Nubira 2.0L turbo exhaust manifold

Nubaroo · Post by **Nubaroo** » Tue Dec 11, 2007 7:05 pm

Hi there all. I am having some problems with my Nubira`s turbo exhaust manifold developing cracks - I have had 3 x different manifolds built here in SA by 3 x different manufacturers and all 3 have developed cracks on the welds. We have added supports ETC ETC and it still cracks after about 5000KM???? Any ideas????

Audacity Racing · Post by **Audacity Racing** » Tue Dec 11, 2007 7:16 pm

What material are they made from?

gse_turbo · Post by **gse_turbo** » Tue Dec 11, 2007 7:34 pm

Audacity Racing wrote:What material are they made from?

+1 do you have pics? is it cracking at the flange or the tubes? how are your supports configured?

Nubaroo · Post by **Nubaroo** » Wed Dec 12, 2007 5:24 am

The last one is made from "steam pipe" and the cracks are mostly where all 4 x pipes come into 1, and where the wastegate pipe comes out of the 4 in 1. Will post pics soon - some people reckon there is a vibration on my motor causing the branch to crack????

gse_turbo · Post by **gse_turbo** » Wed Dec 12, 2007 5:22 pm

interesting, pics would help because where the cracks start and how big they are tell a lot. "steem pipe" or schedual 10/"weld els" are an ok (not perfect) header material but not ideal. you have to keep very simple with the lay out and from the sound of the lay out it was pretty involved.

the idea of the exessive vibration is a good one but then it becomes the fault of your support brackets. do the supports you made link from the header flange to the turbo flange? even though that isn't a bad idea, what you (and EVERYONE) needs to do is make turbo supports that actually hold the turbo up without the turbo manifold being there and very few builders take this very important extra step.

if the turbo itself is supported separate from the manifold and it still cracks then the problem is in the weld quality, material quality and/or the materials ability to heat up and cool down properly.

gse_turbo · Post by **gse_turbo** » Wed Dec 12, 2007 5:28 pm

before the question comes up... i'm sure some one who reads this is going to say "why not just buy the cast turbo manifold from Boshart Motorsports" and even though this is a great option, with the exchange rate you would be spending well over 2,400 Rand.

one quick question, are you having these custom made for you or are these a "shelf" item in a performance shop?

Nubaroo · Post by **Nubaroo** » Wed Dec 12, 2007 9:06 pm

These manifolds are custom made by performance shops - there are not any production ones made here is South Africa as far as I know. The car is still drivable so I will only remove the manifold for propper inspection early next year, but I can hear a small leak from the manifold when the car is cold. I do not have ANY support brackets in place from the turbo to the engine block, and the complete manifold, turbo and exhaust assembly "hangs" from the exhaust flange bolts - I will try and fit a support from the turbo to the engine block when I redo the exhaust manifold early next year??, as well as have the complete engine balanced - I hope this will sort out the problem.

You mentioned getting a cast manifold for approx. R 2 400. - this is a very good price if you think that every time I have one custom built it costs around R 3 500. Where could I look at getting a cast one imported from - maybe you have a web address??

gse_turbo · Post by **gse_turbo** » Wed Dec 12, 2007 9:18 pm

'kinky' from this forum has one for sale hopefully if he catches this topic he will give you some pics and prices you can also go to Boshart directly unfortunately they don't have a picture up.

i think having your turbo firmly supported will solve all your problems.

in the meantime, do you have any pics of your car to post in the members section? i'd be interested to see what you have going on.

exist3nce · Post by **exist3nce** » Thu Dec 13, 2007 1:53 am

I would agree on the turbo supports. After my wastegate cracked off back in April, we made a nice turbo brace to support the rest of the manifold to try to help with some of the weight.

pics:

Nubaroo · Post by **Nubaroo** » Thu Dec 13, 2007 6:16 am

I have some pics in the members section - "Daewoo Nubira Turbo 2.0L from SA" and some video clips in action. There is also some pics in the "PICS and Videos" section - will post some pics of the engine and branch this weekend. In the first couple of pics you can see one of the first branches with an OLD giveaway wastegate - not the best design ever.....the latest one is and looks much better and has a Turbonetics wastegate attached.

Thanks for the pics of the turbo support Exist3nce - I should be able to make a similar plan on my branch quite easilly - it seems very simple to do.