Does the 5AT automatically downshift in manumatic mode?
Originally Posted by phatsingh
so couldnt that potentially mess up ur tranny?
Your car is not designed to use your transmission to stop the car.
It does not mean that you cant do it.
By using your tranny to slow down the car you obviously putting some stress on the tranny and the clutch.
Unlike semi truck you slowing your car down with transmission only. Semi truck also uses air. Basically the higher the engines RPM the more air will be forced through the exhaust back into the engine. So Semi truck can almost come to a stop using only engine brake without downshifting at all.
When you downshift in the car you must make sure that you keep engines RPM at the proper levels.
You car still has the ability to gain speed even tho you did down shift to a lower gear. So brakes still must be applied.
Originally Posted by kmckis1029
no its called engine braking... its the same thing truckers do to slow down their huge loads quickly... that loud drone you hear coming from a truck slowing down is the tranny engine braking.
the G35 has a great sound when engine braking!
Plus it saves your brakes.
if you look in your owners manual every gear has a max speed... and they recommend a use for each gear, and even use the term "engine braking"
engine braking is using the tranny to slow the car down by down shifting early.
example say you are driving 60mph in 5th gear... and you see that stop sign coming up ahead. If you drop the car to 3rd gear and release the accelerator... the car will easily slow to 40mph then drop it again to 2nd and you will drop another 20 mph... all with out hitting your brakes. then you finally hit the brakes as the tranny down shifts to 1st for you. (or you can go to first earlier too)
my very conservative rules of thumb for engine braking
above 100 down shift to 4th
above 50 down shift to 3rd
50 mph and below down shift to 2nd
i never down shift to first in general
the G35 has a great sound when engine braking!
Plus it saves your brakes.if you look in your owners manual every gear has a max speed... and they recommend a use for each gear, and even use the term "engine braking"
engine braking is using the tranny to slow the car down by down shifting early.
example say you are driving 60mph in 5th gear... and you see that stop sign coming up ahead. If you drop the car to 3rd gear and release the accelerator... the car will easily slow to 40mph then drop it again to 2nd and you will drop another 20 mph... all with out hitting your brakes. then you finally hit the brakes as the tranny down shifts to 1st for you. (or you can go to first earlier too)
my very conservative rules of thumb for engine braking
above 100 down shift to 4th
above 50 down shift to 3rd
50 mph and below down shift to 2nd
i never down shift to first in general
the "trucker" you refer to are using a JAKE BRAKE! It and REAL engine brake and uses an entirely different technology than our cars use... Commercial tractors actually have the "engine" braking when they use the "Jake Brake" (I don’t want to go into detail - google it)...
It is NOT a good idea to slow your car by downshifting - unless you are in safe rpm range...
PLEASE people don’t shout out information unless you are entirely certain you know what you are saying.
I'm not trying to call anyone out, but bad things happen from bad information.
Originally Posted by JOKER
you need to use this technique properly.
Your car is not designed to use your transmission to stop the car.
It does not mean that you cant do it.
By using your tranny to slow down the car you obviously putting some stress on the tranny and the clutch.
Unlike semi truck you slowing your car down with transmission only. Semi truck also uses air. Basically the higher the engines RPM the more air will be forced through the exhaust back into the engine. So Semi truck can almost come to a stop using only engine brake without downshifting at all.
When you downshift in the car you must make sure that you keep engines RPM at the proper levels.
You car still has the ability to gain speed even tho you did down shift to a lower gear. So brakes still must be applied.
Your car is not designed to use your transmission to stop the car.
It does not mean that you cant do it.
By using your tranny to slow down the car you obviously putting some stress on the tranny and the clutch.
Unlike semi truck you slowing your car down with transmission only. Semi truck also uses air. Basically the higher the engines RPM the more air will be forced through the exhaust back into the engine. So Semi truck can almost come to a stop using only engine brake without downshifting at all.
When you downshift in the car you must make sure that you keep engines RPM at the proper levels.
You car still has the ability to gain speed even tho you did down shift to a lower gear. So brakes still must be applied.
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Originally Posted by Jeff92se
All autos will automatically down/upshift.
Put it this way, if you are in MM and come to a stop, you aren't starting out in 5th!
In MM, the gear shown on the dash represents the highest gear it will automatically shift into. ie... let's say you select 3rd. From a stop, it will start out in 1st and auto shift into 2nd and 3rd. But will stay in 3rd until you shift.
Put it this way, if you are in MM and come to a stop, you aren't starting out in 5th!
In MM, the gear shown on the dash represents the highest gear it will automatically shift into. ie... let's say you select 3rd. From a stop, it will start out in 1st and auto shift into 2nd and 3rd. But will stay in 3rd until you shift.
Not true at all. You can't put another number on the dash after it's automatically downshifted in MM mode because it will show a "1" for first gear. In MM mode the only way to get it to display another gear "3" in your fantasy description, is to drive and MM shift to 3 and stay there. IT WILL NOT LET YOU SELECT A GEAR TO STOP IN UNTIL YOU GET TO THAT GEAR, MEANING YOU HAVE TO SHIFT THROUGH 1, 2, 3 YOURSELF. There is no way in MM to select a number to stop at unless you shift it there yourself and then shift no more.
Originally Posted by OCG35
The "air" is the standard braking (to the wheels)... "Engine brake" (i.e. Jake Brake) is actually a reverse engineering within the combustion to slow the vehicle... its way more advanced than anything our cars do.
I was talking about Engine brake.
There are two diff "Engine" brake systems used in commercial trucks.
Engine brake and Exhaust brake.
Both are very very diff things.
In Exhaust brake system combustion gasses are held in the cylinder creating a pressure and slowing down the crank shaft.
This system mostly used in small diesel trucks towing/and other service trucks.
With Engine brake system that you'll find in most semi trucks it slows down with vacuum.
it basically uses the exhaust to stop it self.
here is a colorful explanation of the system
http://www.svfd.net/SVFD%20Files/Art...a%20diesel.pdf
Last edited by JOKER; Nov 27, 2008 at 02:52 AM.
Originally Posted by dmitriylm
Ok there you go, thats exactly what I thought. So I can drive around all day with 3rd gear selected and it will basically use gears 1, 2, and 3?
Originally Posted by phatsingh
ok, how about someone explain how to use the MM mode safely without putting the engine or tranny etc. in any danger.
On the up shift, it will hold a gear to rev limiter, so just dont be stupid about the unshifts and you will be fine
Use MM only in conservative rev ranges...I don't downshift mine above 3k revs, but I also don't have rev-matching.
I actually had a compression release valve on my 1977 Yamaha trials bike; by releasing the compressed gases at the top of the stroke, it bleeds off the energy (compressed gas) that helps push the piston back down, hence power from the crankshaft must be used to pull that piston down, slowing the bike/truck/car. Worked great for negotiating steep downhill trails without burning out the brakes.
I actually had a compression release valve on my 1977 Yamaha trials bike; by releasing the compressed gases at the top of the stroke, it bleeds off the energy (compressed gas) that helps push the piston back down, hence power from the crankshaft must be used to pull that piston down, slowing the bike/truck/car. Worked great for negotiating steep downhill trails without burning out the brakes.
I have a very early 03 (Feb 02 build date), and if I stick it in 3 from a stop it will go 1-2-3, but not shift past 3.
If I hit it at 20mph when I'm in 3 or 2, it will downshift to the gear that gives it the most thrust but it will not upshift at redline.
When I go to the track, I leave it in 2, MM, from the start so the car shifts from 1-2 by itself and I shift 2-3 and 3-4.
If I hit it at 20mph when I'm in 3 or 2, it will downshift to the gear that gives it the most thrust but it will not upshift at redline.
When I go to the track, I leave it in 2, MM, from the start so the car shifts from 1-2 by itself and I shift 2-3 and 3-4.
Originally Posted by phatsingh
ok, how about someone explain how to use the MM mode safely without putting the engine or tranny etc. in any danger.
And use that information when you are down shifting
If you over 3k RPM then you not gonna get much help from the engine. It's likely to speed up (going down hill) then slow down.
So keep it under 3k.
Originally Posted by JOKER
I wasn't talking about air brakes
I was talking about Engine brake.
There are two diff "Engine" brake systems used in commercial trucks.
Engine brake and Exhaust brake.
Both are very very diff things.
In Exhaust brake system combustion gasses are held in the cylinder creating a pressure and slowing down the crank shaft.
This system mostly used in small diesel trucks towing/and other service trucks.
With Engine brake system that you'll find in most semi trucks it slows down with vacuum.
it basically uses the exhaust to stop it self.
here is a colorful explanation of the system
http://www.svfd.net/SVFD%20Files/Art...a%20diesel.pdf
I was talking about Engine brake.
There are two diff "Engine" brake systems used in commercial trucks.
Engine brake and Exhaust brake.
Both are very very diff things.
In Exhaust brake system combustion gasses are held in the cylinder creating a pressure and slowing down the crank shaft.
This system mostly used in small diesel trucks towing/and other service trucks.
With Engine brake system that you'll find in most semi trucks it slows down with vacuum.
it basically uses the exhaust to stop it self.
here is a colorful explanation of the system
http://www.svfd.net/SVFD%20Files/Art...a%20diesel.pdf
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Joined: Aug 2008
Posts: 472
Likes: 13
From: Socttsdale, AZ
Originally Posted by OCG35
its based on rpms - no matter how hard you are braking (at least in my car)... see a few posts above
but if i am just barely braking it will go to 2 for a split second and then straight to 1
i have tried to brake lightly and keep it in 2 by stopping braking right when i see 2 flash in the little box where it shows the gears and it has stayed in 2 before, but only if i try and time it right
Originally Posted by 03BaseSedan
I have a very early 03 (Feb 02 build date), and if I stick it in 3 from a stop it will go 1-2-3, but not shift past 3.