360S in Charleston(ish)

[Austin David]

FYI I manually checked timing, the crank sensor appears to be rotated 275*, where the ME map expected 265.  I also saw reference to 255 in other docs, so ... reminder to double-check what you think are sensible defaults.  

[Austin David]

Some minor catch-up to share my joy.

 

First, the good: I've been pulling a lot of logs and I can see (measured) 0.1s between throttle open and RPM leaping.  Throttle response is VERY fast at idle, where the original plenum had a noticeable lag.  The plenum lag is probably fixable with tune, but not doable on the locked factory ECU.

 

When it works (see below) it does work well.  Throttle response is what it should have been from the start, sound is great, and torque is stronger at very high RPM.  The stock 360 kinda started falling off at 6500-ish, this tune pulls through to 7k.  I have not tested, but there is an ignition cut programmed at 7400.

 

I also got a free* knock sensor, which does seem to work well by default.  Very little actual knock, but I've found a couple events including the one I looked for.

 

Learnings:

0) "sharp tools" are important.  In this case it means a laptop, software for log analysis, experts ready to help (remote tuner), and literal tools for repinning cables, properly making terminals, etc etc.

1) the ECU probably doesn't "matter".  If doing this again, I'd pick my tuner and hardware kit (intakes, fuel management, etc) THEN select an ECU recommended by the tuner.  That said, I am getting good support from overseas, though with a lot of overnight-waiting.

2) science is important.  This would be easier if I knew what the "baseline" 360S acted like: fuel pressure, AFR at RPM range, etc.  The "factory tune" might not be perfect, but with all this new control and measurement I am tempted to make the new tune perfect.  Hard to tell how "perfect" it needs to be, to be better than the factory tune

3) there are a lot of variables, and some things that can only be done once (like cutting a hood) and some things that can be re-done without too much cost, like making a custom harness or cutting an air filter backplate.  This would have been easier, and maybe 5% more expensive, if I'd planned some of these ahead.  

 

Some annoyance, which led to delays but probably not show-stoppers:

- alternator electrical noise... and while troubleshooting, seem to have led the ECU to dwelling on plug 2 which fried the driver.  Couple days of troubleshooting + offline exchange, but will be getting a new ECU (see above, excellent support from ME)

- maybe ignition noise, TBD.  infrequent "lost sync" events at ~ 4k RPM.  More data required

- to work around the fried driver, may (temporarily) run a traditional coilpack + wasted spark setup.  I assume I'll eventually go back to COP

- assuming the alternator noise persists, I'll go with a 1-wire "Denso" style option.  Appears to be a 90mm / "mini race" alternator, they run $150(ish) for 55A or ~75A.

[Austin David]

Some investigation about the size of the bonnet cut, which led to some investigation about heat and airflow

 

tl;dr:

• the intake hole may let hot air out of the engine bay, which will increase IAT 15-25C above ambient. 
• the air filter is sized for 300+ HP, and can be blocked off to prevent heat intrusion, without significant impact to intake performance.
• the actual bonnet penetration can be fairly small, provided excess heat from the cooling system has somewhere to go

Some offline investigation into runner length.  This ITB kit offers 70mm, 100mm, and 130mm intake runners, I currently have 100mm.  The manufacturer (or their associated engineering company) won't offer CAD, but do offer 30mm machined extension "tuning rings", with 50mm ID and M59 x 1.5 threads.  The process appears to be something like "add 30mm, see if that's what you want, repeat as necessary", then get custom runners and/or screw-on trumpets to match the required length.   Literature is thin; I THINK the math is linear with distance to the valve top, but the path is not straight and the tube is not a cylinder so changes may not be PERFECTLY linear, but I expect it to be close.  Experimentation underway with printed rings.

 

Peak VE is about 120% at 6500 RPM, with soft cut around 7400.  Shorter = peak at higher RPM, longer = peak at lower RPM.  The literal "tuning" here is setting the length from valve -> trumpet such that a standing wave bounces closed valve -> trumpet -> open valve, and forces its way in... hence the > 100% efficiency in a specific range.

 

Butt Dyno indicates very linear performance to soft cut, but I'd like to see if I can shift the curve down a little.  The attached model fits snug without trashing threads on my intake runner, and 20mm fits inside the air filter so I can run with the bonnet in place.  I also added +15mm outside the filter, which is about the minimum extension because of the thread pattern, and happens to just barely fit under my bonnet. 

tuning ring 15mm.stl

[Austin David]

Analyzing some data, the trumpet lengths appear to make a difference but it's subtle, and really only relevant at WOT.  I assume this would be a lot more effective when paired with cam changes, which I'm avoiding.

 

White = RPM

Yellow = "airflow est" from the ECU

Red, Green are AFR & AFR err.

 

Hypothesis is that length changes would shift the shape of the airflow graph.  I've reviewed about a half-dozen pulls from each and these are representative.

 

normal 100mm extension:

 

+20mm inside the filter:

 

+35mm total, with 15mm outside + 20mm inside the air filter:

 

note that the extensions are cylinders so I expect they would have a small net dampening of total airflow at WOT, so the before/after aren't perfect comparisons, but I do expect the 20 vs 35mm measures to be really good internal comparisons.

 

net/net: I think the graphs DO show a subtle lowering of the airflow / torque curve.  Butt dyno confirms, but the effect is SUBTLE.  Mostly at WOT I can feel it tapering off around 7k RPM, where the standard pulls smooth to the soft cut.  In midrange it still feels great both ways.  The airflow is also 35mm further out from the bonnet and the bonnet-hole would need to get a lot bigger.

[sltous]

I had some fun with the extreme version of your tape experiments if you want to take a look at the RAM air scoop data I had

 

 

[Austin David]

On 10/27/2024 at 3:38 PM, sltous said:

I had some fun with the extreme version of your tape experiments if you want to take a look at the RAM air scoop data I had

 

 

 

 

Great writeup, thanks!  There's definitely a lot more auditory feedback with so little between the intake valves.

[Austin David]

ITB update: heat soak in the injectors.  Symptom is a rising AFR (lean) at idle or after resting when hot.  Does not correspond to IAT, and drops with a few minutes running.  These are different injectors + fuel rail, positioned in the TBs, further out from the stock locations.  Heat is most likely conducting through the ITBs and into the injectors, and they're warming enough that they open slower than expected... less fuel -> higher AFR, enough that the ECU cannot compensate (it's limited to 20% correction).  When the throttle picks up and more fuel flows, the injectors cool off and the effect goes away (but returns with a few minutes idling at temp).

 

This appears to be due to the "dead head" fuel rail, which doesn't move any fuel (or soaked heat) at low duty.  I assume the stock rail also has this problem, and is somehow managed by the stock ECU.

 

The simplest solution is to bump VE around idle, which gives the ECU a little more room to compensate for the changing flow rate when hot or cold.  +20% VE and -20% startup tuning leaves the cold starts still correct, and the ECU then has plenty of room to trim out any changes with injector behavior.

 

A conventional return-style fuel rail would mostly hide this problem, as the fuel gets a chance to cool off on the way to/from the tank.  I'll put this near the bottom of my list for next time I get bored, below "rewire the whole engine".

[Austin David]

some catching up: the ITBs work really well with the stock deadhead fueling, using a 3D table to manage pressure feedback, and another 2D table to trim out injector timing.  BUT at certain high-consumption periods I can see what looks like pulsing indicated from the pressure sensor.  Between this and the heat soak, I've decided to re-plumb the fuel lines and install a proper regulator and return system.  This is still work-in-progress, but I'm recording what works well and what I had to figure out the hard way.

 

The stock fuel line is terminated with 5/16 ford quick connects; the fuel tank side is a male fitting.  To remove it you press in on the tank side to release the clips, and just pull the line straight out.  I had to 3D print a tool to help facilitate this, think of a 5/16 washer with a section removed.  Pliers would probably also work.

 

The fuel tank is sealed with a sort-of standard ford part; the magic search seems to be "fuel pump seal".  The black ring is screwed on; I wasn't able to loosen it by hand, and hammer + screwdriver (or hammer + several gentler implements) didn't shake it loose either.  In retrospect I bet penetrating oil would help.  Fortunately the part seems to run about $10 online and $20 locally.  The hanger itself (the plastic housing)  is standard Ford, there's a seal under it.  I'll update when I figure out a car that used this same part.  Note that the pump-hanger is clocked, mine was also marked with sharpie on the hanger and an etched arrow > on the tank.  The hanger module is not vertical, and I assume rotating it would change where the fuel level reader rests.  Note to future self: tinker with that arrangement.

 

Accessing the tank is unsurprising, but removing the big honeycomb panel is annoying.   I elected to cut mine in half, and I'm glad I did.  While I had it out I removed the washer line, I never installed my washer bottle/pump.  About 60 zip ties held it in.  The electrical for that was run separately and seems bundled with other wiring, it might have to stay or get hidden somewhere else.

 

I will be using AN6 hose and fittings all around.  The new pressurized line from the pump uses an AN6 to 5/16 (male) fitting, which I've test-fit.  A 45* or 90* bend will get it aimed about the right way, TBD.  For the return I've elected to mount a bulkhead fitting through the top of the tank, near the back of the car where it has a lot of clearance.  The top of the new pressurized size looks like it will ride a little higher than the "factory" fuel line, so I assume I'll have to shim and lift the driver-side panel a little to make room.  The bulkhead fitting is a little more shallow than my hanger so it will definitely clear.

 

Plenty of room for a small inline fuel filter, near the tank, and probably just under the wooden panel for easy access.

 

On the engine side: my chosen fuel pressure regulator is a tiny Radium model, with a 3-bar Bosch preset regulator.  ITB = no vaccum, I've sealed the vac port.  My ECU doesn't want pressure changing anyway.  The regulator will also house a pressure gauge, which means I'll need to "clock" the regulator to the right angle.  A 6AN ORB / 6AN female swivel fitting on the regulator side, then an M12 / 6AN (male, provided with ITBs) on the fuel rail.  This will LIKELY go on the aft / #4 end, and I'll run pressure up to the front / #1 cylinder.  The second regulated port gets plugged, the return is on the bottom.

 

Plumbing will be: pump ->line -> filter -> line -> fuel rail, then rail -> regulator -> return line -> tank.

 

The two lines will follow the same path through the tunnel.  The old line was zip-tied in about a dozen places along the way, including 3-4 that aren't accessible unless you drill out the riveted panel at back of the tunnel near the diff.  Electrical and brake runs along the right side, fuel seems solo on left.  There are a few more zip ties up front under the battery, hopefully I can reach them from the cabin and won't have to remove the battery, heater, and that riveted panel.

 

I'll post final pics and any other gems if I figure them out along the way.

[JohnCh]

6 hours ago, Austin David said:

The fuel tank is sealed with a sort-of standard ford part; the magic search seems to be "fuel pump seal".  The black ring is screwed on; I wasn't able to loosen it by hand, and hammer + screwdriver (or hammer + several gentler implements) didn't shake it loose either.  In retrospect I bet penetrating oil would help

 

They sell tools specifically designed to remove the black ring. I use this one, but there are likely cheaper alternatives.  Works great. No penetrating oil needed.  https://www.amazon.com/dp/B0079GPYA4?

[11Budlite]

I bought a tool similar to John's suggestion. It works fine too: https://www.amazon.com/dp/B004FDL3BS?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_6&th=1

[mrmustang]

19 minutes ago, 11Budlite said:

I bought a tool similar to John's suggestion. It works fine too: https://www.amazon.com/dp/B004FDL3BS?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_6&th=1

I have a similar tool that I've used over the last 20 years on numerous vehicles. Can't beat the right tool for the right job. I have a cabinet draw filled with them. Some used once, some used multiple times, all saving me a headache.

 

Bill

[Austin David]

light update, I've got pressure and will be buttoning it all back up slowly.  no surprises, but I'll leave some notes about what I ended up with:

- AN6 hose in both directions.  16' wasn't enough for me to feel comfortable, maybe a single 20' would do it.

- The plastic Ford hanger does have a sealed port for the return, but on the underside it appears to just dump mostly down.  I opted NOT to use this, for some concerns about aeration.  I have no idea if those concerns are valid.

- the Ford assembly is "interesting".  It's angled, but I'm not sure if it sits directly on the bottom of the tank.  The very bottom of the tank feels more angled than the hanger, which means it probably strands a lot of fuel at level (like ~ 1 gal).  No attempt to measure.   @JohnCh has a much better diagram showing the problem.  The fuel pump and what I assume is a sort of in-place filter are inside a significant plastic housing.  That housing is actually a sort of swirl container, and I don't think there are any baffles in the rest of the tank (maybe 1, I didn't look very far).  That housing has a small one-way valve at bottom, and it holds a fair amount of fuel.  So when you're repeatedly taking it out and putting it back, you'll develop a sort of motion to tip it sideways enough to get the float out, then pour the contents back into the tank without sloshing too much on the garage floor.

- there are a few bad choices for mounting the return line.  I elected to plumb an an6 bulkhead near the outlet, with the logic that if I wreck it I'm getting a new hanger anyway.  I did not drill a hole in the tank itself, but in some ways that would have been easier.

- Even with a low-profile 90* to the bulkhead, I'll probably lose about 1cm of floor clearance in my boot.  I do not consider this a significant problem, but it's something to sort out.

- running the two fat AN6 lines through the tunnel was about the easiest part of the job; I assumed it would be harder.  

- under the hood my setup was approximately what I expected.  In the boot / at the tank took some fiddling, and I ended up trying I think 4 different arrangements for the final return hookup.  Each of those comes with several days of waiting on delivery, hence all the delay.  The final insult was submersible return line, which is absurdly costly to source locally.

 

So far it seems fine, I was able to pressurize the system on the first try.  I'll post some pics of the fuel pump housing, it's interesting.  

Edited yesterday at 02:57 AM by Austin David

[Austin David]

One last shot about fuel lines, showing the return placement and my lines.  The blue fuel filter is maybe obvious; I hung a few more nylon brackets under that crossbar to hold the two lines and float that fuel filter.   The lines are run well away from the pointy ends of the screws for the wood panel, and the metal deck screws are now embedded in the plastic risers, and the risers are held down with machine screws up from the bottom.

 

They have a good foot of slack before going unto the tunnel, grommeted to pass through the frame over the diff.  The two lines are tied together (plastic fittings I made -- @JohnCh are we competing on how much of the car is 3d printed) and zip-tied along the driver side of the tunnel.  THe only "gotcha" here is the full width of the tunnel is required around the handbrake, between fingers and a few layers of leather.  I have juuuust enough room for the AN6 lines to tuck together up against the tunnel, and under the top of the frame member.  No real problems getting around the shifter turret or past the wiring harness and into the engine bay.

 

NB: this is MOSTLY the final layout.  The blue tape was to hold the FPDM still while I did some test runs to be sure everything was snugged up.  As of now the module is back up under the deck in the original mounts, carpet and everything is right back as before, with a little less clearance on the left side with the deck raised up 2-3cm to clear the return elbow.

 

I'll post some "final" shots of the fuel rail eventually, but for now: feed line runs along the rail and up front, away from the coolant hose and along the tops of the 4 intake trumpets.  There's a swivel apter at the back #4 side of the rail with my regulator and gauge, which barely clears the valve cover.  The return hose comes out the bottom of the regulator, then back down into the tunnel.

Edited yesterday at 03:09 AM by Austin David