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Lexus V8 Dyno Results

Posted: 14 Sep 2016 09:55
by Alex Roux
I have had some concerns over the power and torque of my car for a while.
But had to sort out the petrol pump in the main tank first before doing the dyno tuning.

Secondly, the Lexus is argued by many to be sub-optimal for most 44 applications.
But whatever you believe an engine should ideally be able to do in terms of torque and power, and at a given engine rev level, the figures below is what matter.

Note, that I use the original ZD30 airfilter, which is not ideal for a big breathing engine.

Power summary:
Power from the flywheel:

IF (a big word), the air filter is disconnected, and having adjusted for altitude (pretending we are at sea level), then the power reached at 5,000 revs, is 190Kw (232HP) - off the fly wheel - which is what the engine is spec'ed to do.

Power from the wheels:
The impact off the air filter is about 16kw (reading off the flywheel is thus down to 174KW). But the airfilter only seems to have an effect at revs above 4000, so for most applications this is not a concern, in itself.
Measuring the power off the 33" tyres the reading is way down to 116 KW (about 155HP)/b]

Torque Summary:
Torque from the flywheel:

This is the interesting part, the torque from the beginning (seen on the chart from 1000 revs) is 373 NM (off the fly wheel) and remains at exactly that level and only starts to creep down after 4400 revs.
As with the power, the level of 373 NM is apparently what the engine is spec'ed to do.

Torque from the wheels:
Without the air filter, it the torque level of 373 NM starts creeping downwards at 50000 revs, but again, the application at that rev level is only of use on dunes.
Measuring the torque off the 33" tyres the reading is way down to 250NM.

So in summary, it is not as great as I had hoped it would be.
But an important thing I learned is that that there is not such thing as "poor low down" torque in this engine. As least not relative to the high end torque. It is all the same at all rev ranges at 373 NM (measured from the flywheel) and 250 NM (measured from 33" tyres).


Attached are the figures, comments are welcome.

Dyno Results 2016-09-12.jpg
Dyno Results 2016-09-12.jpg (378.86 KiB) Viewed 2940 times

Re: Lexus V8 Dyno Results

Posted: 14 Sep 2016 10:03
by jonathan
That's very interesting Alex. I can't remember, but do you have the non-vvti Lexus motor?

If so, what is encouraging is that after so many years it still produces the power and torque it was meant to!

Re: Lexus V8 Dyno Results

Posted: 14 Sep 2016 10:58
by Alex Roux
jonathan wrote:That's very interesting Alex. I can't remember, but do you have the non-vvti Lexus motor?

If so, what is encouraging is that after so many years it still produces the power and torque it was meant to!
Yrs, this is the old 1UZ, pre VVTi

Re: Lexus V8 Dyno Results

Posted: 14 Sep 2016 11:28
by Tinus lotz
Mooi dude met daai figures hoef jy glad nie die lepel te trap nie hy moet al die goed kan doen regwyl hy idle :salute:

Re: Lexus V8 Dyno Results

Posted: 14 Sep 2016 11:31
by Tinus lotz
Wat het hulle verander?

Re: Lexus V8 Dyno Results

Posted: 14 Sep 2016 12:07
by Alex Roux
Tinus lotz wrote:Wat het hulle verander?
Ek moes seker maak na ek die pomp in die tenk vvervang het, dat die enjin nog reg is, want die goed is so fyn ingestel.
Dit was alles min of meer reg.
Maar die kar was tog traag wanneer ek wegtrek van doodstil staan af. Dit was blykbaar weens die TPS pomp wat nie gewerk het op die enjin nie (ek dink dit is die throttle position sensor).
Op die ECU settings kan mens hom disaktiveer dat die ECU eerder die werk doen van die TPS.
Nou is hy baie lewindiger van wegtrek af.
So sy hantering in die verkeer is baie meer bevredigend.

Re: Lexus V8 Dyno Results

Posted: 14 Sep 2016 12:44
by Michael
Alex, those are very good numbers and they should be more than enough.

I have never seen a petrol engine developing such high torque from 1,000 rpm and staying flat all the way. That means you should be able to idle up anything without effort.

Interesting how 33% of the power and torque is lost between the engine and the 33" tyres. :surprised:
Would love to see the loss with 31" and 32" as well to see the difference.

Re: Lexus V8 Dyno Results

Posted: 14 Sep 2016 13:09
by David M
That torque curve is not a curve so it is brilliant.

Maybe we should start looking at putting 195 X 70 X 16 on our lorries.... :rolling:

Re: Lexus V8 Dyno Results

Posted: 14 Sep 2016 13:32
by IanT
ViVa Petrol Power Viva :thumbup: :blonde:

Re: Lexus V8 Dyno Results

Posted: 14 Sep 2016 13:37
by johanp
A V8 always sound good, but what does it sound like at 50000 revs? :rolling: