Cast manifold upgrade
Please note I am making the parts fit the car NOT the car fit the parts!
This is my latest project, upgrading from the budget kits adaptor manifold to a cast manifold with a T4 turbo flange. As ever all for as little money as possible!
The first problem is that on the cast manafold the turbo sits in a much different place to the budget kit. It also sits perpendicular to the engine rather than at an angle.
All this means is that the down pipe will need some serious modifications.
The turbo sits approx 100mm further back and 53mm further away from the head.
The height is approx the same.
The next little problem is the wastegate. The manifold has a 3 bolt pattern which I believe the cheaper ebay wastegate's fit, I have a 4 bolt HKS wastegate an adaptor will be needed, however space is tight due to an engine mount being in the way.
The last issue is the screamer pipe, it looks like it will be possible to bend the one I have to suit but im looking into plumbing the wastegate back into the exhaust, at the moment that looks like it will have to enter the first decat pipe due to space available. This will also depend on my obtaining the correct flexy pipe and doing a fair bit of welding.
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Small update: 3 composite images of the turbo on the cast manifold and the existing downpipe. The red line shows the edge of the flange.
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Ive decided that a cut and shut job on my existing downpipe is not a good idea, so I have decided to make a new downpipe from parts of the existing one and a new 3" 90 degree elbow and some straight 3" pipe.
First start cutting the old one up.
Then start to sort out new parts, the old parts im reusing as the flexy, the 2 end flanges and the probe flanges.
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Here's the new downpipe ready to be welded.
Here is the wastegate adaptor.
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Here is a pic of the new downpipe all welded up.
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After fitting the new down pipe im not too happy for a couple of reasons, 1, There really isn't room for the screamer pipe without restricting flow or bending it into too complex a shape. 2. The bend in the downpipe is really too close to the turbo outlet for good flow.
What I have decided to do now is make yet another downpipe, coming straight out of the turbo as far as practical towards the bulkhead before the bend. I will then have to modify the 1st decat pipe to suit. I will also probably do away with the outsized UK spec flanges and put something a little smaller in place to free up yet more room.
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Well, I have bit the bullet and actually paid to have the pipe done. Not happy with not being able to do the job myself but it was proving impossible with the car stuck in my garage with no room to park and no power for tools ect.
The pipe work was done at Stealth Systems in Southampton (023 8063 1166) and they have done an excelent job.
First up was the dump tube.
The new downpipe Will also replace the first decat pipe. I will never be able to refit the 1st cat with this setup.
With the dump tube in place and the 2nd cat held in the correct position it was time to start making the down pipe.
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The finished downpipe.
While I was there I also had a second decat pipe made as it worked out cheaper than buying one at a later date.
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The finished decat pipe, less the O2 boss which I didnt get a pic of.
Finally all assembled and back on the raod!
