Interesting note about the copper cap mod...

[triggz]

I did the copper cap IAC mod a few weeks back on my 2000 GT at 3/16".. The revs did seem to drop a little quicker and I saw no adverse effects so I left it in.
A few days ago I noticed a nice side effect of this mod. Normally when going down a steep hill, say at 70mph, if you put an auto in N the revs drop down to around 1k for a second then shoot up to like 3k. However now with the cap in place the revs stay down at around 1100. Now I can actually take advantage of downhill travelling

 

[tangerine]

Inform me of what the copper cap mod is because I have never heard of it.

Thanks

 

[mike2858]

bump me either

 

[smttysmth02gt]

It has something to do w/screwing w/the IAC, which are known to be faulty from Ford...so I won't be screwing w/it anytime soon, as mine was bad when my car was brand new.

 

[triggz]

http://forums.stangnet.com/showthread.php?t=451080&highlight=copper+cap

You basically take a 1/2" copper cap, drill a 3/16th inch hole in it and stick it in the tube for the IAC. This 'chokes' the IAC (not harmful) so that it wont force the ECU to rev higher.
It's for people who think the mustang revs hang for way too long.

 

[dmarco_4u]

a copper cap with a small hole drilled in it that goes between your IAC and intake hose. It helps the revs drop faster.

Here ya go man.

 

[GinoGT]

My question: Why are you bothering with the copper cap trick if you have an auto?

 

[KJ Hoppus]

does it make a difference if its an auto?

 

[GinoGT]

The issue is how the RPM's tend to "hang" between shifts (manual). You're not shifting an auto.

 

[triggz]

Ever rev an auto mustang? It takes 3x as long to drop as it does to raise. We like to sound off too And thats all this mod does is drop your IDLE revs/revdown speed.

This mod has no effect if the throttle is open at all, so no it will not do anything for an automatic. And technically, it would have an adverse effect if it worked overly well on a manual car. You dont want to fall out of the power band during a shift.

 

[Blev]

The issue is how the RPM's tend to "hang" between shifts (manual). You're not shifting an auto.

That's not the only issue. Do you ever rev. your engine to hear your exhaust? Maybe rev on someone? How about just sound off? You know us auto guys like to do that to.

 

[DaNd4Speed]

When I had my 99 Cougar, the copper cap mod worked really well because the Duratec's really took forever for the RPM's to drop between shifts. However, I haven't had any issues with the 4.6 nor have I heard anybody ever complain about this before.