are these a good idea, ive heard from a few people now that stainless steel is known to crack when it gets really hot and is under stress (supporting a heavy turbo!)

I can't find anyone local who can weld cast steel (existing manifold) so have been looking into custom stainless ones. I've found someone who will make me one, but he also mentioned about stainless cracking. He just said he'd have to make it out of thicker steel!

any ideas people

There is a place local to me called maniflow. Their stainless manifolds come with a 10 year gaurentee on them. I'm not sur eif powerflow are a chain or this is the only shop. So if it breaks, they will make a new one.

Fred

fredjudd said:

There is a place local to me called powerflow. Their stainless manifilds come with a 10 year gaurentee on them. I'm not sur eif powerflow are a chain or this is the only shop. So if it breaks, they will make a new one.

Fred

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Powerflow are a chain doubt they will be much good for these though tbh

its not getting it replaced if it breaks.. i don't want it to break to start with. if stainless is known for cracking, then i don't want to be using it really.

Edit: The shop is called maniflow, not powerflow.

yeah, like i say there is a place local that'll make one for me, for around £120-£150 - but he did mention cracking, wanna hear from people who've run turbo'd cars before, see what they think to stainless

Maniflow have been going for years (and years), they're mainly older classics, Minis, MGs etc.

Since this is a main part, I doubt the costs will be cheap, I can't remember a turbo car which uses SS so I'd go for cast TBH. Look for specialist weldign and engineering firms in your area for that, kind of places that does coded welding etfc, they will take on anything I'd say. It won't be cheap though.

Liam

You can get s/s manifolds for turbo cars, there are plenty for the integrale but there have been many failures due to cracking, its all do do with the extreme heating and cooling that they are put through due to the turbo and dependent on design the weight of the turbo.

But i know that on many of the better integrale ones the holes that are made for you to bolt it to the head are slotted rather than blank holes to let the manifold contract and expand and therefore lessen the chance of cracks.

there are also many s/s manifolds for R5GT Turbo's as well.

I would be interested in a decent s/s manifold if you are getting them made dependent on cost.

Aaron.

What benefits are to be had through SS over cast though? Longevity aside.

Liam

bloomfieldliam said:

What benefits are to be had through SS over cast though? Longevity aside.

Liam

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Better flow, less back pressure, more power, quicker spool up of turbo so less lag. I know on an integrale the manifold alone gives 20bhp 25 lbs/torque and you get full positive boost some 300rpm lower in the rev range.

Aaron.

J333EVO said:

Better flow, less back pressure, more power, quicker spool up of turbo so less lag. I know on an integrale the manifold alone gives 20bhp 25 lbs/torque and you get full positive boost some 300rpm lower in the rev range.

Aaron.

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And they look nice Lol

i should be going up to a place in stoke that specialises in R5GT Turbo's sometime this week, see if they can held with getting the cast one modded - or if they can recomend any place that could do one that shouldn't crack.

does the GT15 use the same mounting flange as the KKK K03, as i'm using a K03. Can't see it being hard to swap between the two if i get a few made up but its soemthing worth checking.

Is there anywhere down where the turbo would be sat that could support some of the weight of the turbo to avoid overstressing the manifold?

J333EVO said:

Better flow, less back pressure, more power, quicker spool up of turbo so less lag. I know on an integrale the manifold alone gives 20bhp 25 lbs/torque and you get full positive boost some 300rpm lower in the rev range.

Aaron.

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Thats due to the surface finish on the interior of the casting Id think mainly...
The manufacturer isn't gonna do any unnecessary machining...as cleaning up the inside of the casting counts as that!

arseofbox said:

Thats due to the surface finish on the interior of the casting Id think mainly...
The manufacturer isn't gonna do any unnecessary machining...as cleaning up the inside of the casting counts as that!

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You also get smoother bends, equal length headers etc which all in on a turbo is paramount to efficiency of it, although on the Cinq there is not as much improvement to be made as the turbo sits directly below the manifold, not off-set like many standard fit turbos are, but believe me aeven an 150rpm drop in positive boost will be felt lot.

There are heart designs, 4-1 designs, twin scroll designs you name it its available for turbos, but granted a lot will be down to the finish of a better quality product.

To give you an example I know of 2 manifolds for the integrale, which are £1500+ so we’re talking big money on proper race proven designs.

I am also aware of a very interesting heart design manifold that is being proposed at the moment for manufacture in Switzerland that will cost only £400 delivered in 316grade S/S.

I am gonna ask about this once i return to work. Though thinking about some of the Lotus stuff we have just sent out, this was done in 304S/S. It wasn't the manifolds admittedly but it was the casing for the catalysts. Now catalysts run hot at the best of times but the ones on the Esprit turbos probably run quite warm.
I shall enquire as soon as the last of the gate-post fragments that have been residing in my left eye leave, and i return to work

its not just the temperature, its also to do with having to support the turbo itself.

arc said:

its not just the temperature, its also to do with having to support the turbo itself.

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This is true, though i believe that the way the manifold and turbo connect the problem may not be as bad as it is on some other cars as the weight can be evenly distirbuted across the manifold, for instance the integrale is of set, heres some pics to show you where the turbo hangs and therefore why cracking is a problem http://www.lanciadelta.ch/images/Tuning/Kollektor-Delta-16V.jpg http://www.lanciadelta.ch/images/Tuning/Kollektor-Delta-16V-1.jpg interesting heart design one, this is prototype http://img354.imageshack.us/img354/1803/dscn04173lm.jpg and a twin scroll one http://www.saito.it/lancia delta.htm

Aaron.

ah i see what you mean, where as with the cento its located centrally.. spreading the weight nicely.

thanks for that

arc said:

ah i see what you mean, where as with the cento its located centrally.. spreading the weight nicely.

thanks for that

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Exactly, though I would still recomend that who ever makes it looks at slotting the holes rather than just leave them round as this is what the better integrale manifolds do to allow a little movement when the manifold expands and contracts to stop the cracking, but this would be upto the expertise of the person making it and going on there experience.