First question:

Have any of you with the Hahn turbo-kit used 4g63 8mm exhaust manifold studs on ALL 8 locations on the head, and gotten the manifold to fit and tightened down?

I have 4 of the 8 4g63 studs on but keep breaking the 2 lower allen bolts on the manifold. I am frustrated!

Second question:

Do you think that getting the 3" dp from Hahn will cure the allen bolt-breaking problem that I have since the DP will be one solid unit? The CRAPPY original offering that Hahn has NEVER seems to stop leaking, and no matter how tight I get the clamp on, I cant help but think that there is still some movement and vibration that causes the allen bolts to break......REPEATEDLY.


Thanks for the help. AND YES I know that the 3" dp will be much better than my current setup performance-wise. I would just like to know from those with 4g63 studs and HRC 3" DP, if the re-occuring problems that I am experiencing will continue to be my nightmare.

Thanks a bunch
Jonathan

When you say "clamp" - that no matter how tight you make it still keeps leaking ... are you talking about the exhuast clamp that you're supposed to use to connect the Hahn Dp to the cut stock Dp? If so, I was never able to get that to stop leaking either. I ended up taking it all off and having it welded together for like 50 bucks. Best thing I ever did. And no, I don't that clamp/leak and all that has anything to do those studs snapping. I didn't use any 4g63 manifold studs, just the 420A stockers - no problems. Maybe you want to try that?

Jon, if you're gonna use the 4g63 studs you might as well replace all of them. The allen bolts included with the kit are garbage and the stock ones aren't much better. If the manifold still doesn't clamp down all the way then it's probably warped.

Well FWIW, I have a custom fabbed 3.5" down pipe with V-band clamp, but also have snapped the 8mm studs on the driver's side outter edge of the manifold twice. I think it has more to do with the weight of the Hahn manifold and the fact that the turbo is non supported...

In my case I now have a broken tap in the head with a fragment of a heat treated 4G63 exhaust manifold stud purchased from Buschur. After it gets helicoiled out, I am making a tubular stepped primary manifold and hope to never deal with this crap again. Reason being it should be lighter, but will be more sufficient in supporting the weight of the turbo also. I'll let you know how that turns out.



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know me as santiago
boosted 420a and ej2o..(my 2liter v8 eaters)

Originally posted by ner947
Jon, if you're gonna use the 4g63 studs you might as well replace all of them. The allen bolts included with the kit are garbage and the stock ones aren't much better. If the manifold still doesn't clamp down all the way then it's probably warped.

Nathan,

Thanks for the response. I dont think that the manifold is warped. The exhaust leak that I am referring to is from the half-dp mated to the stock dp. THAT keeps leaking. ONLY when then allen bolts break, does the manifold leak at the head.

Also, thanks to all for the repsonses. I will try to put the studs in all locations and finesse the washers and nuts on there.

Thanks again
Jonathan