Manifolds

[Poohbear]

As some may know I've had a company manufacture some new manifolds as part of a semi complete system they are supplying. They have sent me a picture of said manifolds and I'm interested in your honest opinions good or bad. (I have my own thoughts which I will reveal later).
The main opinion I want apart from with regard to quality is do people think these manifolds are any better with regards to flow over the standard cast ones??

http://www.twobrutal.co.uk/forum/images/recovered/2008/12/122.jpg

Bob

[Garbe]

I think the one on the left should be fine, but the left one's middle pipe doesn't look to 'improve' flow. Almost as bad as the T-section of the orignal downpipes.

Quality looks fine, just the design looks off

[loadswine]

I am looking at them and can't really see how the flow would be much better, as the first part of the pipes doesn't really sweep into the direction of flow. Maybe the one on the left is slightly better, but they don't look like I would expect a purpose built manifold to look. I thought it would be mandrel bent pipework, like others I've seen, but there again, I don't know what brief the fabricator had.

[Jiff Lemon]

Nice quality, shame about the design.

I'd have thought equal lengths primaries would have been a starting point!

[MRV6]

Quality looks fine but mine has 3 equal length/ish pipes going into one.

http://www.twobrutal.co.uk/forum/images/recovered/2007/10/56.jpg

http://www.twobrutal.co.uk/forum/images/recovered/2007/10/55.jpg

[Poohbear]

Most of the thoughts being given here echo my own....quality of manufacture looks spot on but.....they aren't quite what I expected I have to say. I'm possibly to blame for making assumptions I think and maybe not explaining myself very well to them. I envisaged manifolds like MRV6's and just assumed seeing their other work that that's what I would get.

Question is what do I do now, there is a lot of work gone into them and really they have supplied what I asked for. I think I may have to take it on the chin, have them fitted and maybe look to get them changed later on...I feel like a right thick twat :(

Bob

[antnkel]

It's not your fault you thought they knew how to make a free flowing manifold, if it's there job why is the design not right:hmm:
If I were you I'd be asking questions!

[Marksman]

Might be worth going with a picture of Tony's efforts to show what kind of thing you were expecting.

Owen.

[Garbe]

Yep agree with the above, they make these things on a daily basis, and can't in a million years expect you to take the above items as acceptable. Even if they weren't equal length, at the very least they should sweep in one direction.

Have you paid any money yet?

[Garbe]

When you do speak to them about it, you should point to the examples of their work that they showed you, as in your thread.

http://forums.twobrutal.com/showthread.php?t=13692

and say thats what you were expecting, as opposed to you not making it clear what you wanted. Thereby not placing the blame on yourself, as you appear to have done. - which is not the case.

[MRV6]

I sure I've read somewhere that the pipes should be equal length, this is something to do with the venturi effect???

[Poohbear]

Thanks for the advice guys, I've emailed them and am awaiting their response.

Bob

[gtech]

I would of thought given the amount of work these engineers put into these, that they would of mocked them up first then asked you what your opinion was, rather than blasting away and hoping its right.

Really think Bob, that you should go back to them and explain that its just not good enough, their other work should of been enough to satisfy you that they would do EQUAL length manifold.......to be honest that looks like something an apprentice with no understanding would design.......go back and chat with them.

[antnkel]

Have they got back to you yet mate :eh:

[Paul Woods]

Ive held back posting but i have to agree with everyone here,those manifolds look worse than stock in terms of flow.... hell even the cheapo 1mz jobs i bought off ebay looked better for flow... i think this is the sort of thing you should have been expecting at the very least....

http://www.twobrutal.co.uk/forum/images/recovered/2008/01/209.jpg

http://www.twobrutal.co.uk/forum/images/recovered/2008/01/210.jpg

[dgh938peg]

http://www.twobrutal.co.uk/forum/images/recovered/2008/01/209.jpg

http://www.twobrutal.co.uk/forum/images/recovered/2008/01/210.jpg

I'm no expert on manifolds but have designed a fair bit of ducting in my time. But it's all basically airflow right. You should use equal lengths, or near as poss if the pipes converge into the same point as in your pic Paul

http://www.twobrutal.co.uk/forum/images/recovered/2008/12/122.jpg

The equal length theory does not ring true though if your pipe sizes increase like on Bob's fannymolds. My biggest concern with those Bob is the intersecting angles of the converging pipes into the larger main pipe. This should always be 60 degrees included angle or less, preferably 45 degree.

Like i say though i'm not manifold expert, just applying good airflow dynamics. From a Design & Engineering standpoint, i would not let one of my draughtsmen get that through to manufacture.

I think you'd be well advised to have 4v6 to flow test them for you as of course if there is an improvement over stock even only 1cfm then they're better unfortunately.

[Poohbear]

Well I ended up having them fitted to my car, (negotiated a suitable cost reduction) and whilst they are not what I expected they do actually seem to make the car feel a bit more responsive and quicker (only a dyno will tell). Although they don't look much different to standard manifolds the tubing size is considerably larger and less restrictive than the standard manifolds although the merging, especially on the middle runner is pants. Marks out of 10 for design of the manifolds 6 lol

As for the quality of workmanship 10 out of 10, welds are high quality, material is good and the downpipes/merged 'Y', flexi's and high flow sports cat are all well manufactured and integrated nicely with my Mongoose. (I will get some pictures up when I get a chance to get under the car.

Needless to say I wont be recommending them for their manifolds, but the rest of the work is worth a thumbs up, and they do give a lifetime warranty which is transferable with the car.

Bob

[Portgordon]

Bizarre though that the examples you posted up in your other thread all look spot on, completely different to what you ended up getting!

Does it make a noticeable difference to the sound of the engine?

All i ever seem to talk about is the sound of the v6 lol!

At any rate you now have nice shiny manifolds and we all know how you like your shiny bits!! :)

[ukpaisley]

I hope that the diameters are larger , giving better performance as the flow path is not the best ?

[OlberJ]

All i ever seem to talk about is the sound of the v6 lol!


That's cos they're slow and make no power. Obviously.

[loadswine]

Ah you've heard that too Olie? lol
I looked at the original pics again and I think those bits of pipework have been done in a similar way, with off the shelf pipes joined at angles, but they look better as they appear to be on longer pipes with a larger or longer joint, if you see what I mean. The new manifolds are compact, so the joins that they use don't look to work so well.
I'm not explaining it well probably or I'm just pissing in the wind!!:hehe:

[Poohbear]

Noise wise there isn't much difference to be fair, even though I now have a CAT fitted it sounds pretty much the same as before, which the best way I can describe it is 'rorty'.
And as for shiny...they didn't stay that way too long as they are now a nice multicoloured, bluey purple colour from the thrashing I gave it on the way home :)

Bob

[jimgreen]

Shame about this Bob, as I'm a big fan of that shop. I'm surprised they didn't show you the mild steel mock up they do, as I'm sure they said they do one before letting the guys loose on the SS.

[Limeymk1]

Use these as an example of your expectations.

http://i82.photobucket.com/albums/j256/4v6/frontbank4.jpg

http://i82.photobucket.com/albums/j256/4v6/frontbank2.jpg

http://i82.photobucket.com/albums/j256/4v6/frontbank3.jpg

Hope this helps.

Sorry if this is OT.

Tony how do you get all the pipes sealed on the 3-1 collector? I can't picture how the inner sections of the pipes can be welded. Even where the runners join to the collector it must me a royal PITA to get the torch between them.