which gives better power numbers on a s4 n/a motor??
-s4 ported intake manifold
or
- s5 ported intake manifold
or
-stock s5 intake manifold

tell me what you think and throw in some input to back your theory. thanks alot
jack

 

On a otherwise stock or lightly ported S4 motor, the S4 LIM with S5 upper (VDI) intake will provide the best increase in HP.

But on a moderate ported or heavy ported the S4 upper and lower will provide the best power.

 

why not the s5 lower..... i know there is another port for some function that the s4 does not have but im sure that is no big deal or is it?

 

i also have a stock port s4 engine just for reference

 

The entire S5 intake manifold has been dyno proven to provide less power than the stock S4 manifold on a S4 non turbo motor.

The advantage of the S4 LIM/S5 UIM combo is that the much larger S4 LIM runners allow better flow. In fact the S5 UIM/VDI section will need to be slightly ground/ported/port matched to the S4 LIM to get reasonable flow gains.

 

icemark has spoken......wise words.....i bet not too many people know thats the best combo

 

so um, any idea if that would work for an S5 motor? the S4 LIM/S5 UIM combo i mean. my knowledge of the S4 NA when there are differences is very lacking .

 

im gonna have to take a look at the s4 lim and compare it to my s5 lim and compare them.... but the s5 intake manifold i have is gasket port matched.

 

Now remember this is for non turbo motors...

The S5 motor follows a simular set up, that if you have a stock motor (or a very mild street port) the stock S5 intake system, port matched and cleaned up internally will give you the best power.

But for moderate to heavy ported S5 motors, a port matched S4 intake system will produce better power.

These are all based on testing both real world and at a dynojet up here in Northern CA, but I think you will find most of the big or better engine builders will agree.

 

thanks alot for all this info icemark