Quote:
Originally Posted by Soorena
Great numbers OP. I like your enthusiasm. SC from day 1, and now raised rev limiter plus more boost. Good stuff. Oh and you surely need a set of different cams to see the benefit of raised rev limiter. 
IIRC something was wrong with OP's boost sensor. I don't know though if he has replaced it or not yet. But let's be realistic, 5.7psi is not gonna give you anything close to low 500's, let alone 580-ish numbers. |
Thx. Yeah the readings are low for sure but at least they are consistent as I've dyno'd over 30 times.
EAS is measuring boost from the manifold on the dyno using the bypass valve. Early on, EAS even hooked up a mechanical boost guage directly to the manifold because we were assuming the dyno either wasn't reading correctly or something. But the mechanical boost guage read the exact same numbers. EAS dyno's dozens of supercharged e9X M3's and they know how to hook up the boost sensor/guage.
Further, the readings are also consistent when changing things around. With the 96mm pulley I was at 5.1psi with the stock exhaust. When I went with the MRF catless mid-pipe, I dropped to 4.9-5.0psi (the delta is consistent with what esquire found from changing from Akra Evo to MRF). When I changed to the 92mm pulley, I went to 5.7psi. That was about the same boost as my first couple pulls with the 650 pulley system (the last dyno pulls I got weird boost spikes from what looked like throttle closure). So if you assume my original boost reading of 5.1 was correct with the 96mm pulley and stock exhaust, all the changes from that point make sense.
I'm open to more ideas if anyone has any.