White smoke just from one side

My 85 QV also has white steam/smoke that seems to come out more on the left side then the right upon start up in the cold. Steve once posted an explanation with diagrams of the baffle setup in our mufflers that favours the outlet on the left. Why this was done has not been explained yet.
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My '85 QV does the same thing. In my case it is on the passenger side and that side has the exhaust coming out at a noticeably higher pressure. I often wonder if this is normal or if I have a clog somewhere. Maybe this is normal?

Mine is US spec so I thought maybe I had a bad catalytic converter... I am assuming yours is Euro spec so that throws my theory out the window.

 

Uh oh. Mine is US, now what? Also on the 84-85 QV we only have one cat and I think one inlet to the muffler so the digram wouldn't apply, sorry.

 

If you have an exhaust system that comingles the two exhaust streams (either upstream of the muffler, like an '84-'85 US 308QV, or in the muffler, like a euro 308QV), white smoke out the tips on one side = no problem.

If you have an exhaust system that has completely separate exhaust paths for each bank to the tips (like a US TR with a Tubi muffler installed), white smoke out the tips on one side = needs more investigation.

alext - if your euro 308QV has the stock muffler = no problem.

 

Yes, there can be no other logical cause (since the exhaust streams are fully mixed). The flow rate out of each tip is also different because of the stock muffler's asymmetric internal construction -- you should be able to "feel" this by just holding your hands in front of the tips while an assistant gently revs the engine.

 

Not sure about the 308's but I believe it happens on the 328 when cold as one bank is choked and the other is not.
Regards Roy

 

Thanks again Steve!

 

Its just water vapor from condensation being cooked out of the exhaust system. The imbalance is because one of the two discharge paths in the single inlet US muffler takes longer to heat up than the other.

 

Makes sense to me. Is there a performance loss with the single inlet system overall or did Ferrari find a way to simplify the exhaust system and maintain the performance level?

 

I had the same problem, it was related to the mufler (U.S. version with one single inlet). It was due to an internal obstruction caused by insulation material who falling off and blocking the small holes on the outlet tube (visible during the borescope inspection)
After replacing my mufler the problem was solved and my engine had more power

Check the flow between L/H and R/H outlets
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Hmm.. Maybe I should replace my muffler with a Tubi so it can sound a bit more like its stable mate...

 

This was the new mufler I installed
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Thanks for another great, timely thread and great info...again. I was warming up my '85 QV after the coolant leak repair today and was thinking the same thing..."is this normal"? For some reason, I had it in my head that each bank had a side on the output.

 

Nice! Which one is that?

 

Gents,

FWIW...a view of the innards, found on a french Ferrari forum (not copyrighted).
Of course, take notice this is a Euro NON CAT exhaust...
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I get it from Superformance UK


http://www.superformance.co.uk/a-328/exhausts.htm


He is very loud, too loud...