juggernautjoee Posted August 7 Share Posted August 7 (edited) I've got an l28et, P90A head swapped to solid lifters. 5 angle valve job. Dished pistons, so low compression. Cooling head mod. 440cc injectors. Stock 280zx throttle body and intake. Aeromotive FPR. Home-made detcans. MS3x COP AEM Wideband 2.5in downpipe into a 3in exhaust Cam is a Schneider 270-60F-14 degreed to what the cam card said (I think it said 108?). At cold start I get ~10in of vacuum. Once warmed up, the best I can get with ~850RPM idle is ~14in of vacuum. I talked to Schneider about this and they told me to open up the lash to .010 and .012 respectively. That improved my idle by 1-2in of vacuum. I know the cam might be causing the wideband to not give a true reading, but at warm idle it likes ~12.2-12.5:1 AFR to achieve a smooth albeit weak vacuum idle. I have checked for vacuum leaks everywhere. Totally removed the intake/exhaust manifold, purchased new gaskets and applied a very thin coat of rtv. I made sure the intake was flat with a very large bastard file. All ports have been plugged including pcv for testing. I put it all back together and got the exact same amount of vacuum. No change. I have verified with a timing gun, set to 2 stroke mode, cranking and idle ignition are lined up perfectly with what tunerstudio says. No drift. I've got my idle set to 20 degrees advanced. Does anyone else run a cam like this with a similar setup? I'm guessing I need more advance at idle, maybe 25-28. But I want to compare to someone who has a similar build, or has more experience than me. Specs of cam: Part Number: 17043 Grind Number: 270-60F-14 Intake Duration (gross): 270 Exhaust Duration (gross): 260 Intake Duration (.050”): 230 Exhaust Duration (.050”): 220 Intake Valve Lift*: .460" Exhaust Valve Lift*: .460" Lobe Separation: 114 Intake Valve Lash: .008" Exhaust Valve Lash: .010" RPM Range: 2200-6400 Edited August 7 by juggernautjoee Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 8 Share Posted August 8 22 hours ago, juggernautjoee said: l28et, Dished pistons, so low compression. https://www.schneidercams.com/270-60F-14_LET6.aspx Did Schneider give you an idea of what vacuum reading you should be able to get? Opening up the lash effectively "detunes" the cam. Less lift. Seems like an odd suggestion. Does your engine have any EGR remnants? The EGR passages have been known to rot inside the manifold and leak internally. Quote Link to comment Share on other sites More sharing options...
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