Porsche Enthusiasts Club Forum

Yes I'm still working on it but progress has been slow recently due to a heavy garage workload. I picked up a virtually new condition interior for it too.

Time for an update, exhaust manifolds, we don't have any that work in a 944 with a 1uz fitted, the stock 1uz headers are.......well..... garbage!

So i've seen some attempts on the internet that made me roffle, log style....well logs are only fit for burning in my opinion, so i put a bit of thought into it and measured available space between the engine and chassis rails (it isn't a lot).

So with the brief to get some flow going, make them out of something more robust than tinfoil but ultimately fit in the space i have (flow can go screw itself if it means it not working at all) i set about with a big box of 45* and 90* steam pipe weld els, a 1uz 10mm thick header flange and a 2.5" output flange.....



About 25-30 man hours later we have this....







I'm very pleased with that, they are thick wall tube so will last forever, but i am only 50% of the way there, the amount of fabrication this took was insane.

I bolted the flange to a 3/4" thick plate of steel so that the welding would not pull or distort the flange, and it has ended up very straight.





Sadly none of this work will get seen from the engine bay, they are totally obscured, still i'm happy with that, one of the hardest things i've ever made.

Let us compare mine v the original LS400 one....



One down one to go!

that's a real nice bit of pipework, I can imagine that took mountains of thought and effort, custom tubular headers will be a second line of business for you now

good job man

Screw that, nobody could ever pay me to do this again, i don't even want to build the other side!

I had an idea you might say that, but a brilliant job anyway

i've now completed the other bank manifold, there is a slight difference between the two because the drivers one needs to clear the steering shaft which narrowly misses the pipes, but at least they are done now, next step is Tig welding the rest of the stainless system which will be 2.5" on each bank, going into a crossover X then splitting into two separate silencers and twin exit out the rear.





I think there has got to be a BHP gain from my manifolds given the state of the stock ones, i think i have some decent flow going on. Going to look into getting them Ceramic coated.

Coated white even if you can't see them

Yes definitely, i will probably leave that until last though, still so much to do, but it's getting there.

Ok so time to get stuck back into the 944 again, this project feels neverending as i am finding one thing i modify is causing a dozen other things to need modifying.

I put the car on one of the lifts to start making the exhaust system and get a general poke around underneath, carry out any welding and a few other jobs that are a nightmare on the ground.

The plan was to use 2.25" stainless coming from the headers and cross them over, the reason for this is that if you keep the banks separate you effectively have two 2ltr engines running, and not a V8, so the crossover section brings the V8 burble back and also helps with tuning, a pulse from one bank will help scavenge the gases from the opposite one, so not just a sound requirement.

Here is everything tacked into place, i ran out of pipes to complete the system so they are on order now. 45* drop down from the headers, then 30* kick them straight before the crossover.







This is as far as i got at the rear, the pipes will run under the driveshafts then swing up a little before going into two silencers and out the rear panel....



Now part of being able to have a twin silencer system on a 944 V8 means i had to ditch the original fuel tank, it sat above the gearbox but with one side of it hanging down to completely fill the right side, so nowhere to put a silencer or route the exhaust out the back on that side, and having a twin system on a v8 is a must for me, so the tank had to go, then i cut out the vertical spare wheel well to leave this large hole....



We're making an alloy tank to sit in this area, which will go into the boot by about 5", i will hardly lose any space and it solves the exhaust problem, the tank will be 18 gallons and will look something like this...... i am making a 100mm hole for the original 944 fuel sender and will be fully baffled for surge etc....



Doing away with the original tank also gives me the opportunity for those rear mounted turbos idea we've discussed, but that is one for the future.

My 944 turbo gearbox will be here this week so that will be fitted too.

I have also cut the vents out of the right side for the right silencer pipe to exit, it's lucky a 944 has this design as it will look completely stock and meant to be.



You can see i have some rust issues to fix around the original number plate panel area.

That's looking nice, good work on the pipes and I like the idea of making a smaller tank as of course you will have junked all the emissions rubbish

Think the two pipes will give a nice balanced look to the rear and it's easier to route two smaller ones than one drain pipe.

Getting close to fire up day then a drop of paint and good to go

Indeed, looking forward to getting some paint on it, i'm very fussy about my paint finish so i will take a lot longer over the prep and finish than most would, going to drop about 6ltrs on it in stages.

Glad to see some progress on this

whats the box able to handle in terms of power?

Not sure what the upper limits of a 944 turbo gearbox are to be honest?

If i think about its original application it was designed for 243lbs.ft of torque, manufacturers usually engineer in at least 50% tolerance so i would guess it can handle at least 360lbs.ft

My V8 will have roughly 260lbs.ft , so around the same torque output as a turbo motor at full boost, the only difference being it will probably produce that torque a lot earlier.

Should be fine.

I know sumpcracker has been having a nightmare with boxes on his (now) turbo 944, with the most recent being a dogleg box thats gone bang. Hopefully yours lasts longer