Autocrossing the DOHC 88 Fiero

[Series8217]

At least they have a warranty, if you are the original buyer.

I am, but I have an autocross tomorrow. Would have been better if it had failed after the last event of the season!

[Series8217]

I ended up autocrossing my Subaru instead of the Fiero on Nov 3rd, so this coming weekend will be my 2nd event.

I still haven't revalved the shocks, nor replaced the front left. The reason being I haven't had a chance to take the car somewhere with scales, since I had to replace my clutch and flyhweel. The shocks will just have to do for now.

Notable changes since the last event:

New wheels and tires
(see The SERIOUS Wheel & Tire Thread for more details)

Motegi MR116 17x7-48mm and 18x9-45mm with 215/45/17 and 275/35/18 Hankook RS3:



The fronts weigh 42.6 lbs with tires. The rears I Iost my notes on, but they should be ~50 lbs.

They're light, but they were cheap, and had the right sizes and offsets.

Fieroguru's lateral link relocation brackets
These brackets lower the lateral links by 38mm at the knuckle/upright end. You can buy them directly from Fieroguru.

The brackets should improve the camber gain and increase the roll center. Both of these factors will help improve rear grip.

New alignment
I redid my alignment. New settings:
Front camber: -1.0 deg
Rear left camber: -1.8 deg
Rear right camber: -2.3 deg
Front toe: 0"
Rear toe: 0"

I might change the toe before the autocross. I previously ran 1/4" toe-in up front and 1/16" in the rear. I want to see how it handles on the road with neutral toe first.

New front springs
West Coast Fiero 400 lb/in springs with ~3/4 coil removed (if I remember correctly).

Ride heights are now 350 mm up front, and 370 mm in the rear.

I can't find my notes on my previous front ride height. I didn't adjust the rear since last time, but the front got new springs. All ride heights are measured from the top of the wheel arch to the center of the hub, with 3/4 tank of gas and 140 lbs of ballast in the driver's seat.

Note that the new front tires are shorter and the new rear tires are taller, so the actual attitude of the car has changed (more forward rake) despite the arch-to-hub distance being pretty much the same.

Revised link lengths
I reverted my adjustable lateral links to stock lengths (based on Bloozberry's measurements), and adjusted the toe link for neutral toe. Despite this, I have about as much camber in the rear as before (same on RL, 0.3 less on RR). I probably picked up some static camber from fieroguru's link relocation brackets.

New exhaust
My new exhaust system has a Magnaflow 12265 with resonated tips. It's still a 2.5" system. My previous muffler was a custom thing I made myself that probably didn't flow all that well. It had baffles and stuff in it.

New clutch/flywheel
Clutchnet organic/clutchtex disc with stock steel flywheel. The aluminum one came loose for the 3rd time so I gave up on it; it's poorly designed and the aluminum cold flows under the bolt heads when properly torqued.

I think that's it. I will add more if I remember something else.

[Aaron]

Did the new exhaust quiet it up any? If not you could always add a turbo, quieted mine quite a bit!

If I ever find the motivation to pull my motor back out for the rear main seal, I'll probably replace the flywheel after reading your horror stories with it. So far I don't think it's having any problems, but it still has fairly low mileage on it.

[Series8217]

Did the new exhaust quiet it up any? If not you could always add a turbo, quieted mine quite a bit!

As a matter of fact, yes. From the outside it sounds more like a performance exhaust for a normal sports car now. It no longer sounds illegally loud, and it's very smooth. This is the only muffler I will recommend for a street-driven naturally-aspirated Fiero now. Hat tip to Darth Fiero for sharing his finding.

[Aaron]

Nice, I always liked the Magnaflow mufflers, ran them on my old Lumina Z34. It's a good thing it quieted it down, that car was loud! I remember you freaking out when I accelerated normally and there was a cop in eyesight haha. I'm pretty happy with the Spintech I have now, it's not the smoothest but it sounds great.

[Series8217]

Finished phase one of Evolution Performance Driving School today. The car ran flawlessly and was very fast. I actually beat most of the cars there including a Lotus Elise, Lotus Evora, E46 M3... Now obviously these people don't have the same driving ability as me, but I also beat some of their instructors' runs, at least those that I saw or asked about.

My times were a tenth off from the poi's S2000 (prepped to STR class, running 255 Hankook RS3s) and a few tenths from his bro's 2008 Cayman S (stock besides 255/285 Hankook RS3s on lightweight race wheels). I'll post exact times later as I can't remember right now.

The handling was pretty much flawless. No more bad behaviors like terminal or unpredictable oversteer or toe change under acceleration. Body roll with the lateral link brackets (roll center adjustment) and stiffer front springs is minimal. The steering is phenomenal.

The car received a lot of praise from the instructors. "... Best Fiero I've ever driven", "great job on the setup", etc.

I will post a full update, analysis, and videos after phase two (tomorrow).

[Aaron]

Now you just need more power.

[Shaun41178(2)]

how are the street manners with this setup?

[The Dark Side of Will]

Body roll with the lateral link brackets (roll center adjustment) and stiffer front springs is minimal. The steering is phenomenal.

The car received a lot of praise from the instructors. "... Best Fiero I've ever driven", "great job on the setup", etc.

I will post a full update, analysis, and videos after phase two (tomorrow).

Sounds like it's rocking and rolling. So you do have FieroGuru's brackets on your knuckles?

[Series8217]

Day two was also quite good. I ran even closer to the S2000 and Cayman S, which had also picked up a lot of speed. The instructors today liked the car a lot too.

There isn't much I'd change in the front setup. I think I could get some more bite on the steering with additional caster, as the front tire wear isn't ideal.

I'm still working on my driving, but there were a few places where I feel like sharper turn in could be helpful. I may just need some toe out up front.

Overall the car feels very planted, stable, smooth, and predictable. It inspires confidence rather than keeping you off the edge out of fear of the rear stepping out.

I drove the car hard as all hell all day. The only problem that developed is a red-colored oil leak........ but I don't have any red fluids. Turns out my brand new K&N filter somehow "released" all its oil... maybe it got too hot, or was over-oiled at the factory. It was dripping out from under my car like a leaking fitting, and my car billows white smoke when I start it from the burning oil. WTF K&N?

Still need to process everything, and then I'll post a formal update with pics and videos.

how are the street manners with this setup?

It rides nice. Except for the exhaust and intake noise, not much else is bothersome.

I daily drove it for years while it was worse to ride in than it is now.

Now you just need more power.

Got plenty of that for now. There are only a few places on most autocross courses where I'm power-limited with my current tires. If I was able to go much faster I would overwhelm the front tires in braking to get all that speed back down. If I start running R-comps... sure.

So you do have FieroGuru's brackets on your knuckles?

Yes.

Rear tire wear is quite good. I could probably get away with a bit more static camber, but I don't want to loose too much straight-line traction.

The car is no longer tail happy, and it doesn't plow unless I do something to overwhelm the front tires, like brake and turn (durr). However, some gas on corner exit does still help the car rotate. I spun it once or twice, and twice had some serious side to side action but saved it. I have hours of videos to process... I'll post them when I get to it.

[Series8217]

Here's the last run from today: https://www.youtube.com/watch?v=we8JNa_KOxk

Unfortunately the sound is not very good. I usually use an interior cam for sound since it's out of the wind but I tried using a GoPro for the interior this time and the sound quality was really bad...

[Series8217]

I weighed my car today at Lang Racing Development (www.langracing.com) in Irvine with 1/2 tank of gas and all loose items removed.

WITHOUT DRIVER
Total Weight: 2779
Left Front: 604
Right Front: 579
Left Rear: 780
Right Rear: 816
Rear: 57.4%
Front: 42.6%
Cross: 48.9%
Left: 49.8%
Right: 50.2%

WITH 140-LB DRIVER
Total Weight: 2920
Left Front: 655
Right Front: 595
Left Rear: 833
Right Rear: 837
Rear: 57.2%
Front: 42.8%
Cross: 48.9%
Left: 51%
Right: 49%

[Series8217]

Made a blog post here: http://steventsnyder.com/autocrossing-t ... ro-part-2/

I haven't had time to write a proper review of Evo School yet, but I'd like to. To summarize, the school was worth every penny, the instructors are awesome, and I will go back next year for a refresher and to pick their brains for more useful advice.

[Series8217]

These are the most aggressive settings doable with STOCK '88 Fiero suspension with stock hardware, and Fieroguru's lateral link relocation kit.

Despite having fully-adjustable lateral links, I left the fixed link at the same length as the stock fixed link, and only adjusted the toe link for toe. So that's just like stock. I have OE-style camber bolts. They do not add any range of adjustment.

The front geometry is completely stock, the ride height being different due to my WCF 400 lb/in springs.

Front ride height with these settings is 14 inches (fender arch to wheel center; so this is independent of wheel/tire size). Rear ride height is 14.5 inches.

Code: Select all

All measurements are in degrees.

Front           Left       Right
-----
Camber          -0.9       -0.5
Caster           8.9        9.2
SAI              6.6        6.0
Toe              0.02       0.01

Rear
----
Camber          -1.9       -1.8
Toe              0.37       0.31

Thrust Angle           0.03

Using offset camber bolts you can get more rear camber. I can also dial in a lot more rear camber on my car by adjusting the lateral links to be longer, but I left them at stock length for this test.

Camber/caster at the front is pushed to the mechanical maximum. The front camber can be increased by lowering.





Note that I made no adjustments on the alignment rack. I just checked what I had done in my garage with strings and a SmartCamber gauge. The only thing that was off was the rear camber -- I had measured -1.6 on one side and -2.3 on the other. It appears my garage floor (or the camber gauge) was not level, despite me leveling and shimming the garage floor with a long bubble level where the tires sit. Nice to see that the actual settings are even from side to side.

[Series8217]

Ran an SCCA autocross this weekend at Auto Club Speedway. No changes since last time except adding the front splitter, and using a slightly-modified stock Fiero V6 air filter box because my K&N got ruined when I did some high-speed testing on a dry lake bed.

Finished around mid-pack (13th out of 21). I had cooling problems all day due to my fan relay burning up and not having a spare (oops), but fixed it for my last run and dropped 2 seconds off my time. I guess that's what confidence in the car buys you.

Full results here: http://members.quixnet.net/free2000/csc ... in.htm#CST

I ran in the California Street Touring class, which is open to anything legal for street use in California on 140+ treadwear tires, so there's not really any equality between the cars.

[The Dark Side of Will]

Running hot while moving or just while still?

[Series8217]

Running hot while moving or just while still?

Dead fan relay, so I was overheating while stopped in grid, and during runs (not moving fast enough to keep things cool under autocross conditions). I forgot to bring a spare. They wear out over time because the contacts oxidize and vaporize due to arcing when the relay shuts off. Eventually the resistance gets too high and the relay overheats and melts.