[86TOYO2k17]

Originally Posted by gtengr

Use a photo viewer and zoom. It's clear enough to tell it's not close to 10 psi at 3500 rpm.

Maybe your computer is better than mine resolution is very unclear, what is max psi its making?

The log does show RPM and MAP pressure. It's a run to redline so I can't imagine why it'd be at anything other than full throttle.

Many tuners often slowly ramp into throttle on a dyno for two main reasons, eliminate traction issues on the dyno, and to be easier on drivetrain/engine as WOT under 4500rpm especially in 4-5th gear (typical dyno gears) is very hard on everything. Peak torque is typically around 5-5.5k rpm and peak power typically around 6.5-7k RPM (varies a little by setup) and when shifting near redline RPM is never under 5k rpm, so little reason to ever be at WOT under 5k RPM besides in 1st. I doubt that pull was for the specific intention of tuning either, (main reason for tuner to WOT at lower rpm) but more to see peak power changes. And how the DBox benefits the MAP. Because of all that unless throttle is logged showing otherwise, it’s highly likely WOT didn’t happen until 4500+ rpm, Im curious what boost it makes at 5k RPM and at 7k RPM according to that log then you can attempt to extrapolate what boost would be at 3500rpm and compare what % of max boost it makes at what rpm.


I'm not reading into anything. You said 10 psi at 3500 rpm on a PD kit and I think that needs some backup since my research and records, which was all done before I bought a PD charger myself, suggest otherwise.

You stated I didn’t mention certain things when i clearly did. Also I said MY PD (not all) instantly makes 10PSI on WOT at 3500rpm slowly ramping up to about 13-13.5psi according to my mechanical boost gauge. (I video recorded pulls and played back in slowmo to verify) To be fair i have a sprintex and they make the most low end boost out of all the PDs but the other PDs still make a lot compared to centrifugal, and have instant throttle response/boost compared to turbos on WOT engagement.

Smaller turbo properly sized/setup can make near peak boost (will usually still slowly ramp up as rpm goes up/back pressure builds, or using boost controller to limit boost) by 3500rpm IF it was spooled from 3k rpm. That doesn’t mean if you are at partial throttle cruising and go WOT starting at 3500rpm you will already instantly be at peak boost. From partial cruising throttle to WOT at any rpm it’s typical for a 300-700rpm spoolup after going WOT, smaller turbo with boost controller limiting boost can make “peak” boost and spool very quick only because you are limiting peak boost, not because it’s capable of maxing out the turbo instantly. Like using a small turbo only capable of maxing out at 12psi but limiting it to 7psi, it'll spool up to 7psi very quickly and make 7psi at low rpm, but change it to max out at 12 it’s not spooling to 12psi or making that 12psi nearly as quick or low of rpm.

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