sgroer

dude. That’s like super deep man.

Porsche-Suchtig

I suspect you are fine. These engines are strong and it does not sound like it was enough over the limit to actually damage the motor.

Idk if this will make you feel any better... but one time in a two hour race I went from 5th at high speed on the banking at Phoenix International to 2nd just before turning down to enter the infield. Yeah... that was supposed to be 4th not 2nd. By some miracle the engine lasted the rest of the race but the next day it was toast. That’s my one and only money shift story. Fortunately it was an M3 rather than a Porsche. The top end rebuild wasn’t all that expensive in the scheme of things.

ipse dixit

Only if the cat was driving.

rhk118

Will be impossible to tell even with the readout...the cat was behind the wheel and not behind the wheel at the same time. Cats are so weird.

NBoost

Oof, found the dashcam footage of OP's incident

Outlaw 06

Here are my calculations that apply IFF the OP is absolutely certain about being at 5,500 engine RPM in 3rd gear before downshifting into 2nd gear.


Given the following specifications of the OP’s car:

Engine redline = 9,000 rpm

Rear tire diameter = 27.2 inch (for BRAND NEW 305/30R20 tires) = 85.45 inch rear tire circumference (using C = 2 x Pi x R)

Final drive ratio = 3.76:1

1st gear ratio = 3.75:1

2nd gear ratio = 2.38:1

3rd gear ratio = 1.72:1

4th gear ratio = 1.34:1

5th gear ratio = 1.08:1

6th gear ratio = 0.88:1


These are the calculations:

Step 1.

The car’s rear tires have a circumference of 85.45 inches or 7.12 feet, so 5,280 feet ÷ 7.12 feet/rotation = 741.57 tire RPM per mile.

Step 2.

Multiply the 3rd gear ratio of 1.72:1 by the final drive ratio of 3.76:1.

1.72 x 3.76 = 6.47:1 overall 3rd gear ratio (from the engine and driveline to the road).

Step 3.

Dividing the OP’s stated “at like 5,500” engine RPM by the overall 3rd gear ratio of 6.47 equals 850 tire RPM.

For reference, 850 tire RPM / 741.57 RPM per mile = 1.1462 miles per minute x 60 minutes per hour = 68.8 MPH at 5,500 engine RPM in 3rd gear.

Step 4.

Multiply the 2nd gear ratio of 2.38:1 by the final drive ratio of 3.76:1.

2.38 x 3.76 = 8.95:1 overall 2nd gear ratio (from the engine and driveline to the road).

Step 5.

850 tire RPM x 8.95 overall 2nd gear ratio = 7,608 engine RPM at 68.8 MPH in 2nd gear.



Conclusion. As calculated in Step 5 above, 7,608 engine RPM isn’t even close to the OP’s car’s 9,000 RPM redline, so the OP stating that the engine “Flys up to I think 9000+” doesn’t add up given that the OP “smacked it into 2nd from 3rd at like 5500 rpms”. Based on the gear ratios above, this car can be downshifted into 2nd gear at 80 MPH without overrevving the engine (even though there’s absolutely no valid reason ever to do so). In other words, the OP has nothing to worry about.

Please feel free to check and critique my work (the numbers I used, my calculations, etc.).

JustinL

Your answer is correct, but you did it the hard way! The final drive and tire size cancel out. All you need is the ratio of the 2 gears and the speed in question. (2.38/1.72) * 5500 = 7610

CTDan

The car is ruined. Im doing you a favor by offering 50k for it... you should take me up on it ASAP.
Also, would you mind asking the young lady in the background to step A LOT closer to the camera?










(I really hope this post comes off as funny & not serious.... really REALLY hoping that’s not your daughter or wife in the background, I promise I mean no harm).
PS... I’d be shocked if your car was hurt. I’m not sure when the technology to trace a bad shift began, but you can bet there are a lot of Porsches that have had a missed shift. Enjoy your car & don’t give it another thought.

drl

Was out in the 991 today and thought of this thread.
Multiple times I downshifted 3-2 at 5600, could not get anywhere near 8000, 7600-7700 at most.

IORR

how's the car now?

drl

not clear what you are asking. Are you suggesting 7500 rpm is damaging to this vehicle?

Outlaw 06

True, but I also wanted to calculate the car's speed at 5,500 engine RPM in 3rd gear, in order to provide the OP with another point of reference (just in case the OP's estimated engine RPM is inaccurate, he might have a better idea of the speed he was traveling at the time). Simply put, 5,500 engine RPM in 3rd gear does not equal "9,000+" engine RPM in 2nd gear. The OP is clearly mistaken about something.

Here's my theory:

The OP states that he's owned/driven "67 camaro rebuild. 2014 z28. Audis jeeps yadayada".

The small block V8s in 1967 Camaros redlined at 6,500 RPM.

The 2014 Z28 is a great car that redlines at 7,000 RPM.

The I-6 engines in typical Jeeps redline at 5,500 RPM.

A driver who's ear is conditioned to hearing redlines in the above ranges his whole life will probably equate anything over 7,000 RPM as an engine overrev. That's my theory anyway.

LexVan

What happened to the OP? He posted the same question in 3 different forums (991, 992, and Glitches), and never returned.

IORR

my update question was directed to the cars owner and starter of this thread....is the car ok, or did he go back to Camaro in Temecula?

rob944s2

He’s not coming back. OP abandoned his own thread.