PerfExpert - poor man's dyno (1 Viewer)

GTSSportCoupe

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Thought I'd try out a poor man's dyno. :) Home - PerfExpert

Did a bunch of research on smart phone accelerator based power estimators. PerfExpert seemed to have the highest reviews for realistic results (when used properly). I went for it and installed it on my Android phone.

I also have a 'G-Tech Pro' device which was popular over a decade ago. Also known to be very realistic (again when used properly). I have used this with other vehicles and it is usually dead on.

I have a weight scale near my house, so am able to get a pretty accurate weight for my truck. I meticulously entered all the specs for my vehicle into PerfExpert.

So the G-Tech device on multiple runs on many different roads gave me a solid average of 78hp to the rear wheels.

And here is the result from PerfExpert (a typcial result of five different runs). I exported the raw data and made a graph in Excel so I could post it here. This is power and torque at the rear wheels. Matches the G-Tech result very closely.

It is an automatic. Done at sea level at 10 degrees Celsius. This is my daily driver and towing tune.

LJ78 with 2LTE engine:

- Intercooled
- 17.5psi (post intercooler)
- EGT's less than 800F on this test
- 2.5" exhaust and high flow intake
- 3L camshaft (breaths better apparently)
- Methanol/water injection
- Tuned by way of spill control valve and boost sensor

I'm quite impressed with the app to be honest.


2LTEDyno.jpg
 
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GTSSportCoupe

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Oh, and from my research, a stock 2LTE with a manual transmission puts down 42 hp to the rear wheels. So I am seeing nearly double stock power unless I'm missing something here.

Also, we used the G-Tech on my friends mildly upgraded HDJ81 (1HDT - 14psi with Supra compressor, 4" dump, 3" exhaust), and saw 85hp to the wheels. This was done under the same conditions I tested my truck. However I think the A442 slips a lot more than the A343 at lower speeds, also it is AWD. So he was experiencing higher drive train loss.

I'd be interested to know where all the power goes in a landcruiser between the motor and wheels though.....LOL.
 
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GTSSportCoupe

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That or the app is completely inaccurate. My HDJ81 put down 163 hp at the wheels with the slightest of fuel tweaks.

Torque converter was not locked on it (or mine for that matter). Did not use the app for the HDJ81; just used the G-Tech Pro.

My understanding is a stock HDJ80 auto puts out 70-90kw at the wheels (with TC locked). So yours is obviously not stock.
 
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mudgudgeon

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From my Ellerey's aftermarket workshop manual.
1hd-t is rated at 115kw@3800rpm, 357Nm@1800.

115kw is approx 154hp.
357Nm approx 263ft/lb

Not sure if those figures are supposed to be engine hp, or at the wheel. I expect it's engine.

20170127_210644-1.jpg
 

GTSSportCoupe

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The point I was trying to make here guys is that PerfExpert is a pretty impressive little application. Carefully enter the vehicle data, and it can be a very useful tuning tool for those that don't have access/time/money for a real dyno. Easy to see the impact of different upgrades or modifications.

How much power each engine makes to the wheels is a whole different can of worms.
 
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From my Ellerey's aftermarket workshop manual.
1hd-t is rated at 115kw@3800rpm, 357Nm@1800.

115kw is approx 154hp.
357Nm approx 263ft/lb

Not sure if those figures are supposed to be engine hp, or at the wheel. I expect it's engine.

View attachment 1390079

This is the first I have seen mention of taller 5th gear in the H150 vs H151. Curious the source of that document. I would love to know if a taller 5th could be swapped in to my H151. "the book" shows same 5th gear between the 2.

Screenshot_20170127-092840.png
 

mudgudgeon

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@tweeek I would take your info as correct. The photI I posted is from a non-genuine workshop manual. It's pretty good, but has errors.

As for 5th gear. It would not be possible to change only the 5th gear ratio in the h15* boxes, as all the forward gears use a single cluster gear
 

mudgudgeon

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The point I was trying to make here guys is that PerfExpert is a pretty impressive little application. Carefully enter the vehicle data, and it can be a very useful tuning tool for those that don't have access/time/money for a real dyno. Easy to see the impact of different upgrades or modifications.

How much power each engine makes to the wheels is a whole different can of worms.

Looks like it could be a useful tool.
 
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To me it's bennifit would be in its +\- margin for error so I could tell if a mod was bennifical or not. If it's margin is high then would make it not so useful. I envision the user being the greatest source for error.
 
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I've used cellphone dyno apps before. Specifically ADyno & Dynolicious. They're quite good for baselines and probably as accurate as the average dyno plot. I've seen some horrendous dyno plots and even the same car with wildly different results on 2 different dyno's.

I should check this one out because I don't have any i devices and ADyno was discontinued. Other dyno apps I tried had smoothing and stability problems. Get a whole graph full of noise!

Previously I uncovered such hilarity as a 50% performance improvement from swapping fuel filters. Was 20kw to the ground prior, jumped to 30kw after!
 
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mudgudgeon

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I've used cellphone dyno apps before. Specifically ADyno & Dynolicious. They're quite good for baselines and probably as accurate as the average dyno plot. I've seen some horrendous dyno plots and even the same car with wildly different results on 2 different dyno's.

I should check this one out because I don't have any i devices and ADyno was discontinued. Other dyno apps I tried had smoothing and stability problems. Get a whole graph full of noise!

Previously I uncovered such hilarity as a 50% performance improvement from swapping fuel filters. Was 20kw to the ground prior, jumped to 30kw after!

What brand fuel filter? You might be on to something :hillbilly:
 

Locked79

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Interesting little app, so I thought I'd have a play. This is how my vdj79 went. Its all standard apart from 3.5" exhaust. This graph show engine power. Factory numbers are 151kw/430Nm. I did 3 runs, this was the average.
Screenshot_20170130-215048.png

Torque seems high, but peak power and flat torque curve seems correct. Any comments?
 
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Interesting little app, so I thought I'd have a play. This is how my vdj79 went. Its all standard apart from 3.5" exhaust. This graph show engine power. Factory numbers are 151kw/430Nm. I did 3 runs, this was the average.
View attachment 1392194
Torque seems high, but peak power and flat torque curve seems correct. Any comments?

It's probably reading high due to the vehicle pitching under acceleration. Soft suspension with the rear squatting and front rising will add to the accelerometer readings.
One app I tested had fields for spring stiffness to try and account for this, but it is far more complex than that as squat and antisquat due to the suspension geometry comes into play.
 

GTSSportCoupe

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It's probably reading high due to the vehicle pitching under acceleration. Soft suspension with the rear squatting and front rising will add to the accelerometer readings.
One app I tested had fields for spring stiffness to try and account for this, but it is far more complex than that as squat and antisquat due to the suspension geometry comes into play.

PerfExpert does have a degree's/G Pitch setting. It recommends 4 degrees/G for a soft suspension, 3 for regular, 2 for hard, 1 for very stiff. I set mine to soft. But now that I think about it my truck does not really pitch noticeably while I accelerate. Rear springs are pretty heavy. Maybe I should try a stiffer setting? Might get more power...:rofl:
 

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