BUILD-OFF CHALLENGE: MichiganMat Options

[Andyrew]

Your likely to get there before me.. Im still wrangling wiring issues and then I have to redo my steering linkage. Just trying to make it driveable for WCR 2019..

[matthepcat]

This car sounds awesome. Seems like you were moving pretty quick when it spun out, does the car want to rotate like that at slower speeds?

[MichiganMat]

Took the cars out to Laguna Seca yesterday, my 914WRX and my brothers 912STI.

• Got about 4hrs of sleep the night before, anticipation and anxiety woke me up at 2am and I couldn't get back to sleep.
• Cold as balls on the way there, terrible, but sooooo glad Im towing instead of driving a racecar to the track these days. Stereo, cup holders, heat, relative silence.
• Laguna is the most convenient track I've been to yet, so close and easy to get to. I'll be going back soon.
• Soooo glad my Rover has a low gear because the 16% grade going into Seca is *steep*.

We get all set up, get the 914 off the trailer and prep some things for the first session...

• I roll out onto track, accelerate into turn 3 and theres a 5' wide stream of water going across the track. Cold tires and I go full opposite-lock, Tokyo Dorifto through the entire corner, thinking to myself "please don't be that guy, please don't be *that guy*". I save it.
• By the time I start going up the hill I see water shooting over my shoulder. By the time I the corkscrew, the car is full-on puking steam and boiling water. I pull over to the far right of the screw and shut it off. I wait for a quiet moment and coast the car down the screw, down 9, into the paddock. allllll the way across the paddock, and pull it directly into our pits, all on gravity power. Not even a full lap of Seca
• I triage the situation for ~1hr, finally pull the thermostat and cut it open, rusty water drains from the motor (not good). We fill it, and after an hour I try for the 2nd session. Temps are all over the place, 170, 220, 190, 230(!!!). I get a few laps, maybe 3, and the car is spitting again so I bring it back in. Another hour goes by and we finally get it burped, temps are stable.

Meanwhile, Mike is driving the doors off the 912 and having a blast

• Session 3 we go out together, temps look great, so we chase each other for the whole session. It was amazing. The 912 is sooo goddamned fast, he walked me on every straight, but I would catch him on the tight corners. The sway-bars we added to both cars have worked wonders, so stable and predictable through all steering input. The 914 is still a bit tail-happy, may need some bigger rubber.
• Session 4, no drama, just fast and fun laps
• Session 5, getting *realllllly* tired now, the lack of sleep has caught me bad. About 3/4 of the way through the session I loop the car diving into 9 at pretty high-speed. Wiggle-wiggle-scccccrreeeeaaacccchhh. 360, all on the pavement, but the car won't start or bump-start, so I coast it down 10 into the pits, alllll the way past the pit garages, and ever-so slowly into our pits. Got some weird looks, seeing the car silently rolling by, so I yelled "ITS A HYBRID!" and just kept going.

Car is fine, just needed a moment to cool off and she started right up. A few take-aways:

• The '02 WRX motor really isn't enjoying life at 5500+ RPM. All the grunt in the power band is 3-5K. The engine is vibrating, not smooth, at 5K+, so not sure whats going on there, so I kept it under 6K for the whole day. Redline is 7K.
• The Racecapture computer in the car is pretty good but the shitty Fire tablet Im using for it kinda sucks, makes things complicated. Going to find a fix.
• BRAKES. OMG, the 914 needs race pads. I had good pressure and decent proportioning, but no bite. Going to upgrade those for sure.

We stopped in Salinas for mexican food and beers, had the trailer parked in the driveway by 8pm. A solid day. Can't wait for the next one.

[mepstein]

Sounds fun. What engine is the 912 running.

[MichiganMat]

Sounds fun. What engine is the 912 running.

Stock '06 STi mated to a Porsche 915 box + Wavetrak LSD

Makes 315hp at the wheels and revs to 8K, its a savage motor. Equal-length headers to twin-scroll turbo too.

[Andyrew]

Sounds like a blast! Congrats on the successful day!!!! What group did you run with?

[MichiganMat]

Sounds like a blast! Congrats on the successful day!!!! What group did you run with?

Still shaking the bugs out of it, so we both ran in Solo, which basically the novice group. Plenty of fast cars in the group, we didn't feel held-up by anyone but a single car, so it was the right choice.

Been thinking about ways to squeeze more speed out of the car all week, heh. Definitely needs better brake pads. Also thinking a lot about that top-end 5500+ RPM vibration / lack of power too. I never hit the rev-limiter during the day, I just didn't have confidence in the motor and wanted to get through the day. The next day out will be exploring the top-end of the rpms.

Baby-steps I suppose. Before this car, I had loads of days in my 911 and all the bugs were worked out. This new chassis and motor are taking some time to get sorted.

[andys]

Interesting thread! For your track days, do you have a tire pyrometer to run some tire temp profiles? It would aid greatly in how the suspension and tires are behaving, and what course of action you need to take. Can't remember, do you have LSD, or open diff?

Good luck,
Andys

[Andyrew]

Sorry I was curious what organization you went with for Laguna. I normally run OnGrid and they just picked up Laguna a couple times this year I believe. But I don't trust myself at Laguna with the 914.

Braking was an issue for me but more locking one tire and not feeling confident in it. Hard to push a car hard ok the track if you can't get on the brakes... Especially a track like Laguna with turn 2 and a HP car.

Did you limit yourself on the front straight? I know I doubt I would take turn one over 100... That is one of the scariest corners I've driven in simulation, especially in an mid engine car.

[Andyrew]

Also did you add just front sway bars or both front and rear?

Sounds like that was a great addition

[MichiganMat]

Tire pyrometer: No, tire tuning will be part of my next day. I tried to keep the pressures when hot at ~ 27 rear, 24 front. Will be chalking the sidewalls next time out. The car also sits a bit high (because of the WRX oil pan and exhaust hang low) so Im not getting optimal negative rear camber.

Diff: Yeah, its open. Really didn't feel any tire-spin while out there tho. I used to get it a lot in my 911, but doesnt feel like much of a factor in the '14.

Run group: This event was with NCRC, who I recommend. Low on BS. I run other events with TrackMasters and HOD, all good orgs.

Limits: No limits baby, foot to floor, deep into 5th gear. Just a bit of drift but nothing terrible. Hug the wall and point her straight! Found that I was much more hesitant in 9, and maybe 4, and eventually got stung in 9 as I got tired and looped it hard.

Sway-bar: Added a front sway from Tarret, worth every penny. Not running a rear bar. The car is transformed (as expected) and feels so much less twitchy, it was nearly undriveable without the bar.

[andys]

Tire pyrometer: No, tire tuning will be part of my next day. I tried to keep the pressures when hot at ~ 27 rear, 24 front. Will be chalking the sidewalls next time out. The car also sits a bit high (because of the WRX oil pan and exhaust hang low) so Im not getting optimal negative rear camber.

Diff: Yeah, its open. Really didn't feel any tire-spin while out there tho. I used to get it a lot in my 911, but doesnt feel like much of a factor in the '14.

Run group: This event was with NCRC, who I recommend. Low on BS. I run other events with TrackMasters and HOD, all good orgs.

Limits: No limits baby, foot to floor, deep into 5th gear. Just a bit of drift but nothing terrible. Hug the wall and point her straight! Found that I was much more hesitant in 9, and maybe 4, and eventually got stung in 9 as I got tired and looped it hard.

Sway-bar: Added a front sway from Tarret, worth every penny. Not running a rear bar. The car is transformed (as expected) and feels so much less twitchy, it was nearly undriveable without the bar.

For me, monitoring tire temp profiles is a great tuning tool. Takes much of the guess work out of making adjustments, and gets you close in a much shorter period of time. This is particularly important for setting up your suspension during a track day, where your time is usually limited. Getting the camber and tire pressures right is very quick and easy. I simply make it a habit of recording the profiles every time I pit. You'll be able to answer that rear camber issue right away. I think you said you're a 2 degrees, right? I ran 2.5 degrees on my LS1/914 (not a track car), and the tire temp profiles were perfect. Also, I like to run a little toe out to help turn-in; I know many don't like to, claiming it tends to wander at high speed, but I've never had a problem in that regard. Yeah, the front sway bar is a must. With the open diff, don't run a rear sway bar.

If you ever decide to run Willow Springs, give me a heads-up and I'll meet you there (I'm only an hour away). BTW, The Streets of Willow is a good track for suspension tuning, with its many low and medium speed turns; gets the tires working quickly.

Cheers,
Andys

[MichiganMat]

So what has MichiganMat and the 914WRX been up to in the last couple of months anyways? Well.....

Took the car to BWillow back in May and had a grand ol' time until I spun two rod bearings in session #4 and had to put it back on the trailer. I knew something was up because the exhaust note changed, it got *louder*, and a few laps later I got a hard tap-tap-tap out of the engine and knew something had gone seriously wrong. Took the car home, a few days later had the engine torn down and washed, and sure enough the bearings were toast.

Ordered a new crank, rods, and bearings from FlatIron's Tuning and slapped on a lightweight flywheel while I was in there. I also installed a performance baffle plate between the oil pan and the block to prevent the oil from washing out, and filled the engine with 20w50. I cleaned, but did not replace the oil pump, the oil cooler, or the oil pan... more on that later.

Lightweight flywheel review: An affordable upgrade that makes a *huge* difference in engine rev response. The new fw is 10lbs, taking nearly 10 lbs off the rotating assembly and its soooo noticeable. Im glad I bought that bit, however the green break-in compound on the face of it bound up the clutch and it would not disengage. I had to fight the car repeatedly to break it loose and that was unfortunate. Now that it has a few miles on it, the clutch has not froze up on me since.

OK, so back to the story...

Buttoned up the engine by the end of May and was feeling good about it, scheduled another track-day in late June at Seca. Had a wonderful day on track, but did have to fight a few gremlins, specifically overheated the front brakes and had to bleed them 2x before just removing the front air-dam altogether which solved the problem. End of the day though, well, the exhaust note got louder and louder and by the last session of the day the rod bearings let go again and tap-tap-tap back to the trailer.

So, Im living that EJ-rod-bearing-lifestyle and I've said goodbye to $1000 in parts. The car is on the trailer while I wait for my 2nd child to be born and Im looking forward to January where I'll start tearing into the engine for another rebuild. I've started going through the data from the day and its clear as day that the oil pressure was going down down down after nearly every lap... I can only guess at why, but I suspect the old stock 10mm pump, combined with hot oil, contributed to bearing wear lap after lap until it just let go.

I'll be starting the rebuild in Jan, but this time I'll be doing it better. The rebuild plan:
• replace the oil heat exchanger with a proper oil cooler
• replace the stock 10mm pump with a shimmed 12mm pump
• standard size rod bearings instead of the oversize ones I used last time
• calibrate the oil pressure sending unit to perfection, as the numbers it was producing for my computer were far from acccurate

It makes me sad, really sad, to have to dig into this engine again but ya know, thats racing and theres still much to learn about this setup.

[MichiganMat]

Some pics of the carnage from the May BWillow date (because who doesn't love a bit of disaster-porn, right?)...

[76-914]

Any changes to the stock oil pan coming? (IMG:style_emoticons/default/beerchug.gif)

[MichiganMat]

And some pics from the Seca date in June...

[MichiganMat]

Any changes to the stock oil pan coming? (IMG:style_emoticons/default/beerchug.gif)

I've not read anything about needing to change the stock pan for performance reasons. Cleanliness yes, but not performance.

I have read other issues though:
- the pick-up brazings can fail
- the oil can spill out over the top of the pan at high-g's (which I've solved with a block-off plate)
- oil capacity can be an issue, so the subaru guys suggest running an extra 1/2qt over the full mark.
- bearing material can be hard to remove from the pan once its in there, but I saw good results with a good gasoline flush of it. Still, may replace, not sure yet.

I guess its cheap insurance to just replace it, right?

[mepstein]

Any changes to the stock oil pan coming? (IMG:style_emoticons/default/beerchug.gif)

I've not read anything about needing to change the stock pan for performance reasons. Cleanliness yes, but not performance.

I have read other issues though:
- the pick-up brazings can fail
- the oil can spill out over the top of the pan at high-g's (which I've solved with a block-off plate)
- oil capacity can be an issue, so the subaru guys suggest running an extra 1/2qt over the full mark.
- bearing material can be hard to remove from the pan once its in there, but I saw good results with a good gasoline flush of it. Still, may replace, not sure yet.

I guess its cheap insurance to just replace it, right?

I think it was asked because some people need it modified for ground clearance.

[914forme]

Dry sump in your future (IMG:style_emoticons/default/poke.gif) Reason Porsche did it back in the 60s. 1/2 Quart over was used by type-4 racers also, what is old must be new again.

Sorry about your luck with the motor as you said it is racing or lapping and things happen.

[MichiganMat]

A few updates to the project:

• Added an oil cooler and remote oil filter. Welded up the brackets in aluminum, painted, etc. I located the cooler in a place where Im hoping theres going to be airflow, and with its size and all the added lines I should be increasing oil capacity by a quart or two. Looking to keep those temperatures in the safest possible ranges.

• Added brake cooling ducts with aluminum pipe redirects to the existing 993 air deflectors mounted to my a-arms. I cooked the crap out of my M calipers at Seca, boiled them in multiple sessions. The last session of the day I ran without the front airdam an survived the session without fade or boil, so it made sense to me to work on getting more air into the rotors. I like the aggressive look of the larger ducts too.

• Currently working on a skunk-works project to add more pad capacity to the front brakes by using calipers from a Volvo 240, which just happen to be the 3" bolt spacing of my existing M calipers and Boge struts. This will require that I drill, then trim, the Boge's , but the 3" struts are unloved enough that I don't feel *too* badly about it. The extra size in pad area is significant, so thats the appeal here. It doesn't make sense to me run brakes that are jusssstt on the edge of boiling, thats not gear that is confidence inspiring, and its not safe.