cautionary tale for the 914 racers here, vid gets a bit long waiting for the tow truck but worth a view Options

[byndbad914]

check out my channel

http://www.youtube.com/user/byndbad914?feature=mhee

The latest track day adventure. Had a couple friends out and was going to split the first session of the day giving them both a quick ride while I warmed up the tires... turns out to not be the case but also get to learn a new lesson.

[Randal]

check out my channel

http://www.youtube.com/user/byndbad914?feature=mhee

The latest track day adventure. Had a couple friends out and was going to split the first session of the day giving them both a quick ride while I warmed up the tires... turns out to not be the case but also get to learn a new lesson.

You were cranking out some fast laps there Tim, and with a passenger. (IMG:style_emoticons/default/huh.gif)

Love your car!

So the wheel was the only issue? The transmission was OK?

Just shows we all should re-check the wheel nuts before every session on the track or hill climb.

And if you go watch the historic guys at the track everything is wired.

[byndbad914]

yeah, car was feeling great and already off to a good start with 1:59s considering I was also having to let off and brake incredibly early for every turn.

and yes, trans is fine, the only issue is the hub nut. Even tho' it is a locking design, apparently you have to check them periodically. And I know to torque the crap out of them when they are installed, I normally hit it really hard with my impact gun and then verify the gun cleared 150 ft-lbs with my torque wrench. Sort of surprised it loosened up.

To be honest, the car was a little skatey the last track day when I ran the 1:54.97 under heavy braking, so I think it was loosened up a bit even then and I didn't catch it even tho' I replaced the brake pads! I really think the car is worth consistent 1:53s if I ever got everything right in one day. I can say that one day last year we were timing my car in three sections on top of my lap timer, and if you pieced together the best three sections I would have had high 1:53 and I know the car is faster than that now with a few more changes. That is pretty much smoking for that track.

[naro914]

slightly OT, but what trans/shifting linkage do you have? you can do some awfully fast shifting in that car. Very nice...

[Mugs914]

You were cranking out some fast laps there Tim, and with a passenger. (IMG:style_emoticons/default/huh.gif)

Love your car!

Me too! Great laps... (IMG:style_emoticons/default/aktion035.gif)

Just shows we all should re-check the wheel nuts before every session on the track or hill climb.

Absolutely! We always impact gun, torque, then put paint marks on the hub and nut to provide a visual clue as to whether anything has loosened. Then we check 'em again... everytime!

BTW - Isn't that hub nut supposed to be torqued to somewhere north of 200ft. lbs.? I can't remember off hand and might be confusing the 914 with a 944 or something... (IMG:style_emoticons/default/wacko.gif)

[byndbad914]

naro - I have a Mendeola S5 (Sequential 5spd) transaxle with a simple cable shifter setup. I had a S4 (4 spd) before and it would miss shifts all the time, especially on downshifts, and I split the case nearly in half slamming 2nd on a downshift (the bellhousing and rear cover were holding it together) after only 15 hours on the track. I about died. I shipped it to Mendeola and then flew out there to watch it being rebuilt and they told me I had to swap to a 5spd which they assured me I didn't need when I bought the S4, but alas it has less dog teeth so it shifts better at high rpm. Now I have to admit it has never missed an upshift and shifts like butter, but I have had it miss downshifts a couple times still, so that is still a bit of a bummer. You have to just smash the shifter and go, but on downshifts, I am still a little gun shy given my previous issue when downshifting (IMG:style_emoticons/default/blink.gif)

When it is working tho' it is a thing of beauty!

mugs - yeah, the torque is way up there. My wrench will go over 150 ft-lbs but I just always make sure it clicks there. My 1/2" impact is pretty harsh on the highest setting and I have the line pressure at around 100 psi which is consistent since I am the only guy on the line. In 8 yrs of seriously messing with the car I have never had it loosen up. So I got used to not being worried to check them. Instead, I typically only mess with them when I pull the stub axles out when I go through and re-grease the CVs each year. Last year, early in the year, I put new bearings in there and re-greased the CVs and that would be the last time I torqued them or checked them.

So I put the video out there for others to see that the symptoms of that nut loosening up are like, because for me, it mimic'd the symptom of having too much rear brake bite. If anybody is tracking their car and the rear is skating under braking, it may not be the brakes! Just go in right away and verify the wheels are tight on the car first, then if they are, consider the brakes. Oh yeah, forgot, I had to pump the brakes a couple times to get pedal on the last lap and that was when I pointed I was going to go in - I was so baffled at that point as new pads wouldn't cause that problem of course. It was really because the pads were being knocked back by the flopping rotor.

And what seemed like a clutch slippage issue was really my LSD clutches freaking out when I stopped putting power to one wheel altogether because the stub was loose enough to back out the splines.

[andys]

Tim,

Good race....er practice report. You always learn something, so thanks for sharing the experience. I'm glad you didn't have an outright failure and you safely got back to the pit. So yeah, when you experience a new sensation/noise, it usually means something's up. Human nature is to analyze first; you made a sound decision to pull it in. Any other damage like brake line, caliper, rotor, or?

Andy

[SirAndy]

Even tho' it is a locking design, apparently you have to check them periodically.

I was going to ask, did the locking pin break?
(IMG:style_emoticons/default/idea.gif)

Because with the pin intact, you should not get that much slop ...
(IMG:style_emoticons/default/popcorn[1].gif)

[byndbad914]

Andy1, everything else looks fine. I am sure the new pads have a little uneven wear but I expect them to be just fine, the rotor looks good, and all feels pretty solid once I torqued the nut back up. As for analyzing, I have to say I stayed out much longer than I would normally would have with a weird issue - I usually come in immediately. It was just one of those really strange set of coincidences that I put new rear pads in and changed the camber, and the way the car was acting, it appeared to have bias issues with the new pads and oversteer from getting the camber a bit wrong. Until I had to pump the brakes to get the pads pushed back out and then losing power in that turn, I was on a path to try to resolve the two. Just one of those flukes where I had a new issue that acted like expected with the other two changes made, so I never once thought "loose wheel". I am actually really happy the stub can come disengaged before the nut is fully off, it is a bit of a safety feature in a way.

Andy2, As for a locking pin, the car doesn't have that. I have late model Carrera hubs and stubs so maybe that is different than the stock 914? I admit I forget what the stock 914 was like, been quite awhile I have had this setup, and these just have a lock nut as the only locking feature, well torque also is a locking feature, but you get my point.

[byndbad914]

So it has been a couple months while I focused on driving the trailer out to CA (hitting SEMA on the way), picking up the Nova I bought last summer for my new project, and then getting everything in the garage prep'd to build a chassis for it.

In between I broke an extension standing on my breaker bar with 4ft of pipe over it trying to get the axle nut back off after the last time I tightened it up pull the car out of the trailer and into the garage, borrowed my buddies torches only to find out his acetalyne was empty, blah blah, finally got the bottle filled yesterday.

Took 2 hrs of beating and cutting to get the nut off! I was trying to be careful to not damage the hub, figured I yielded the stub threads...


then I found I had to hammer the stub out! Here is what I ended up with


the sharp eye will quickly note I need not have bothered with protecting the hub while cutting - I sheared the damn thing off! The hub section that rides on the bearing is stuck on the stub axle, a few teeth were tore up so it is holding that onto the stub! What I had to hammer apart was the bearing to get the stub out. Guess that would explain the slipping in the diff (IMG:style_emoticons/default/laugh.gif)

Literally, the only thing holding the wheel on was the stub axle and the nut, the hub was completely broken off (IMG:style_emoticons/default/blink.gif)

[stewteral]

So it has been a couple months while I focused on driving the trailer out to CA (hitting SEMA on the way), picking up the Nova I bought last summer for my new project, and then getting everything in the garage prep'd to build a chassis for it.

In between I broke an extension standing on my breaker bar with 4ft of pipe over it trying to get the axle nut back off after the last time I tightened it up pull the car out of the trailer and into the garage, borrowed my buddies torches only to find out his acetalyne was empty, blah blah, finally got the bottle filled yesterday.

Took 2 hrs of beating and cutting to get the nut off! I was trying to be careful to not damage the hub, figured I yielded the stub threads...

then I found I had to hammer the stub out! Here is what I ended up with

the sharp eye will quickly note I need not have bothered with protecting the hub while cutting - I sheared the damn thing off! The hub section that rides on the bearing is stuck on the stub axle, a few teeth were tore up so it is holding that onto the stub! What I had to hammer apart was the bearing to get the stub out. Guess that would explain the slipping in the diff (IMG:style_emoticons/default/laugh.gif)

Literally, the only thing holding the wheel on was the stub axle and the nut, the hub was completely broken off (IMG:style_emoticons/default/blink.gif)

Hey Tim,
As always, I loved your in-car video, but sorry for your bearing failure.

I was trying to make you feel better, but my failure was far less of a mess: Last May, I towed 7 hours north for a 3-day outing at Sears Point (Infineon) Raceway. However, I only got 2 sessions in when I notices the rear feeling SQUIRELLY in left-hand corners. Once in the pits, I found the right rear could flop around by +/- 1/4". After nervously towing the 7 hours home (and leaving some $400 of track time behind) I found that the bearing failure was due to slipping and wear between the wheel flange and bearing, but not the bearing.

I scored a new wheel flange from eBay, put in a new bearing and all was good.
I believe the failure was due to the axle nut loosening and allowing the rotation to start. After 8 years of on-track running, I'm surprised I went this long without a problem. Praise to Porsche Engineers!

Best,
Terry

[Randal]

So it has been a couple months while I focused on driving the trailer out to CA (hitting SEMA on the way), picking up the Nova I bought last summer for my new project, and then getting everything in the garage prep'd to build a chassis for it.

In between I broke an extension standing on my breaker bar with 4ft of pipe over it trying to get the axle nut back off after the last time I tightened it up pull the car out of the trailer and into the garage, borrowed my buddies torches only to find out his acetalyne was empty, blah blah, finally got the bottle filled yesterday.

Took 2 hrs of beating and cutting to get the nut off! I was trying to be careful to not damage the hub, figured I yielded the stub threads...

then I found I had to hammer the stub out! Here is what I ended up with

the sharp eye will quickly note I need not have bothered with protecting the hub while cutting - I sheared the damn thing off! The hub section that rides on the bearing is stuck on the stub axle, a few teeth were tore up so it is holding that onto the stub! What I had to hammer apart was the bearing to get the stub out. Guess that would explain the slipping in the diff (IMG:style_emoticons/default/laugh.gif)

Literally, the only thing holding the wheel on was the stub axle and the nut, the hub was completely broken off (IMG:style_emoticons/default/blink.gif)

Sure wish you would keep that beauty together and continue your campaign! (IMG:style_emoticons/default/biggrin.gif)

[byndbad914]

I have all the parts I need to get it back together so I hope to get a couple more track days in with it. I did get all the 2x3 rectangle tube last Friday to start the Nova frame so will be working both in parallel for a bit. I bought a new, complete wiring harness for the Nova as well, so I will be leaving all the wiring in the 914 and may just build new suspension uppers and have the lowers cut out again, I still have the solid model, so I might leave it as a roller, no shocks. We will see, wouldn't be that hard to drop parts in it again at a later date and track it.

edit - was thinking about it as well and considering I have ran the car pretty consistently the past few years, other than the transaxle BS I dealt with Mendeola, this is the first track failure I have had that put the car on the trailer in quite some time so I really can't complain (IMG:style_emoticons/default/smile.gif)

[Randal]

I have all the parts I need to get it back together so I hope to get a couple more track days in with it. I did get all the 2x3 rectangle tube last Friday to start the Nova frame so will be working both in parallel for a bit. I bought a new, complete wiring harness for the Nova as well, so I will be leaving all the wiring in the 914 and may just build new suspension uppers and have the lowers cut out again, I still have the solid model, so I might leave it as a roller, no shocks. We will see, wouldn't be that hard to drop parts in it again at a later date and track it.

edit - was thinking about it as well and considering I have ran the car pretty consistently the past few years, other than the transaxle BS I dealt with Mendeola, this is the first track failure I have had that put the car on the trailer in quite some time so I really can't complain (IMG:style_emoticons/default/smile.gif)

To me, you were looking like going into the low low 50's in the video. Slowly working up on it and increasing speeds in and out of corners, which is the smart way to travel.

Now, once you get there, next to the cup cars, anything else will just be playing. know what I mean?

And not many guys get to have the satisfaction of doing it by building their own cars. That has got to feel pretty good. (IMG:style_emoticons/default/flag.gif)

[byndbad914]

And not many guys get to have the satisfaction of doing it by building their own cars. That has got to feel pretty good. (IMG:style_emoticons/default/flag.gif)

Yeah, there is definitely a satisfaction when I make a few tweaks and the car picks up more. I was thinking about it and this car, since I started the race car project roughly 12 years ago, has been the longest I have had one car my whole life! I have had 8 other vehicles in that same 12 year time frame! I think right at 3 years is the longest I have had any other vehicle in the last 12 (IMG:style_emoticons/default/blink.gif) So I have been jonesing for a different car to track, but then when I click off a good time, it gets hard to move on.

But, along with the satisfaction mentioned earlier, I really want to see if I can get a 66 Nova with no flares, complete interior, completely street legal into sub-2 minute laps. I know Corvette Grand Sports are 1:57s with ballast to meet SCCA weight. I should have a bit more power than a tuned LS3 but will break even at best dragging that brick of a body shape through the breeze, Vette suspension may be better given all the engineering it has, similar tire size, and hopefully 300-400 lbs less weight... that might add up to a bit slower but maybe 2:00s or less.

[Randal]

And not many guys get to have the satisfaction of doing it by building their own cars. That has got to feel pretty good. (IMG:style_emoticons/default/flag.gif)

Yeah, there is definitely a satisfaction when I make a few tweaks and the car picks up more. I was thinking about it and this car, since I started the race car project roughly 12 years ago, has been the longest I have had one car my whole life! I have had 8 other vehicles in that same 12 year time frame! I think right at 3 years is the longest I have had any other vehicle in the last 12 (IMG:style_emoticons/default/blink.gif) So I have been jonesing for a different car to track, but then when I click off a good time, it gets hard to move on.

But, along with the satisfaction mentioned earlier, I really want to see if I can get a 66 Nova with no flares, complete interior, completely street legal into sub-2 minute laps. I know Corvette Grand Sports are 1:57s with ballast to meet SCCA weight. I should have a bit more power than a tuned LS3 but will break even at best dragging that brick of a body shape through the breeze, Vette suspension may be better given all the engineering it has, similar tire size, and hopefully 300-400 lbs less weight... that might add up to a bit slower but maybe 2:00s or less.

I raced a couple of well driven LS-6's at Cascade Lakes. Think I would have got them without a huge 1 to 2nd (901 (IMG:style_emoticons/default/hissyfit.gif) ) mistake on my last run. Was within 1.2 seconds of them and that missed shift cost me 2 seconds.

Would love to see you running Cascade Lakes. You do it once and you would never take that beautiful car apart. Honestly, nothing like a hill climb. (IMG:style_emoticons/default/biggrin.gif)