MAP(Kpa) question

SHINOBI-X · 07-15-2005, 12:57 AM

just curious about MAP(KPA) at idle for mostly stock C4's or even you modded motor guys? i saw on a snap on scanner today at my shop that my 84' vette was around 34. does this sound too lean or just right? can someone explain to the noob here about MAP(kpa)?

a big thanks to all

STL94LT1 · 07-15-2005, 09:57 AM

That sounds about right. My stock 94's MAP Kpa at idle was 32-33. Now that it's modded, that has been raised to ~58 Kpa.

tjwong · 07-15-2005, 11:41 AM

MAP Pressure can be a little misleading to some. All it is is manifold pressure. At atmospheric pressure meaning zero vacuum your MAP sensor would indicate approximately 101 Kpa. At its highest vacuum the MAP sensor could read 1 to 5 kPA and that is if the engine could produce enough vacuum to pull it down that far. A totally stock engine would typically produce higher vacuum levels than that of a cammed up modified engine. Stock engines would idle around 30 to 40 kPA, while modified engines with cams would range from 50 on up. Heavily modified engines with large cams would idle at around 60 on up. That 572 620hp crate engine idled at 1000 RPM with about 60 kPA of vacuum.

SHINOBI-X · 07-16-2005, 12:37 AM

BIG THANKS!

Mo_Bandy · 07-16-2005, 12:44 AM

Hi TJ!

Mo