legacycentral bbs

Have a wrx engine in my jet boat with an after market exhaust manifold. It has the exhaust from each head in a separate pipe and they meet up at the turbo so was hoping this would suit the vf37, but was wondering if the legnth of each pipe has to be the same coz the one on the turbo side of the engine is way shorter.

Am running vf10 at the mo but can get hold of a vf37 which i hear are awesome. Any sugestions??

Please disregard my previous comments......I missed the twin scroll part.

I don't recall if the factory setup is equal length....if it is....then yeah you may have to go that route.

are you sure. im pretty sure the stock exhaust that match this turbo have equal legnth thats why you need the different sump as one of the pipes goes throught the middle of where the sump would be

I dunno much about subaru twin scroll setups but in general the header needs to take into account the firing order to time the exhaust pulses correctly to really take advantage of the twin scroll. subaru is 1-3-2-4 correct, 1 and 2 feeding one side, 3 and 4 feeding the other.
I would imagine that is how the subaru twin scroll manifold is set up since they are a specific design.

206er wrote:I dunno much about subaru twin scroll setups but in general the header needs to take into account the firing order to time the exhaust pulses correctly to really take advantage of the twin scroll. subaru is 1-3-2-4 correct, 1 and 2 feeding one side, 3 and 4 feeding the other.
I would imagine that is how the subaru twin scroll manifold is set up since they are a specific design.

I agree with 206er, if you are going to have to use a modified preturbo exhaust, you should probably save your money and get a different(better). I have always considered the actual turbo part of the VF37 twinscroll set up to be the restricting factor, it is just pretty small.

For twin scroll to work properly and to its full advantage, it is IMPERATIVE to have the runners leading to the turbo be equal length.

Honestly, on a boat, where lag really isn't an issue, i wouldn't go to all the work.

what would u suggest a good turbo then.
Lag definatly is an issues as u wanna get up and going as quick as poss coz all my boating is in water no more than a foot deep, and the deep hole in the river might only be half a boat legnth to get going.
I have got a 94 twin turbo engine on the way that has been converted back to single turbo, hhas had forged pistons put in it and strethgnd cams whatevr that means.
When I had the old rs engine i was running a vf10 which worked well, but this new engine maybe able to handle more boost so maybe a vf23?? or the like maybe better. Or will this be pretty laggy.
Whats spools quicker out of a TD04 and VF10?? Keen for advice