Pinz on dyno

Engine troubles? Try here.
Post Reply
JimmyC
Posts: 217
Joined: Tue Feb 18, 2014 4:59 pm
Location: Lafayette, LA and Highlands, NC
Contact:

Pinz on dyno

Post by JimmyC »

I was surprised to find a nice Dyno set up just a few minutes from my house. I ran the Pinz to get a baseline for my smell reduction campaigne.

i found out the mixture is pretty good except at idle, where it is rich.

The Dyno and the people who run it are geared towards high performance. The Pinz is on the low end of what can be measured. So far I have only run against roller momentum which I think under ,erasures HP.
image.jpg
image.jpg (228.66 KiB) Viewed 5136 times
Trying to attach pictures
Attachments
image.jpg
image.jpg (993.19 KiB) Viewed 5136 times
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect
kdiqq
United States of America
Posts: 270
Joined: Tue May 26, 2015 3:30 pm
Location: Houston, TX

Re: Pinz on dyno

Post by kdiqq »

Wow!!

Awesome to have! This is definitive proof that it's better to be shifting before the limiter haha power tapers off hard.

Did you run it on a 4WD dyno or just left the center unlocked?

EDIT: It's a 4WD dyno. I'm dumb.
1977 Austrian 710M
JimmyC
Posts: 217
Joined: Tue Feb 18, 2014 4:59 pm
Location: Lafayette, LA and Highlands, NC
Contact:

Re: Pinz on dyno

Post by JimmyC »

The Dyno is really for "super cars". It is rated at 2,000 HP. It has rollers for the front and back wheels for cars with stability control. The front and back rollers can be connected with a clutch. I just used the rear wheels and the front did not turn. If you run a car with stability control and the front tires do not turn just right the traction control will back off power and apply the brakes.

Take the HP numbers with a grain of salt. The eddy brake was never engaged. The only resistance I pushed against was the angular momentum of the drum. The machine calculates torque and power based upon how fast the angular momentum changes. What is not clear is how the power to spin up the truck's shafts, gears, axles, wheels and tires is accounted for. My guess is that they are not. I could see losing maybe 10% in the gear train and maybe another 5% at the tire/roller interface, but not 40%.

If you look closely at the fuel mixture one you will see it is a double line. One line is running the drums up and the other is the drum driving the engine with the throttle plate closed. There are a couple of spots where the mixture goes real lean which I do not understand.

I thought the stench was over rich on trailing throttle, but that does not seem to be the case. Now I suspect that it is a matter of the exhaust valve opening before combustion is finished when engine braking. When you get a vacuum in the intake manifold it takes like 10 degrees more of crank angle to burn the mixture, at least according to what I read.

Does anybody know if there is a distributor that fits that has vacuum advance?

Does anybody have a exhaust gas analyzer ( HC, CO, and NOx) to lend or rent?
Last edited by JimmyC on Tue Oct 06, 2015 6:12 am, edited 2 times in total.
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect
kdiqq
United States of America
Posts: 270
Joined: Tue May 26, 2015 3:30 pm
Location: Houston, TX

Re: Pinz on dyno

Post by kdiqq »

Those analyzers are high dollar. I wouldn't lose sleep even if the dyno said 3rwhp. I've been on dynos a LOT chasing horsepower. This isn't a performance machine. I'm just thankful someone did it. I'm blown away how ultra smooth power delivery is!

A lot of folks report the PinzSSI reducing stench and you'll get two different ignition curves with it. They may be worthwhile. Having had lots of cars and bikes without cats though, they all smell. I think the guys around here call it character ;)

Sent from my Z30 using Tapatalk
1977 Austrian 710M
User avatar
Jimm391730
United States of America
Posts: 1456
Joined: Wed Apr 14, 2004 10:58 pm
Location: Idyllwild, CA

Re: Pinz on dyno

Post by Jimm391730 »

When I first installed EFI we dyno'd the system to ensure that it wasn't running too lean, and (within a relatively short time - dyno time is expensive!) optimize for best power. As this was on Jim L's 2.7 conversion, with better pistons and cam timing, the dyno system said I peaked at 66HP. The operator/owner said to expect to loose 1/3rd of the true engine power in the driveline and tires, so he said the engine was making about 100HP. If his 1/3rd loss is true for most vehicles then it is worse in a Pinz, as "normal" vehicles do not have gear hubs nor nearly as many ring and pinions as a Pinz does. So with this in mind I estimate my engine might be making 110-120HP. This vehicle is also a 712, so we had to remove one set of rear wheels to just clear the floor and have one set left to drive the rollers.

So your (stock?) engine, making ~54HP at 3100rpm is doing very well in comparison.
Jim M.
712W and 710M
User avatar
ako
Posts: 159
Joined: Sat Jan 17, 2015 11:41 am
Location: UAE

Re: Pinz on dyno

Post by ako »

Amazing how much low end torque it makes for a small displacement petrol engine.

When people talk about doing Subaru boxer transplants and such I don't think they understand how the original unit was designed, then only compare peak horspower.
JimmyC
Posts: 217
Joined: Tue Feb 18, 2014 4:59 pm
Location: Lafayette, LA and Highlands, NC
Contact:

Re: Pinz on dyno

Post by JimmyC »

As far as expense, these guys charge me $100 for 3 runs which seems pretty reasonable.

I am sort of getting fascinated with a homemade Dyno, like a hydraulic pump you could bolt onto a hub.
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect
JimmyC
Posts: 217
Joined: Tue Feb 18, 2014 4:59 pm
Location: Lafayette, LA and Highlands, NC
Contact:

Re: Pinz on dyno

Post by JimmyC »

Got the raw data from the tuner and it looks a bit different. I see some real lean spots when engine braking. They are lean enough where ignition would be problematic.

All the lean readings have the same value of 18.4 grams of air per gram of fuel. I think I am bumping the edge of the A to D converter so the real values are yet leaner (but see below).

Alternatively, the apparent lean mixture spots might actually be artifacts of a misfire. The machine is supposed to measure air fuel ratio but I would not be surprised it goes wacky on misfire.
Attachments
dyno.jpg
dyno.jpg (41.59 KiB) Viewed 4967 times
Last edited by JimmyC on Wed Oct 07, 2015 10:14 pm, edited 1 time in total.
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect
User avatar
edzz
United States of America
Posts: 1309
Joined: Tue Aug 11, 2009 12:13 am
Location: Coeur d'Alene, ID

Re: Pinz on dyno

Post by edzz »

Just a thought.

Possible lean conditions due to leaks in exhaust system not great enough to cause audible backfiring however great enough to influence sniffer?
Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.
JimmyC
Posts: 217
Joined: Tue Feb 18, 2014 4:59 pm
Location: Lafayette, LA and Highlands, NC
Contact:

Re: Pinz on dyno

Post by JimmyC »

There was some minor exhaust leakage but it did not seem like enough to matter.
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect
Bruce Berger
Posts: 135
Joined: Wed Jan 24, 2007 9:39 pm
Location: Tehachapi, CA

Re: Pinz on dyno

Post by Bruce Berger »

Well now I don't feel so bad. When I had my 710M on the dyno it came up with 58 or 59 hp at the rear wheels. That's with a 2.6l engine (92mm X 92mm), high compression pistons (relatively speaking), Beck-LaGuardia EFI, and a stock cam. Unfortunately their printer was down that day so I didn't get the final graphs.


Sent from my iPad using Tapatalk HD
Bruce Berger
'72 Pinzgauer 710M 2.6i
mit Beck-LaGuardia Elektronischer Einspritzung
JimmyC
Posts: 217
Joined: Tue Feb 18, 2014 4:59 pm
Location: Lafayette, LA and Highlands, NC
Contact:

Re: Pinz on dyno

Post by JimmyC »

I am curious to see how the HP compares running against the brake rather against inertia. I think inertia will be small because it is net of the HP required to spin up the rotating mass of the vehicle.
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect
Post Reply