Tranny 101

[90tsiawdturbo]

Ok I Have a few driving habits and was wondering if they were bad for my car or not...I just would like your opinion. Thank you
pulling it out of gear into neutral without using clutch
skipping gears. example: going from 3rd to 5th
roll down hills or up to stop signs in neutral in an awd (helps save gas )
they may seem like stupid questions to some but I'm just curious

 

[habitatguy187]

Even when you skip gears while downshifting it will be much better on your trans if you double-clutch it.

 

[90tsiawdturbo]

to the people that dont understand....read it a few times and deeply think...thats how i understood....it would almost be the same as push starting your car....im sure the ecu feeds it just enough fuel for it to stay running...am i right ramsack?

 

[ramsack]

to the people that dont understand....read it a few times and deeply think...thats how i understood....it would almost be the same as push starting your car....im sure the ecu feeds it just enough fuel for it to stay running...am i right ramsack?

When the engine is being spun by the wheels it doesn't need any fuel to "run." It doesn't need to "run." It is performing braking by compression. I don't really know if it is very little fuel or none at all, but I lean towards that it's no fuel at all. As soon as you press the gas any amount there will be fuel again. It's seamless. Anyone can test it by coasting down a hill with ignition on and another time on the same hill with ignition off and tell me if you notice any difference.

 

[90tsiawdturbo]

why you sayin it to me, i understand what your saying chief!!

 

[AndrewD5418]

When I "Skip" gears, I still go into the gear that is up next. I'll clutch in, shift from 3rd to 4th, and then put it into 5th then release the clutch.

 

[dented_coffee]

WOW. I got confused with all of the back and forth back and forth .

The way I have been told and taught with the 10 hours of tuning on the dyno with my old 1990 GS-T. On the coasting is that fuel don't cut fully. It lowers to the point of idle when ever the throttle plate closes(I.E. TPS and throttle stop switch). Anyone with a AFR gauge will notice the change when they let off the gas pedal to shift. Coasting down hill in gear or in neutral didn't change any fuel consumption with my 1G AWD Talon. I have been doing it for over 1500 miles now. When I shift I go to the next gear in order without skipping any. I can reach 50mph in 3rd gear shift to 4th to get to 56mph then go into 5th and set the cruise. Only when I'm in a really big hurry thow. Had to rush to the hospital a few times NOT RACING.

I only down shift when I'm on state road and the speed drops from 55mph to 35mph. I go from 5th to 4th. Coming up to a stop from being in any gear I just coast to it in neutral. Coming up to a road to turn on I coast in neutral grab 2nd in the turn because I'm usually going about 15-20mph. I was just yelled at the other day for not riding the clutch on take off for longer than needed. The person yelling at me has never driven a stick let alone know where and what the clutch pedal is . AWD transmissions are harder to replace a clutch on than a FWD is so I'm gonna baby this one till she really needs to be replaced before it starts to possibly warp, crack, or break the pressure plate or flywheel.

I'm just adding my own $0.02 in on this now that I got to test a few things out and hear some other views on it. I could be wrong but I'm going by tuning information that I have gotten from more than 4 50+ year old great dyno tuners who have tuned hundreds of cars by them selfs that were all over the 700HP range.

 

[ramsack]

It does cut fuel. It doesn't just lessen it to whatever the idle fuel requirements are. Just look at idle surge. When you have a vac leak that makes it rev more, you have the throttle switch closed. When the RPMs reach 1500 the fuel cuts. This is what makes the up and downness of idle surge. They cut fuel on decel so the catalytic converter doesn't heat up too much and melt, and I'd imagine a safety feature if there were to become a giant hole after the throttle plate making the car rev more.

There was a writeup I saw a few weeks ago about fuel consumption this guy did. I believe he has a log on the internet somewhere of his mileage. A FWD turbo Laser that gets over 40 mpg. Not coasting in neutral is part of his scheme. The other is shifting at like 1500-2000 and having a high comression engine. Not really practical for most people. 7.8:1 and AWD will always get poopy mileage.

 

[BrokenTsi]

On the highway, I log anywhere between 33-40mpg.

1450cc, bosch 044, welded diff, built 2.0 (8.6:1 CR)