940 & 960 Need opinions on exhaust manifold of RWD T4 build


I need to hear some opinions about the exhaust manifold options on RWD T4 whiteblock setting.

Stock manifold does not work, I thought I could flip it and be all good, but then the holes wont line up.

Full custom job is too expensive for me, but I thought that maybe I could buy an aftermarket 4cyl rwd manifold for some other engine and weld it onto a T4 exhaust flange.

What do you think? Is it impossible or are there some common engines that have similar bore spacing?



I have done some research and found some possible options

  1. Miata 1.8 turbo header, (bore spacing 91mm) cheap and correct spacing, but has incorrect turbo flange.
  2. Log manifold DIY kit, super cheap but more work needed ofc, and I dont know about performance and looks.
  3. Nissan SR20 header, (bore spacing should be 97mm) super cheap and with correct turbo flange, but probably need to cut off the block flange, heat and bend the tubes a couple of mm and reweld on a whiteblock flange.
  4. .. to be found


  • Arcwelder from Bunnings is $150?

    You could make a log manifold, sell the welder and be done for under $400 easily

  • One of the BMW i6 motors shares the spacing with the whiteblock (iirc m52....)

    I wonder if the bmw 4 of same erra shares spacing with the 6 of the erra such that a bmw 4 manifold might work....

  • That would be a good option if I can source one for a decent price. Otherwise I might go for that log thing you recommended earlier. Although making it not look like a complete turd would be an issue with that plan.

  • Ex850RSnoopy @Ex850R Somewhere Over the Rainbow. Melbourne.

    Cut mani in half , rotate 180 ° And get a bloke to weld it back together.

  • edited January 21

    There is also a very ghetto budget option, depending on where you want the turbo.

    Make a J/ UP pipe from the stock turbo manifold

    Or use a non turbo manifold where the merge collector is central

  • jamesincJames @jamesinc Oz Volvo Ice Fortress
    edited January 21

    If the Miata manifold isn't cast, you could easily have an exhaust shop lop the flange off and weld on the right one. If you bring them the manifold and new flange I can't see it costing too much.

    Otherwise buy a ebay manifold and get that modified to suit.

    It seems unlikely that you'll get this sorted out without doing some sort of modification work, unless someone out there is selling RWD T4 manifolds (maybe check the Swedish performance shops e.g. KL Racing, l-m-r.se)

  • SpacSpac @Spac Canberra-ish.

    BMW M44B19 motor has 91mm exhaust port spacing.

    Bolt pattern and port shape are obviously very different to B4194T, but it is a start.

    Other info that is probably irrelevant but is dribbling out of my brain regardless:

    I am almost certain that the M42B18 uses the exact same exhaust pattern. This may widen your search?

    The BMW motors are leaned heavily over to the right (driver’s side) which makes most LHD manifolds useless in a RHD BMW. I do not imagine that this would be a problem with a whiteblock in a Volvo, even if you are using the standard 960 lean.

    The BMW M43motors (basically the single cam version of the M44) have the same bore spacing as the M44 & M42 and round exhaust ports. If you happen to find anyone making turbo manifolds for these, they could be a good option.

    I have never found anyone who can weld a used petrol Volvo turbo exhaust manifold with any success - this includes a now-retired workmate who spent lots of time welding up cracked bus turbo manifolds.

  • I appreciate all your ideas, I tried to source some ebay manifold that could be easily modified for my needs, but did not really get anywhere...

    Eventually I got really lucky and found a guy selling his custom manifold. It was made for FWD and a different turbo so it needs an angled adapter, but still less hassle than modifying something made for a different engine.

  • SpacSpac @Spac Canberra-ish.
    edited May 18

    Looks like a good start.

    Just FYI, Toyota 3S motors have 91mm bore spacing.

    Edit: But that doesn't help because the exhaust port spacing is unequal. Larger gap between #2 and #3.

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