Secondmessiah

yeah, i know i post a lot of useless hypothetical threads

i was reading on the saab forum that someone accidently put their saab into first gear on the freeway. Valve float destroyed the engine. (to be fair, his shifter was severly fucked)

my point: if this were to happen to an rx-7, at say, 70mph, that would put the engine at about 16,000 rpm. What would happen? would it survive for a moment until you could disengage the clutch?

from my knowledge, one or more of the following would happen
-rotors slapping against housings
-cracking an iron
-severe wear on components in general
-seals likely messed up

J-Rat

iTrader: (2)

I did it once.. I doubt I hit 16,000 though, thats double the redline. I think I hit around 10,500 or so, maybe even less. Engine seemed to be fine, although it scared the living crap out of me.

I would be interested to see if the engine would even GET to 16,000 before something happened...

trainwreck517

iTrader: (1)

If you where doing 70mph, and still some how managed to put it first, its a pita to put it in first without rev matching) you will most likely lock the rear tires and spin out of control before you do any enegine damage.

Now, if you miss shifted going from 3rd to 4th and hit 2nd instead, engine will spin, depending on how high you let the engine go you will either get apex seal chatter marks on the housing, rotor bearing damage, exploding flyhweel/clutch assembly.

I have miss shifted a few times going going to 3rd to 2nd instead of 4th will no ill effect, although I'am able to recover my mistake in a second, so the engine doesn't really see high rpms to long..

But I would think bearing damage,stationary gear damage would be one of the first things to happend.

Secondmessiah

hmmm. . . what a about a turbo? probably wouldnt make a difference right?

AbortRetryFail

That's if it goes into gear at all. I downshifted on the highway doing ~65mph and missed 3rd into 1st. I stopped myself before letting out the clutch because of the noises the transmission made at that speed.
I'm pretty sure doing that set this tranny on the road to it's grave. It doesn't like to go into 1st much when stopped anymore

micah

On http://www.rebuildingrotaryengines.com there's an "inspecting rotor housings" video.. and Rob from pineapple shows one of them where the guy downshifted from 5th to 2nd and disintegrated the apex seals.......

J-Rat

iTrader: (2)

Cool link man, thanks!

Aaron Cake

iTrader: (1)

That's a very cool site! But I can't find the downshift video?

My5ABaby

iTrader: (7)

If I'm going anywhere near 30mph and I try to shift down into 1st, it's hard as hell to do. As in... even if I keep the clutch pushed down I have to jam it in. I've only done it once to see if I could. It's the same way on my dads Miata. You really have to force the thing to get it in.

I'd be surprised if you could even get it into 1st.

fredster102

yeah thats alot like my 7 too , i can shift from 3rd to second but when i even try to put it from 3rd to first without releasing the clutch it wont even budge to go in most of the time , oh well lol

micah

No kidding. That'd be blast to watch!