Long time no see! I'm still kicking, still driving the 85 around bumping Huey Lewis.

HPDE - I stopped by California Speedway for the first time in 2 years, had a blast. I figured I'd post a few photos to motivate you armchair racers. The last time I went there I forgot to change the front pads beforehand. This time I did, but got lazy and used a dusty old bottle of Motul brake fluid.

BRAKE FLUID - I figured the high wet boiling point should be good enough despite sitting on the shelf, but it boiled anyways, causing the pedal to go to the floor in the afternoon heat. After the first boil it seems to go sooner the second time around. It went from boiling on lap 10 to boiling on lap 4. And you don't get much warning, so I quit pushing my luck and skipped my 4th run session.

My online research since says don't buy brake fluid until you are ready to put it in. And preferrably from someone that moves good volume of it. If it's sat 2+ years in a sealed container, plus however long in the store... use it for your commuter car or clutch. One trick I did learn, was to swap between Motul and Wilwood fluid each time. The wilwood is green, and the motul is orange, making it easy to see when bleeding is complete.

ROTORS - The brakes when not boiling the fluid, are strong enough to detach your retinas. I'm considering getting rid of the drilled front rotors (13.1") and going to the slightly smaller C5 rotors, (12.8") which would require a custom mounting bracket. Either that or some plain slotted wilwoods for $180 each. Nothing else fits the current geometry.

The drilled rotor holes fill with brake dust within a single run session, defeating any possible cooling/breathing benefit. I'm fairly certain they cause the calipers to run hotter because of the reduced surface area for heat transfer. The calipers have stainless steel pistons but that still isn't enough. I only got these rotors to begin with because the undrilled were backordered. They have some badass metallurgy though, the rotors look great still, despite aggressive pads, and despite running the pads down to metal last time at the track. This layout has some heavy braking zones so it's an easy way to make up ground on the guys with more than 200 rwhp.

TRACK EXCUSES - That's my friend in the VW pitted near me. He is paralyzed from the waist down and races with hand controls. So I don't want to hear any more excuses from people with legs! He also has the slowest car on the track, yet still passed some guys, including the beer gut driving the 80 Corvette with his matching clothing making us look bad. Normally my 85 is the oldest car at these events.

TRACKDAY APP - If you guys haven't heard of Harry's Laptimer, try it out. Does video and lap times, G force graphs and all that bs and is quick to turn around into a video with guage overlays. The lap times were all within 1/10s of the AMB transponder, so I'm going to skip the transponder rental next time! I'll try and get my video uploaded for you guys. I used to spend days or weeks going through video and adding guages. I'm not sure if it works for drag racing.

REAR BRAKES - In other news, I noticed Wilwood now has a bolt-on rear brake kit with 4pot calipers for the 84-87 C4, for $1500. I don't know what they're smoking designing kits for this application. It even keeps the stock parking brake drum. Tempting, but I think I'll just stick with the factory setup in back, although that alone will be about $350 for rotors, pads, and hoses that are in need of replacement. The stock master is already having to deal with the added piston area up front.. and I don't feel like dicking with the bias again.

BEARINGS - Who's the preferred mfr for rear wheel bearings these days? I have a loose right rear. Again. I see Timken and SKF on rockauto for about $100. The Delco ones are $400!

OIL PAN GASKETS - I put a new oil pan gasket in which reduced some of the oil leakage. Both mains still leak, and the valve cover gaskets will be the death of me. I mean it just keeps dripping even when parked, when no surfaces should be wetted except the drain plug. Its been looking like Exxon Valdez parked in my driveway. I learned the Mr. Gasket 1pc is preferred to the Felpro, which gets brittle with age sooner. Time will tell. The factory oilpan stamped surface is as flat as pamela anderson, it looks like the gasket didn't even make contact in parts. I RTVd the pan to gasket this time. BTW, stay away from The Right Stuff in the self dispensing tube, unless you use it quickly, it dries in the can. 90% of it goes to waste. In the past I could unplug it with a long wood screw but this time I finally punctured the seal in there and the entire thing oozed out the size of a softball. At least the tubes are cheaper and easier to unplug. I contemplated just putting a road race pan on but I'm expecting interference with the oil cooler or other things I don't want to deal with. Maybe on the next motor.

LOWERING KITS - Everyone has these stupid wedges. Stay away from them! I've replaced them several times. I wish I could go back to stock. The front end kept dropping and turns out the wedges came loose again, one fell out entirely. The frame was digging into the spring. I was googling for better ways to bond them and all I came up with was my own griping posts on CF, and a bunch of hacks boasting about running their springs against the frame. Last track day, the car was clearly bottoming out on the banked oval portion, which is a frightening place for hopscotch. So I put in new wedges, again, this time trying Gorilla glue, which is advertised as being less bad at polyurethane. Apparently there is no such thing as good polyurethane epoxy or glue. I also drilled about 8 dimples into the underside of the wedges, to give the glue more surface area to bite. It seems to have held up at the track, definitely felt controllable on the banking, but I'll have to get under there and see if they held up, it is making some new noises.

REBUILD OR REPLACE - I've been contemplating the needs of this car vs. upgrading to something in better shape and with more power, perhaps a 96 CE. I still enjoy the C4, cringe at the C5, and can't afford a C6, and I'd hate to toss all that knowledge. I guess a replacement C4 with 80K miles on it is likely to have mostly original suspension and drivetrain parts, whereas mine are almost entirely replaced over the past 10 years. Mine is a mess cosmetically though. If you ever watch David Duchovney on Californication in his beat Porsche, that's me in a nutshell. (And I look just like him of course.) I've been suspect of the engine leaks being due to excess blowby, despite good compression and the magentic drain plug always picking up small metal bits. The valve guides are worn out and even with new seals leak like crazy. I can't even drive the car without a cat due to the smoke while idling. The cat actually burns the oil enough to prevent visible smoke. I can't really do anything yet though except hope the motor stays together until I can build a real garage at my new place. The night before my track day I saw a massive thick smoke plume behind me on the freeway, I thought for sure the motor was going. I couldn't duplicate it, so I supposed it must have been some diesel dually in my blindspot. The engine held up just fine at the track beating on it at redline, albiet with 20w50 oil in it this time.

EXHAUST - speaking of exhaust, my stock double wall 2.25" ID was cracked at both header connections and leaking. I wonder if the loose C-beam helped that along. So I installed a stainless Y pipe from the guy who supplies Ecklers (Art's?) but the part was substandard. He used a crappy flaring tool for the stock header ball connection, which shaped it more like an octagon, and didn't seal. Rather than ship a massive heavy part back I paid a local shop (JBA) to clean up his work. Also, the Y section had some severed metal flashing and extra pipe protruding, blocking the flow. I was able to grind this out to the full pipe size with a porting tool and long bit. I then got stubs welded on a CARB legal cat, to allow me to swap it out with a test pipe. I had to get that redone at JBA also. (I need to buy a welder!) I also learned the $60 universal cat costs $150 if you want the one with the CARB number engraved on it to be legal. Same exact part otherwise. I love California.

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looks like fun!

Side bar... ATE makes brake fluid in 2 different colours...

just say'n... Will comment more when I get home and can digest the rest!

Glad to see you around!

Well you wrote a years worth today. Good to hear from you.

Excellent report!

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Good one.

Welcome back, CC.

Bogus, you can't get the ATE blue anymore. The USA ruled that the blue additive didn't comply with ASE requirements.

It is literally considered a controlled substance and is illegal to stock or sell.

...but I know a guy who knows a guy.

Also, I have at least one NIB C4 rear bearing. I don't know what brand it is but I'll make you a sweet deal for it...

After spending $2800 on the SKF C5 bearings, replacing my C4 ones regularly doesn't seem so bad.

Nice pics! I thought these cars were extinct. Don't let me anywhere near that thing, I'll screw it up!

I think you can still get the OEM rear bearings with Mobil 1 grease in them... IIRC Tommy Archer ran these?

I will forward you an email.

I have these and they are very snug.

Here is my first run session. The first three minutes are kinda boring. Most of my mistakes were in the 2nd one, not sure where the video went.

This is all with the iphone app and a simple a suction cup mount on the rear glass. The quality is better before compression but this is good enough for me.

The G meter doesn't always read correctly in the banking. I wasn't able to carry much more than 120 through there before it started drifting up the track though. It's very deceiving, you have to really increase the throttle to maintain speed as the tires scrub it off.

https://www.youtube.com/watch?v=3dFNyBWri50

Mostly C6s, M3s, a pair of BRZs/FRS coupes that were doing well. I kinda like these things for some reason.

I found these for fronts: http://hoosierpe.com/tech-info/4th-ge ... front-wheel-hub-assembly/

I found these for the rear, but maybe its the same as the timken bearing. Timken supposedly does tapered rollers, not ball bearings. It's also listed on their own website in the 2nd link.

http://www.vetteworksonline.net/catalog/index.php?cPath=25
https://www.vansteel.com/index.cfm?fus ... Item&subgroup=202&ID=1569

And this looks like a good price for OEM, I'm thinking they just have it listed incorrectly as being for C5:

http://www.corvetterecycling.com/product-p/7470501.htm

I like those... pricey, yes, but REBUILDABLE... that will save you serious cash down the road.

Figure that GM bearings are $460 each (at rockauto.com)... and that cheaper non-GM are still $205 for Timkin... this does not look like a bad investment.

I can't imagine a rebuild is more than $50-$75... Plus you can service them along the way (clean/grease) to keep those bearings running longer.

Pricey yes, but a damned good value. I would bet they would last 250k miles in normal street use with regular maintenance, that's three times the lifespan of OEM bearings (dying at a nominal 80k-100k miles).

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What's that?

yea, good point.

Nice report.

Less posts = more track time.

FYI My front rebuild-able is still going strong after 3 years.

I wish, that's the first time in 2 years and I was a little rushed to even get the work done to be confident in taking it back out.



I unlocked the video, youtube is messing with me.

Now I'm looking for front sway bar end links, these factory ones suck so bad. Or maybe there's another type of sway bar (or adjustable?) that could fit.

check with Tom at Banski... he might have some suggestions... or, perhaps, Gary at Hardbar...

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I'd check the thread on CF before trying to get a hold of Hardbar.

Guys, I am surprised to see the C4 wheel bearing topic open again. CC, you were the guy 10+ years ago that did all the legwork which proved that the C4 bearings just plain suck and there isn't a better option out there.

All of us who raced C4's took your advice and stopped looking for the magic fix. We ran the cheapest ones we could find and just replaced them when necessary (LR every couple weekends, RR maybe once a season). THAT saves money in the long run. I checked that rebuildable link above...$650? You're out of your mind if you pay that much for a bearing. I bought them for $50 each from a local auto store and they lasted as well as any of the "fancy" ones we tried...Hardbar, VanSteel, blah blah blah.

The fronts, in general, were never a problem, so I would never waste more money than whatever Rock Auto sells the cheapest ones for.

Putting a car on a track is hard on this stuff. It takes more effort if you're fast. Give up on bearings, they're a wear item just like your brake pads. I replaced two LF stock bearings in ONE DAY on the C5. Be happy you have a C4

As for end links, if Banski is defunct then you should be able to easily make a set using some decent heim ends and threaded rod. The C4 aftermarket is all but dried up...sad but true.

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Not defunct, at least from a business sense. I had a design for swaybar end links that I thought improved on the existing products but found that the cost of the product was more than the market would bear to make it worth while.

Can't justify putting resources towards new products with low margins.

Tom, glad to see you're still out there. I saw your other thread as well. Any plans for C5 components?

I am glad Tom is around, too! It's going to be small operations like Tom's that give us options until the C4 cycles around again as being viable.

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The only thing I have for C5s right now is Hardbar's Pin Top Shock Mount.

I had a design for an adjustable sway bar link but the design was pretty expensive to make in small quantities so it wasn't viable enough. I might revisit that though.

I'll contact you off line to discuss some test fitting.