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NA 3.1L=>head & camshaft questions. No shortcuts, max


zredbaron

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1 hour ago, zredbaron said:

Thanks Leon, good feedback. Your profile slogan is particularly on cue here. Hah!

 

I've prepared ahead on the swapping parts routine, definitely changed my hardware and tools in the process. Jon M and Joe H can attest that I've learned the swapping parts lesson a couple of times now. Clearly didn't learn the first time. Feeling confident this go-around.

 

Good call on the tire pressures! I likely would not have thought of that. I'll be sure and warm up the drivetrain as I arrive, too. I'll also take a log on temperatures as I am able. I'll print a table. Everything will be with an informed grain of salt; at least it's the same car on the same dyno, same day.

 

Agreed, there will not be enough time. But, I can certainly say there are enough variables that I won't lack for  follow the hp/torque vs. data collection. I imagine my plan of attack will adapt as the day unfolds.

The obvious is often missed. 🙂

 

Glad I can be of some help! If I were closer, I'd attempt to involve myself more. I've done some exploratory dyno sessions like this and always either run out of time, something goes wrong, and/or I question my data because I didn't log engine temps. Doing my best to pass on my experience.

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6 hours ago, bradyzq said:

As long as you walk away with useful data, your dyno day should be considered at least a partial success.

 

AAAAaaaannndddd, you mention that part throttle torque gains are your main goal. I strongly suggest that once you get the car to make clean pulls that you switch to ignition tuning. That's where your part throttle gains will come from. What do you have for measuring load on the Electromotive, TPS or MAP?

 

Agreed! Simply stated, this dyno session is for data about stacks, so I and others can select appropriate parts for our application(s). (It is explicitly not a dyno session to dial-in "my" engine.)

 

(Is it even mine? John Coffey's head and cam R&D, Jim Thompson's work, Joe Harlan's work, and "my" combination of go-fast parts that others invented or recommended.)

 

I don't know if I will still be using the Electromotive loaner unit, my old unit or a new-to-me unit. So... for the purpose of venturi comparison, I will do a few pulls at the beginning of the day with the Weber long stacks and refine my timing knobs for the baseline setup. I don't anticipate revisiting timing, as I don't anticipate having much spare time.

 

The XDI ignition doesn't have a TPS input, but I do have a MAP sensor installed. It's been hooked up for years. I don't notice much difference when it is unplugged (I do have a lot of cam overlap, after all), but then again I haven't unplugged it in years. It's worth a revisit.

 

 

 

6 hours ago, bradyzq said:

And, I'm curious about the EMF issue. Did you happen to try to start the car with the water pump off, and then turn the pump on once the engine was running? If so, was the resulting intereference enough to cause issues? That whole issue seems VERY weird since the ECU shouldn't be firing coils until it knows the engine angle (passes missing teeth on the trigger wheel) and gets to the right angle to fire a pair of coils. On average, this would be a minimum of about 40 teeth counted including a valid missing teeth pair. Seems impossible for an electric water pump to generate an accidental waveform that perfect!! Are you sure the coils weren't being fired accidentally WITHOUT the ECU being involved?

 

A waveform is a waveform. If the peak high and peak low is sufficient, then, depending on circuit design, a crude waveform will easily become a clean square wave. (This doesn't mean it sees a consistent frequency.) The integrated OPAMPs within the Hall Effect sensor do help clean up waveforms, but the tech seemed to think the later model likely worked due to the upgraded onboard signal logic. It does some intelligent filtering also.

 

[Electromotive final analysis still to come.]

 

This is a very painful and long story. I missed two race weekends, an engine dyno and my first ProSolo because I refused to "just put the mechanical pump back on." This is still quite abridged.

  1. Car wouldn't start. Autometer gauges didn't pass their startup test with key in IGN position.
  2. Unplugging a spark plug wire and connecting a spark tester (term?) to ground revealed the coils were firing, with crank at rest.
  3. Unplugging water pump immediately stopped the sparking.
  4. No water pump: gauges pass startup tests, car fires right up.
  5. Plugging water pump back in and unplugging mag sensor also stopped the sparking.
  6. Moving the mag sensor around the engine bay resumed sparking if mag sensor was within about 6" of either the pump or the damper (the damper is magnetic, therefore it builds up a field, also).
  7. Placing shielding between the sensor and the pump was effective with mag sensor in hand, but ineffective with mag sensor installed. (I spent a lot of time on shielding attempts, trying to MacGyver my way through the weekend.)
  8. The solid damper (BHJ?) truly exacerbated this field condition. Shielding attempts would delay the onset of when spark would occur. Depending on shielding, sparking would delay 10-90 seconds even. (With the 12A pump running.) I'm not an electrical engineer, but this is definitely indicative of a buildup of inductance, I reckon.
  9. (My theory: shielding is impossible. HAS to be solved by Hall effect / chip logic, etc. Why? The engine block is a big piece of iron electromagnet.... big magnets take more energy / time to build a field. Shielding slows it down but since pump is installed metal on metal to the engine... shielding can't help you.)
  10. Calling Electromotive resulted in "oh yeah, that's why we made the Hall Effect sensor, part no...."
  11. Part arrived. The instructions indicated those with "serial numbers less than..." were to call Electromotive. I called Electromotive. "You have to send us your unit and we can modify it to be compatible with a Hall Effect sensor."
  12. I send my unit to them, they send it back. Mod doesn't work. Mag sensor doesn't work anymore either.
  13. They overnight me a loaner unit. Doesn't work at first, but it was my fault this time - the jumper wasn't fully seated. (the later serial numbers allow Hall effect sensors by installing a jumper. earlier models like mine need to be opened up and hacked.)
  14. Sure is nice when stuff just works and your car just fires right up when it's supposed to!

 

 

5 hours ago, Leon said:

The obvious is often missed. 🙂

 

Glad I can be of some help! If I were closer, I'd attempt to involve myself more. I've done some exploratory dyno sessions like this and always either run out of time, something goes wrong, and/or I question my data because I didn't log engine temps. Doing my best to pass on my experience.

 

Thanks Leon! You've already been of influence.

 

Speaking of engine temps... my engine keeps pretty consistent temps. It's running the 10qt oil pan from DRP and the aluminum radiator from Arizona Z with dual fans. On the road and at events (doesn't idle very long), the water runs at whatever temperature I set the thermostat. Dyno pulls with electric fans only is another story... I seem to recall it needing to cool down in Portland now that you mention it.

 

EDIT - How does one monitor under hood temps? Such as the intake manifold and carburetor bodies. Ideas or experience? Heat gun on a few areas?

Edited by zredbaron
disambiguituation; additional detail
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I also omitted that I had two techs helping me the first day, a general mechanic and an electrician.

 

My lithium battery didn't survive their techniques, despite me highlighting bold warnings from Braille (the battery manufacturer). I was arguing with experts in their back yard, and I've previously been burned by my ignorance / arrogance (having gone down similar roads in the past). This time, I was the expert. I had technology they didn't have an education on, and I was the one that read the manual. They were good guys, genuinely trying to help. Expensive battery, made to order, ships via ground only.

 

Sometimes the story just hurts so damn much you don't want to say it out loud. Especially when you were right but allowed wrong to happen.

 

Always go with your gut. 

Edited by zredbaron
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Gaaaa. Didn't mean to dredge up old (or not so old) wounds.

 

You bring up a good point about batteries. As a chassis dyno tuner for the past 12 years, I can tell you I HATE lightweight race batteries. You can't boost them, they often safely charge at only 2 amps or less, and they're expensive and finicky. Weight savings don't matter on the dyno! For the dyno day, I suggest using a "real" car battery. I know in your case, everything runs, and there will not likely be much cranking away, but still....

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For a quick and dirty measurement, use an IR gun on your oil pan, radiator, cylinder head, and intake. Otherwise, you're looking at plumbing in oil temp and IAT sensors (assuming you already have a decent water temp gauge). You can also get creative and mount some thermocouples to the important bits but you'd want a datalogger to read them.

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5 hours ago, bradyzq said:

Hopefully the dyno will have an air temp probe. I know my Dynapack does.

 

It's the famous orange wire that increases power if you put it under the hood.;) (Dynapack tuner in-joke)

 

Dynapack is king of chassis dynos as far as I'm concerned. A much more precise machine than any roller.

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Thanks guys. I'll try and have an IR gun on hand.

 

I had a chance to road tune the 38mm venturis this weekend. It has better mid-throttle response than it has had in years. 190 main jets, F9 Emulsion tubes, 220 Air Correctors. I can actually floor it under 3000 RPM! (Still have to gradually roll-on the throttle, though.)

 

This week's plan:

  • Monday (tonight)
    • Install 40mm venturis (with Weber long stacks) for dyno testing
    • Road tune 40mm venturis, write down jets, air temp, etc.
    • Get a feel for driveability of 40mm venturis with Weber long stacks (ready for baseline dyno data)
  • Tuesday
    • Order more main jets if 40mm venturis are thirsty (I have up to 205 main jets)
    • Fine-tune the throttle linkage synch for dyno testing
  • Wednesday
    • Road test and confirm the jetting again, if the synch was adjusted.
    • Swap to and road test the Weber short stacks, noting if the same jets can be used.
    • Rehearse velocity stack swaps, organize parts, etc.
  • Thursday
    • Backup day for final road testing
    • Stage trailer, fuel and parts
    • Finalize R&D flowchart
  • Friday, May 18 - Chassis Dyno @ 9am PST

 

I'm allowing myself to feel a little excitement. Trying to allow more.

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Excited for the results on this, will be following along closely. I'll be particularly interested to see heat gain on the gear-train over the course of several pulls. 

 

I did a little testing of my own with the T3 stacks and adding/removing a filter element on back to back runs, and did see a notable pickup. 

 

Good luck on the day!

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Thanks for being so upfront with the information sharing!

It's interesting that the XDi supports hall sensors, as I was under the impression that only the XDi2 and XDi200 did.  I've toyed with upgrading my XDi for just that reason, as the hall seems like a much more solid solution - zero chance of signal interference, and it's very difficult to avoid the spark plug wires, alternator and starter with our engine bay layout.  Do you recall the serial number it was to check to see if you're below?  I'm pretty sure mine will be too old as it's the same design as yours is...  

Have you considered upgrading to the newer XDi200 at all?  It has onboard datalogging with lots of input channels, which would certainly be really useful for backroad carb tuning I would think.  Some of the little extras like shift light control and the 3 programmable rev limiters might be useful as well.  More money though, and the basic functionality is unchanged. 

Hope you get big numbers and lots of useful data on Friday, good luck!!

 

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Thanks Ben! About the T3 stacks - I have both their 47mm and 49mm ID varieties. Do you know the ID of your setup? Since the (Weber) sleeves have an ID of 48mm, the T3 stacks are an exciting wild card to me, because I can also test with / without the inner (Weber) sleeve inserts that will be cut. When I have more time I'll post a table  of the impressive list of combinations I will be able to play with. More than I will have time. Fun!

 

Ryan - it's truly my pleasure to share. About the ignition upgrade - I will be calling their tech today. It's not an option for this week or maybe this summer... but I'd love to incorporate a throttle position sensor. I believe that means a TecS is a good option? Not sure. I owe the tech a call about the loaner unit anyway. Would allow software to map both throttle position (TPS) and manifold pressure (MAP). That'd be awesome to pair with carbs set up for WOT but retains driveability across a 5k+ RPM band.


I think it can be done. Between fancy fuel, fancy ignition and fancy head work... I think one can have their cake and eat it too. But they might have to have fancy intake and exhaust setups! LOL

 

Speaking of exhaust, I still haven't announced some of the other upgrades. The 3" mandrel exhaust now has two straight-through Magnaflow mufflers in series after the merge collector. The first is 14" and 1/2" thick(14x4), the second is 6" long and 3" thick (6x6). The sound is very balanced. The second muffler, since it is a different shape, attenuates a different sound frequency and it just-so-happened to work out the way I hoped: it didn't muffle the tough, but it did nip the high pitch resonance perfectly.

 

I still prefer it raw -- just remove the exhaust after the merge collector. No hood and no air filters, windows down. Just open air horns and a merge collector. That's my favorite sound. One day maybe late this summer I'll take the car to a drag strip without any exhaust attached... one milestone at a time.

 

 

Edited by zredbaron
Clarity about sleeves and stacks
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Also, I road tested the 40mm venturis last night... and they are not yet drivable or able to be dynoed. At first I was discouraged, but then I realized this might mean that they have more power potential than I realize. It must be tuned.

 

With 40mm venturis installed, it was way lean. I was afraid to touch the pedal to get past the "iffy" airflow and into the WOT performance where it was happier (but not happy). In the end, my largest main jets (205) aren't remotely close to being big enough. Choking the Air Corrector down to 145s still wasn't enough for an AFR that didn't make me nervous as all heck.

 

So... in my mind this means one or more of a few things:

  • Loss of aux venturi signal
    • The Weber book notes that jumping from 38mm to 40mm venturi will result in a loss of signal at the aux venturi.
    • I haven't read much carburetor theory about the aux venturi, so I'm not fully sure how this impacts WOT.
    • My impression is the aux venturi serves to assist mixtures at low RPMs and lesser throttle positions.
    • My impression is this is a less desirable drivability issue, but a drag or road race engine would like it just fine!
  • The main jets are just too damn small.
    • More air needs more fuel, duh.
    • More fuel means more power, duh.
    • I would love this to be the fix!
  • Emulsion tube experimentation is in order
    • See aux venturi notes... it's my understanding tubes are for mixing at low RPMs, not WOT.
    • I have 5 other tubes.
  • "Ram" tubes / velocity stacks are now crucial
    • That's the point of Friday, after all... but if I can't safely get on the throttle I have to test at the 38mm level.
    • Cleaning up this increase of air may clean up the signal loss at the aux. venturi.

 

Today I will order more main jets. I'll do more road testing as I'm able. Any experience with 40mm venturis out there?

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Hey gang. I haven't had much time for road testing the 40mm venturis yet (let alone stacks). Still not driveable, so at present, the forecast is testing via 38mm venturis tomorrow unless I pull off a good tune tonight. I have main jets up to 245 now (!) and with 6 sets of emulsion tubes one would think a solid setup is within grasp.

 

Attached is my tentative dyno flow chart:

 

It assumes unlimited time. I don't yet know if I'll be running 38mm venturis or 40mm venturis or both. At some point I will abandon broad data collection and proceed toward focused data collection. The results will navigate this flowchart, and so will the limited timeline. If half of those boxes have data at the end of the day I'd say that's a win. Any advice or thoughts here is always welcome.

 

Ryan - The electromotive hall effect upgrade instructions are attached. The XDI 200 ($895) would meet/exceed my needs for carburetors, but if I'm going to rewire my ignition... I might as well rewire everything under the hood and integrate all of my fan controllers, etc. into one computer: the GT200 ($1,695!), which would also be forward-compatible with sequential fuel injection one day (should ITBs ever occur on the car).

 

1226387013_XDIhack.PNG.be4ebb82b49c13d4598deaa5469949f3.PNG

 

That's an $1,700 upgrade for a TPS at present. For now I'll save my cash and I'm buying the Electromotive loaner XDI unit from them, so I can get out there and race! I may have built a race motor (RIP, RIP...), but I'm a driver first and a builder/owner second. I'm already late to race season as it is!

Edited by zredbaron
Flow chart attachment; current Electromotive pricing
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Larger chokes will tip in the mains later so your mixture is showing lean due to that. Try tipping in at a higher RPM.  You shouldn't have to make an abnormally larger step-up in mains for a 2mm increase in choke size.

 

E-tubes affect both tip-in and the AFR curve when on the mains. The interaction between float level and emulsion tube is critical to both. Run what you got tomorrow and do your best to keep the tests controlled, otherwise it will be impossible to tell the difference between runs. Sounds like you did a pretty good job of preparing. Looking forward to hearing about what you find.

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Well,  I may have a decent handle on tuning Webers… But in general automotive proficiency… I couldn't get the 40 mm to run due to user error. I'm not sure what happened Monday night, but on Wednesday night I had a spark plug wire disconnected and didn't notice it. How embarrassing!   That's what I get  for checking the plugs late at night. 

 

 

 

I have really awesome jet presets for both the 38 mm and 40 mm venturis. 40 mms like the short stacks so far! Better AFR plot, but perhaps less peak horse power.

 

I've got about 2 1/2 hours of daylight for more testing this morning. Every minute I get done in preparation means more day that we get at the end of the day. 

 

More when I got it. Today is looking and feeling like it's going to be a solid day!

 

Video below, while still tuning 40mms last night. 3rd gear. So far it behaves identically to the 36mm venturis in the 40 mm carburetor body, which makes complete sense. Gargly until the cam kicks in... I think the reverb is allowed to travel outside the carb body with wide open venturis. I remember seeing fuel mist in person at the engine dyno. I'll capture it.

 

Cheers.... 🍻

IMG_5108.JPG

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The Weber short stacks made the most power by about 270 whp.

 

I never swapped any parts. Frustrating day. Showed up with a singing car that refused to sing for the first hour, oddly, and ultimately broke on the dyno while tuning the timing for my initial baselines -- excessive vibrations above 35mph. Never even got a good initial baseline!  🙄

 

My new driveshaft was installed by a speed shop and my right rear CV axle was also removed and reinstalled in the offseason. They were found loose after I finally demanded to unstrap my Z, and two bolts on my bigger driveshaft lost their nuts today. So to speak.

 

I'll attach media when I am able.

 

I have my suspicions about the dyno itself, nothing but issues with ignition signal today (due to dyno? very odd day). The car was smooth as silk at the top of 4th on asphault... and on the dyno it not only shook itself apart but the ignition was so inconsistent I don't find tuning to be useful on their equipment and doubt I will return. Very cool shop though... just not for my car evidently? Weird.

 

I'll revisit this sometime this summer -- I still need to digest the day. It simply didn't add up from the beginning. For now, I am going to bed and still not attending my first race of the season tomorrow. I've literally made myself sick today. It was all I could do to get the car in the trailer in and out for the 4th time today as a shop with a lift helped me confirm my vibration issues. For now.

 

At least the motor remains stout and sings beautifully on road tests. 🍻

 

🎻

Edited by zredbaron
general grammar and typos
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Well it sounded great in that video! Sorry to hear but glad you caught the issues before tossing driveline bits all over the road (or track).

 

I highly recommend finding a shop with a Dynapack in your area, you can thank me later. ;)

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