My 3.4 DOHC powered red and black camo '88 Fiero Track Car

[Emc209i]

Any possibility of using the Camaro hub and larger axle while retaining the stock Fiero bolt pattern? My hubs have miraculously held up well over the years, but when they do go out I want to keep my Enkei's.

If not I'll do the J body bearing swap if they're still available.

[Series8217]

Any possibility of using the Camaro hub and larger axle while retaining the stock Fiero bolt pattern?

No, the Camaro bearing OD is 98mm.

If your Fiero isn't a track car with big sticky tires, the rear bearing you want is the AC Delco 20-25K (J body application). It requires some machining to fit the 88 Fiero upright but is a nice durability upgrade and you can still buy new OEM ones.

[Emc209i]

I figured as much.

The achilles heel of the Fiero is that the axle sheers where it meets that bearing. I have zero interest in tracking my car, but it would be nice to upgrade to a larger diameter axle while having an overbuilt and readily available sealed bearing design. Switching to the dustbuster van upright also changes the bolt pattern.

Anyway, carry on, car looks good.

[Series8217]

Getting serious.

My new prototype rear uprights are on the car, and a massive stack of wheels and tires has arrived.

Unfortunately while installing the uprights I discovered my Konis have dumped most of their gas charge so I need to move forward my Bilstein project or get the Konis rebuilt (and might as well revalve) before I can test the new setup in anger.

315/30/18 and 265/35/18 Nankang CR-S... This is what the wheel bearing upgrade is for.

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[ericjon262]

That looks great! I take it the ATS rotors worked out, or at least so far they do?

[Series8217]

Getting close to ready for real shakedown run. Maybe an autocross or track day in February.

New wheels and tires mounted. 265/35/18 front and 315/30/18 rear on Apex SM-10 wheels 18x9.5 front 18x11 rear.

Wheel speed sensor cables routed and working. Laptop in the pic is running INPA for bleeding the BMW Mk60e5 standalone ABS and calibrating the accelerometer/yaw sensor. I coded it with a custom vehicle model for my Fiero, including the new location for the sensor.

I did a brief shakedown run and it all seems to be working but I need to cut the rear wheel arches and add flares because it's just a bit too much tire for the stock body.

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[ericjon262]

That's awesome! I didn't realize you were adding ABS, it's neat that the BMW unit can work in standalone. Anymore details on that?

[Shaun41178(2)]

You have the meats!

[pmbrunelle]

Can the BMW unit just work with a vehicle model, or does it also need empirical trial-and-error tuning?

[Series8217]

Can the BMW unit just work with a vehicle model, or does it also need empirical trial-and-error tuning?

Most people using these on race cars don't even customize the model. At least for ABS it seems to be quite competitive with the stock M3 programming. If I ever enable the DSC functionality there's probably some more tuning to do. There are TONS of parameters in the model though. Contact patch compliance, effective friction radius, weight distribution, center of gravity height, wheelbase, track width difference front to rear, IMU location, steering ratio (there is a steering angle sensor which I'm not using yet), and a few hydraulic pressure models (for different caliper types I think). May be more to discover as well.

[Series8217]

Slayed some cones over the weekend at a PCA event and then Corner Exit Autocross.

I definitely lost a lot of skill due to my 8 year hiatus from motorsports, but I picked up a lot of speed throughout the weekend. At least it's coming back.

No major issues with the car other than my rear camber slipping out of adjustment. I torqued the bolts to the factor spec BUT my knuckles don't have the knurling/ridges like the stockers. I'll probably fix it by replacing the camber bolts with regular bolts and a laser cut spacer that fits in the strut clamp slot.

ABS is unreal on a Fiero. Stab the pedal and let the computer sort it out. Trail braking is no longer an ass-clenching maneuver, and uneven surfaces no longer cause lockups. Also don't have to rebalance the car for having a passenger. The brakes were totally flawless.

My buddy set the fastest time in his 67 Camaro with a 450whp LS3, IRS and race IFS, BMW DCT, ABS and square 315 yokes. So for the fun runs in the afternoon I let him drive my car and he ran times that could have also won the event, with me in the car adding weight.. so I think the new uprights/brakes/wheels/tires/springs are working. Just need to improve my driving skills.

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[The Dark Side of Will]

Awesomesauce!

And your suspension is stiff enough to keep the fenders off the tires, apparently!

[Shaun41178(2)]

Very cool

[Series8217]

Awesomesauce!

And your suspension is stiff enough to keep the fenders off the tires, apparently!

I don't want to cut the fenders until I have my widebody flares designed, so in the meantime I added a long polyurethane foam bump stop that gets to around 1000#/in close to fender contact. It works but you can feel the lack of travel.

[draven]

Dude, massive thumbs up for executing and seeing this through...

Let us/me know the prices on reproducing the front and rear hubs when you've worked out the kinks...

Also, I'm sure everyone here would like to know more about the BMW abs... read about a few NASA C5/C6's that use Mk60 kit supplied from Doug Wardell. Same setup?

again...

[ericjon262]

are the clips you're using to hold the speed sensor cable to the brake line 3d printed? how are your prints holding up in environments like that? care to give us a run down on your printer and process? I 3d printed some hubcap adapters for my car at one point, but they warped in the heat here in SC.

The track time looks like a blast, I wish there were events like that here.

[Series8217]

Dude, massive thumbs up for executing and seeing this through...

Thanks! I'm glad I stuck with it. This is a really fun car now.

Also, I'm sure everyone here would like to know more about the BMW abs... read about a few NASA C5/C6's that use Mk60 kit supplied from Doug Wardell. Same setup?

No, this is a MK60E5 that I wired and tuned myself. One of the C5/C6 guys tested Doug's "motorsport flashed" MK60 units back to back with a stock MK60 on track and there was no practical difference. The MK60E5 is an evolution of the MK60 that has a different pressure control strategy (proportional instead of bang-bang on the valves), more detailed CAN frames for logging, integrated pressure sensors to simplify the plumbing, and other benefits. The physics model (vehicle weight distribution, wheelbase, lateral stiffness, etc) is also programmable without needing proprietary motorsport software.

[Series8217]

are the clips you're using to hold the speed sensor cable to the brake line 3d printed? how are your prints holding up in environments like that? care to give us a run down on your printer and process? I 3d printed some hubcap adapters for my car at one point, but they warped in the heat here in SC.

They are printed with nylon-CF (carbon fiber filled nylon) on a Voron 2.4. I've also experimented with plain nylon6 (which is probably what's in my pics above) but the clips that I forgot to anneal didn't hold up well. Nylon absolutely needs to be annealed after printing to get the best high temperature performance. The nylon clips I annealed seem to be working OK but I have more confidence in the nylon-CF parts.

[Series8217]

The track time looks like a blast, I wish there were events like that here.

I'm not sure about autocrosses, but for track days you're less than 2 hours from Carolina Motorsports Park. That's a great facility. I've done a couple track days there.

[ericjon262]

some quick googling looks like the Voron is a custom build it yourself printer? looks very well built from what I can see. I need to get my printer out and dusted off, but I could also use to make some significant upgrades to it as well, unfortunately, that will have to wait until I get this dump of a house I'm working on closer to "finished"

I'll have to check out Carolina Motorsports park, although, my car is far from ready for a true track day.