Project MKIV Supra: Part 10 – Dyno testing – We Hit 800 WHP!

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Here's Mike Cho, who grabbed some of the shop’s E98 pure ethanol blend to bring us up to what turned out to be a measured 80% ethanol for the higher boost pulls.


With 80% ethanol in the tank, the car saw a whopping 817 WHP and 702 LB-FT of torque at 29 PSI.  And it’s a pretty clean run to boot!  Unfortunately, as it is with most turbo cars on an inertial dyno, the boost doesn't hold up top.  What you're seeing is a peak 29-30 PSI in the midrange, dropping off to 25-26 PSI up top at around 7000 RPM.  On an actual straight, however, this boost level is sustained through redline.

To hit the 700 LB-FT in the midrange, the boost actually hit around 29-30PSI before dropping to 25-26 PSI in the upper midrange.   The efficiency of the motor, however, has gone up significantly since the previous setup, so much that we’re now making around 53 more horsepower–with a 67-mm turbo–than we were with the old setup–which had a 71-mm turbo–at the same 29 PSI (817-plus vs 764 WHP)!  In fact, to make that same 760-ish WHP we once made on the old setup at 29 PSI, we can now do so at around 24 PSI.  It’s just great to see how much better the aftermarket components for the Supra are today—and by no means was this car a slouch before!

With our previous setup on 93 octane with an AEM methanol injection kit, we had hit 764 WHP at 29 PSI.  We showed a picture of this dyno run by itself in Part 9.  However, we refrained from comparing it to our current 29 PSI setup because it would only cause confusion with the spool up.  Since the tach pick-up wasn’t working in the old run, we had to use MPH, as you’ve seen in a few runs today.  The problem, however, is that the aforementioned 764 WHP run was also done on 275/35-18 tires, whereas these runs were done on 305/35-18 tires.  Hence, the runs will show an unrealistic spool difference between the two tires that will only complicate things, and show the old PTE 71-GTS relatively worse than it actually was.  The previous graphs you saw the comparisons with–at 25 PSI–are with the same tires, which is why we showed them.

With turbocharged cars it’s always important to use the same height tire while testing parts or the taller tire will show a way better spool-up in RPM and a worse spool-up in MPH.  Ever seen the difference in your turbo car’s spool up on the dyno between third and fourth gear?  That’s what we’re talking about, only at a smaller scale—yet very significant still.  And now you see how easy it is to potentially show unrealistic spool-up gains by an aftermarket company trying to sell some stuff!

 

Here’s a log of the 800 WHP run.  First off, look at the lower section, which shows raw knock value.  What we don’t want to see are sudden large, multi-volt spikes, which would indicate potential knock.  But at less than a quarter-volt for a peak, t’s clear that this engine is a happy camper.

Even with this octane from 80% ethanol, the ignition timing up top was only around 15 degrees.  The boost up top dropped to only 270 kPa, or roughly 24 PSI, where it's still sustaining around 750whp.  This confirms the tremendous flow of this 2JZ 3-liter.  To illustrate it further, a friend's fully-built 3.2-liter E46 M3 runs a 67-mm turbo, and everyone knows an M3's cylinder head really flows.  If you don't believe us, check out our Project E46 M3 which, with a stock cylinder head, makes over 100whp/liter all-motor!  And yet even that turbo M3, with more displacement, makes 700 WHP at the same 24 PSI on this dyno.

 


Ok, I'll even geek it out some more.  Now here is something I didn't expect.  This is not to post a comical difference between Project E46 M3 and Project Supra's power levels.  Some of you guys know how much I've raved about the torque curve of the E46 M3, and the fact that it can make 260 LB-FT to the wheels (which is the same torque as the 4.0-liter V8 M3 on this dyno) with just a 3.2-liter, while sustaining all of that flow up top, which is amazing.  But take a close look.  Even Project M3 only has the 3.0-liter Supra beat up to a paltry 3500 RPM, which is not even an RPM one would use with these cars that can both rev to 8000-plus RPM.  To put it into perspective, our previous setup on this Supra needed 4600 RPM to start “catching” the M3 here.

If you want to geek out some more, check out the plethora of cars and dyno curves of some big turbo cars we found parked inside Modified by KC!

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