So, it seems like I have been blowing turbo gaskets every event. Why is that? Turbo is a CBRD BBK-B. Exhaust manifold is the Buschur ported and coated stock mani. The nuts are torqued every session and it still blows. Typical session for me is 1 warm up lap, 1-2 hot laps, cool down and come in. Or 1 warm up lap, 1 hot lap, 1 cool down lap, 1 hot lap, come in.

This is the 3rd time a turbo gasket blew, which creates a pretty nasty exhaust leak. Starting to get really annoying and ending my day early. Lots of sustained wot in 4th and 5th gear.

Fuel is E85. Boost is 27psi peak tapering to 25psi. Makes 450whp/390wtq mustang dyno on a Buschur 2.3L RPM.

After the 2nd time, had the shop even swap to GTR hardware, which suppose to be much stronger, and made sure the exhaust manifold flange is truly flat and even.

 

Exhaust gasses getting too hot blowing out the seals ?

 

are you talking manifold to head? or turbo to manifold?

last week was my 10th trackday and i ended the day with a lot of soot on the front of my valve cover...im assuming one of my gaskets is toast too.

 

I am talking about turbo to manifold gasket. Maybe I am getting very high EGTs for some reason. Or another plausible reason is either my exhaust manifold is warped some how or the turbo/turbine housing side is warped.

 

Get egt sensor , so you can monitor it, and see what's really going on.

 

Is your exhaust flopping around? This happened to me when I had an aftermarket O2 housing that wasn't bolted to the block. The exhaust would act like a big lever and pry on the turbo to manifold or turbo to O2 fittings.

 

Lots of people seem to have this happen. Is your turbo just hanging off the manifold or is it attached to the block? Did you use the turbo/manifold lock washers? I had to resurface my manifold flange to get it too seal right. Havnt had a problem since.

 

You sure it's not the bolts backing out? And are you using the oem gasket? Only time blowing gaskets out has been a issues (and it's a rare one) is when those bolts come loose. We use nordlock washers on all of them now and hasn't seemed to be a problem yet.

 

im gonna take a closer look at mine this weekend, but in my case i have stock turbo/manifold/o2 none of which has ever been removed.

 

The 3rd time, the bolt did back out. The first 2 times it did not. I will try adding those nordlock washers. locking washers right? What do you normally torque them down to for tracking purposes?

 

The nordlock washers are locking type of washer. It's basically two serrated washers that lock together when you tighten the bolt down. They have worked well for us so far

 

As someone mentioned above, i would look at a warped flange where that gasket is located, get some good quality nuts and bolts, and torque the bolts in a cross pattern. My guess its a combo of what I mentioned but that flange being flat is critical or it will never seal.

 

Zhong

Kevin is correct: either nuts/bolts backing out or as you pointed out one or both sealing surfaces are not flat.
I don't see a third option: the EGT is unlikely to have an effect on gasket itself, the issue seems to be in the above mentioned options.

I am even surprised that the gasket would totally burn off because of the bolt backing out- its a metal-laminate-gasket?
I think so, than it should be fine as long as you tighten the loose bolt.
I've personally never burned out a metal gasket, but certainly experienced warped sealing surfaces and loose bolts/nuts/studs.

I now use Stage 8 hardware, plus when possible Inconel studs, and even Helicoils in Exhaust Manifolds where Studs will be fitted, to gain stable grip on the bolt: cast iron is very hard material that seems to slowly loosen inside threaded holes, as if material is crumbled, dusted, and the threads become shallower. By using Helicoils, there is a degree of elasticity and elastic force that grips the stud/bolt and continues providing pressure inside the thread in cast iron.
When you buy these types of kits they come with awesome thread-locker specifically made for high temperature that locks like a rock soon after aplication.

If you happen to need some Inconel studs, 8x1.25 or 10x1.5mm, speak to my friend Andrew Kidd at Trackspeed Engineering in Sunnyvale.
He has them in stock usually, the length is specific to Mazda Miata Turbo kit by Flying Miata, but it may fit your/Evo needs- on the Evo I have not had issues yet...

Another possible resource is LIndsy Racing that focuses on Porsche 944 Turbo, notorious for similar problems ( I had it/the problems too), and/or maybe ask Buschur or AMS who may have had issues and applied solutions to their successful race cars.

 

I know Andrew Kidd. I crewed for them last year at the 25 Hours of Thunderhill and all their other endurance races in 2012. Small world.

I will look into all those above suggestions for sure. Thanks guys!

 

I had bolts coming loose and blew out a turbo gasket. I've since safety wired them all. no problems to date.