Yup. Something we learned in the T25 days was that is was far more efficient to stay WOT and just keep shifting just past the torque peak. Thats where BMEP and BSFC will be highest, more or less. Lower pumping losses. using high revs and "feathering the throttle" sucks fuel. Thus the plan to run it at low revs.
My guess is we'll be shifting somewhere between 5200-6200 most of the time.

Josh,
I recall the same reg on fuel cells in LDR. There is an upper limit IOW.

Goal for now is to just get it running on the stock tank, learn how to tune it. Get the team used to the car, see if its competitive or not. If not, we reassess and see what steps we need to take to make it competitive.

 

Following with interest

 

Camshafts & Gears | Heads | 4 Piston Racing

 

Those are designed for the A2, not Z3. Z3 has a wildly different head setup.

 

Ah, interesting. Good to know.

 

Just learned about this. I think we'll add this to the build. So many benefits from having this data on the pit wall.

https://www.autosportlabs.com/produc...ems-to-podium/

 

This is gonna be a fun combination! It’s pretty much the ideal drivetrain. I’d take a lower powered engine with Quaife sequential over a high powered manual anyday. It’s just matches the fluidity of the Miata better.

Glad to hear Vegas is getting repurposed. That shell is well prepped (stripped, seam welded, FIA cage etc) Great strategy to maximize fuel consumption. Does the ECU/VTEC have enough control to run Atkinson cycle during maintenance throttle? That would really help stretch the tank during cautions etc.

Once again many of us get to live vicariously through you.

 

Dunno on mapping. From our experience with N/A BP's, we know we can get away with really lean mixtures at part throttle/light load. The K is so much more resistant to det.

I think the combo of DBW and the sequential will make it supremely easy to drive and place on the track. We have an EPS unit here but I don't think it'll fit without some significant cage revisions. So we'll just dial the caster down.

 

Have you considered an electro-hydraulic pump like an MR2 or Mercedes unit?

 

Nope. Not interested in embarking on a new R&D project. Just doing our right side exhaust and the flywheel are keeping us busy.

 

Finally getting to this stage. Project was on hold for a while. Dropping long block & Quaife in so Renderos Racing can fab the exhaust and mounts. We're deleting the PPF and routing exhaust down pax side. Spoke with the guys at Haltech and settled on the 2500 series ECU. At least one US tuner has mated a Haltech and a Z3 so we'll have a starting point for a base map.

 

Huh, not sure how I missed this build, but very relevant to my interests.

I found their data capture software and UI to be ... *****. I guess the hardware was fairly OK, but I found the software incredibly frustrating to use. I tried it on iPhone, an Android tablet, and my Mac. They use a UI abstraction layer instead of writing code for each platform and it seems to end up on screens or in dialog boxes where it doesn't know how to behave. I would approach with caution. I'm done with my RaceCapture device, I'll send it to you if you'd like.

This is good to know. They explicitly state on their website that they support the Z3. I haven't been able to establish the same for MegaSquirt. So far I've found "yeah, it should work", but not "I'm running it and it works great".

Without spoiling any secret sauce, what do you see as the strongest motivation to go DBW? I haven't decided on a throttle for my build yet, but may go the same route because someone smarter than me has already done the thinking.

 

Something to consider on the DBW setup for ~180rwhp. The WF guys ran into issues where the throttle blade will be open at say 35% to hit the target power for that RPM, the vacuum within the manifold can actually pull the blade closer down to say 25%. Their quick fix was to short-shift as it only seemed to happen at high RPM. So in this build's case, it probably won't be a problem. But hey, might save some time later if it does happen?

They talked about it on this Slip Angle podcast: https://www.stitcher.com/podcast/slipangle/e/75408329

 

That's good info. They're running K24A2's though right? A little harder to choke those ones down. I've got the Bosch electronic throttle body here that Kmiata offers...

 

Double Post, thanks IB.

 

They have at least two cars running A2s (Leichty and Manocherhri) and at least one car running a Z3 (Tabb).

 

DBW for both power management and to complement two pedal driving with the Quaife sequential. We don't currently have plans for flappy paddles, just going to use the load cell built into the shift lever.

 

4 Piston Racing has pre-orders going for their CNC heads for the Z3...

 

Any reason for the 2500 over the 1500? As far as I am aware the only differences are 4 extra ignition and injector outputs, along with an additional knock input. Those seem like they are not needed on a K-swap.

I have been happy with my 1500 so far. Definitely has some quirks and there are some things I think the MS does better.

 

Nope. But now we're investigating the new Nexus R5 which has integrated power management and full data logging. The data logging would be redundant as we'll use the Aim MXG for that. But the power management would allow us to delete the Racepak Smartwire. We're having to build pretty much an entirley new harness for the K24 anyway so de-pinning the Smartwire for the Nexus swap isn't too much extra work. John's looking at the available I/O differences to see if we'll be able to run everything I'd like to run.
We don't yet know if the Nexus can com with the MXG through a single CAN. Hope so.

From memory so I'm probably missing something

Power management
engine main power
fuel pump
diff oil pump
trans oil pump
fans for both diff & trans coolers
radiator fan
radio
driver suit refrigeration system
headlights, LED, FTP (flash to pass)
tablet for driver info on center console
wipers, 2 speed
heater blower
under hood light
interior light
inside trunk light
running lights
brake lights, triggered of pressure switch
Possible EPAS if we can figure out a way for the GM motor to fit under the dash bar
Gear position sensor
Telemetry transmitter

ECU functions /logging
Bosch temp/pressure combined sensor for engine oil
Bosch temp/pressure combined sensor for engine coolant
brake line pressure, single
3 axis accelerometer
GPS speed
wheel speed from LR ABS tone ring
Diff temp
Trans temp
Gear position
Sequential ignition
Sequential injector
Cam angle sensor
Crank angle sensor
Knock sensor