Matt Lane

Until you do it yourself, well, you never think it will happen to you.

Driving the 993 at the season-ending (cold!) event at Mosport, missed a shift coming out of 3 at the exit. Reached for 4th and got 2nd instead.

Buzz. Ugh.



Limped the car gingerly back to the pits. Initial observations:

- no CEL or codes
- no unusual valvetrain noise
- car runs as normal
- definitely was over-run: the AC belt was flipped inside out and 1/2 off it's pulley...

Drove the car home 300 miles, and now planning next steps. My initial thoughts:

Oil change, look for bits?
Oil analysis?
Leakdown test?

My gearing may be relevant here - 3 to 6 are regeared shorter, see below. Assuming I short shifted and actually engaged at 6K RPM 3rd down to 2nd, does anyone know how bad this was RPM-wise in second gear? It happend within a second, just wondering how bad it really was.

Thanks in advnace for any thoughts on what to look for now - want to assess potential damage and avoid any more.

Best,

Matt

race911

Yay for money shift. Or not.......

You drove it home. That's a plus.

Usually, it's just pistons tagging valves. And you fix that. Leakdown will give you the what's what. But we know that any damage means the heads are coming off.

Back to the event. Guessing once you felt resistance on engaging the clutch you immediately depressed it again. Without data logging, yeah there's no way to know how high you went. I'll leave it to the experts to comment on 3.6L rod bolts/temporary overrevs.

NYC993

Did you fully release the clutch?
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Some had no effects, some had immediate problems, some had problems later on. I did 3rd into second 2 years ago going up the esses at watkins glen. Caught very quickly (i don't drop the clutch) and had old clutch. No issues at the time or 2 years later. So you might be lucky.

Steve Weiner-Rennsport Systems

As Ken said, do a leakdown to see if you tagged the valves or not.

If the leakdowns are normal, consider yourself VERY VERY lucky and make every effort to ensure it cannot happen again. This means checking the shift linkage as well as exercising more patience (DE prize money is notoriously poor, no trophies or even stunning trophy girls to kiss!).

Ish993

Love this

race911

Why we all aspire to pro--gotta have great memories of the trophy girls! (Memories of Gianpierro Moretti's MOMO pits back ~35 years ago.)

Matt Lane

Thanks guys - sounds like the leakdown is the next step. We'll see, and will report back.

And check the linkage. And get a remedial shifting lesson...

Feel like such a doofus.

Steve Weiner-Rennsport Systems

Wellllll,....maybe not.

You aren't first nor last guy to do this so you are truly in fine company. The key here is maintaining perspective around the activity at hand.

When a pro racer does this, its easily understandable given the context of the moment and being a commissioned entrant, paid to do a specific job to an expected level. For amateur racing or driver ed events, its hardly worth the potential consequences, given the financial rewards at stake.

Dwane

Steve, I beg to differ...won the RennSpoon drover of the year in 2014 and was offered a prestigious prize from my peers.(see pic below)
First event of 2015 broke 2 teeth on fourth gear...they say you aren't serious about this unless you got a spare transmission!

Steve Weiner-Rennsport Systems

I stand corrected; that's a mighty nifty shirt right there.

Holytin

[QUOTE=Matt Lane;12684838]

Feel like such a doofus.


Don't. There are other's that did worse. I'm one of them...

Never thought you could overrev a Porsche engine. It's a Porsche you now. And they are build for racing!

Hit mine hard in first gear and did not have a problem immediately. Parked the car in the garage and a week later...ticktickticktick.

Ended up in an engine rebuild. Worn valve guides plus an overrev will do it for you.

NC TRACKRAT

Suggestion for the OP: If you haven't already done so, here's a great excuse to purchase a Golden Rod and Fister Short Shift Kit.

Ponchobroke

On the not so dim side, as opposed to bright. You can look at it as an opportunity for head work (guides), bigger valves and an RS cam... Thx Steve.

michel j

I had the same misfortune years ago. I completed the rest of my lap (under less power - I knew I had done a bad thing ) and car stopped in the pits for good. End result was two broken rocker arms and many bent valves, hence $ shift indeed.
IMO, the fact that you made it home is amazing. Did you notice any loss of perceived power, any new engine sounds after the event?
Hopefully you were lucky and no damage was done.

Steve Weiner-Rennsport Systems

Anything can be overrevved, even race engines.

Remember, racing engines have a LOT of custom & non-standard parts in them that are specifically designed to withstand extended high-RPM use including an occasional slip up. Street engines are not so forgiving.