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I thought I should put a post up because searching has not been working since last night (so my apologies if this was already answered elsewhere ages ago)

For the past few weeks I've been slowly been upgrading the factory turbos on my GTR with the HKS 2530's I bought ages ago but never had time to fit. I'm only spending an hour or 2 each day on it (missing some days for various reasons) and I'm right up to the end and I've hit the biggest snag I've hit in the whole project.

This is the situation as simply as I can put it - The aftermarket dump pipe from the front turbo touches the compressor housing of the rear turbo, which then touches on the aftermarket HKS metal intake of the rear turbo. Aside from this being a far from ideal situation for heat, the main problem is it stops the intake pipe flange from sitting in position on the turbo (ie, I can't bolt it in). I will post pics when the forum starts working again, it currently won't let me.

The problem is due to the aftermarket dump pipes being wider than the factory ones due to the split wastegate outlet, but I think it is also compounded by aftermarket the front pipe (unknown brand, came with car) being slightly pushed up and out of position after many years of hitting the occasional speed bump. There is no flex pipe in the front pipe so it's going to affect the fitting of the turbos and dumps directly.

Here are the things I've already thought of to fix it, along with my misgivings about each option.

1. Rotate the rear compressor housing slightly to allow fit - I'm not entirely sure that this will allow it to fit, but I may give it a shot anyway (it's hard to get to the bolts without removing the turbo though)

2. Replace the front turbo's dump pipe with the factory one, which will clear it - Ugh, for several reasons.

3. Take front turbo back out again and hammer a flat spot onto the bit that touches the rear turbo parts (already tried this in car, not working) - Not as much "ugh" as above, but still ugh.

4. Try to bend the front pipe inlets back into a more normal position to provide the extra 5mm or so space I need. I think there is enough free play n the manifold and turbo mountings to accommodate this - This is my prefered option, but it is very difficult to bend tough tubular stainless steel without using the road (speed bumps).

5. Replace front pipe with a new one and/or one with a flex fitting - kind of ugh because the front pipe is in good condition aside from being bent slightly out of shape. I imagine any second hand front pipe will have the same issues if it's ever scraped the concrete. I can't justify this expense without first trying to bend the old one back into alignment.

6. Tow the car to a mechanic and pay them to sort it out (ugh, and maybe even impossible given the location of my garage)

7. Grind some off the flange of the rear intake pipe, which will allow it to sit further back onto the turbo and clear the dump pipe - It's only aluminium so will probably weaken it more than it should be, and also I'd need this done professionally to get it 100% flat.

8. Replace rear intake pipe with one that fits - It'd have to be metal or it'd melt onto the dump pipe, and any metal ones would probably have the same issue I have now.

I'm sure there are other things I've thought of but can't remember them right now. Any other ideas?

What dump pipes are you using?

Assuming they are a decent brand everything should bolt up with no messing around at all.

I wouldn't be looking at modifying, grinding or bending anything, but rather find the cause of the fitting issue and fix it.

If your front pipes are bent and out of place, replace them.

If they are HKS dumps then you have them the wrong way arround, they are actualy slightly different front and rear

They aren't HKS dumps, just ebay cheapies. I will take another look when I get home tonight, but I think they won't go the other way around because of the different angle and height of the dump-to-front pipe flange. If they are the wrong way around though, the previous owner has shoehorned the factory dumps in the wrong way around too because I made note of each dump pipe as I took it out and matched them to the new ones.

Righto, check just in case anyway... With my hks ones the rear one was a bit longer then the front one and the front one had a little bend in it to clear the comp cover of the rear turbo. Ill see if I can find some pix later tonight if you want

Ok I had a look at some photos I took during each step when I was removing stuff (still can't attach files here) and even when it was the factory dumps and turbos, the exhaust flange almost touched on the rear turbo compressor housing. So I've definitely got the dumps pipes on the right ends, short on front and long on rear. It' s just a combination of the slightly bigger compressor housings and the dump pipes which take up more space than the factory ones even with the heat shields on.

I have gained some extra space by loosening everything and shifting it around a little and tightening back up. It would fit except for the heat wrap which makes it too thick, but without it then I will have hot stainless steel touching on the aluminium intake, which is not good. So I might have to hammer a small dent into the dump, but not as much as I first thought. I also found I have to either drop the front turbo down again or rotate the rear compressor temporarily to fit the bolt for the intake in.

I'm gonna have dinner now and and watch some Benny Hill.

Jim, we've had nothing but trouble with the fit of ebay dumps. one set we bought was literally so bad the rear dump fouled on the flywheel (yes the flywheel not just the bellhousing or firewall).

just whack a dent for clearance you will be fine. and think youself lucky they were so close to fitting :domokun:

I can finally upload pics so here is the before and after shots. As you can see, even the factory dump pipe flange is touching on the rear turbo compressor. Don't mind the heat wrap, it's been re-used from my old Skyline and that's why it's shredding all over the place. It's only a temporary measure for now.

I've been carefully bending the front pipes back into shape with a scissor jack levering a breaker bar off the chassis. If I can't get it happening in the next hour or so I'm gonna quit it and try the Duncan dent on the weekend :domokun:

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