Misshift from 4th to 5th on 3.2

Porsche 911 · 04-06-2011, 07:47 PM

Well, it finally happened to me today, as i was focusing on different clutch techniques with my feet. At 60 mph & about 3600 rpm in 4th gear, i shifted down to 3rd by accident instead of going up to 5th, causing the tacho to spike momentarily to 5200 rpms before i caught it and clutched in to disengage.

Reading through google search results it doesn't sound too bad (this thread shows the same situation, but at 100+ mph: 5-3 Miss Shift on a 3.2, what are we looking at here?), but how bad does the damage sound on this G50 transmission? The car drove home fine & i'm probably just overly paranoid but I did notice a slight burning smell after stepping out of the car

DRACO A5OG · DRACO A5OG's Garage

You are fine, I did the same thing and redlined it. Just take care & be conscious until it comes naturally

sc_rufctr · 04-06-2011, 07:55 PM

5200 rpms is nothing to worry about.

Make sure your shift linkage is adjusted properly. That always helps.

aadrew10 · aadrew10's Garage

The red mark on the tach indicates the RPM's you do not want to exceed.

Porsche 911 · 04-06-2011, 09:29 PM

Quote:

Originally Posted by aadrew10

The red mark on the tach indicates the RPM's you do not want to exceed.

I know that.

But the sudden spike in RPMs near redline and then steadying momentarily at 5200 can't be good for the G50, nor the burn smell afterwards. Just hope no permanent damage was done..

DRACO A5OG · DRACO A5OG's Garage

Did it grind?

You may have burned the clutch a bit, again no worries. If it really bothers you.

At stop, put into 2nd then drag her up to 2000 RPMs then punch it to redline, If she pulls all the way with out hesitation, your clutch is fine.

initial · 04-07-2011, 02:56 AM

Umm. 3600 in 4th and a downshift to 3rd...... Sounds like my usual driving... I am always dropping from 5th to 3rd on the highway to pass vehicles...

If what you did once is bad, then my car is a ticking time bomb... I do try to line up the revs but I don't think I have 100 % success rate...

sc_rufctr · 04-07-2011, 03:40 AM

Quote:

Originally Posted by Porsche 911

I know that.

But the sudden spike in RPMs near redline and then steadying momentarily at 5200 can't be good for the G50, nor the burn smell afterwards. Just hope no permanent damage was done..

A smelly clutch after some track time is fairly normal. I've slipped the clutch getting up a steep and twisty driveway.

Just drive her the way she was meant to be driven. Some people forget how well these cars these cars are built.

ivangene · 04-07-2011, 03:59 AM

this is a non-event

had you been at 5600 rpm in 4th when you hit 3rd - whole nutha story

go drive it and practice!!

etcmss · etcmss's Garage

60 in third gear is ok----recent posts told me to pay attention to RPM----so I found out---20 in first---40 in second and 60 in third with no concern for RPM.

KTL · 04-07-2011, 07:38 AM

Your engine is completely fine. These engines were built to withstand the high rpms within their operating limits. 5200 is well within that limit, even if held there.

Let me give you an example of how i've driven my 3.2 on the track for several years. At Blackhawk Farms, a series of turns after the carousel (which is driven with extended high rpms of 4500-6000) is a tight right-left switchback that leads to a short straight, turn left, another short straight into a long left sweeper. This is turn 3A after the carousel, T4 and T5.

I downshift to 2nd at 3A, which puts me @ ~4500 rpm get hard on the gas thru this switchback and shift to 3rd at 6500+ right before tap of the brakes for the T4 lefty, engine is around 4500 now still in 3rd, throttle to floor for short straight leading to T5, breathe the throttle slightly to set the car (and i'm a wimp and still can't go thru there flat out yet), floor it and turn in for long left sweeper, wind it up to 6500+ onto the short straight from T5 to T6, and shift to 4th before getting hard on the brakes for the hard right T6 2nd gear turn where revs are kept @ 5000+ downshifting 4th>3rd>2nd.

That's just one section of the track. I don't think there's anywhere on the track that the rpms are below 4500 rpms. Engine just keeps on taking the punishment lap after lap after lap for 25-30 min.

In my 3.0 the engine hates being below 5000 rpm. It's not a super high strung race engine. Just mildly modified 3.0 for longevity; 9.8:1 Mahle pistons, more aggressive cams and Weber carburetors. It's spun up to 7500 rpm all day on the track.

cgarr · cgarr's Garage

Our last Grattan event I checked my miles and for the weekend we ran 350 miles on the track, most not below 4500 and most between 5 and 6.5

cmcfaul · cmcfaul's Garage

When the tach needle goes a full 360 degrees or points streight down then you have a problem. like redline in 3rd to 2nd instead of 4th....doe

Chris

Matt Monson · 04-07-2011, 08:41 AM

Sounds like just another day at the track to me...

JeremyD · JeremyD's Garage

Hopefully you knocked off some of the carbon - If you do not take your 911 to 5500 rpms you are missing out on some major fun. Especially the g-50 Carreras - they seem pretty sluggish below 4500 rpms - I know my 1987 - the only way to get her on her feet was to live above 4500 rpms.

This is what these cars were designed for... no kidding... They tend to develop carbon on the tops of the pistons if you don't wring them out on a regular basis.

ivangene · 04-07-2011, 09:29 AM

+1 Jeremy... I let a guy drive my 3.2 once and he kept the rpm so low I kept saying, dont shift YET! and he asked if he could go about 3k rpm without hurting it??? I said dont go BELOW 3k!! - then I drove his new 911 with PDK (read BORING) and we pushed the right combo of buttons and I showed him where the redline was.... he crapped a brick and said he "had no idea his car could do that"

needless to say, he bought a 3.2 and kept the PDK but doesnt drive at 1400 rpm like he used to (seriously 14-1800 rpm is where it shifts iin "normal mode")

Joe Bob · Joe Bob's Garage

The tranny is tough....mis shift over revs usually kill the valves. If you feel the need for protection, get a shifter that has a lockout detent for fifth gear.

ivangene · 04-07-2011, 10:20 AM

I dont think they make a lockout from 4th to 3rd do they?

915 lock out seems to be more 5th to 2nd (or R) or 4th to 1st, 3rd to 2nd....not 4th to 3rd... anyone know what the intent is of shifters like WEVO? does it cover 4th to 3rd miss

Matt Monson · 04-07-2011, 10:22 AM

Quote:

Originally Posted by ivangene

I dont think they make a lockout from 4th to 3rd do they?

915 lock out seems to be more 5th to 2nd (or R) or 4th to 1st, 3rd to 2nd....not 4th to 3rd... anyone know what the intent is of shifters like WEVO? does it cover 4th to 3rd miss

The mis-shift on the 915 to watch out for is zinging reverse as you come out of 5th and head downwards...

Joe Bob · Joe Bob's Garage

Quote:

Originally Posted by ivangene

I dont think they make a lockout from 4th to 3rd do they?

915 lock out seems to be more 5th to 2nd (or R) or 4th to 1st, 3rd to 2nd....not 4th to 3rd... anyone know what the intent is of shifters like WEVO? does it cover 4th to 3rd miss

No, you're right it doesn't. But knowing there IS a lockout/detent on fifth will slow you down on the upshift for 4th to 5th. As you have to push over to get to 5th after hitting neutral.

Downshifting from 5th the detent pops the shifter over to the left to be in line with 4th, missing reverse. The same detent allows for a quick downshift to 3rd while braking and allowing revs to drop to a safe limit.