Its done!! T70 with a 50mm gate.

[Toysrme]

I am sorry for saying it was dumb. I really am. Sometimes I get too use to Honda-Tech & that type of discussion.

Anaema That's correct, but not really what we're talking about. This is more in line with what you're talking about.
Why do big diesel engines and race car engines have such different horsepower ratings?
How Force, Power, Torque and Energy Work: What is Torque?
AFA what me and Maxpower & whoever else are talking about on the dyno:
How do you convert engine torque to horsepower?
How Horsepower Works

The dyno itself has incorrect conversion factors.
NM is standard, as well as lb-ft. By that I mean there is no confusing the math to convert one to another. Unlike horsepower - where there may be a dozen different "horsepower" measurements used over the years. There are no ways to confuse one person/countries/system's NM of force, or another's Lb-ft. There is only one.

NM to Lb-ft Calculators & conversion factors.
http://www.boltscience.com/pages/convert.htm

http://www.iis-servo.com/conversions.asp

http://www.usda.gov/rus/electric/pubs/1724e216/appendix_d.htm


1438nm does not compute to 1566 lb-ft. 1438nm = 1060.613 lb-ft
Yet again proving that Dyno is poor. Not only can it not read & compute the correct function of torque in the first place - it's torque conversion to SAE doesn't even work correctly!!!


You're wondering what happened? I can tell you exactly what happened. The thing is dumb. It took the incorrect 1438nm reading , and instead of correctly converting it from NM to LB-ft, it used the OPPOSITE formula. It converted lb-ft to nm. 1438lb-ft = 1949nm.











Guess what... I'm right AGAIN!!! Go look at your written figures on the dyno.
631NM = 465lb-ft. Look at your peak torque on the curve.
It's @ approximately 3917rpm.
It's making approx 300whp @ 3917rpm
As stated Torque= (5252 x HP)/RPM
(5252 * 300)/3917 =
402 lb-ft peak via the real math.
Obviously, it's hard to interpolate the RPM & horsepower on the curve explaining the 63 lb-ft difference, But yet again my numbers are believable, the numbers on the dyno, and the numbers you two are quoting are impossible.

The dyno is dumb & incorrect, yet again proven by basic math.


MaxPower you (at length), and ozvenom just went on and on about gear ratio's, torque convertors and what not, and you've YET to realize they have 0 bearing on what we're talking about. Because you couldn't defend against what I've said, you COMPLETELY changed the subject to something else.


Gearing, torque convertors etc. has NO bearing on going from 400lb-ft actual meausurements to 1400lb-ft measurements.

If gearing changes & gearing correction has not been entered, guess what... IT STILL DOESN'T MATTER. As I said previously... If the actual 1920NM dyno was correct, it wouldn't read around 300whp making 1920NM, it would make:

Horsepower = rpm x torque / 5252
(1438/5252)*4050
0.273 * 4050 = 1105.65 wheel horsepower.

Not 322whp.






And another point that I am right about... Dyno's calculate horsepower, and find torque from that.

Horsepower is torque applied over both time & distance

like I said. The reason why dyno's read horsepower, is because you're taking measurements over both time & distance. You're not taking a static measurement like pushing on a lever.
http://www.bristoldyno.com/info/whatis.htm

Many of you are familiar with the hp = rpm x torque / 5252 formula. In many situations, that formula is the way horsepower is calculated. In the case of the Dynojet dynamometer, it is not. The Dynojet calculates horsepower even if there is no torque reading, and it does this in the manner that I am in the process of describing. Those of you that have had your vehicles tested at my shop and have watched the computer screen closely have seen that the computer plots out only the horsepower after each run, and I have to click the mouse a few times to get your torque. It does this because sometimes there is no torque reading, or the torque reading is faulty. This can happen because inductive and optical rpm pickups may not be perfect, and/or your ignition system may make things go a little haywire. If the rpm readings are not perfect, and the computer used the rpm x torque / 5252 formula, the hp reading would be inaccurate.

Like I said... Sorry for being an ass, and I REALLY don't want this detract from the car - I really wanna see the car. It sounds leet, sweet & ready to eat & msot of us wanna see it.

 

[Lextreme II]

From the initial dyno sheet it show 465 rw tq. I wonder if that is the conversion of the n/m

 

[Toysrme]

What the person wrote on the sheet is correct. 631NM = 465lb-ft.
Using any combination of conversion factors - including wrong ones (Like the backwards conversion they did) using everything I could think of from 300-320bhp, or the torque figures shown on that dyno (correct & incorrect) I couldn't figure out how they came to their 1950 NM numbers. I'm sure I missed a few, but I think the dyno is bad, or they were having big problems.


Obviously they know the dyno is bad, or they wouldn't have been able to provide (write down) plausable numbers.

 

[george]

hey toysrme some dynos do measure torque these are the hydraulic one which im guessing was used here which would account for the inacurate torque figures. other dynos "the inertia type" measure power directly

 

[ozvenom]

Some pics .

Some pics for those that can see them . Thats the ones that dont have pair of hairy balls hanging in front of their eyes. The fact is i wanted to give some info out on how to make a 1uz work well with a single turbo . It works just fine. It is a cheap t70 from ss autochrome but i have no complaints about the turbo it has worked great.
A dyno has a load cell placed under a torque arm which is attached to the retarder unit which holds back the rollers .I guess thats why it measures TORQUE. A dyno is nothing more than tuning tool .
The 120 mph wheel spin was in my cobra which was running 16psi and making over 450 hp at the wheels. and it made almost the same rear wheel torque as this most recent conversion. Enough is enough here is some pics . I learnt a lot from my first big single turbo install and corrected a lot of little problems i had the first time around. things like exhaust leaks and serviceability.
Regards oz

 

[JBrady]

Very nice. I would rethink the air feed to the turbo.

The dyno is fine. Most US operators convert the RWTQ back to engine RPM as that is an easier way for most people to compare numbers. The fact of the matter is that actual RWTQ is a function of gearing. Taking a torque converter out of the equation the gearing is the transmission, the differential and the tire diameter.

For this test we know the car has a 4.11 differential ratio. I would also assume that it was done in 4th gear which is a 1.1 ratio. Tire diameter affects the net gearing. Pounds feet creates a good way to deal with tires as 24" is a 1 foot radius. Larger than 24" will reduce the net gearing.

Looking at the dyno nearest peak torque we can use the line for 4180rpm. Nm for this rpm at the TIRES is a little over 1900... I will guestimate 1910Nm.

1910Nm is aproximately 1415 lb/ft. Since HP cannot be gear multiplied we can easily calculate RWHP at 310rwhp at this speed. Now we can also calculate engine torque LESS drivetrain loss. 310hp*5252/4180 = 389.5 lb/ft of torque CALCULATED back to engine RPM.

BUT, the tires are obvioulsy not turning engine RPM. Their speed is gear reduced. If we want to compare the engine RPM adjusted torque to the actual FORCE present at the tire to road contact we must correct for the differential ratio and the tire diameter.

If the tires were 24" in diameter we could just use the differential, in this case a 4.11 ratio. Divide 1415 by the ratio of 4.11 gives 344. That would be with 24" tires. Most likely the car has 27" or so diameter tires. Divide 24 by 27 gives apx 88%. Divide the 344 from above by 88% and you get 390.

All of the above calculations are actually not needed. They are only to show the relationship between engine output less drivetrain loss vs. actual torque at the tire to road contact. The dyno used here is giving the road torque.

 

[ozvenom]

Finally

Yea finally some one who knows what they are talking about.
The air inlet is temporary as we are against the clock to get the cobra ready for the next race meeting.
I have never put much faith in dyno figures as ther are so many variables. But recently i put an Engine in a cobra sorry its not a 1uz but a very healthy cross ram injected windsor 412ci small block. it made 625 flywheel hp on the engine dyno and after it was fitted to the cobra with different exhaust and airfilters fitted it made 456 rwhp . its not very often you get the opertunity to do a direct comparison between the 2 dynos but it did give us an accurate idea of drivetrain and friction losses.
another interesting fact is that it made the same sort of torque on the chassis dyno as the turboed 1uz did but heaps more hp . Then i guess when the boost is turned up it will head to wards the 450 rwhp mark as well.
The only truly accurate comparison that is out there is the dyno dynamic shoot out mode acredited dyno operators which have to have regular load cell calibrations to keep there shoot out status.

Regards oz.

 

[ash]

dyno sheet isnot true...
hp and torque curves ALWAYS cross at 5252 rpm......
if not ... it's fake
end of story

 

[ozvenom]

The so called expert has spoken.

Wanker! with

 

[ozvenom]

The so called expert has spoken.

Wanker! with out a clue.

 

[ash]

? you go and work it out then....

 

[Pro]

keep it clean fellas.

no namecalling ozvenom.

this is a good thread with everyone placing down their POV and we wont let it slip into mediocrity and have it locked now, will we? i hope not.

JBrady is very right when he says

the tires are obvioulsy not turning engine RPM. Their speed is gear reduced. If we want to compare the engine RPM adjusted torque to the actual FORCE present at the tire to road contact we must correct for the differential ratio and the tire diameter.

and toysrme - your calcs are spot on too.

but you're all arguing for different measuring techniques on the same outcome.

this dyno that has been used - is it one that you roll the car up onto and spin the rollers, or bolt the hubs to individual meters and then test? i think that would account for difference.

 

[MaxPower]

The dyno used is load brake dyno with rollers. So the tyres and roller dia come into the equation. The torque in the posted graph is the torque as seen by the dyno's load arm, the other figure on the dyno sheet is the linear motive force (LMF) which is the torque acting on the rollers. LMF (or tractive effort on a dyno dynamics dyno) is the measurement that should read the same for all dynos, the torque at the load arm will vary from dyno to dyno based on its roller dia and measuring equipment so LMF is used to keep a level playing field for comparison.

Ash: If you work out the engine torque and power at 5252RPM they will be the same. You are tyring to compare torque at the load arm with engine power which is incorrect.

 

[Pro]

my thoughts were tractive effort too.

so the tractive effort is higher than the actual torque reading at the wheels?

 

[MaxPower]

Tractive effort is the torque at the wheels, it is the linear force acting at the surface between the tyre and the roller. Dyno manufacturers call it by differnt names. The graph posted shows the torque as seen by the load arm deep inside the dyno. That reading still has the "error" of the roller dia and load arm to take into consideration. The tractive effort is a corrected figure that is independant of the dyno's physical properties.

 

[ozvenom]

read the first post.

I dont like being called a liar . If you had of said it to my face you probaly would have ended up on the floor.
I have nothing to gain by producing a false dyno sheet.
If you read the first post it said rearwheel figures which is what the dyno reads the horse power is a number calculated as a result of load applied to a load cell attached to an arm on the retarder unit. how these numbers are calulated is upto each dyno manufactuer and there software.
one of the true indicators of horse power is a 1/4 mile run as your terminal speed and car weight gives you an aprox hp which has been used for years and is a standard thru out the world its not exact but is a real good guide of how much real Hp a car has.
If any one has a moroso power speed calculator put these numbers in and see what comes out. the car weighs in at 2480lbs with driver and fuel its terminal speed was 120mph and et of 12.1 . lets see how close it realy is.
OZ

 

[Pro]

i don't think it came down to someone calling you a liar ozvenom, but ash's post was a little "black and white" in reference to what was posted and maybe a little inflammatory but nothing to get nasty over. that said, you have every right to be offended though - but the pair of you need to ease up a bit before it gets outta hand.

no sides are being taken because you're both in the wrong a bit so let's just box it all up and let bygones be bygones, okay? please? coz i have having to lock threads like this.

we are all above average people on this forum. you run a respectable business ozvenom and i don't think anyone on here would question your credibility.

 

[Pro]

ps - if you'd have bid $3 more on that 9.5L diesel turbo on eBay, you'd have sniped me for sure. 228 was my max bid!!!

 

[ozvenom]

turbo

Yea i thought it was mine but any way i have another t70 in the box so that will have to do .

It is intesting that all I wanted to do is put up a bit of usefull info and I hammered for it. I dont mind if it is constuctive comments but this definatly got out of hand .
I guess if i said it had 550 hp at the wheels everone would have accepted it.
they are the numbers and they would come out much the same on any dyno.

When the boost controller is fitted we will be running it up again on the same dyno so that should show the effect of low and high boost has on a 1uz.

OZ

 

[Pro]

yeah it did get out of hand and has tarnished a useful thread too. never mind - you're the one with the car and if you say it has "x" amount of torque then so be it. i personally think it sounds high but i don't fully understand dynos so i'll keep my trap shut.

did you know the specs of the turbo before you bid? just for a bit of useless trivia, it's off a Deutz Stationary Industrial Earth Compactor, 9.5L V10 diesel that spins at 2300rpm making 200kW and star-destroyer type torque.