Recently I was asked to make a downpipe for use with a cast manifold.
I was curious how much downpipe space would be lost when using a cast manifold. The turbo flange on the cast manifold sits square is offset 40mm vertically from exhaust port centerline.
Usually I make manifolds with the turbo flange located at port centerline and rotated by 8 degrees... something like in this sketch. (The red line shows the firewall / frame lip.)
It turns out that the relatively small difference in location and orientation of the turbo flange has a significant influence on how the downpipe can be made.
This is an 80mm downpipe for a cast log
To get it to fit the firewall lip will have to be trimmed ( ~10mm) for the cast manifold downpipe as there is not enough space otherwise. Also the downpipe has to be made in 2 pieces as in order to be able to fit it. Flow also suffers due to the arrangement.
And this is an 80mm one for a port centerline manifold.
This fits without modifying the frame, can be made in one piece, is easier to make and has better flow characteristics compared to the one for the cast manifold.
Ever wonder why the stock NA downpipe has a kick mid way along the length as opposed to being a straight pipe?
Wonder no more
It is to allow clearance / access to the automatic transmission sump.
This came to light as I was asked for the first time to make a turbo setup for an automatic which ended up looking like this.
And in another first, I recently made an externally gated wrx turbo manifold with an 80mm downpipe.
Which reminded me of some kind of Tie Fighter....which starred in Downpipe Odyssey iirc ?
How much would it cost make a turbo down pipe elbow for a top mount t25? It's got to be a tight 90 degree turn to clear the chassis. I have the HKS top mount and will have to make a custom down pipe. Can you can make the whole thing? I'm on the search for at least a elbow.
I've been furiously researching/looking for suitable parts for my recently acquired MX and came across this amazing thread. Sturovo I'm amazed by your fab skills! I was thinking of fabing up a turbo dump pipe that would connect to the standard exhaust, and you've done it (and way better than I ever could)! Are you still making these kits?
Adam, yes I am still making parts.
Plus I have a new helper
Hi there Sturovo,
Are you still, still making manifolds/kits etc or moved on to cast mani's now?
Either way, I'm new to the forum & can't PM, could you send me info for a NA with TD04 manifold, please?
In fact if you could send me the price for a manifold, oil & water lines, and a down pipe as well as the manifold price, that would be great.
I won't be able afford a "kit" of parts as I've just been made redundant (which is why I have time to start working on my MX5 again) so may have to start with just manifold and go from there. But if I have both prices then I can work out what I need to save for both situations.