Similarities Between Na & Turbo Manifolds

[Drift Freak]

Hi guys, I'm in the process of making my own frount mount intake manifold for my R32 GTS-T and was wondering if i can use my old naturally asperated intake runners as a base for the manifold mounting plate. The reason I'm asking as i don't want to remove the intake runners from my turbo motor as its my daily driver. So, any one got any idea??? Cheers guys

[mad082]

i'm not a big fan of front facing manifolds that aren't aftermarket. choping the stock manifold means that number 1 and 2 don't get nearly as much air as 5 and 6. even though it is pressurised, there is still little airflow going to the first cylinder. and number 6 will be running rather lean. your afr's will stay the same, but each individual cylinders afr will be screwed up.

[chrissso]

i'm not a big fan of front facing manifolds that aren't aftermarket. choping the stock manifold means that number 1 and 2 don't get nearly as much air as 5 and 6. even though it is pressurised, there is still little airflow going to the first cylinder. and number 6 will be running rather lean. your afr's will stay the same, but each individual cylinders afr will be screwed up.

I'm curious, what have you got to back that up?

[Drift Freak]

Yeah i can understand what your saying mad082 but i'm not cutting the manifolds but unbolting the top half from the bottom runners and fabricating a new top chamber. I'm also going to shape the manifold much like the jun and plazmaman manifolds, aswell as use the trumpets on each individual runner to maximise good airflow. I'm not after huge gains just shorter intercooler pipes for better spool up and colder charged air. At the moment i'm running a HKS 2540 on my RB20 and it doesn't spool up till nearly 4thou and i guess with all the extra pipe work the cold air would soon become quite warm again.

And as for testing the manifold I am going to try and find a flow bench so i can hopefully get each runner fairly close to each other (hopefully)

[fresh]

will make bugger all difference, u realise how much air a car goes thru when on full boost at high RPM

only the air touching the sides of the pipe would be affected by heat soak, and even then for a very brief period of time, will probably make bugger all difference

[1kool34]

Point taken fresh, but if the manifold only costs me say $150 to make at work then spool times and tidiness of the engine bay is justification to undertake the project. So my question remains are the intake runners of the naturally asperated RB20 the same as the runners off the turbo RB20???? Pls help