Ian's 99 build thread
#982
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Down the front straight in 5th though, the speeds are high enough that aero is a big factor. The hard top is good for 5-10 mph in top speed, and even with that the Miata is still a fairly high-drag car.
--Ian
#983
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RE Fuel starvation.
Spent some time getting intimate with the Miata gas tank. There is a bucket that the fuel pump sits in. Should hold fuel in cornering, when the level is below it.
I'm wondering if your return system is returning the fuel up high, which is allowing it to fall out of the bucket in high G corners. Where cars that came with a return system are dropping it back in the bucket.
So its not an aeration issue, it could be the fuel is going to the wrong place. So a 90* fitting might make it worse. I would suggest returning the fuel right next to the stock, and allowing it to stay in the bucket.
Its also possible that you are just using so much fuel that you are emptying the bucket before it is able to be filled again.
Spent some time getting intimate with the Miata gas tank. There is a bucket that the fuel pump sits in. Should hold fuel in cornering, when the level is below it.
I'm wondering if your return system is returning the fuel up high, which is allowing it to fall out of the bucket in high G corners. Where cars that came with a return system are dropping it back in the bucket.
So its not an aeration issue, it could be the fuel is going to the wrong place. So a 90* fitting might make it worse. I would suggest returning the fuel right next to the stock, and allowing it to stay in the bucket.
Its also possible that you are just using so much fuel that you are emptying the bucket before it is able to be filled again.
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So whats interesting is that the fuel gauge will read zero before the fuel is below the top of the bucket. So it usually fills up just by being below the fuel level.
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#995
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I think the "not returning to bucket" idea makes sense. Here's a datalog of turn 5 in a case where it didn't starve:
![](http://www.codrus.com/miata/fm2r/turn-5-starve.png)
Red is the computed fuel pressure error, green is TPS, blue is lateral accel. The corner starts about halfway along the graph (19.98 km), where the blue line dips down below the center (centered on 0). The green line comes up (cornering throttle), then at 20.072km the FP error dips into the negative range. At 20.12 km I get back to WOT and FP error drops HARD, down to -15 kpa. By 20.17 km it has fixed itself, and is hovering right around zero again.
Here's a datalog from the same corner on the next session with a full tank, no dip.
![](http://www.codrus.com/miata/fm2r/turn-5-good2.png)
So it makes sense to me that when the car is loaded up, the stream of fuel from return that's dumping halfway down the bracket is getting bent by the gee force and is missing the bucket. That would mean that the fuel pump is busy emptying the bucket while in the corner, then has no fuel available when I'm coming out of the corner and getting on the throttle.
I bought one of these fittings that G pointed to, with the intention of running a hose down to the bottom next to the sock.:
![](http://www.codrus.com/miata/fm2r/fuel-fitting.jpg)
--Ian
![](http://www.codrus.com/miata/fm2r/turn-5-starve.png)
Red is the computed fuel pressure error, green is TPS, blue is lateral accel. The corner starts about halfway along the graph (19.98 km), where the blue line dips down below the center (centered on 0). The green line comes up (cornering throttle), then at 20.072km the FP error dips into the negative range. At 20.12 km I get back to WOT and FP error drops HARD, down to -15 kpa. By 20.17 km it has fixed itself, and is hovering right around zero again.
Here's a datalog from the same corner on the next session with a full tank, no dip.
![](http://www.codrus.com/miata/fm2r/turn-5-good2.png)
So it makes sense to me that when the car is loaded up, the stream of fuel from return that's dumping halfway down the bracket is getting bent by the gee force and is missing the bucket. That would mean that the fuel pump is busy emptying the bucket while in the corner, then has no fuel available when I'm coming out of the corner and getting on the throttle.
I bought one of these fittings that G pointed to, with the intention of running a hose down to the bottom next to the sock.:
![](http://www.codrus.com/miata/fm2r/fuel-fitting.jpg)
--Ian
#996
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EDIT: If you want me to, I will flare a 6" piece is stainless tube and send it to you. You can se what I did at post #119 of my build thread.
Last edited by DNMakinson; 06-04-2017 at 10:29 AM.
#997
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I was thinking of just shoving a piece of hose on there. Let me try that and see if it solves the problem before going with hard parts.
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thanks,
--Ian
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This weekend we added a new feature to the DashKitten (the Arduino-driven LCD dash): It now transmits its analog inputs back to the MegaSquirt.
We now need to find 6 more channels of data to log. We're considering: Oil pressure, fuel tank pressure, injector current, injector temperature, EGT, brake pressure.... Oops, we're out of inputs again.
Source code and instructions are here for anyone else who wants to try it: https://github.com/keepiru/dash-kitten
We now need to find 6 more channels of data to log. We're considering: Oil pressure, fuel tank pressure, injector current, injector temperature, EGT, brake pressure.... Oops, we're out of inputs again.
Source code and instructions are here for anyone else who wants to try it: https://github.com/keepiru/dash-kitten
Hi, turbokitten
Thanks for your sharing.
I want to make a dashboard for microsquirtmodule. I wanted to use your code for learn but not working for me.
I have a nextion 2.8 and use mcp2515 module , arduino UNO
Wiring the MCP2515 Controller Area Network CAN BUS Diagnostics 14Core.com
I connected :
- Nextion : Black - GND, Red - 5v, Yellow - Digital pin 4, Blue - Digital pin 5. Bauds 115200.
- MCP2515 module 8Mhz: int - Digital pin 2, Cs - Digital pin 9, Si - Digital pin 11, So - Digital pin 12, SCK - Digital pin 13, GND - GND, Vcc-5v
- Microsquit Module: CANH - pin 10, CANL - pin 12
http://www.msextra.com/doc/pdf/Micro..._Guide-3.3.pdf
In Tunerstudiio: CAN Menu is not the same for MS3 and microsquirt (i can not t setting frequency by group 0,1,2,3 there is only one choise), i have tested, Enable CAN realtime data broadcasting with ID 1520 And rate 50Hz. Do not works. Then i have tested Dash broadcasting in automatic, do not work again.
Can you help me for just display a sample (rpm by example).
#999
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Swapped out the shocks on the truck for some Bilstein HDs today. Dunno what the old ones were -- they came with the truck and might have been 150K originals. The Bilsteins are a huge win.
![](http://www.codrus.com/cars/truck/truck-bilstein1.jpg)
![](http://www.codrus.com/cars/truck/truck-bilstein2.jpg)
$272 shipped from Tire Rack. Highly recommended if you've got a big tow vehicle.![](https://www.miataturbo.net/images/smilies/smile.gif)
--Ian
![](http://www.codrus.com/cars/truck/truck-bilstein1.jpg)
![](http://www.codrus.com/cars/truck/truck-bilstein2.jpg)
$272 shipped from Tire Rack. Highly recommended if you've got a big tow vehicle.
![](https://www.miataturbo.net/images/smilies/smile.gif)
--Ian