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Dyno'd my stock L28ET today - coolant everywhere!

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Went to the Dyno today expecting to do 5 pulls and get a horsepower number. I am planning a significant amount of upgrades soon so I wanted a baseline. This place lets you run the car yourself on the dyno. I had never done something like this before, so my first run I stopped at 5500 RPM.

 

The second run I went all the way to 6200 RPM. Better numbers, but we thought there was an air leak. Upon closer inspection, we saw coolant going everywhere! Apparently a weird old T-fitting on coolant lines had failed. It killed my dyno session. Luckily, the shop let me replace the T-fitting there myself using their equipment and I was able to head home.

 

But not without this interesting dyno chart! This is a 99% stock L28ET. Swapped by previous owner around 2004. The only thing not stock is that the air intake is moved in front of the radiator and there is an oil cooler.

 

Dyno Chart

 

Peak Power: 148.86 hp at ~5700 RPM   -   MEGA POWER!!!

Peak Torque: 161.37 ft/lbs at ~4400 RPM

 

EDIT: Done with 1978 280z 5-speed transmission and rear diff in 3rd gear.

 

I'm gonna be honest - I thought there was more power under there lol. But I'm not complaining! It certainly feels like it with how light this car is.

 

But what the heck is with everything taking a dump @5k?

 

9qxjQVO.jpg

 

Action Shots:

 

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9Abvt7L.jpg?1

 

Coolant Pouring!!

T0amyve.jpgHnraZEQ.jpg?2

 

The busted T-fitting - wtf is this thing?

 

HrGiY1M.jpg?1

 

Fresh T-fitting Installed!

 

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My buddy who was nice enough to come by and help!

 

q6Ms4m0.jpg

Edited by AlbatrossCafe

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This was a baseline. In the next month, I plan to add the following:

 

  • Megasquirt 2 with electronic boost controller
  • Electric Rad fan
  • Intercooler with 2.25" piping
  • Blow-off valve
  • 240sx 60mm throttle body
  • Supra 440cc injectors
  • Walbro 255 Fuel Pump
  • MSA 2.5" downpipe
  • 3" custom mandrel-bent exhaust with Aeroturbine 3030XL muffler

 

Looks like I should probably add "inspection of all hoses and fittings" to the list haha!

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24 minutes ago, AlbatrossCafe said:

But not without this interesting dyno chart! This is a 99% stock L28ET. Swapped by previous owner around 2004. The only thing not stock is that the air intake is moved in front of the radiator and there is an oil cooler.

 

Dyno Chart

 

Peak Power: 148.86 hp at ~5700 RPM   -   MEGA POWER!!!

Peak Torque: 161.37 ft/lbs at ~4400 RPM

 

I'm gonna be honest - I thought there was more power under there lol. But I'm not complaining! It certainly feels like it with how light this car is.

 

But what the heck is with everything taking a dump @5k?

 

Believe it or not, those numbers aren't THAT BAD.

 

Sure, lots of stock L28ET's dyno closer to 160-170who, but there's a myriad of things that could be reasons why your numbers are low. Regarding the dip in power, that could be a million things as well. The AFRs show stable though, so it's likely mechanical in nature of some form. If it makes you feel better, here's a random dyno I found of a 350Z with a similar dip, and that's a heck of a lot newer design in all areas:

 

Rick-B-Z33-Baseline-to-Mods-768x690.jpg

 

I bet with a proper timing curve tune it'll just... go away. Also, could be something as simple as the factory knock sensor getting triggered by valvetrain noise or what have you. That'd be the kind of thing to check when doing FIVE runs instead of TWO. ;-)

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2 hours ago, turbogrill said:

I wouldn't bother until you have ms installed! You should get a wideband, what about timing?

Yeah, exactly. I barely know anything about this subject. Turbos and engine stuff is all new to me. I am getting a tune put on the megasquirt from user Chickenman I believe so ideally I'll not have to mess around with timing and whatever else barely if at all.

I'm assuming the stock O2 sensor is not wideband? I was hoping that MS would pick that all up for me.

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4 minutes ago, turbogrill said:

I assume controlling timing is very important for turbo. He also needs a DIYAUTOTUNE trigger wheel to pop into is dizzy right?

 

 

You only need that trigger if you want to run COP/Wasted Spark with an easy to setup config. The stock 82/83 turbo can send signal to MS (any version) and manage the coil directly, as long as you have a high current driver you can use for it. Otherwise you can use some form of ignition box to activate the coil from signal with MS. Look up "mobythevan". His setup used MSnS + a GM HEI module to control a factory coil. This is no different than many direct coil control setups that have existed since the first days of MSnS, in that you send MS basic tach signal from any digital distributor and let MS inject it's own control over the ignition module that fires the coil.

 

That said, looking at what I spent I'm not sure I'd go any other way than full Sequential COP. Using MS2 would mean you have to run batch injection, and wasted spark, but that's not a big deal in the grand scheme and gets you GOOD coils with WAY more power. Not to mention I can get replacement coils anywhere and they're not very expensive.

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" Moby The Van " article is getting pretty dated theses days. You are better off following the MS Extra Hardware manual and using either a BIP373 for a Ignition driver or a PRW2.  Bip 373 is a whole $8.50. PRW2 can be found for as little as $10 to $15. 

 

 A lot of changes and improvements in Builds and Firmware since that article was written.

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9 hours ago, malibud said:

Innovate is terrible i am on my 4th controller (its brand new in the box still in the box they just keep sending me new ones i have practically rewired everything trying to get it to work 

Biggest problem with Innovate and why it kills O2 sensors is that " apparently " if it detects any Error message, even a temporary one. it shuts down the heater circuit. Until the next restart. That will kill O2 sensors in a real hurry. 

 

Other WB controllers including OEM don't do that. You log the error message( Contamination, out of range  or aging ) you don't shut down the whole heater circuit.

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9 hours ago, Chickenman said:

" Moby The Van " article is getting pretty dated theses days. You are better off following the MS Extra Hardware manual and using either a BIP373 for a Ignition driver or a PRW2.  Bip 373 is a whole $8.50. PRW2 can be found for as little as $10 to $15. 

 

 A lot of changes and improvements in Builds and Firmware since that article was written.

Oh I agree wholeheartedly. My point was that we've had docs on how to control spark in these cars LOOOONG before anyone was making trigger wheels.

9 hours ago, Chickenman said:

Individual COP is nice, because you can do spark timing trim per cylinder. #5 and #6 running a bit hot?  You can trim them back a degree or two individually. Very nice feature. 

I spent $166 on my trigger wheels, coils, plug wires, and connector kit... It's peanuts in the grand scheme.

Edited by Gollum
Correct price looked up

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Unrelated to your fueling, but something I noticed with your setup that wasn't addressed, 


The original T-fitting you replaced on the ZXT heater hoses is a bypass reverse thermostat for warm up! 

You cannot simply replace it with a T-fitting, you've created a coolant bypass. 
Hot water is now coming out of the head, and going straight back into the water pump. 
Cap or put the single outlet fitting on the back of the head.  That way the only time coolant will flow back there is when the heater core valve is open. 

I made the same mistake and my car would never stay cool on the track until I found that out.

Also generally a good idea to check all hoses, clamps, and fittings. 

Edited by stupid_fast

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22 hours ago, turbogrill said:

 

What is your concern about innovate? 

 

I had an MTX-L and it's gauge was never reading the same as the data sent to MS and Tuner Studio.  I researched it and found voluminous info on the internet about the issue and how Innovate builds (wires) their controllers. 

 

The 14point7 Spartan 2 has an interesting feature to assure that it's output to the ECU is calibrated properly.  (the way you wire your install can have an affect on your sensors...)

 

(I also have to say that my L28ET has never run this smoothly since adding MS3X and implementing full sequential COP and full sequential fuel...  I thought it was overkill for this old tech engine but I'm loving the way it's running now)

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4 hours ago, stupid_fast said:

Unrelated to your fueling, but something I noticed with your setup that wasn't addressed, 


The original T-fitting you replaced on the ZXT heater hoses is a bypass reverse thermostat for warm up! 

You cannot simply replace it with a T-fitting, you've created a coolant bypass. 
Hot water is now coming out of the head, and going straight back into the water pump. 
Cap or put the single outlet fitting on the back of the head.  That way the only time coolant will flow back there is when the heater core valve is open. 

I made the same mistake and my car would never stay cool on the track until I found that out.

Also generally a good idea to check all hoses, clamps, and fittings. 

 

I was worried about something like this. Unfortunately I have read your comment like 15x but I am still confused...

 

I mocked up a pic of how I think the coolant flows. Is this correct? (Red arrows are hot coolant flowing through the system, blue arrows are coolant after it has passed through the heater core). I guess I don't understand how the T-fitting is a thermostat and when it turns on. Here is the original pic if you can wanna draw something yourself to explain it better.

zsd8uKc.png

 

Furthermore, are you saying if I remove this hose and turn the T-fitting into basically an elbow fitting (that doesn't connect to the back of the head) it will solve my problem?

 

wj17hrv.jpg

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There's some discussion of this valve in this stickied thread 

 

Specifically this post by Tony D says the valve is a poppet valve that only bypasses coolant when pressure surges (high rpm, thermostat closed) or when the heater valve is open. Based on that, I would say an elbow connected only to the heater (as on earlier engines) and not revving while cold (shouldn't do this anyway) would work fine.

 

 

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On 9/6/2018 at 3:22 PM, malibud said:

Innovate is terrible i am on my 4th controller (its brand new in the box still in the box they just keep sending me new ones i have practically rewired everything trying to get it to work 

FWIW I've been running an LM-1 for years now with zero issues.

 

Also, if it's truly a stock setup, they only rated it for 180hp at the flywheel to begin with.  You're maybe a little low, depending on what trans you have, but that's right in the ballpark of what you should expect.

Edited by TimZ

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16 hours ago, AlbatrossCafe said:

Thanks @ZHoob2004 that makes more sense. Of course, I could also just replace the T-fitting again with a proper bypass valve and make it work as it was intended on the ZX engines. If only I can find that part....

I think Zhoob answered your question sufficiently, It looks like you had the right idea in your post. 

The cold thermostat bypass was more for people who hop straight in their car and run it up on the highway at high revs cold, that is the only condition where you need additional coolant bypass.  The L series block already has a built-in bypass for the coolant which is sufficient for most street applications.

If you still want to put the correct valve in there, I believe the part number is 27188-Q0105, around $36. 
Personally I deleted the one off my setup, one less thing to go wrong on the track.  27195-E4400 is the single outlet fitting for the back of the head. 


@timz, yes the L28ET is only rated for 180hp from the factory, however 148 seems a bit low even for a stocker.  I thought I saw some old dyno sheets that were closer to 160whp. 

The AFRs at 5000rpm seem a bit rich, but the fuel curve is right on match with the factory fueling map.  Possible the AFM spring is worn out.

@OP what ignition timing are you running?  Stock EFI should be 20 degrees with idle switch plugged in. (ask me how I know) 
Although this probably doesn't matter much if you're going megasquirt anyway. :)

Edited by stupid_fast

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52 minutes ago, stupid_fast said:

I think Zhoob answered your question sufficiently, It looks like you had the right idea in your post. 

The cold thermostat bypass was more for people who hop straight in their car and run it up on the highway at high revs cold, that is the only condition where you need additional coolant bypass.  The L series block already has a built-in bypass for the coolant which is sufficient for most street applications.

If you still want to put the correct valve in there, I believe the part number is 27188-Q0105, around $36. 
Personally I deleted the one off my setup, one less thing to go wrong on the track.  27195-E4400 is the single outlet fitting for the back of the head. 


@timz, yes the L28ET is only rated for 180hp from the factory, however 148 seems a bit low even for a stocker.  I thought I saw some old dyno sheets that were closer to 160whp. 

The AFRs at 5000rpm seem a bit rich, but the fuel curve is right on match with the factory fueling map.  Possible the AFM spring is worn out.

@OP what ignition timing are you running?  Stock EFI should be 20 degrees with idle switch plugged in. (ask me how I know) 
Although this probably doesn't matter much if you're going megasquirt anyway. :)

 

Thanks for the part numbers! That helps a lot. I tried looking around at those diagrams but was lost. So you are saying there is another bypass in addition to the one I just blew out?

I have a 1982 L28ET with a 1978 280z 5-speed trans and diff. The pulls were done in 3rd gear. Maybe if they were done in 4th gear they would read a little higher. As far as timing goes, I have no idea. I haven't configured anything.The swap was actually done in 2004 by the previous owner and I bought the car in fall of last year.

Edited by AlbatrossCafe

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