Is it common to read a few pounds more boost on the street vs on a dyno? after some reading it kinda makes sense, because there is a little more load. Reason being, we read about 7.5 on the dyno. But i finally installed an autometer guage, and it will read 8-9. I just figured it was off by a little. Im wondering because im going to pulley down,, I was going to go down 4 points, which i was thinking would put me around 11.5.. But if my actual street boost is 8-9 that would put me at 12-13 lbs on the street... Im also reading that as it cools down you can see a boost increase. its on a stock 4.8, 5 speed rst. whipple. Thanks for your thoughts

 

Yep, more load on the street. Dyno has a hard time simulating this load. Boost is typically higher than on a chassis dyno.

As the air gets better, you may see a slight increase in boost as well.

 

I was on board with your theory until I read 'pulley down'... Turbos are affected by load, as boost can vary at the same RPM. But with a blower at a given RPM, neglecting the effects of weather, the boost will always be the same. Stab the throttle in neutral and watch the MAP readout on a scanner...if it doesn't smack the limiter before the scanner has time to sample the data, you'll see full boost from your whipple.

From what you said, I'd say there's a measurement difference... Dyno read 7.5, your autometer gauge reads 8-9...well they're not the same measurement device, are they? My cab boost gauge never exactly matched what my MAP sensor said, but I didn't pay much attention to it; they're just different measurement devices.

 

yeah the dyno measurement was through the map sensor i believe. "KPA" . Im just trying to get everything lined out and have a good idea where im going to be with everything before i order parts and head back for meth/tuning

 

I had to go back and reread. I missed that it was a whipple. Disregard my comments and carry on.