I think you might find Rob himself is interested in what has been discussed. I'll not bother maybe?!?

ok guys don't start reaching for the hand bags yet

firstly i'd like to thank the guys involved for the information and time they put in

my fault for any issues as i was happy to let this run for the mine of information it unearthed which i should have realised was of no interest to anyone but me and the guys debating

knight thanks for the thought but as i say i allowed it to run i'll explain why in a minute
biggenz my apologies to you and anyone else thats been reading just to generally keep up with how it's going..i am still getting regular texts asking whats happening from all over!

the reason i was happy for it to go this way (though i now realise i should have opened a different thread) is barbz has built me such a sweet motor that to stall at the manifold and not be able to go any further yet is so bloody frustrating especially after buying the best on the market in terms of quality

i am desperately trying to take in as much as possible about manifold performance and design and there is so much information that comes from the main players in this that to me it's all i could wish for..if the solution we try next doesn't take us far enough i will have to have tig art make me a new manifold which they are happy to do free of charge but i have to design it! daunting for someone as clueless about manifolds as i am..ok i have barbz who although brilliant is not a manifold designer so i didn't think any thing but good could come of this thread and the way it's gone.. from my point of view that is

i will try and keep it to it's original subject matter from this point

i personally think the WAFFLE Is very interesting and educational! Obviously the 'knight&biggenz' tag team don't....

nick

It was all reletive to the issuse, I followed the whole thread from the begining. I suspected the collector might be at fault at the point when I said "can we see some pictures of the inside of the collector".

Forget Tig art, if this build is as serious as you make out you will want better than that.

Okay, so Tig Art are the company that made the manifold? And if you are saying 36mm ID, then that says to me it's this manifold, whereas, if you look at the 16v manifolds they do, the 'race' spec has 40mm ID and the normal one is 36mm.

right for a start i am enjoying the knowledge and info brought to the thread but what i was saying is it would of been better in its own thread and not in this one.

begbie that is interesting you should point that out as i had no idea they did 2 manifold sizes for the 16vt if i had spotted that from the start i wouldn't be in this situation as i would have queeried from that point..
it seems they only do the one for the 20vt and thats why i ended up with 36mm.. if i had had an option it would have been 40 straight away ..
they did believe the 5cyl 36mm would do the 600 though and have 2l's at over 500..though they had never run one on a 2.5..
for now that is all i can say
guy (the owner i think) seems a genuinely descent individual and is going to do all he can to make a manifold to do what we require so watch this space for results..the biggest issue with that is i am having to state what we require hence me encouraging and appreciating this technical last section to the thread

Well now you know it needs to be 40mm ID , what about the other variables - (not in order of importance, as there all important factors)

1> Material choice,
2> Collector merge angle,
3> Collector outlet size,
4> Runner length,
5> Bend center line radius,
6> Expansion allowance.

The ID is just one small part of the bigger picture, I haven't put equall length because that pretty much goes without saying.

I can help you a little with 3 or 4 of those on the list but, surely Tig art should know ???? I guess what I'm saying is if they don't and are asking you to design it, somethings not ringing true prehaps.

also

Manifold headflange that's not causing trouble
Exit angle off the head for the runners
Symmetry of the runners when compared to each other
Symmetry of the exit off the head
Symmetry of the approach to the collector
One of the hardest things, no cheated joins. It's so easy to settle for not 100% perfect join but there's a lot lost if your not that fussy. Unless you make your own though you'd never know if it was truely as good as it can be.
The order the runners are arranged around the collector.

The list goes on and on.......

Again an nice surpise to read all of this. If i only had some 20v flanges i would love to struggle a bit .

If you would make your own, you will never be happy 100%.

And in my case not even 50 maybe :0.

You all do know that you made it impossible to have an decent manifold for him now. The money,design,fabrication etc etc will cost him a fortune. If you have time enough then i might be easier to get it a bit right.

Only 50% happy, that's a bit harsh on yourself. I agree though to be fully happy is probably impossible but I'd say I'm 95% happy with mine.

Not even touched on welding tech yet ! - i'm starting to put myself off now, better shutup

Thank goodness, that the Integrale is a 4 cylinder and no 10 cylinder engine...
With your mathematics you then would adopt the same diameter for the tubes as well?!
5x36mm tubes do minimum the same flow as 4x40mm tubes...
An example
http://www.youtube.com/watch?v=nG9gXerj8v4&feature=mfu_in_order&list=UL
This Integrale belongs to Markus, he has a manifold with 38OD - outer diameter!!!, uuuups...

Juergen

Not that impressive the graph, a big power number at 5000 rpm then nohing but weak revs all the way to 7500, I wonder what could be causing it ????????????????

Very first comment posted on you tube,


" great car!

if you can find a way to just keep the boost on higher rpms..that would awesome!

i think you can reach almost 600hp and a better sprint of course.

that's too bad the torque falls down that much at 5500rpm...isn't it? "


Again I rest my case.

Hahaha...
Yeah - now I understand you... it's the manifold, which restrict's the performance of his car...
Maybe that Markus will get more power out of his small Garrett GT30 unit with a 40mm ID... :-)
This is the best Integrale with Tuev in Germany. And I bet, there will be probably no Inte's in UK with such a performance and TUV for legal daily driving.
Ps: Markus wanted a street car with boost in low revs, no 1/4mile racer, as you prefer...

Felix Pailer, the best hill climber in Austria, has a 40mm OD- manifold with twinscroll technology for his Integrale... he drives a GT3582R with 1,06AR and about 650HP
But I think, in your opinion this manifold is too weak as well... he could gain 700HP with a 41mm ID for sure :-)
http://www.youtube.com/watch?v=jzOMhjmzxUw&feature=related

Juergen

not wanting to give the wrong impression i will clarify the tig art situation..having only mentioined they wanted me to spec it may have given off a vibe of not quite knowing what they are about... but what they wanted me to do was give them the id i wanted,and to specify as much as i thought would make it good..i think they thought i knew a little more than i do!..so length of runners,where i want the turbo,how i want the collector etc but i have spoken to them this morning and they are happy to do whatever we want from refund to design a new one.. for me to me specify everything or any stage in between..he has offered to design one which he thinks will work better with longer straighter runners as the one we got was the superstock designed for stock 2l with maybe bigger turbo etc whereas we have quite a different set up which they have never tested or even seen before...i do need to know enough to make sure it looks likely to work before it's made and i give the go ahead but i feel confident this will come to a good conclusion after speaking with them again this morning...anyone want to stick thier neck out and saywhat they think would be the way to go?

I'd take the manifold and turbo off the car and create as much space as possible and then offer up just the turbo in the space you have until you are happy it's in a position that best suits exhaust route and easy routing for the runners (not forgetting the oil drain needs though that can be got round even if mounted very low). Make a bracket to hold the turbo where you want it, do a good job of this as it'll likely be permanant. Then make a simple jig that can be sent to tigart, doesn't need to be anything fancy just something that will survive shipping. If your struggling with the jig send me a mail and I'll do you some pics and explanation.

Do you really have enough information about the engine to be able to explain the shape of the torque curve is purely down to the primary pipe diameter? I really don't think so.

Three things I would note: 1) The engine is producing 576PS from 4 cylinders, therefore a five cylinder engine would be able to produce 720PS with 5 primaries of the same diameter without a problem. 2) a GT30 is pretty much maxed out in terms of flow at 576PS - it is rated at around 53lbs/min I believe - so I would think the turbo is a limiting factor in this case. 3) I know I am repeating myself here, but 576PS at 7000 RPM would produce the same mass of exhaust gas per second as 576PS at 5682 RPM does and so would place exactly the same demand on the manifold primaries, so an engine set up with lower boost, but producing the same power from the same mass flow at higher revs would have the same exhaust requirements.

Question: If you join 5 primaries of 41mm ID - total area 6600 mm^2 approximately, into a collector, by your estimation/calculation what area would the exit from the collector need to be to avoid choking?

You are right I dont have enough information to say the primary D is at fault, but what I will say is that we are still discussing small displacement engines, OK and a 2.5l but not 3l - 6.6 litre range. So which ever way you look at it they still need to rev to make power and a small cc engine that can't breeth at high(er) RPM is a pointless excersise.

Watch this space

ah now heres something i have neglected to mention we are not making the power we expected to make anywhere..at 1 bar we are well down on a standard manifold and gt30 set up and we are only mapped to 6k as we had reached the 407 threshold but still hadn't gone further than 6k ..(just thought i would add that little snippet).. but whatever the boost we couldn't make more..i was going to set the limiter to 7600 or 7700 depending really on what was happening

i am however on full boost by 3200 revs which i like

The same car with 525lb/ft of torque and 568BHP @ 5682 RPM will achieve the same top speed but out-accelerate the car that fitted with an engine producing 397lb/ft and 568BHP at 7500 RPM, so I don't understand the need for higher engine revs than are necessary to deliver the target. In this case I'd say the target has been pretty much achieved as the result is more or less all that the turbo will support.

That would suggest to me that the problem is probably somewhere else in the setup. Not being funny, but have you double-checked the cam timing?

why am I answering questions in the style of straight and when I ask all I seem to see is either no answer or something that skirts round the edge?

The collector exit is sized to complement the entry into the turbine scroll, not the same size as it and in honesty I'm not saying which way of that size but something close to it. Common sense will tell you the approximate size :-)

I just thought you would know the answer - that's why I asked you. You made a statement about primary size based on valve size, so I'd like to understand the whole picture by knowing the proper sizing for the collector related either to valve size, or primary size - if there is such a thing. The answer you have given doesn't really deal with the choking issue; what will cause the choking to be in the collector rather than in the primaries? (which I imagine could happen if the collector was too small).

Certainly for a normally aspirated engine, there is a relationship between the area of the primaries (whether that be two, three, four or more) and the collector area. I would expect that to be true of a turbo collector too, but I guess from your answer it's not critical. In the case of a T3 the exit area would be about 2426mm^2 and in the case of a T4 about 3810mm^2, so the velocity in the T3 entry would be 1.57 times that of the velocity in the T4 housing, all other things being equal - does that not matter? Wouldn't there be a big difference in back pressure?

There isn't a definative answer for much in an engine, more usually a ball park area and scope to shape but certainly I'd see the collectors smallest point being in the 2426 mm2 region. I think as long as it's close the biggest gains are in the radius either side of it. I'm not sure I know much about creating a choke on the exhaust side, I'll leave that for the turbo to decide.
A turbo engine deserves as much effort as a NA, built to be a good one of them but boosted (obviously not massive Cr and there are other differences I know) is the way forward in my mind. Critical is my middle name even more so to myself.

A 10 cyl integrale! that'd be amazing

If we can hatch a plot to build it Juergen and we can fit a pair of 28mm exhaust valves in each cylinder I'll be fighting the corner for a runner made from 1 3/4" tube.

I don't know him but without doubt Markus has a fine looking integrale. Trouble is he's not proud enough, very little moving footage even after watching all the videos (accelerating away like he was is like integrale do) and absolutly no engine bay pictures. Where else can I learn a bit more about Markus and his car? I'd like to see the dyno as it ran live and look at the jewel that must be under that bonnet

weak ? what graph are you talking about ???

that car peaks quite early but still holds 550hp and way over 500nm up to 7500rpm.

and look at the other videos and the speedo. that car is rapid !

like group5lancia already said we unfortunately don´t know nothing about the engine specs or especially the boost curve of this car. so none of us can really explain the shape of the curves....


macki