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914World.com _ 914World Garage _ Dyno day
Posted by: emerygt350 Nov 20 2021, 02:32 PM
Just got back from the Dyno. We were able to tune the mps reasonably well. Still have a little leanness at wot and lower rpms and richness at wot at high rpms but overall pretty smooth. Waiting to get the figures from the shop. If I remember right it was 77 horsepower and 105 lbs of torque at the wheels. I am running big 225/50r16s so I suspect I would pick up some more with lighter stock rims and tires....
I will post the graphs as soon as I get them.
Posted by: mgp4591 Nov 20 2021, 03:18 PM
Just got back from the Dyno. We were able to tune the mps reasonably well. Still have a little leanness at wot and lower rpms and richness at wot at high rpms but overall pretty smooth. Waiting to get the figures from the shop. If I remember right it was 77 horsepower and 105 lbs of torque at the wheels. I am running big 225/50r16s so I suspect I would pick up some more with lighter stock rims and tires....
I will post the graphs as soon as I get them.
What engine are you running?
Posted by: Shivers Nov 20 2021, 03:34 PM
So about 93 horsepower, plenty to be fun. (+-) This a 2056?
Posted by: emerygt350 Nov 20 2021, 03:45 PM
Stock 73 2.0 djet. I do have an ansa muffler and a k and n filter on it. And a 123 dizzy (not Bluetooth)
Posted by: Shivers Nov 20 2021, 04:55 PM
Great
Posted by: Van B Nov 20 2021, 05:17 PM
That’s so f***ing cool.
Posted by: emerygt350 Nov 20 2021, 05:42 PM
Tom at overdrive automotive in Binghamton NY is great. Drilled a bung in my exhaust (muffler, not the stainless) for the 02, probably 8 pulls plus all the idle and part throttle tuning. He really is great to work with. I described how the mps works, the ECU idle richness, etc. I have the tangerine racing tuning kit on my mps. He just dived in and had fun with it. One thing I will mention, we tried to advance the timing a hair to see if there was more there. We lost 20 horsepower with just a couple degrees of extra advance. Crazy how bad it was.
Posted by: PanelBilly Nov 20 2021, 06:25 PM
I want a video with sound!!
Posted by: emerygt350 Nov 20 2021, 06:45 PM
I knew I should have taken a video... Stupid not to. You will just have to imagine the vroom vroom sounds when I post the graphs.
Posted by: Van B Nov 20 2021, 07:51 PM
Yes, yes you should have. And we are all very disappointed in you.
But, I get it. Most people don’t think like you tubers. We go to a shop to do stuff, not film a video lol…
Posted by: emerygt350 Nov 20 2021, 08:17 PM
Funny thing is everyone in the shop "knew" when we screwed up the timing. They were not paying any attention till that pull then everyone was like "ouch!" What happened!?
Posted by: Van B Nov 21 2021, 09:17 PM
Deleted* I need to think more about what I was about to recommend
Question instead: what happened to the richness at high RPM WOT when you advanced and by how much did you advance?
Posted by: emerygt350 Nov 22 2021, 08:52 AM
It got super rich, black smoke everywhere. Lost 20 horsepower. Tom said he maybe put 5 degrees into it.
Judging by the couple hundred rpm at idle increase I think that was about right.
Posted by: Van B Nov 22 2021, 09:17 AM
doesn't the 123 ignition let you create a custom ignition map; as in being able to advance at high RPM without being forced to advance across the whole curve?
I'm struggling to get my head around how advancing further causes increased richness. Unless it was so much advance that it was igniting prior to sufficient compression was reached to achieve a full burn.
Posted by: ValcoOscar Nov 22 2021, 09:20 AM
I just noticed the rear FUCHS spinning
Congrats 
Oscar
Posted by: emerygt350 Nov 22 2021, 09:32 AM
doesn't the 123 ignition let you create a custom ignition map; as in being able to advance at high RPM without being forced to advance across the whole curve?
I'm struggling to get my head around how advancing further causes increased richness. Unless it was so much advance that it was igniting prior to sufficient compression was reached to achieve a full burn.
I think that is exactly what happened.
And I have the non-bluetooth 123 so I believe I only have the built in mapping to work with.
Posted by: Van B Nov 22 2021, 11:47 AM
Maybe one step up on the plug heat range then?
Posted by: emerygt350 Nov 22 2021, 12:37 PM
Maybe one step up on the plug heat range then?
I thought that was just for chamber temperature differences. Although I have always been unsure about heat range differences in plugs.
I also have a very old coil. I wonder if my spark can keep up with the high rpm firing?
Posted by: Van B Nov 22 2021, 02:39 PM
More resistance in the plug means more energy build up before the spark can jump the gap. So, a more powerful can overcome the sparkplug resistance quicker and provide more arc energy to the spark itself... but there's a lot of other assumption on that as well: plug wires, etc. But treating the coil as a constant, a higher resistance plug can alter the actual spark timing just ever so slightly. Going to Coil On Plug (COP) is what gave manufacturers the ability to really tune engines for efficiency. Even differing length of plug wires varies resistance between cylinders.
Regardless, you want to be a little rich at high RPM and WOT... the last place you want detonation is during the most stressful parameters for engine operation. Being a little lean off the bottom can give a more snappy throttle response too. The problem you run into when trying to nail the AFR is that you have no forgiveness in the fuel. I'm sure we all run premo fuel, but let's say you fill up one day and the premium is 1 octane point lower than what you used for tuning and you dialed in a perfect 14.7:1 AFR... well now you have a detonation problem.
So, there's no point in running a street engine at 14:1 AFR. I'd like to know the ratios you were seeing at "a little lean, and a little rich" for my own curiosity. But if you're even 12:1, I'd say you're just fine.
Posted by: JamesM Nov 22 2021, 02:52 PM
Tom at overdrive automotive in Binghamton NY is great. Drilled a bung in my exhaust (muffler, not the stainless) for the 02, probably 8 pulls plus all the idle and part throttle tuning. He really is great to work with. I described how the mps works, the ECU idle richness, etc. I have the tangerine racing tuning kit on my mps. He just dived in and had fun with it. One thing I will mention, we tried to advance the timing a hair to see if there was more there. We lost 20 horsepower with just a couple degrees of extra advance. Crazy how bad it was.
What wound up working the best as far as timing goes? 27-28 degrees total advance?
Posted by: emerygt350 Nov 22 2021, 03:43 PM
I am still waiting on the graphs, that has the afr across the pull as well. If I remember correctly I think it was 15 max lean climbing to 4k then over 4500 it richens to 11 up at 55 maybe even richer.
Timing is unknown. I have no faith in the marks on my fan. I have tried to verify them but just a 1/4 inch off means my reading is worthless. I have been doing it by ear and off a good idle speed. I suspect I am maxed out on advance, since even the smallest change sucked HP big time. That said, when I checked the timing with my crappy marks I was at 28ish at 3500.
I am also using the retard mode on the 123.
Posted by: Van B Nov 22 2021, 04:31 PM
When I checked my 1.8 yesterday, the red mark came back in the window with 38 degrees set on the gun while holding 3000RPM. But since the red mark is the only mark and is aligned for 7.5 degrees BTDC, that would tell me I’m achieving 30 degrees maximum advance. So, yeah, you gotta be close to the limit.
Posted by: emerygt350 Nov 24 2021, 03:48 PM
Finally got the graphs! I am color blind but at least I can figure out the last run was the best. I am now thinking about maybe spark issues up high. I am still running the ancient coil (123dizzy) and perhaps that is too weak and worn to keep up? It's got a little over 3ohms but I don't know if that means anything about spark strength at rpm.
Posted by: bkrantz Nov 24 2021, 08:35 PM
Can I ask how much you paid for how much time?
Posted by: Van B Nov 24 2021, 08:40 PM
Other than the wavy A/F line on the last run, your runs look pretty fantastic! If you’re going to put a coil in, do it for the hell of it. You might get lucky in that some extra capacitance helps out, but really man, your car is a healthy boy!
Posted by: emerygt350 Nov 24 2021, 08:57 PM
Can I ask how much you paid for how much time?
I gave him 160. 11 pulls and he welded a bung in my exhaust for the O2 sensor.
Posted by: emerygt350 Nov 24 2021, 08:58 PM
Other than the wavy A/F line on the last run, your runs look pretty fantastic! If you’re going to put a coil in, do it for the hell of it. You might get lucky in that some extra capacitance helps out, but really man, your car is a healthy boy!
Yeah, I just feel like something is happening to have such healthy torque but then have the hp fall off like that. Wasn't peak horsepower at 4900 from the factory?
Posted by: JamesM Nov 24 2021, 09:04 PM
Finally got the graphs! I am color blind but at least I can figure out the last run was the best. I am now thinking about maybe spark issues up high. I am still running the ancient coil (123dizzy) and perhaps that is too weak and worn to keep up? It's got a little over 3ohms but I don't know if that means anything about spark strength at rpm.
If you could get the AFRs stabilized and dialed in there are a couple more horses hiding in there. Every one of those runs is lean down low, a couple lean enough that I would be worried about head temps, then all runs but the red one go overly rich above 4k rpm
Posted by: emerygt350 Nov 24 2021, 09:17 PM
Yeah, the issue is adjusting at WOT. The mps is a bit of abracadabra. We tried many combinations to try and get WOT richer at lower rpm and leaner at high rpms but it just ended up being a compromise.
I have sent this on tho Chris Foley as well so maybe he will have some tuning wisdom.
Posted by: Van B Nov 24 2021, 09:33 PM
@http://www.914world.com/bbs2/index.php?showuser=5834 these are WOT. Part throttle will be much richer.
@http://www.914world.com/bbs2/index.php?showuser=25740 I know I’m a 914 newb, but I’m no stranger to tuning for performance… granted most of my experience is from my days racing superbikes, the principle is the same.
A motor is basically an air pump. And what I see is that your big pistons are drawing a lot of air down low, but as engine speed picks up, Bernoulli is your limit. Some combination of valves (size and lift), ports, or even intake runners are not able to let enough air through. And also, your fuel is not mapped to match the air that is being drawn in.
Also, torque will fall off even as HP climbs. Horsepower is a made up number after all. (Torque*RPM)/5252 = Pretty Ponies.
My advice is not to obsess. The potential of your engine is not much more than where you are currently. And that last little bit you’re talking about are the most expensive horses you can buy!
I would focus on refinement and drivability: flow match intake, exhaust, get a hot coil for fun. And then maybe lighter wheels, etc.
You got a real cool car man, I’m impressed with it!
Posted by: wonkipop Nov 24 2021, 09:50 PM
Other than the wavy A/F line on the last run, your runs look pretty fantastic! If you’re going to put a coil in, do it for the hell of it. You might get lucky in that some extra capacitance helps out, but really man, your car is a healthy boy!
Yeah, I just feel like something is happening to have such healthy torque but then have the hp fall off like that. Wasn't peak horsepower at 4900 from the factory?
yes.
torque peak at 3500 105 ft/lbs i think.
just a bit over a 100
looks like your dyno curves are right on there.
its a real monster look your car. love it.
Posted by: JamesM Nov 25 2021, 10:22 AM
@http://www.914world.com/bbs2/index.php?showuser=5834 these are WOT. Part throttle will be much richer.
WOT is really where you need to worry about heat the most as that is where the motor is the most stressed. I have seen 100deg differences in head temps on a type 4 just from dropping the WOT AFRs from 13.7 down to 12.3 across the board.
Posted by: emerygt350 Nov 25 2021, 12:44 PM
Yeah, we were able to get part throttle tuned in pretty nicely.
I just ordered a new coil from 914rubber, my old one can sit on the shelf with the old distributor. I don't have high hopes but they are inexpensive and so why not...
I wish I had thought to take the air cleaner off. That would have given me a hint towards air starvation being the issue.
Posted by: JamesM Nov 25 2021, 06:36 PM
Yeah, we were able to get part throttle tuned in pretty nicely.
I just ordered a new coil from 914rubber, my old one can sit on the shelf with the old distributor. I don't have high hopes but they are inexpensive and so why not...
I wish I had thought to take the air cleaner off. That would have given me a hint towards air starvation being the issue.
Unless the filter itself is clogged I wouldn't think that is an issue, I have seen cars swapped from d-jet to Megasquirt pull ~105 hp on the dyno using the stock intake/air filter once the AFRs were dialed in perfectly. Taking drivetrain loss into account I would say you are probably not to far off from factory output for a stock 2.0.
Posted by: emerygt350 Nov 25 2021, 07:38 PM
Yeah, we were able to get part throttle tuned in pretty nicely.
I just ordered a new coil from 914rubber, my old one can sit on the shelf with the old distributor. I don't have high hopes but they are inexpensive and so why not...
I wish I had thought to take the air cleaner off. That would have given me a hint towards air starvation being the issue.
Unless the filter itself is clogged I wouldn't think that is an issue, I have seen cars swapped from d-jet to Megasquirt pull ~105 hp on the dyno using the stock intake/air filter once the AFRs were dialed in perfectly. Taking drivetrain loss into account I would say you are probably not to far off from factory output for a stock 2.0.
It's good to know that wonki air canister flows enough for 105.
All this gives me ideas and stuff to shoot for. I mean when there is nothing left to fiddle with half the fun is gone...
Posted by: wonkipop Nov 25 2021, 07:50 PM
wykres_power_lbft_3.php.jpeg ( 50.23k )
Number of downloads: 57
Posted by: emerygt350 Nov 26 2021, 07:21 AM
Is that real or is that a model?
Posted by: wonkipop Nov 27 2021, 02:45 AM
Is that real or is that a model?
i'm pretty sure its what they are supposed to be when they were new.
its just drawn graphically using modern computer graphics.
i found it when i was looking for the torque power curve of the 1.8
(which is hilarious, all torque and no horsepower)
i came across the same graphs for the 914/6 and the nsu RO80 (original rotary).
funny thing there was they were almost identical.
there is a whole website where you can look up your car from any time / any era,
and the power curves are there.
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