Exhaust gasket blown, loss of turbo power???

sticky nicky · Postby **sticky nicky** » Wed Mar 11, 2015 4:01 pm

Just want to pick peoples brains. I had my first day back on the track on Sunday after a 5 month break. My course time (5kms long) was dissapointingly 4 seconds down on my PB. When I got home I checked the join on my exhaust that is about 350ml down from the turbo. The gasket has blown and the 3 nuts had come loose, I suspected this by the noise. I know I can get this sorted locally and cheaply as its happened before......................my question is would this have affected the power I had on Sunday?..... because that would explain the time difference, or am I just making excuses. I just felt there was no way I could have found another 4 seconds from anywhere.

Cheers

hks_kansei · Postby **hks_kansei** » Wed Mar 11, 2015 4:32 pm

A gasket should be simple to replace at home.

it should just be a matter of purchasing a new gasket, remove the 3 bolts, bin the old gasket, then put in the new gasket and retighten the bolts. (depending on the gasket type you may need to tack it with RTV or something)

In areas like exhaust, depending on how long you ran with the ruined gasket, the heat may have warped the flange, in which case you'll need to take both pipes to a machine shop to be machined flat again.
you can check for warping with a good straight edge/metal ruler.

Once the new gasket is in, and the bolts torqued (tighten them evenly otherwise you'll just repeat the problem) you'll take it for a drive, get it warm, then once the car cools again re-torque the bolts.
Forgetting the second torquing can cause warping if the bolts shift during the first heat cycle.

None of that above is turbo specific, it's just normal exhaust manifold stuff.
There may be some extra things you need to do since turbos get so stupidly hot.

sticky nicky · Postby **sticky nicky** » Wed Mar 11, 2015 5:24 pm

Thanks hks kansei for your advice.
Ive got a guy I go to an he does the lot for $50, materials included and he has a hoist. I find one of the bolts so awkward to tighted as access is not good and I only have hand tools and a weak girls arm. I will however will try to retighten after Ive had a run............... So would it reduce HP running on the track with a blown exhaust gasket etc?

hks_kansei · Postby **hks_kansei** » Wed Mar 11, 2015 5:29 pm

Depends on the side of the turbo the gasket has blown out.

Pre-turbo (so, engine side) power would drop since there's exhaust leaking out and not spooling the turbo. ie: less boost.

Post, maybe a little bit, but not that much. However, a leak upstream of the o2 sensor could cause the mixtures to read incorrectly, and make the ECU fuel wrong.

if the mech is doing it for $50 go for it, you'd probably pay $30 for the gasket anyway.