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Fujitsubo flanges Manifold to downpipe
Posted: Thu Jan 23, 2020 6:10 pm
by vanzep
Has anyone else seen this before?
The mani flange and downpipe flange dont appear to be flat they come to a slight peak at the back where the single stud is - seems flat elsewhere

Sure the gasket might take up the slack but surely they should be dead flat. Just wondering if it is a deliberate design by fujitsubo or if just caused by overtightening of the flange or slight distortion caused by impact when the downpipes get their inevitable flats spots.
Would be easy enough to get them back flat..
oh and is there any issue with this manifold in this area? a lot of folk seem to need new gaskets at this join...just saying
any input is welcome!
Fujitsubo flanges Manifold to downpipe
Posted: Fri Jan 24, 2020 6:13 pm
by wurlycorner
Should be perfectly flat AFAIK - never noticed anything else when I've looked at them.
I have one sat in the shed I would check for you, if I wasn't away this weekend.
Will try and look next week if I can.
Most people need gaskets not because they fail, but because the manifold is sold on (now on its second or third owner

) and the seller either doesn't include the gasket, or it feels right to replace it, IMO?
Fujitsubo flanges Manifold to downpipe
Posted: Sat Jan 25, 2020 5:34 pm
by vanzep
Thanks wurly..tbh im only asking because someone else has said they had noticed this on their flanges but thought this was ok or thought it was a deliberate design and that the gasket would fill the gap..this threw me...hence asking on here. One other thing that got me wondering was that the slight raised section on both flanges is at the same point on the flange but facing each other so it makes quite a large gap when both flanges are put together..its raised over quite a small section at the back of the stud/bolt hole so should be easy to file/machine it flat.
Fujitsubo flanges Manifold to downpipe
Posted: Sun Jan 26, 2020 3:15 pm
by vanzep
Fujitsubo flanges Manifold to downpipe
Posted: Sun Jan 26, 2020 7:57 pm
by Scott560
Doesn't look quite right to me? I haven't seen any others to compare with, but obviously it should be flat at the mating surface.
That stud is longer than the others, and has damaged threads by the looks of it - perhaps its been abused somehow, or maybe just got too hot and has warped a little?
Fujitsubo flanges Manifold to downpipe
Posted: Wed Feb 05, 2020 7:00 pm
by wurlycorner
That's definitely not right at all - they don't come like that and a gasket won't fill a gap that big.
Has the flange been re-welded? If so, could be they did it without tacking it to a large heat-sink and have warped the flange through over-heating.
Fujitsubo flanges Manifold to downpipe
Posted: Wed Feb 05, 2020 7:31 pm
by vanzep
hi wurly
the manifold flange was missing the stud at the back (it had been replaced with a thin bolt and nut) and i think it may have been heated up to remove the damaged stud and that warped the flange in that area - so got it fixed today with some heat and a hammer and also got a genuine fujitsubo gasket from newkid so it all goes together now like it should

the only piece of the puzzle left to do is to replace the cat with a 60mm decat pipe jdm size and connect it up to the kakimoto cat back - wondering how this will compare to the plm with scorpion cat back thats on the BB1 right now.
Fujitsubo flanges Manifold to downpipe
Posted: Mon Feb 10, 2020 7:01 am
by imkerya
A familiar problem. Have the same issue on 2 sets of used fujitsubo headers.
Curved the flanges due to operation without an additional downpipe bracket under the oil filter.
Maybe you now what gasket can use for this header?
I've just try this one, it similar but not ideal, 1-2 mm need make hole greater where using studs.

Fujitsubo flanges Manifold to downpipe
Posted: Mon Feb 10, 2020 9:12 am
by vanzep
Thanks for the info
i have seen the fitting kit that comes with this header and it did have a u clamp and a metal strap and im wondering if this is the clamp that you mention is missing - nobody seems to know where this part goes

I got a genuine gasket from newkid as he is able to get them imported at a reasonable cost.
He is ordering more of them in -i can send you the one i have here if you need one now to get the exhaust on the car.Just let me know
link to group buy for gaskets:
viewtopic.php?f=81&t=23372
Fujitsubo flanges Manifold to downpipe
Posted: Mon Feb 10, 2020 9:49 am
by imkerya
vanzep wrote: ↑Mon Feb 10, 2020 9:12 am
Thanks for the info
i have seen the fitting kit that comes with this header and it did have a u clamp and a metal strap and im wondering if this is the clamp that you mention is missing - nobody seems to know where this part goes
So, I've just modify the standard bracket by welding and grinder.

And I advise you to use some.