im reading a 15vac@idle on my boost gauge with vortech sc

is that fine? i heard other ppl having 20vac@idle..

 

My idle is 18-20 mmHG. you might have a leak somewhere.

 

I dont know the elevation of where u are in AZ.
Vacuum is 22" HG max. at sea level only. At 5000 ft it drops to 17 max, at 8000 its round 14 max.
If ur way up in the Rockies---It will drop to 14.

Use that as an initial guide line---Then start looking for leaks

 

Well Phoenix is only 1100 ft ----always chk ur boost gage Vacuum with a Shop Vac Gage and also use a shop gage to chk when u tighten up potential leaks

 

I think I used to get 18 when I had stock engine. Now with the cams I think its usually around 16.

 

Overlap on some cams will drop it a little on the Z---It used to be much worse with the more radical V8s--- A vacuum canister would generally fix that to operate brakes and Vac devices. It wont hurt him to do some checks--I was running a strong 18 with my Vortech here in Tx. ---Timing will drop it also---If u are SURE u have no leaks---Have ur tuner Play with ur Split Second

 

nismo cams.....11 to 13 at idle . 1,000 ft above sea level