"Princess" A Mazda 323 like no other.

[Crazycanadian]

With that much spring in the rear, for such a lightweight car, plus the trailing arm with that wide poly bushing, how much passive steering do you plan to use?

You may not get that much flex, and not need to worry about it with this current set up.

The passive steer isn't coming from bushing flex. With heim joints and polly bushings, there isn't really any flex. The passive rear steer is a function of the arcs the lateral links and trailing arm move in and how it dynamically shifts things. My goal is to dial out the passive rear steer and hopefully make the car rotate better.

The increase in rear spring should allow me to run my rear shocks and rear bar on softer settings and give myself some adjust ability. I was running with the rear bar and shocks pretty much full stiff last year.

 

[phate]

@phate i found you a friend

Yays.

Next up.. Bump steer. Using my laser level and work bench, I marked where the laser hit my bench. From there I cycled from full droop to full compression. Once done, that high school math you never thought I'd used comes into play. I measured the distance from the marks to the laser. Then measured the distance between the marks. From there you can math out how many degree of movement you have. In my case it's about 1.7 deg of toe change.. specifically toeing out. This makes sense, some toe out during bump is going to induce some understeer. Manufactures want a car to have more understeer characteristics for safety.
View attachment 34267

That's all for now. I've gotta come up with an excel sheet in order to track all of this.

Nice thread! Not many people go through the effort to measure all of this but it really helps in understanding where not to set things. Where to set things is forever a subject of debate and ever flawed data analysis (lol).

I will say that measuring bump steer like this can be done, but you have to account for scrub (change in lateral position of the wheel surface). You can severely influence bump steer curves when you don't. An alternative way to measure that cuts the error down by a factor of ~300:

 

[phate]

Camber set aside lets look at a different aspect. The rear suspension of these cars is known to have what's called "passive rear steer". This means the rear tires turn slightly as the suspension moves. I've never measured this or looked closely at it. It's been assumed that it helps the car rotate when turning. It's also been theorized the bushings helped with this. Non of that is the case. As the suspension moves up, the trailing arm moves through an arc that pushes the knuckle backwards slightly. This shifts the lateral link alignment, causing the rear to toe in for more stability. I have a plan to relocate the front of the trailing arm with the hopes of eliminating this.


I am running into another problem. It's the reason why I don't like Poly bushings. In order to get rear camber I have tilt the knuckle in. When doing this it twists the trailing arm. Well the bushings don't like this. It's causing them to bind up. For this season it is what it is, but in the future I've got to find a way to get a spherical bearing in the front to allow the arm to twist and move smoothly.

View attachment 34335

For the passive steer in the rear, it's worth considering what happens when the system sees that lateral load and how different bushings stiffness can influence that behavior. It comes from both geometry changes and bushing deflection. It may do something in the air on stands that could be changed drastically with some bushing deflection.


On the trailing arm side of things - what does that forward mount look like? I converted to sphericals several years ago in the 6 and did this for the trailing arm:

 

[Crazycanadian]

Yays.





Nice thread! Not many people go through the effort to measure all of this but it really helps in understanding where not to set things. Where to set things is forever a subject of debate and ever flawed data analysis (lol).

I will say that measuring bump steer like this can be done, but you have to account for scrub (change in lateral position of the wheel surface). You can severely influence bump steer curves when you don't. An alternative way to measure that cuts the error down by a factor of ~300:

Thank you for that video. I haven't see bump steer measured that way before. I'll have to try it and compare my results. All though I am in the process of screwing up all my testing data. I have some spherical bearings to install in the front control arms. These came off my old SMF car. I've got adjustment in the rear bracket, plus the rear bushing being off set, and some planned modifications to the front control arms, I am hoping to gain another 3 deg of castor.



The front bushing for the trailing arm will be fairly easy to convert to a spherical bearing. I just need a friend with a lathe and some time.



With heim joints in my lateral links the only bushing flex I have is the poly bushings in the trailing arms. A long time ago I took a video of my rear suspension during an autocross run. I don't remember seeing anything going on that makes me worried about bushing flex in the trailing arms.


The issue I do have with the trailing arm is trying to get camber. The upper bolt is slotted for camber. This twists the trailing arm as the bottom mount moves outwards. As we know, polly bushings hate being misaligned.

 

[phate]

I wish I had a CNC machine or mill. I've got a custom throttle body adapter to build in order to make an ND2 throttle body fit. This will give me a proper IAC valve. I wont have to fight with tuning around the stock coolant controled high idle valve and "Idle up" valve that's not really designed to be modulated by a stand alone ECU. All though you can do it and it works. I've found cold start tuning tricky to get right. You can't really anticipate the high idle valve and how quickly it closes and when you need the idle up valve to start taking over.

Shameless plug here - I make custom parts and focus on the racing community for projects like this. I've made some pretty nutso complicated TB adapters with bent passages and ORB ports and whatnot, and I've even made some IAC housings recently. Prototypes, one-offs, and small runs of parts are what I do.

I had a thread like this on MSF (rip) with all the suspension data for the MS6. I also went through spring and bar math for setting up a car by the numbers, and replicated that over here when MSO went live. Link.

My MS6 has been in ESP for ~10 years now. We (my wife and I) campaigned it nationally with pretty good success. I've been 2nd at nationals in ESP once or twice, won several tours, and indexed as high as 11th at nationals. We took last year off since we had a baby, but should be back out at some point this year if things go well.

 

[Crazycanadian]

Shameless plug here - I make custom parts and focus on the racing community for projects like this. I've made some pretty nutso complicated TB adapters with bent passages and ORB ports and whatnot, and I've even made some IAC housings recently. Prototypes, one-offs, and small runs of parts are what I do.

I had a thread like this on MSF (rip) with all the suspension data for the MS6. I also went through spring and bar math for setting up a car by the numbers, and replicated that over here when MSO went live. Link.

My MS6 has been in ESP for ~10 years now. We (my wife and I) campaigned it nationally with pretty good success. I've been 2nd at nationals in ESP once or twice, won several tours, and indexed as high as 11th at nationals. We took last year off since we had a baby, but should be back out at some point this year if things go well.

I appreciate the offer. I've been slowly learning how to do 3d modelling in order to have a file that I could send to someone like yourself. I am not there yet but I'll keep you mind when I do. I remember hearing about your early success and started following what you were doing quite a while ago. I appreciate having you coming in and passing along some of your thoughts and knowledge. I read through your thread a long time ago, a lot of it was way over my head back then. I am starting to grasp more of it now.

Justin Brabry did an extensive FSP build back in the day on a Protege. It's been retired from autocross to track duty. I used a lot of what he was doing as a frame work 10+ years ago.

It's interesting when you talk about roll bias, This has been talked about as front and rear roll stiffness to me. Despite some of the math I've been doing with tuning my Speed 6, doing motion ratio calculations, sway bar calculations ect is a bit beyond me for now. I think I understand most of the concepts.

For anyone interested. He's a fun video of the LF suspension and tire in action. If you watch it close enough you'll see the front control arm mounting point flexing. That's the sub frame flexing, not bushing flex. I had the solid spherical bearings previously posted installed at that point. This car eventually got a 2 point brace to help fix that. Princess has a 4 point brace.


Another old video. This one is the rear suspension. I have the same lateral links with heim joints here. But I am running stock trailing arm bushings. You don't get a good shot of what the trailing arm is doing. If it's flexing back and forth. but it's a fun video to watch. Plus both videos you get to hear the glorious sounds a 2.5L KL V6 makes as it's revving out. The 1.8L V6 versions in the Mx3 were known for the amazing exhaust sounds.

 

[Crazycanadian]

Just because its poorly executed, home made from scraps, without a plan, measurements or even a ruler. Doesn't mean it was a stupid idea..

I present to you a Camber adjustment tool, for those of us stupid enough to try and do things the hard way.




If you are looking at this scratching your head wondering what kinda stuff I have been smoking. Let's take a little step back, you'll realize it's even worse considering I was sober while creating this monstrosity

The upper bolt holes on the strut are slotted. This allows the knuckle to pivot on the lower bolt, tilting the wheel in and out adjusting camber.
the problem with this method is adjusting things when the weight of the vehicle is on the suspension.. It's forcing the knuckle to tilt inwards as much as possible. There's a lot of force fighting against you trying to make this adjustment.

Based on an OTC tool for adjusting older GM's with slotted struts, I came up with this monstrosity. It hooks into the knuckle and pushes against the strut body. This tilts the knuckle out allowing me to adjust the camber accurately with the car at ride height and weight on the suspension. Once the desired camber is reached. I tighten down the bolts and we are good to go.

Some of you might ask.. why don't I just used camber bolts instead of slotting the struts? Simple, I tried... They don't provide enough adjustment for what I need...

 

[Easter Bunny]

Its not stupid if it works

 

[Crazycanadian]

Setting up coil overs and doing a custom alignment takes a lot of time. Time I was running out of this week. The car needed to be road worthy for this Saturday. I had committed to putting the car in Tuner Bash's opening event. This is a Car show series with some drifting and drag racing. Overall it's good times. A close friend of mine is part of the crew that helps put the local show together and does some of the media work. This year was a little more special as I got to enjoy it, not only with my kiddo but a few other local Mazda Econobox enthusiast.



If you know what you're looking at, the bone stock white sedan next to the Mx3 would be the special car this line up. It's an all original 89 323 GT with 100,000 kms on it. The 323 GT is the Turbo fwd cousin to the Rally homologated GTX. North America got this car for 88 and 89 only. With lower sales numbers then a GTX (some where between 800-1000) this is an unknown jewel. This perticular car is a bit of a unicorn. It had been optioned with electronic adjustable suspension that still works!

Trust me, this is the kinda stuff to geek out on.... Or maybe I am just getting old..

Friday at 5:30pm I washed the car and realized it was in ruff shape. I also remembered, that I had not road tested since redoing all of the suspension and it didn't have any insurance on it. Sooooo an hour later I took my first drive around the block. During which I relized the wheels hadn't been properly torqued, the rear control arm lock nuts hadn't been tightened down, and intake wasn't tightened down. No big deal.... at 2:30 am I left the shop to get some rest. 8:30am I was back at the shop to finish a couple things and help kiddo get ready. Considering all the last min prep, the car looked great.


It even brought home some hardware for the 2nd year in a row.

 

[Crazycanadian]

So what do you do after a scramble to put a car together for a show?

You bring it home a tear it apart again...



This time around it's more track prep and winter project stuff that I wasn't able to get done. One of the new goodies I installed was a RaceCapture Pro MK3. I haven't installed any sensors yet, but I do plan to add oil pressure, Steering wheel position, Brake pressure, AFR. I am also going to add a MAP signal in order to replace TPS.. The electronics on this era of car is a bit archaic. The stock TPS sensor is a 3 position switch, rather then a potentiometer. Since Manifold vacuum corrolates with throttle position, this is the next best thing.


The second thing I installed is a guage pod with some fancy new guages . Rob designed and built this pod 10 years ago. He spent many hours getting the positioning just right so that the other gauges were still readable.

Looks like when I posted this, I forgot to finish it. Oops. Not to self, stop doing stuff like this before bed.

Under the hood you might notice a shinny knew intake pipe, replacing the old stock one. I did this partially because I just wanted to, the other reason was to aid in adding catch cans to the car. Looking at pictures from being out on track last year I noticed quite a few had smoke out the tail pipe. I don't have reason to believe this is a motor issue. The rebuild done on the motor is still relatively fresh.



The intake I built may or may not be hurting performance. Have you ever noticed weird chambers that stick out on the stock intakes? These are referred to has Helmholtz resonators. Not only do they quiet down the fun intake sounds, but they are part of how and engine makes power. Admittedly I didn't know this. A friend mentioned something about it to me after sending him pictures. I've swallowed the coolaid thinking stock intakes are restrictive and upgrading is a way of making more power. For the most part this it true on old stuff like this, but in the Miata world that wasn't the case. The resonators on a1.6L NA miata help prevent a dip in torque around 4000 rpm. When it comes to the 1.8L NB's this might not be as big of a deal. It's hard to find proper information on this since some of this stuff would be trade secrets in the spec Miata world. All though this BP is in essance a miata motor, dyno testing and research hasn't been done. So it's one of those things. Have I made power? Or reduced it? At the end of the day it's sure pretty and my aluminum welding is slowly getting better. If I can get funds together for some dyno time, I might do some of my own testing.

 

[Crazycanadian]

Huston we have a problem. Wellllll ok I wish I was still ignorant to this problem..



Lets back up a little bit. I left things off with tearing apart the car, installing a Racecapture Pro 3 data logging system while I was waiting on some new 225/45R15 Vitour P1 X-01Rs. Well the Vitours fell through. Supply chain issues due to some kinda war caused issues with the ability to get raw materials. Thankfully I was able to back out of the group buy and picked up a set of 205/50R15 Bridgestone RE71RZ's.

Now back to the problem at hand. With a data logger come's the ability to see what's going on with things like.... lets say oil pressure... Yeah, I've been racing all this time with out knowing oil pressure was dropping off during decel. NOT GOOD! not good at all.. So what am I going to do about it? Well.. until I get time to pull the oil pan off and look at baffling, there wont be any Time Trial events for me. Autocross events will go a head as planned.

Some highlights from last weekends event. A meeting of minds while prepping for the first morning runs.


Action shots.


Princess and I finished 13 out of 91 Drivers. The car really needs some new coil overs, but over all she feels fantastic.

A couple of videos for your viewing pleasure.

First up my morning run. A great perspective when it comes to good steering wheel control.


Next up. My quickest run of the day.

 

[Crazycanadian]

I've been busy with other little projects which means Princess hasn't gotten much attention. Local autocross event's aren't fast enough to give me a good idea how the suspension changes handle at the higher speeds I'll see in Packwood. So I don't know what changes I'll need to make. Something doesn't feel quite right though. I ran a 2nd event last month. In the afternoon I changed the rear sway bar from it's softest setting to it's stiffest. I couldn't feel a difference with how the rear end was behaving. With the softer front springs the front end doesn't feel as harsh hitting bumps, but it feels a bit slow/squishy. Getting tire pressure dialed has been important. When dropped them low enough to have the tire rolling over where I wanted it, the front really felt squishy. A couple psi higher made a big difference. I'll have to do some experimenting during the test and tune when I am at Packwood this month.

I did pick up some new seats. These are a new brand coming to market locally. It's $1200 brand new for the pair. The bonus, they get sent off for FIA testing. The black with red stitching is a nice nod to an OEM GTR seat.. Installing the seats gave me an excuse to break out the harnesses Rob and I bought a long time ago. They are out of date by a long shot, but have been properly stored and good for autocross use.


Here's what a stock 323 GTR interior looks like


10 days left till Packwood!

 

[Crazycanadian]

Packwood went off without a hitch. XB was the biggest class of the event with 25 drivers. I knew I was bringing a spoon to a gun fight so expectations were low when it comes to what place we'd finish. My hope was mid pack.

A friend of mine came up from Vancouver Washington to co-drive with me. It's been years since he's been in a 323. I got to the event Thursday evening which gave me lots of time to setup, relax and get ready for the Test and Tune on Friday. I needed some of the extra prep time to wash the car. I drove through some rain, the car was pretty dirty. The Motorhome did well pulling the car down, the 454 big block is a thirsty girl. She got 8.6mpg.



Our local events are to small and slow paced to get a good feel for the car at the higher speeds seen at a National Tour event. I wanted the rear of the car looser so I threw some toe out in the front and rear before I left home. During my first 2 test and tune runs the car didn't do anything crazy which was relieving. I hadn't totally screwed up the car.

After my first 2 runs I handed the keys off to Justin Barbry. Not only is he the Senior National Solo Series Manager but he's a bit of a 323/Protege Guru. Justin campaigned an FSP Protege to multiple national tour wins back in the day. Back when he was winning tour events I was getting serious about the SMF 323. I was using his FSP cars setup as a basic guideline for my build. I've talked to Justin on and off over the years. Getting to meet him in person and having his feedback on how the car drives was amazing. He had good things to say about the car and gave me some good pointers. Nick was taking his turn to get familiar with the car while I was out on course doing my work assignment. When I got back I made some shock changes, stiffening up the front shocks and loosening up the rears. I ran 1 second faster, the car was less pushy mid corner.


After 4 runs Nick felt confident and comfortable in the car.


A Friend of mine from Idaho was at the event running his EST Ford Escort. Justin Barbry happen to be codriving with him.


After the test and tune I decided to make a setup change. I softened up the rear sway bar setting and added a more rear toe out.


Day 1 Saturday! I wasn't sure how the extra toe out and softer rear sway bar setting would effect the car. Nick was the first to drive and man he was excited. The car was feeling really good, the changes I made. Solo storm and my go-pro were having a hissy fit which meant we didn't have video overlay to use when looking at data. Nick struggled with cone his first 2 runs, but cleaned it up and got a little quicker for his 3rd run. Putting him 22nd place.



My first 2 runs were clean, but I was leaving a lot on the table. Sitting 19th going into my 3rd run I told Nick it would be a hail marry run. "Whats a hail marry run look like" he asked. Well either I was gonna mess up big time, or I would lay down a fast run. A fast run it was too, picking up 1 second. I was pumped, thinking I had jumped up a few places. Turns out, everyone went faster as well. I went from 19th to 18th. HAHA! what a kick in the nuts. Oh well Nick and I were having a great time.

Staying on site means lots of time to do course walks while enjoying the sun set.


Day 2 Sunday! Nick and I set a simple goal. Improve our standings by at least 1 place each. This course was going to require trusting the grip in order to thread the needle through some of the elements. Nick felt good coming back from his first run, but he nipped a cone. I screwed up my first run forgetting about a gate. Having to make a quick adjustment as to not DNF, I picked up 4 cones that run. Nick made a mistake on his 2nd run and DNF'd. As the rear tires got some heat in them, the car wasn't rotating as well. I had room to stiffen up the front shocks and soften up the rears. This helped the car rotate better. I cleaned up my 2nd run, but I was to scared to run a few sections flat out. Nick cleaned up his 3rd run but couldn't catch up to my 2nd run. This bumped him from 22nd to 20th so goal achieved for him! I missed 2 braking zones on my 3rd run, pushing out and hitting 2 cones. I was able to jump from 18th to 17th thanks to a competitor coning away all 3 of their runs. So goal achieved, and a good lesson for everyone. It's important to lay down at least 1 clean run.


This years XB class was filled with top competitors. Last years class winner finished 9th showing how much the bar got raised. Nick and I got our buts kicked, but we had a blast. I have some more setup changes to contemplate before the next local event.

 

[Crazycanadian]

I've got videos. Looking back at them, man I left so much time on the table. I do a lot of coaching locally, it's time for me to go back to school and learn how to drive again. lol.. If you watch the video and have feed back, I'd love to hear it. I can see a few things going on with it.

Saturdays best run.


Sundays best run.