6.0-928S

I've never seen them in person but Phil tried to sell me a set & sent me these pics, mounted obviously in the car. I ended up buying the 928 Int. headers as well.
Hammer

atb

Sterling,

Louie's running the DEVEK set. I think it's because they have the shorter collector and therefore are a drop in with the heat shields.

Modular set up of the Internationals seals the deal for me. One piece headers headers are no fun.

RicerSchnitzzle

I believe 928motorsports has a right hand drive header kit.

123quattro

Those do look very pretty. It doesn't last though. Once you run a set hard, it turns from polished to frosted in quite short order.

John Veninger

I have a set of 928intl headers, good for 551hp to the ground, so far

JEC_31

(subscribing)

(need smiley for listening and taking notes)

Fabio421

...

slate blue

Well I think I have to give Phil an A+ for effort, those headers would not be easy to make. Nor would those very complex 180 degree headers made by Tom Cloutier, I mean those look the business. I wonder why the Nascar guys always use the TRI-Y? They do also use the X pipe on restrictor plate tracks. I suppose the reasoning there is that they want every bit of scavenging they can get, to suck in more air/fuel mixture.

I would love to see some of these headers compared on a dyno, looking at both peak and average power, I would go the best average power as the car is a street car and drivabilty on a circuit would also be better that way.

Greg

slate blue

Well the process has started to make the tri-y's, the process starts by mocking up a design, that is a design needs to be proved as to length and fitment. The pipes are taped together. On the left hand side it is quite straight forward, in fact the design would allow fitment to both left and right hand drive.

The main problem so far is the fitment to the right hand side, this has something to do with not have a steering rack to work with so too much guess work also the issue with the fact that the exhaust port is right at the front of the head, so it is effectively 66 mm further forward than the other side.

So what has to happen is that you need to curve the left hand side (5) front pipe a bit to loose that extra 66 mm in length. The reason this is important is that the secondaries are very sensitive to length changes and as such you don't want different lengths on different banks.

The inconel welds pretty well, I haven't back purged it as yet and that makes the weld even easier and better but let me just say that most exhaust fabricators will never have prepared a joint as well as what is required for this stuff. Remember this stuff is only 0.7 mm thick.

Well looking at Phil's headers, the one thing I notice that is completely different to my design is the length of the primaries, mine are between 530 mm and 570 mm around 22" and normally these are around 20" for a Nascar engine but their revs are a bit higher in terms of peak revs but a lot higher on average rpms. So I gave them another 2" or 10% in length and I will give the secondaries as much length as I can and this gives around 36" on both sides all up.

So what this means when compared to Mark A's and Phil T's headers is my headers have the primary collectors where the block ends not down near the X. I will not at this stage use an X as it is not the ultimate in top end power the H is better and in general I think these strokers have too much low end power.

Just for interests sake has anybody got a pic of Tom Cloutiers headers, I can remember a pic of them laid out on the grass. Very impressive in terms of design.

I am also getting a price on the rest of the system too, don't know if I can use my Burns lightweight mufflers so if anybody wants to buy them or buy one or two for a lightweight 3" system.

Greg

tveltman

Holy crap. You're using inconel for exhaust? What weight savings do you expect to see? How long do you think it will stay shiny after you polish them?

SMTCapeCod

slate blue

By tveltman
The inconel weighs pretty much exactly the same as the standard S4 exhaust manifold except it has 19 feet of pipe versus around 2 feet. and the in the other thread one rennlister said that the S4 manifold weighed 8 pounds 12.5 ounces or pretty much 4 kgs. Or for 36" of pipe in length which gets you back to the point where most would put the X. So 8 kgs to that point. The Burns mufflers weigh 1.1 kgs each and the lightened GT mufflers weigh 2.5 kgs each.

Depending on your design, you could do a race exhaust for 20 kgs headers inclusive but mine for the street (as long as I can afford it) will be 22 kgs likely but to a max of 25 kgs. That may not sound that light when another rennlister had an exhaust weighing 46 pounds (21 kgs) not counting headers (I don't know what 928 international headers weigh) but when the four mufflers weigh 6.2 kgs, and I may use a big rear muffler too you can see how it can add up and that doesn't include any pipe.

In terms of the polish, it as I understand it will last quite a long time except it will go that beautiful blue, green, purple color inconel goes when it gets hot. Anyway I will get the pics before that happens!

One ironic thing is that these will probably cost less than my first stainless set.

Greg

stuartph

Greg


Are you planning on making anymore in the future

Iwanna928

Holy Cow John Only 551rwhp! You need a little boost for some extra HP!

slate blue

Hi Stuart I have basically enough inconel to make two sets of headers, I bought 3 sets of primaries and 2 sets of secondaries, there is of course some waste and the 928 requires more twisty tight turns than a Nascar that is built to accept headers so you end up have more straight bits over but basically there is enough for 2 sets. The other set will be for a 4 V engine, I always planned 2 sets which was the reason I bought what I did before they were no longer available.

Greg

PS on the dry sump front I did some more research as I sold my Barnes pump the other day and had to answer some question from the buyer. Depending on what vacuum you are pulling you will need a relief valve. 18 inches of vacuum is max but if you are only around 12 inches max you don't need a relief as the vacuum isn't too high.

The other thing I thought about was if you put a relief valve in and kept the vacuum lower but had a large flow you may evacuate the bottom end better, it just wouldn't have the benefits of operating in such a strong vacuum, that is lower friction. Just thought I would throw that in because I know you were interested.