Track Days in the DOHC Fiero

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Aaron
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Re: Track Days in the DOHC Fiero

Post by Aaron »

Series8217 wrote: I will probably leave the oil warmer in place when I install an oil-to-air cooler. I'm thinking about putting the oil-to-air cooler in the location where the stock cat was located, and building a little duct for it. This will keep the lines short and eliminate any bodywork for ducting.

I have no problem with the current engine oil capacity. What is your reason for thinking the engine needs more oil? I have watched some of my videos for any oil starvation showing up on the oil pressure gauge during high speed banked 1.2g+ corners and haven't seen anything yet.

The only oil issues right now are oil temperature and oil consumption through the intake due to the stock PCV breather system, which I'm replacing with a ProVent I got a few weeks ago (but have yet to install).
I think that's a perfect location. My car needs a fuel cooler, and that's where I plan on putting it.

I was afraid you'd ask this, because like everything 3.4 related, I've got no reason beyond speculation. My first 3.4, in a Lumina, had lifter tick and was never exposed to high oil temperatures. Seemed fine until I spun a bearing. Maybe all it needed was better drain back, but I also think having the added capacity will help that quite a bit.

I also need to design and implement a good breather system for my turbo car, but that's a long ways off considering I don't work on it anymore.
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Re: Track Days in the DOHC Fiero

Post by Series8217 »

Aaron wrote: I was afraid you'd ask this, because like everything 3.4 related, I've got no reason beyond speculation. My first 3.4, in a Lumina, had lifter tick and was never exposed to high oil temperatures. Seemed fine until I spun a bearing. Maybe all it needed was better drain back, but I also think having the added capacity will help that quite a bit.
There was at least one (and maybe more) service bulletins related to lifter tick for the 3.4 DOHC, having to do with the cam oiling passages not being appropriately sized or something like that.

I used to get lifter tick after just a few short bursts of full throttle at high RPM, until I improved my cooling system. I think the oil temps can climb pretty quickly, especially since the oil-to-water heat exchanger is fed from the block's water jackets rather than cool air returning from the radiator.
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Re: Track Days in the DOHC Fiero

Post by Series8217 »

Well this sucks.

During my post-track suspension inspection I have discovered both front wheel bearings to have a lot of play in them. One is an OE unit with unknown miles, and the other is a brand new Rodney Dickman bearing that I installed last week.

Going to contact Rodney to see how much radial deflection these are supposed to have...
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Re: Track Days in the DOHC Fiero

Post by Aaron »

Ouch. Time to upgrade the front brakes/suspension to ones from a heavier duty car?
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Re: Track Days in the DOHC Fiero

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Aaron wrote:Ouch. Time to upgrade the front brakes/suspension to ones from a heavier duty car?
I just need wheel bearings that work, not brakes or suspension.

I'll probably need to start designing a new knuckle if I want to keep running this car but that is NOT the direction I wanted to go with the car. Looking into other options. I was going to sell the Fiero and get something else due to the front wheel bearing issue, and when Rodney's bearings came out and racer people said they were working I figured it'd be ok to continue development on...
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Re: Track Days in the DOHC Fiero

Post by Shaun41178(2) »

That's bad news. And based on the video, it didn't look like you were pushing it that hard either so the loads couldn't have been that high. Not to mention your cornering forces were only 1 g or less. I was prob going to get new bearings just to have a pair but I was never planning on tracking mine. a completely new bearing system or even a new knuckle with bigger bearings will need to be looked into I am guessing for any sort of durability.

Pretty sure Pontiac did that with the Indy pace car. Won't help you with your 88 of course but maybe an idea could be brainstormed from it

Edit. thread research has pretty much turned up solutions for larger bearings in the rear not the front who h is of no help. Pretty sure this was what was done on the 84 pace car too with the front being factory stock. Are Rodney's sealed bearings for the 88s greased up with an adequate amount? I am guessing they can't be disassembled to add more or inspect?

Edit 2. Did both shit the bed or just the one where the dust cover came off and dirt got all up in it?
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Re: Track Days in the DOHC Fiero

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Shaun41178(2) wrote:That's bad news. And based on the video, it didn't look like you were pushing it that hard either so the loads couldn't have been that high. Not to mention your cornering forces were only 1 g or less.
I'm afraid you have no concept of speed on track.. This was a 10/10ths lap. This is a very fast lap for this car on this track (would have put me in third if I was running in TTC). Lateral acceleration was around 1.2g which is about right for these tires with some aero.
Edit. thread research has pretty much turned up solutions for larger bearings in the rear not the front who h is of no help. Pretty sure this was what was done on the 84 pace car too with the front being factory stock. Are Rodney's sealed bearings for the 88s greased up with an adequate amount? I am guessing they can't be disassembled to add more or inspect?

Edit 2. Did both shit the bed or just the one where the dust cover came off and dirt got all up in it?
The one the dust cover came off of was replaced with a brand new one right before this last weekend. That unit is junk for track use now, but I'll keep it as an emergency spare for transit after I refill it with grease. I tackwelded the cover on the new one. Some grease did seep out from the cover. I think some sealant would be a good idea.

The cover can be removed and more grease can be injected, but I think it will only reach the inner bearing.
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Re: Track Days in the DOHC Fiero

Post by Shaun41178(2) »

Concept or speed isn't necessary when your telemetry shows your speed and other data. Most of the turns were at 60mph ish. Top speed was around 104 mph or so from what I could tell. 1g is a decent load but could be much higher with newer cars with better suspension. Curious as to how their bearings hold up to 1g loads and 60 mph cornering speeds.

I can't believe stock components on the Fiero can't handle this for 20 laps.
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Re: Track Days in the DOHC Fiero

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Shaun41178(2) wrote:Concept or speed isn't necessary when your telemetry shows your speed and other data. Most of the turns were at 60mph ish. Top speed was around 104 mph or so from what I could tell. 1g is a decent load but could be much higher with newer cars with better suspension.
Wait.. are we watching the same video? Maybe you are watching my old one? Most of the turns in my recent video are 70 to 95 mph
Just a few of the high speed corners:
90 mph @ 1.2G http://youtu.be/rqf3OraBgRM?t=1m13s
95 mph @ 1.2G http://youtu.be/rqf3OraBgRM?t=1m25s

Aero effects aren't too significant in low speed turns (45 to 60 mph), so in those turns the cornering forces simply show what the tire produces with my steady state camber and weight transfer. It's not any higher with "newer cars". Newer vehicles running the proper amount of camber achieve the same ~1G on these tires as my car does. The newer cars just achieve it with better ride quality and durability, and with better control over a wider range of transient conditions.

The 1.2 G turns are the higher speed ones where grip is increased due to aero downforce (front splitter and rear wing).

Here is a comparison using the same tires to show the cornering forces on a new Miata MX-5 in an idealized skidpad test: http://blog.365racing.net/2013/01/22/th ... orts-park/

They achieve 0.8G on street tires (Comp 2's), 1.05G on the Rivals (same tires I have), and 1.2G on R1S's (R-compound slicks).

For comparison, my friend's S2000 with a rear wing and front splitter on 255/40/17 Toyo R888s (R-compound tires) achieved a peak steady state 1.4 G on the same race course on the same day. That's a 16% increase over my peak steady state lateral G's of 1.2, and is the expected improvement with R compound tires vs. the 200 treadwear Rivals.
Curious as to how their bearings hold up to 1g loads and 60 mph cornering speeds.
I'm not aware of any commonly-tracked cars that have any wheel bearing problems. Maybe the "commonly-tracked" part is the key..
I can't believe stock components on the Fiero can't handle this for 20 laps.
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Re: Track Days in the DOHC Fiero

Post by Shaun41178(2) »

I watched the video from April 7 upload date. Many of the corners there with Gs in the 1 range were in the 60 mph range. There were a couple of sweeping corners that were at higher mph but lower Gs.

Your friends s2000 is hitting higher loads. Are his front bearings shot? That's what I'm getting at
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Re: Track Days in the DOHC Fiero

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Shaun41178(2) wrote:There were a couple of sweeping corners that were at higher mph but lower Gs.
Higher MPH and higher G's, for longer periods of time. Those are the ones that tax the wheel bearings the most (and also the subsequent braking from those high speeds).
Shaun41178(2) wrote:Your friends s2000 is hitting higher loads. Are his front bearings shot? That's what I'm getting at
The OEM hubs on the S2000 seem to last just fine. The non-OEM replacements apparently have failed during the 25 Hours of Thunderhill endurance race.

Note that I ran an entire year on unknown-mileage GM 1988 Fiero front bearings until I had any significant play in them. This GM unit that failed over the weekend might have had play in it before, or was about to go. For all I know it had 200k miles on it. However, the Rodney one was brand new and only lasted one weekend (~60 laps) despite the grease cover being tacked on so it doesn't come off like it did with my first bearing.

I don't know why the aftermarket has so much trouble designing durable bearings. Clearly there are units designed to be cheap, but Rodney's weren't (although they were still subject to space constraints and setup costs). I'm talking about things like the S2k stuff too though.
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Re: Track Days in the DOHC Fiero

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Shaun41178(2) wrote: Edit. thread research has pretty much turned up solutions for larger bearings in the rear not the front who h is of no help. Pretty sure this was what was done on the 84 pace car too with the front being factory stock.
Thanks for helping me research that by the way.

I did end up finding this for the front of an '88:
http://www.fiero.com/forum/Forum3/HTML/0 ... html#p2440
EDIT: Will collected all of the info here: http://www.fiero.com/forum/Archives/Arch ... 6.html#p31

It's a 513009 bearing disassembled to harvest the bearings and hub and install them in the 88 Fiero bearing carrier (the part that bolts to the knuckle).
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Re: Track Days in the DOHC Fiero

Post by Shaun41178(2) »

Expensive fixes to keep replacing Rodney's bearings every 60 laps.

I would pack more grease or different grease in new bearings instead of trusting the factory stuff. A thicker grease perhaps will help. Who knows what the factory uses and what its rated for
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Re: Track Days in the DOHC Fiero

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Shaun41178(2) wrote:Expensive fixes to keep replacing Rodney's bearings every 60 laps.
Agreed. It's not feasible. I need bearings that work.
I would pack more grease or different grease in new bearings instead of trusting the factory stuff. A thicker grease perhaps will help. Who knows what the factory uses and what its rated for
I intend to try a different / more grease (and a better grease cap seal) on my one remaining good RD bearing. I'll also take apart the one that has failed to see how it looks inside.

A few things I noticed about the factory bearings compared to Rodney's:
1) The outer wall is thicker
2) The factory grease cap fits tighter and has sealant on it. Rodney's cap still leaked a small amount of grease during the track weekend; there is no sealant on the cap. The caps are not interchangeable due to the thinner wall on Rodney's bearings.

It's possible that the RD bearings distort under load and that's what causes the caps to come off, and probably contributes to failure.

RD also has noted that it's not possible to make a bearing with the same strength as the factory bearing without significant investment. I think this is because on the factory bearing the races are integrated into both the hub carrier and the hub, in order to maximize the size and spacing of the inner and outer bearings. So the factory bearings are still the strongest bearings.
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Re: Track Days in the DOHC Fiero

Post by Shaun41178(2) »

If the factory grease from Rodney's are oozing out then its probably not a good enough grease and it seems its liquifying. If that's the case then the damage should be obvious when taking apart. I guess you will have to see what Rodney says as far as how much play they are supposed to have
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Re: Track Days in the DOHC Fiero

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Series8217 wrote:
Thanks!

Yup, that's the plan with the reclass. Greg now allows people to submit power and request a class, and then he assigns a new base weight, rather than submitting base weight and power and getting a class you don't want or expect. I'm going to request whatever class puts me into TTC with the points I have in aero, suspension, and tires. Whatever extra weight I have to add (if any) I will add as ballast up front so I can run a wider front tire. Then it won't affect cornering speeds, just acceleration.
TTC should be a fun class to run in I think. I hate that my V is base classed in TTC with two asterisks and that they have done away with TTA. Because of my mods, I'm pretty much stuck with moving out of the points based classing into weight/power of TT3...

Do you have a current breakdown of the non-engine mods points you're taking?
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Re: Track Days in the DOHC Fiero

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I ran another track weekend with NASA at Buttonwillow last weekend. This time we ran the #1CCW configuration. It's only the second weekend I've run this track CCW. Air temp was ~103*F on both days, with the track surface way, way hotter. I installed my oil cooler but haven't ducted it yet so I don't think it's doing anything, especially with that hot air coming off the asphalt. Coolant temps were in the 220*F to 230*F range, maybe as high as 240*F. Lots of lifter tap so I'm sure the oil was still 280*F+..

I hooked up my rear swaybar again in an attempt to limit body roll and get some more traction in the rear since I think it was limited by geometry and not weight transfer. Sure enough, the car is hardly looser but I've gained some front grip and the rear feels more planted too. However, the car now wig-wags on slide recovery (see: this part of my bloopers video). I know the 475# springs were already too much for the Koni reds, even at full stiff, but the rear swaybar makes it really obvious. I have a set of Bilstein struts waiting on the shelf for a revalve. I hope to get to those later this summer.

I pulled the carpet out for my interior color change and didn't put it back in before going to the track. I didn't expect to have any problems related to that, but it turns out the carpet is pretty important. The Fiero has a ridge that runs down the center of the footwell in the exact spot where my heel rests. With the carpet removed, it's just that semi-gloss chassis coating on the floor. It's super slippery. I literally could not drive the car on the track in the first session. I got some gaffer's tape from my friend and put a few layers down. Problem solved.

Pretty uneventful weekend overall; only a couple spins and no real offs. I was down on power later Saturday and most of Sunday. I thought it was my imagination until I heard a distinct misfire.. then I thought it was the heat. On the last session, I lost a significant amount of power. At the entrance to a turn where I would normally be going 100+ mph I was down to 85. The induction noise had changed too. I pulled into the pits and packed up to go home.. started the car to leave, drove 15 feet, and it stopped. We thought it was out of gas but after putting 4 gallons in it was doing nothing. The racers finished running so I tried to listen for the fuel pump. Nothing. The relay and fused checked out, but the pump doesn't run. The fuel rail was bone dry -- just gasoline vapor. Ugh. I could've made it to the parts store but not at 105*F at the end of a long day, so I used my AAA tow.

I put together a reel of bloopers and "heroics" for the weekend:
https://www.youtube.com/watch?v=unbIIwKe-4M
If you watch my steering inputs that were necessary for correcting for the rear stepping out, do a quick mental calculation: the stock steering requires ~1.7 times more turning than my rack. Good luck with that.

There's also a short clip of me pulling flat out through a banked left-hander. Watch the oil pressure gauge. It's hard to tell but it looks like it jumps down ~4 or 5 psi once or twice. Might be sucking a bit of air :-/.

Also my AC is busted again.. totally my fault though. When I moved a heater hose to make room for the oil cooler lines I didn't realize that it was pushing the AC hose into the exhaust manifold. It eventually melted through and popped. I knew exactly what the sound was from when I heard it. Ugh. At least I didn't have to drive home in the heat since I got towed.

That's all for now. I am waiting for the photos I ordered to arrive. I also need to check my front right wheel bearing (Rodney Dickman) and see how it held up over the weekend.
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Re: Track Days in the DOHC Fiero

Post by Shaun41178(2) »

Oil in the pan is sitting on the side during a hard turn or the pic k up tube has come off. Did you reverify your oil level after plumbing the cooler and lines. You prob need 2+ additional qts now
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Re: Track Days in the DOHC Fiero

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Shaun41178(2) wrote:Oil in the pan is sitting on the side during a hard turn or the pick up tube has come off.
The pickup tube is welded on. This is still my balanced and blueprinted motor that I had in my silver car (in case you were following that build).

Chris West reported the same oil pressure issue during lefthand sweepers on his 3.4 DOHC V6 car at the track. He came up with some baffles and trap doors that solved the issue. I need to drop the pan to add an oil temperature sensor, so while it's out I may just set up the pan the same way Chris did his. Otherwise an accusump may take care of it.

I'm a bit surprised I haven't had any problems with rod bearings at Auto Club Speedway, since that's a massively banked very high speed, very high g-force, very long left-hander at high RPM.
Did you reverify your oil level after plumbing the cooler and lines. You prob need 2+ additional qts now
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Re: Track Days in the DOHC Fiero

Post by Aaron »

Shaun was probably just making sure, you never know!

I'd be shocked to hear the cooler didn't make a difference, even without ducting. Also, have fun getting the pan off..
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