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Hi, Im going to do a carbon clean soon and was reading a lot of people remove the tumble flap.

What are the pros and cons of doing so?

Better airflow but slight loss of torque at lower rpm I believe.

I left my ones in after my carbon clean as there was no play in them.

Wiki says the tumble flaps are there to assist low engine speed combustion.

It runs a little more lumpy on part throttle openings, especially when cold. But the benefits are less restriction and less to gum up/go wrong!

The tumble flaps simple close off half of the intake path leading to the cylinder. As it's low rpm this isn't a restriction but does have the effect of increasing the velocity of the air into the chamber so when the fuel is injected it can mix up a bit better.
If properly mapped there is no loss in power but will hit economy by a couple mpg when just pootling about

In order for you to remove the tumble flaps you will have to punch out the freeze plugs. There is a company out there that recommends reusing them by applying loctite upon reinstall but I strongly suggest you don't. New freeze plugs can be sourced (not by Audi) but you'll have to dig a little bit. PM me if you need them.

I have been running a deflapped p/p IM for years now with no adverse effects. Highest g/s I saw was 174 per bank. I believe with a tune that removes the tq limiter and considers less manifold restriction, p/p would tie in nicely. Perhaps Doug from MRC can chime in on this.

If anyone here is looking for a port/polished, deflapped IM (work performed by silverrs4) PM me, I have a spare one for sale.

I used a very small ratcheting wrench with a very short torx bit to remove flaps without touching the freeze plugs. Had them all out in 30 minutes

If they aid low down torque I think I'll leave them in as it's a little lacking in the low torque dept.

SkyDude wrote:I used a very small ratcheting wrench with a very short torx bit to remove flaps without touching the freeze plugs. Had them all out in 30 minutes

This is good to know.

Haha, flaps...

coffey555 wrote:Better airflow but slight loss of torque at lower rpm I believe.

I left my ones in after my carbon clean as there was no play in them.

Wiki says the tumble flaps are there to assist low engine speed combustion.

Hmmm I have a different view, I had low end torque pick up, albeit ever so slight

It is a bit lumpy below 3k revs when cold
The power gains post de flap and carbon clean are really very noticeable

No error codes yet either, I vote do it and add I take spacers too at same time

hlbeckley wrote:The power gains post de flap and carbon clean are really very noticeable

Was the power gain due to de-flapping, carbon cleaning or both?

If you did them both at the same time then it's impossible to tell, but anecdotally carbon clean is worth c. 30bhp.

Both same time but driven a de flapped post CC and flaps in, delivery is very different