What is the average vacuum at idle on a stock '88 turbo motor? I had about 13, advanced the cam 2 teeth and lost about 2". Think I'll try retarding it 3 teeth and see what that does. Any thoughts or suggestions?
What is the average vacuum at idle on a stock '88 turbo motor? I had about 13, advanced the cam 2 teeth and lost about 2". Think I'll try retarding it 3 teeth and see what that does. Any thoughts or suggestions?
88 LeBaron convertible 2.5 T2 {garrett} w/555 T-U 3bar plus 40 cal mildly ported swirl w/back-cut valves 86 supra front mounted I/C 223whp@19psi 14.352 @ 99.25mph RETIRED '87 SC (GLHS CLONE) TII with stage II MP currently a/t '89 Voyager factory 2.5 turbo 5spd garrett, 3" from dp back '86 Chysler T&C TII conversion
a healthy 2.2 should have 16-18" a 2.5 should be 18-20 at minimums.
Ok, for starters, moving "teeth" at a time won't get you any more power anywhere. This has got to be done a few degrees at a time, usually in 2 degree increments. I would consider 16 inches or more to be about normal.
88 LeBaron convertible 2.5 T2 {garrett} w/555 T-U 3bar plus 40 cal mildly ported swirl w/back-cut valves 86 supra front mounted I/C 223whp@19psi 14.352 @ 99.25mph RETIRED '87 SC (GLHS CLONE) TII with stage II MP currently a/t '89 Voyager factory 2.5 turbo 5spd garrett, 3" from dp back '86 Chysler T&C TII conversion
You'll want to get an adjustable cam gear, set it to zero, then dial in the cam "straight-up" to see what "normal" would be,then bump it 2* at a time, both up and down. I'd bet you'll see the biggest changes within 6*+/-. I don't recall how many degrees one tooth represents, but it is a large swing, the kind that tends to swing you right past the "sweet spot".
Naturally, you'd want to confirm proper "stock" pulley install, which can be a little tricky due to the engine's inclination towards the firewall and one's natural tendency to use something other than the head as a reference for what's "square". A mirror can help to see if the marks on the pulley align/square with the head. Hold it so it faces the pulley and look at it from the driver's side. There's also a timing light method, but would require the ignition timing to be set to zero, which might be a bigger pain.
Might want to do a leak-down or compression test to see if it's practical to expect higher vacuum ...
Mike
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88 LeBaron convertible 2.5 T2 {garrett} w/555 T-U 3bar plus 40 cal mildly ported swirl w/back-cut valves 86 supra front mounted I/C 223whp@19psi 14.352 @ 99.25mph RETIRED '87 SC (GLHS CLONE) TII with stage II MP currently a/t '89 Voyager factory 2.5 turbo 5spd garrett, 3" from dp back '86 Chysler T&C TII conversion