run a external fitting? running around 20psi

Deffo YES,38mm will do and go turbosmart if you can,

quote:

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Originally posted by westy turbo
Deffo YES,38mm will do and go turbosmart if you can,

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turbosmart all the way.

or tial.

the GT2871R is a horribly matched turbo anyway, but with the 2871R around 22psi is ok on an actuator providing you are not getting boost tail off at higher RPM obviously some of that is determined by the characteristics and size of the engine.

bigger wastegates give better flow - obviously - but flow rate is equally as important, wastegate size has to be matched around a balanced body/valve/spring combination that is designed to work together to allow for maximum boost control and optimum performance.

generally if you have a big turbo or small turbo running high boost you want a small wastegate
low boost you will have better control on a larger wastegate.

- colin.

quote:

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Originally posted by atspeed racing
turbosmart all the way.

or tial.

the GT2871R is a horribly matched turbo anyway, but with the 2871R around 22psi is ok on an actuator providing you are not getting boost tail off at higher RPM obviously some of that is determined by the characteristics and size of the engine.

bigger wastegates give better flow - obviously - but flow rate is equally as important, wastegate size has to be matched around a balanced body/valve/spring combination that is designed to work together to allow for maximum boost control and optimum performance.

generally if you have a big turbo or small turbo running high boost you want a small wastegate
low boost you will have better control on a larger wastegate.

- colin.

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How is to attach one in ur header if not having one allready?if not dont bother and go internal my engine is 2.0 liters,but my previus engine was an 1.6 16v vaux engine with an 28rs(disco potato,then i stroked it to 1.8 ) with an external compared to non external at first,was better response cause u take the gas out from the header,and you dont mesh with both at the same time into the downpipe so the flow is better.

I don't have manifold I'm having one made to suit, so fitment is not an issue

Is it loud? As I want to beat noise regs

what engine u have,it is loud,but u can turn it into the downpipe.

quote:

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Originally posted by westy turbo
what engine u have,it is loud,but u can turn it into the downpipe.

---

What u think

http://www.designengineering.com/category/catalog/spa-turbo-usa/turbo-manifolds/ford/ford-zetec-16v-turbo-manifold

the external wastegate pipe can be plumbed back intot he exhaust downstream of the turbo if you are concerned with noise. otherwise they are quite noisy.. its an unsilenced 38mm pipe 2ft long straight to the floor otherwise lol.

cheap wastegates are pointless, prone to getting stuck etc. fit a high quality item and only fit it once and never have to worry about it again. not just saying that cos i sell turbosmart stuff (i sell them because they are the best) but Tial are also very good.

turbo control is an area you cant cut back at with budget, otherwise its destined to run in reliability issues and poor performance.

cost, by tiem you have bought extra flanges and pipe, and the wastegate itself, your looking around + £500 over an internal set up. you have to also get the internal WG tig welded shut too.

so if you can run a internal wastegate, and can do so with no problems, do it. unless you specifically HAVE to run the external, stay with the internal.

- colin.

[Edited on 11/12/10 by atspeed racing]