Downshifting?

[MikeE30325i]

damn, i have learned a lot through this thread. thanks everybody. i downshifted a few times today, and i r3vmatched and it was pretty smooth.

also my buddy installed some solid aluminum trannt and motor mounts and his car sounded bad ass. though he took them off cause it was vibrating like a mofo.

[moatilliatta]

I used to think the engine ran lean while engine breaking. but there really isnt any accel load on it so...i dont think it would hut it.

I enginebreak when im having fun. other than that i coast to a stop in neutel

[Ryan Stewart]

I do it more often than not, but not all the time.

[AndrewBird]

I downshift by revmatching all the time, AND redline it every day.

p.s. My goal around most corners is NOT to touch the brakes.

Ditto. I used to drive the ~3 miles to school without touching the brakes except when I had to make a complete stop. Traffic circles and revmatching FTW!

I also sit at lights in neutral with the clutch out as to not wear on the TO bearing.

[markseven]

werd

Yeah, I was way off...

[gstuning]

Rev matching = saves clutch
Engine braking = saves brake components

Engine parts are not designed to go only give torque they are only reciprocating metal parts rolling around,

[vivalegreg]

Cool, my mistake - learn something new everyday.

werd


im thinking about getting a clutch stop, sounds worth it...i just want to make sure i properly install it

[808BMW]

Cool, my mistake - learn something new everyday.

Good thing to know, in case you ever get a standalone ecu (I seem to remember someone asking why theres no fuel on decel... because that's how it's supposed to be)

[nando]

So what you are saying is the engine knows you have downshifted and cuts fuel delivery?

No fuel = engine not firing = no power steering, no power brakes...

I think you are mistaken

it is you who are mistaken

the ECU will cut fuel when the RPMS are above a certain level and it detects that the throttle is closed (via TPS). once the RPMS drop to a certain level it will begin to meter out fuel again to keep the engine running. if you are coasting with your foot off the gas and in gear, there is no fuel going to the engine. as soon as you open the throttle though, the ECU will begin firing the injectors again.

[markseven]

When you let off the throttle, the engine will cut fuel. If your rpms are up (being in gear, like while downshifting) the rpm's will keep your motor going. If you are in neutral, the engine will cut down until it hits idle, then the ecu will inject fuel.

If you rev up your car, turn off the key, let it rev down, and turn the key back on before it dies, your car will run. The engine is already spinning, and will continue to do so until it slows down to 0. How can the fuel be injecting while its revving down if your key is off?

The engine doesn't need to fire to spin. PS and brakes are spun by the engine, whether its injecting fuel or not.

Yes, no gas pedal= no gas (until you hit idle, then motronic takes over). They need spark and fuel to rev, but your not revving it, your downshifting.

Cool, my mistake - learn something new everyday.

[808BMW]

anyone here have a clutch stop ?? im pondering getting one....but cant really think how it works?? is it where you kinda set it at a certain engagement point and prevent the pedal from going all the way to the floor, for quicker shifts? wouldn;t that increase wear on a clutch?

also who here when comming to a stop, before rolling off, keeps their car in gear with the clutch pushed in...even sitting at a red light....does that create any wear on a clutch?? as opposed to just putting it in neutral...until the light turns green then putting it in gear??

Clutch stops are adjusted slow the clutch will FULLY disengage. It's just there to stop the dead travel behind it. If you need to only push your clutch down 4 inches, then why go all the way to 7, just put a stop at 4.

Sitting in gear at a red light doesn't wear your clutch, but does wear your throwout bearing. Better idea to wait in neutral.

[808BMW]

So what you are saying is the engine knows you have downshifted and cuts fuel delivery?

No fuel = engine not firing = no power steering, no power brakes...

I think you are mistaken

When you let off the throttle, the engine will cut fuel. If your rpms are up (being in gear, like while downshifting) the rpm's will keep your motor going. If you are in neutral, the engine will cut down until it hits idle, then the ecu will inject fuel.

If you rev up your car, turn off the key, let it rev down, and turn the key back on before it dies, your car will run. The engine is already spinning, and will continue to do so until it slows down to 0. How can the fuel be injecting while its revving down if your key is off?

The engine doesn't need to fire to spin. PS and brakes are spun by the engine, whether its injecting fuel or not.

oh damn my bad, really? i never knew that...so are you saying when you let off the accelerator...your not using any gas? i thought engines had to inject fuel and a spark in order to rev....

Yes, no gas pedal= no gas (until you hit idle, then motronic takes over). They need spark and fuel to rev, but your not revving it, your downshifting.

[Rennsport]

wow, i thought this thread was about shifting, not shifters....

lol, anyways, i r3v match downshifts all the time. just the wat i was tought to drive a stick.

[markseven]

I am rebuilding my E30 and havent got to that portion yet. It was stock, but when done, will not be. I read on here that the Mz3 shifter isnt as knotchy as the Z4, but I dont look forward to finding one.

https://secure15.nexternal.com/shared/StoreFront/default.asp?CS=bimmerworl&BusType=BtoC&Count1=400768458&Count2=317908883&CategoryID=56&Target=products.asp

Looks like B&m has a few versions out as well.

Thanks for the link - bimmerworld: "The fundamentally finest shifter for the pure BMW enthusiast"... maybe I should start a new thread or add to the other one and end this hijack ;)

[misterlance]

Yeah, Lance I saw that thread - I'm still considering all options. What are you using? Stock or SSK?

I am rebuilding my E30 and havent got to that portion yet. It was stock, but when done, will not be. I read on here that the Mz3 shifter isnt as knotchy as the Z4, but I dont look forward to finding one.

https://secure15.nexternal.com/shared/StoreFront/default.asp?CS=bimmerworl&BusType=BtoC&Count1=400768458&Count2=317908883&CategoryID=56&Target=products.asp

Looks like B&m has a few versions out as well.