and found this interesting thread about vacuum switchover "stuff"<ul><li><a href="http://forums.audiworld.com/12v/msgs/4546.phtml">http://forums.audiworld.com/12v/msgs/4546.phtml</a</li></ul>

RPM switch-over settings. With stock cams the car will bog down severely at less-than-stock switchover RPMs.

From Mr. D's old website...I searched for ever to find the pics but no dice.<ul><li><a href="http://edsaudi12v.com/audi/imswitch.htm">http://edsaudi12v.com/audi/imswitch.htm</a</li></ul>

that everyone could benefit from a slight decrease in the RPM setting, even more so with a modded intake...Say 3850-3900 range?

In saying "Those RPMs", you're referring to lower numbers, correct?

seem to actually perform a tad better with stock cams by raising switchover activation 100-200 RPMs. So logic would seem to indicate if at sea-level yes, at or near 3k ft elevation or higher, no.

100-200 RPMS is nothing.

The differance would likely feel like the aerodynamic advantage of scraping the bugs off the front of a semi truck grill. Next to NILL.

right before the manifold switchover, which could potentially be cured by this. Maybe not.

Regardless, I probably won't install an RPM switch, just providing info for anyone who is interested.

or any number of other things either singly or in conjunction with several things. But even without those when are "small" barely perceptable gains "nothing" or something to be scoffed at!?! Even if ya can't perceptably "feel" something does that dictate it a "waste." If so that precludes doing ANYTHING on these cars that doesn't net 10-12HP. Even the slightest, unfeelable gain is still a GAIN, a positive, an improvement and worthwhile. It's "better" than it was before! Even a 1/100 of a second gain is 1/100 of a second "gain" no matter how ya slice it. Any race won by even 1/1000 of a second remains a race "won." Ask the guy who lost that race by 1/1000 of a second if he feels it might be worth the additional effort of "cleaning the bugs off his grill" next time.

And since when is the pursuit of "small" gains folley or inconsequential? If ya find 10 things that net 1/10 second thats a 1-second net gain! I'll take EVERY damn one I can get!

And any efforts in this direction while working on your personal car beats all but a few other alternatives. My car is chock-full of hundreds or maybe thousands of seemingly insignificant and meaningless modifications that in and of themselves wouldn't matter much to anyone. But to me they are important, nay CRUCIAL! And all those little things add up. More often than not they become far MORE effective than the sum total of all the small tasks when added up. Look at EVERY major racing discipline and the teams winning. You call it "meaningless effort" and they call it "preparation." Think they havent missed any sleep trying to find 1/1000 of a second? Think again! And what exactly or where's the inherent fault in any individual pursuing that example or that level of efficiency as closely as he/she is able? I mean "everybody gotta be somewhere doin something" right?

And what is "12V Development" if we are to believe some things are just too small of a gain to consider, mess with or waste time on? Long as we're "gaining" where's the rub? Even if we're not gaining where's the wasted effort when maybe we didn't gain anything but we DID learn!?! I personally will take every 1/1000HP or 1/1000 of a second I can get! Similarly I will take EVERY nano-second, lose every grain, gram, ounce or pound or .01 reduction in drag coefficient or boundary layer disturbances or increase in CFM or 1/1000HP or Ftlb TQ I can and continue to "waste" time doing it till I draw my last breath. I personally find HUGE reward in small gains. They mean every bit as much to me as the larger ones... oft-times MORE! Long as I am "gaining" I'm winning! I'm fulfilling an inherent need. And when I'm not gaining, I'm learning! Neither has nor will EVER be a waste of "my" time. I will NEVER subscribe to the concept of "wasted gain"... seems a "mutually exclusive" term to me no matter how small as it applies to my car. My waistline maybe but NEVER my car!

Anyone that feels ONLY "big" gains are worth the time and effort will soon be out of parts to buy. Then someone with the same deep pockets and the time to invest in "sweating the small stuff" will come along and guess which guy will ALWAYS have the better prepared car or anything/everything else in life for that matter!?!

"It's ALL in the details!"

yesterday when driving and i had room between stoplights i would run it up to the switchover rpms and try to feel or sense anything.. in the end i think i could actually hear a slight sound diff.. right at about the 4.1k rpm level.... I also was tring to take the rpms up high enough on each shift to allow me to put it back above the 4.1k rpm level almost had to take it to 6k everytime ... boy did i use a bunch of fuel yesterday..lol.. Also changed the oil again.. and yes it feels faster .. Just thought it an interesting read after all we have been discussing lately.