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Well if you could educate me some; how is it that those PIDs exist in the ABS module, but are not on the CAN stream.
I’ll also rebuke myself some, because over the years we’ve had a lot of people come on the forum talking about the things you’re doing, but apparently lacked your ability to get there. Clearly I misjudged you on this, like where this is going, and am looking forward to your future posts.
Well if you could educate me some; how is it that those PIDs exist in the ABS module, but are not on the CAN stream.
I’ll also rebuke myself some, because over the years we’ve had a lot of people come on the forum talking about the things you’re doing, but apparently lacked your ability to get there. Clearly I misjudged you on this, like where this is going, and am looking forward to your future posts.
So the ABS module is on the CAN bus, but doesn’t seem to want to respond to diagnostic addresses like one really would. I tried. I have no idea why they chose to do that.
Looking closer at the wiring diagrams we can see a single line diagnostic wire going to the OBD port. Usually in older vehicles, which I guess nowadays this RX8 is, they used a K line ISO9141 which is a single wire serial protocol. It runs at 10.4k baud as opposed to a 500k or 250k CANbus. In 04 there was a lot of transferring over to CAN for communications in vehicle, but some systems still kept the old methods depending on whatever was on the market. While at first I wasn’t complete sure this was what that line was, I was pretty sure because I get paid to do this kind of thing these days.
Luckily I knew this ABS module was a similar, if not the same, module used on some Ford cars of the same era so using a generic autozone OBD reader I was able to confirm the line was an ISO9141 line by querying the ABS module as a 2000 or so Ford Focus.
So yeah. Basically tl;dr it’s a different data bus than CAN because that ABS module was cheap cheap cheap at the time.
More DAQ stuff. Ported all my code over to a new controller which runs at 600MHz as opposed to 24Mhz... not a bad improvement.. though we likely won't actually need all the horsepower since we are limited by the bus speed.. but I am hoping to integrate some CAN logging into this device as well.
Anyways, tonight I worked on refining some code for easy send/receive and also converted data packets into actual engineering units. I'm not sure my scalars are correct...but I think the G sensor is. MC was something I think I saw based on a service tool.. so it may be incorrect.
Some videos of the data collected with a bunch of debug stuff still enabled.. sorry for the Lat G stuff.. it's pretty hard to get the value to move off 0 just by wiggling around as you can imagine. Looks like I got it up to .03G! Yay Recaros and their holding ability... more on that in a moment.
Next steps are to see if I can do multiple PID requests at once, and to see if I can poll data instead of having to request the PID everytime. This will make my software life easier... as well as cut down bus traffic by over half and allow for faster data refresh!
So tl;dr aftermarket seats suck to fit into an RX-8 if you're not willing to custom make your own brackets.
I tried to fit a Cobra Suzuka seat into the car using a Sparco mount. I kind of wanted to use a fixed mount.. but I'm not a tall dude so this deemed to be not quite possible. When I put the Cobra on the sparco rail it BARELY cleared the "B pillar" and was hitting the door quite a bit. When I put the Sparco rails on, it didn't even try to work. 0/10 would not reccomend sparco rails by the way.. were binding up brand new out of the box.
Anyways, this led to to try to find a new rail that was smaller and that I could fit the seat on. I decided to get a Recaro mount with integrated rail.. this was because I knew it was short enough to fit the seat, and I knew it could adjust it so my little legs could reach the clutch. Along with this I bought the offset Recaro rails. This also gave me the option that in the event the Cobra just wouldn't work (title of the post kind of spoils this surprise), I could enact Plan E... or F... or whatever and just buy the Recaro I was trying to not spend the money on initially.
The Cobra almost fit on the rails.. but it was JUST too wide and didn't quite fit.
So then I just bought the RS-GK from Evasive and didn't look back... and let me tell you I am 100000000% glad I went this route. EVERYTHING bolts right on up.. it's got harness eye holes in the bracket I can use.. and the seating position is just 100% perfect for me in the RX-8. You can even see just the size difference in the seat itself. Inches are miles when it comes to seat fitment. The weight of the seat is also waaay less than the Corba (I didn't weigh them).
I tested helmet clearance and boy.. I don't know how you taller people fit in these cars. I had about an inch and a half on the left to the A pillar and maybe 2-2.5 inches to the headliner. I am 5' 6 on a good day.. man...
Anyways.. I am in love with the seat and just need to get some harnesses on order.
the advantage of an aluminum seat though is they can be bent in a bit, which for most people they’re a bit wider than necessary and then that also can make for a better fit. Making custom mounts by using the OE seat slider and adding tabs helped in my case too.
Little more digging on the sensors today... spent way too much time to have a seemingly MEH level of improvement.. but I promise it was time well spent.
Got the driver running at a 40ms update rate (can't do any faster.. think I am hitting bus limitations.. 10.4k bus at half duplex without a "talk until interrupted" is trash). But both data figured being queried at the same time.. all with somewhat proper tasking and parsing.
What slider and bracket did you use? I'm 6'1" but mostly legs and using the same half cage. Trying to figure out seating right now and worried about headroom and width. I pulled my sunroof and headliner out though so i have a bit more room. Stock seat is fine height wise right now.
What slider and bracket did you use? I'm 6'1" but mostly legs and using the same half cage. Trying to figure out seating right now and worried about headroom and width. I pulled my sunroof and headliner out though so i have a bit more room. Stock seat is fine height wise right now.
The Recaro ones.
I think taller people gain clearance because they won't be as close to the wheel, as thus their head won't b as close to the A pillar/roof. Here's to hoping for you at least!
not necessarily due to various factors, but I’m not overly tall and in order to be up close to where I prefer the steering wheel position to be relative to my upper body had my knees all jammed up in the dash. Then the roof and A pillar are crowding in too. So extending the column/wheel position further back which then allows the driver position to be back more is going to help imo.
Thanks to you both. Thoughts on the Buddy Club mounts with slider? I had originally planned on using the Planted mount with a slider and side mounts but i like the idea of just buying one unit even though the side mount on the buddy club aren't as rigid looking as a separate side mount. I just worry about height and simply fitting a seat in. I come from the BMW world where there's usually plenty of space and also people have tried everything given how many of those cars are on the track. I have access to a few different seats to test, just no floor mounting plates yet.
Should I just get the Planted mounts and some nice side mounts like the Recaros with a slider?
I'm not going to run a passenger seat at all, i don't think.
Oh and sorry for hijacking your thread, i'm following it closely.
Man I've been busy with work and tuning my Impreza, the RX-8 hasn't gotten much attention.. let alone been to the race track -_-
Either way, I do have some updates on the integrated gauge screen that are fun to mention:
Got the sensor over CAN stuff all done up and an old sandwich plate and Defi sensors I had laying around for a Subaru (yay same thread sizes) popped on the sensors and ran the wiring in car to my unit to read sensors and populate them on the bus. Don't worry, I tidied up the wiring. The controller for the sensors was STUFFED full running a full RTOS and I think peaked out at 98% RAM usage... not a bad result from a $4 controller though!
The result is pretty good! I need to change the software to look at an external reference voltage for the ADCs instead of living in dream world where everything is 5V, but aside from that I'm super happy.
Definitely think it needs some calibration, like I mentioned I just have the ADC Vref set to 5, when in reality it's probably closer to like 4.6-4.8 which is definitely enough to throw off readings on the low side. Doesn't look like it's far off though. 4.8 bar or so at "high" RPM seem okay, and 1.8 idle may be a little low, but sounds about right. I'd like to see idle around 2-2.2 bar but I have no idea what these engines like to see.
Holy hell I just put in way too much work to have this little to show, but the precedence for the work ahead makes me happy.
tl;dr working a vehicle data logger, finally got the lat G sensor being queried and written to a .csv file on an SD card for easy data review.
Code snippet:
Me just shaking the car while doing a quick log.
Refresh rate will be improved, I have artificial delays in just for development sanity that I can get rid of.
Next on the list:
-add second ISO9141 PID (MC pressure)
-add a rolling filename, easy just didn't enable it in order to clog up the SD card for development
-roll in the CAN data, just need to add some more hardware
So, these seemed like the goto endlinks for low RX-8s.. was a bit disappointment to see they shipped from Thailand, but it's better than China and they seemed pretty decent for install when I get em. The website did say I would receive a rotor plush toy with my order, which unfortunately I did not! Big sad, how am I even supposed to install these now!?
Anyways, install was super pleasent after I spend 2 hours trying to get the destroyed factory endlinks off the rear. One was blown completely out (read: I had no rear swaybar), and obviously the were rusted to hell so I have to get creative to get the bolt off. I've come to accept the fact that literally every I haven't touched yet on this car will be a huge pain in the *** to deal with. Luckily, spare Subaru bolts came to the rescue again on the new endlinks.
Much nicer with these than the stock ones. No endlink preload at all.
I did tighten fully with the car on the ground, but that doesn't make for better pictures.
Not going to dedicate an "official" post to this, but it just shows how literally EVERYTHING I haven't touched is a problem. The PO couldn't even put the battery box on with all the bolts. Just couldn't be bothered :| So I threw some new hardware in there so that the battery would be properly, and SAFELY held in. I do have a optima coming in shortly because this battery doesn't really even fit.. and I've had a non AGM battery leak before me on the track. Just don't want to deal with that...
Also finally decided I should drill holes for the MS skirts to get mounted like OEM.. boy is it much nicer fitment and less of a worry they will take off at speed.
evo rear links are ok, but the front ones not so much, mostly because the loading is so much higher in the front
think I have the front pair minus one joint end if you want them for spare parts.
you need to be sure to put anti-seize on every thread of every bolt on this car to avoid those kind of removal problems. I’m sure it was already salt corroded beyond hope before you bought the car though. For the high heat/exhaust stuff though you need a nickle type anti-seize though because the std stuff won’t cut it. I just put that on everything now.
So this actually took a bit of time to get all the parts (and motivation, work takes up most of my time) to get this in. But hey, found a deal on a set of FIA2020 Schroth harnesses. I intend to throw the otherside in with another fixed back seat.. but that's for another day.
Mounted the shoulders on the harness bar. No issues there.
For the right side mount, the Recaro bracket has a nice convenient loop for the harness to pop on to and is nicely welded to the frame of the sliders. For the left side, I was able to track down some M10x1.25 eyebolts to pop into the OEM mount bolt hole. Had to shop them from Japan and they weren't super cheap.. but it made my life WAY easier, so I bought some extras in case I ever need em.
For the bottom holes I kind of had some issues, and my solution probably is not one I would recommend to a friend. So the issue was that I am pretty short, so the seat is pretty far up. This put the ideal 10-20 degree mounting location right on top of the frame bar under the seat. Not really exactly easy to mount anything too without really starting to chop. I figured I'd settle for some more angle and just write my groin off if I ever really binned it big time so I mounted the eyebolts behind the bar. This would also allow for anyone taller to drive the car safely.
When I started to drill holes the recommended 100mm apart, I realized after I had already drilled the centered up first hole that if I drilled in the second hole I'd be right on top of the fuel lines.
DOH
So again, I settled for the bolt being MORE than 100mm apart and a bit off center of the hole in the Recaro. Once again, I don't think I would recommend this solution to a friend, but it's going to be good enough. It has to be now.
I'd like to go an redo these bolts when I can get a chance. I'll have to do some welding, which fine.. I just can't waste time worrying about that now.
With everything in, I ran the liner on the crotch hole in the Recaro and boom!
I need to double check my loops and add more length to the left side, but other than that I'm super happy with these!
FIA 2020 will expire this year, but as long as I don't get involved in W2W I should be good for the people I race with. Also gives a good excuse to go with some 2in shoulder belts and get a proper HANS
Stock belts are still kept in... well.. mostly because I'm too lazy to pull off the rear door card. My lack of motivation is starting to show and I really need to change that. But work and my Impreza have been eating up a lot of time (yay tuning for a new turbo!)
you need to be sure to put anti-seize on every thread of every bolt on this car
Waaaaaaaaay ahead of you. If I enjoy racing this chassis (ONE OF THESE DAYS) then I'll likely end up picking something new up from the south and junking this one. It's pretty awful, no other way around saying it.
There's much more work I can do on the balance.. but I was getting hot and needed a beer. I've still got the car on the scales so I can play with it more tomorrow.
Pretty not happy with the overall weight and corner balance (balance gets a tad better with me in the car). It weighs more than my Impreza! To be fair, I have pretty much only added weight and haven't put any sort of focus on reduction.. so maybe I can work on that as time goes on.
I am happy with the F/R weight... I'm okay with 48% rear because the rear spoiler PROBABLY should balance that back out. Or whatever. I don't know, I'm a software engineer. Another to be fair, I am coming from my Subaru which had a F/R weight that was laughable in it's best state. So it's nice to see some better numbers.
Speaking of wings... I did a little try at some basic aero testing. Turns out, I suck at this and my camera angle and string population was terrible. I did at least look at speed as a factor here though, so hey gimme something!
tl;dr all I truly learned was that my test was ****, and my uprights cause a ton of drag.
04-20-2020, 07:38 AM
