Has anyone ever had a custom exhaust manifold made?

[JTaylor2005]

Hey all,

Im just wondering if anyone on here has ever had a custom exhaust manifold made for their HDI?
If yes what design was it? How much room was there to play with? And how much did it cost?

Cheers

[pro_steve]

Yes Chris did when he made his >200BHP with the big VNT turbo, he also used it to relocated the turbo as it wouldn't fit behind the engine.

If you're going to do it the best way is to model the exhaust flange and then get it laser cut in 10mm stainless and also the flange for the new turbo in about 6 - 8 mm and then weld the pipes up custom from there. I might be making one up soon for my 1.6 HDI I'll try and get some pictures if I do. I think getting rid of the log manifold will help quite a lot in terms of EMPs.

[JTaylor2005]

Well thats what I was thinking. This is way forward thinking really tbf lol. But what I was wondering is whether there is actually much room behind the engine to work with to create a nice set up one.

[Poodle]

There's plenty of room to play with once the turbo is moved out of the way. We'll be looking into making up a larger log mani in the next year or so, a proper equal-length runner 4-1 mani is going to cost a lot more for not much gain. If you're making it yourself I'd suggest a minimum of 8mm steel for flanges you'll be welding on, get reasonable quality steel too as the cheaper stuff warps more when you weld it.

[JTaylor2005]

I was thinking of getting one made really. But this will be quite a way away.

Im looking along the lines of rather than just wacking more diesel in and upping the boost. Lowering all the restrictions around the engine will help to improve the HP and also possibly the MPG along with it.

I suppose moving the turbo would also require intake modifications, and oil supply modifications. These turbos aren't water cooled are they?

[Poodle]

Might want to take a look at my project thread then.

Yeah it needs changes to the intake and oil supply, also will need to relocate the ecu, relays and battery. The standard turbos aren't water-cooled.

[JTaylor2005]

Wow thats one hell of a build haha. I was just thinking of maybe dropping the turbo by about 2/3" so that it would be possible to get a thicker diameter exhaust manifold made somewhere haha

[Poodle]

Haha yeah, i do like to go all out.

Ah i see, i thought you would be relocating onto the gearbox. You can't really mount the turbo any further down than it's current position as there wouldn't be room for the compressor outlet to go anywhere, thanks to the proximity of the subframe it's a very tight curve there already.

[JTaylor2005]

Ahhh I see. Dammit I was just going to go for mechanical efficiency really. Like smooth out all the little bottlenecks and try run a really reliable 150but doing everything I could do make it run well at that HP. Looks like it might be a bit of a hassle due to all the general packaging of this engine haha.

[pioneer DJ paddy]

Lol just gearbox mount the turbo not that hard to do if ur handy with a welder lol here's my set up :-) if u need more pics check my project out lol


[attachment=20805][attachment=20806][attachment=20807]

[Poodle]

If you're stopping at 150 you could happily use the stock exhaust manifold. You can take a good couple of mm out of each runner on the manifold with a dremel, and the same for the log and outlet. Combine that with a slightly bigger turbo in the stock position and you should be free of any serious back-pressure issues.

[JTaylor2005]

Ahh Okays. All nice setups haha. Dont wan't to really mess huge huge amounts though lol. Need to get some space in my garage sorted lol.