O.E.M Manifold

24th April 2007, 12:51

What do you think about OEM manifold? Is it restrictive or it's ok for about 160hp? I sow many projects using OEM manifold including saxo rally cars.

24th April 2007, 12:53

the original manifold is heavily restrictive and no way will it flow to 160bhp.stainless steel 421 or 4 into 1 is your best bet

24th April 2007, 12:57

Ok look at this http://www.lioliosracing.gr/main.php?id=157&lang=en

24th April 2007, 13:00

yes but look at the work involveed in getting it to there with a less restrictive manifold it would produce more power and torque!!

24th April 2007, 13:25

Agree not sure why you would do all that work to the engine and leave the manifold to the OE spec? Weird

It mainly works like this mate.

4-2-1 will give more low to mid range gains in power and torque
4-1 will give more mid to high range gains in power and torque

The same works in theroy for exhaust systems.

A twin box system (centre box - back box) will create more low down torque
a single box system (no centre box - just back box) will create more high end power

So in theroy if your looking for out and out speed then the 4-1 and a single box exhaust system will be best but you will lose low end torque. Where as a 4-2-1 and a twin box exhaust system will give you more low down grunt but will be abit more restrictive higher up the rev range.

I went for the 4-1 and single box system for my S as Im using more of the higher end power with the 16v but alot comes down to personal tastes in style and budget.

4-1's are generally more expensive.

24th April 2007, 16:13

the manifold they used has been modified though in most cases, either with increased bores and better port matching

24th April 2007, 16:16

Then its not standard equipement then?

Id recommend a 4-2-1 RaceLand items can be had from www.kam-racing.com for under £150 with a decent exhaust system you should see a noticable gain in the way the car pulls

24th April 2007, 16:20

Want a pic of the standard down pipe and a pic of the aftermarket one im suprised the standard managed to flow any gases at all its actually squashed on 1 of the outlets and not even a perfect round bore

24th April 2007, 18:42

Quote:

Originally Posted by VTS_16v_Boy

Then its not standard equipement then?

if you read the site you would see in some cases it does state they modified the std manifold

and its still using std castings just with slightly better flowing.