It's quite well known that USA Horses are a different breed to UK horses, but the following thread over on TT.net from Jan 2011 really highlights the disparity:

 

http://www.twinturbo.net/nissan/300zx/forums/general/view/2416119/Selin-Dual-Intake-and-dual-pop-history-with-Dyno-Chart.html

 

When talking about the limits and correlation between voltage & power using a single OEM MAF, the following question was asked:

 

Is the 500HP figure BHP or WHP?

 

Answered by:

It is a WHEEL HP number and the resolution at the top is really bad the higher you go , so the closer you get to 5 volts the less stable the tune will be.

The ECU can only see 5.1 volts even though the meter will go slightly higher.

You want head room, so try not to max it out.

 

So, apparently 5V MAF voltage = 500hp at the rear wheels in the States, with a linear relationship up to this point (100whp=1V)...

 

Conversely, I've seen 4.5V at 343rwhp (394@fly) on the Zed and around 4.4V on my Pulsar with a T28. Going on the Zed results, that's a difference of around 30% give or take a pony or two.

 

Is there anyone on here (or in the UK generally) that has got anywhere near 500rwhp on a single Z32 MAF...?

I thought it was around 450 fly which would go with the Uk numbers, I'd think most switch to a dual filter ecu even if they are still using one MAF.

Reading that link, I fitted a Selin dual MAF with 2 Apexi filters and it was good but wasn't 30hp good! It revved more responsively in neutral had more of a 5Krpm rush and was a bit quicker. 10hp perhaps? Spooled a bit quicker but I did hard pipes at the same time.

I am stuck at work btw posting at this time of night on new years eve!