Well, it was one of those things on my todo list for a long time, finally got around to it..
I just have a small 1 1/2" 100 psi fuel pressure gauge I temporarily mounted. I wanted to know what the 60mm HX35 was typically running for pressure ratios..
Took it for a test drive
It's *really* close to 1:1 except at high load (as much load as I could put on the truck empty, on a dirt road... sideways in 5th)... When I was really on it at full throttle and 30 PSI boost it was around 35 PSI drive pressure.
Under braking, it was about 35 psi at 1250 RPM, climbing to about 50ish lbs at 2000... never was able to test it much above that.
Now I might have to try putting the stock HX35 on it to see how that compares... I know it spools much faster, but chokes badly, probably with higher drive pressures, especially at the top end...
Very good info here! Thanks for posting
What were you using for a brake ?
I have had a BD exhaust brake on my truck since ever... just never had a pressure gauge hooked up to the manifold port