ashtons300zx

Is there any advantage or disadvantage to either given the same type of collector and same runner size is used?

I know most of you high hp guys are running pretty long runner lengths on your manifolds. The only thing I can think of that would be benificial from a long runner manifold vs short would be that the expansion of the gases through the turbine generates alot of heat and I could see keeping that heat further away from the head could be benificial but is there any other logical reason behind it or is it more for your turbo placement that you end up with the long runners.

My power goals for my setup are between 800-900whp, im using a BW S400SX 67mm 1.10 T4 housing. My manifold as is has a large runner 1 7/8 ID but fairly short lengths at about 12-13" from the manifold to the collector and maybe another 3" to the flange once I install the T4 flange. The manifold has smooth bends and is basicly a topmount ramhorn style manifold. I planned on using a divided t4 flange and thinning out the divider on the collector side of things to help smoothen flow into the divided housing.

Im really debating whether to have a long runner manifold made but i already spent a pretty penny on this manifold when I got it and with the placement of the turbo, it would be hard for me to sell in the sentra community. So with that being said I'd like to know if the runner length really isnt a big deal as long as everything flows well or if having longer runners is benificial enough to make me consider having a new manifold made.

tony1

Keep what you've got. You won't see a big difference if any and the difference may not even be positive.

ashtons300zx

Thanks Tony, just what I wanted to hear. I figured it probably wouldnt matter as long as the manifolds flowed well.

Appreciate it.