Best way to Manually Shift?

Sr240sx · #1 11-08-2006, 04:42 AM

Quote:

Originally Posted by It's Just Eric

...Thats your transmission trying to escape...
I think one thing many people seem to overlook is that the svx, fromn the factory, is far from a sports car. I wouldnt treat it as such unless it has had proper modifications to do so

"sports coupe" is the terminology. It was made to have some of the aspects of a porsche with all the comfort of a mercedes.

The svx isn't a B-road barnstormer, it's a comfortable long distance cruiser with a big boot, good power, and nice handling.

Not something you'd fling around a track, but something you can really enjoy on a nice twisty road or long journey./

on topic- don't shift in an auto. it's not good for the tranny. buy a 5 speed. if you want power, press the manual shift button and step on it.

Hose92SVX · #2 11-08-2006, 08:08 AM

As far as straight line speed goes it won't really matter becuase the shift points will be the same. As far as brake-torqueing to get a jump off the line being hard on the car, yes it's hard on the car but if the drivetrain is in good condition it should be able to handle hundreds of starts like that. On a car like this I would stay away from starts like this since the transmission is expensive to replace and the AWD doesn't allow good tire slip to relieve some of the pressure which means the drivetrain is taking alot more abuse then say a mustang. The main advantage of having the manual shift is that on this particuliar car there is no buttons to unlock the shifts from 4th to 3rd and from 2nd to 1rst, so it makes it easier to downshift a gear while concentrating on the turns. The main advantage of manually selecting a gear is to keep the suspension smooth and keeping the motor in the powerband while navagating twisty roads. Lets say your on a straight away and the straight away allows enough room to shift into third but you are only going to get another 50 feet of power on while in third before you hit the brakes and downshift. In this case you are probably better off staying in second letting it run close to the rev limiter then off throttle, smooth brakes, stay in second and concentrate on taking the turn smooth and to the limit, rather then going to third, then braking while downshifting into second. The reason is because if you downshift during the braking zone there will be a moment where the car will have no engine braking then sudden engine braking while you are applying the brakes. It will upset the chassis and the smoothness of the braking and if you are already at the cars limit of availible traction then you will slide once the the gear changing upsets the cars suspension and brakes. This will also cause panic mode and not allow you to concentrate on the turn. You'll notice on some race cars the driver will heel-toe the throttle and brake while downshifting so the engine braking stays smooth while downshifting. This is hard to master and won't work on a automatic. Smoothness=Speed.

sharky512345 · #3 11-08-2006, 08:26 AM

Quote:

Originally Posted by Hose92SVX

As far as straight line speed goes it won't really matter becuase the shift points will be the same.

This is not true. With the gear selector in 2 the car will shift at 7000 whereas when it is in D it will shift at 6500. I'm not sure about other gears if it is the same or not.

But i don't really think manually shifting the car would be beneficial to accelerating for the extra 500 RPMs, but it could be.

Manarius · #4 11-08-2006, 08:40 AM

Quote:

Originally Posted by sharky512345

This is not true. With the gear selector in 2 the car will shift at 7000 whereas when it is in D it will shift at 6500. I'm not sure about other gears if it is the same or not.

But i don't really think manually shifting the car would be beneficial to accelerating for the extra 500 RPMs, but it could be.

Shift point being 500 rpm different is irrelevant. It's still way out of the torque range.

Earthworm · #5 11-08-2006, 08:53 AM

Quote:

Originally Posted by Manarius

Shift point being 500 rpm different is irrelevant. It's still way out of the torque range.

If I left the shifter in 3rd it would shift to 4th at 210kph instead of 200kph. It took noticably longer to reach 210kph when it shifted at 200kph.

Manarius · #6 11-08-2006, 11:28 PM

Quote:

Originally Posted by Earthworm

If I left the shifter in 3rd it would shift to 4th at 210kph instead of 200kph. It took noticably longer to reach 210kph when it shifted at 200kph.

That's courtesy of having to dig out of 3rd at that point in time. It's still way out of the torque range. Do you think people trying to get max dig out of their 5MT's shift at redline? No. They shift when the torque band runs out. I know my Legacy has no dig after 5500...it's just running out the end of the gear.

TomsSVX · #7 11-09-2006, 08:13 AM

manarius is right. I still rarely take it to 6500 even... just not worth it as there is no power there

Tom

sharky512345 · #8 11-08-2006, 09:09 AM

Quote:

Originally Posted by Manarius

Shift point being 500 rpm different is irrelevant. It's still way out of the torque range.

When have you tried this? I can have the svx shift out of 2nd in D going 80 at 6500 RPMs or wait almost no more time and have it shift out of 2nd going 90 at 7000 RPMs. At 7k RPMs in 2 there is more power than at ~3 or 4k in 3rd.

Hose92SVX · #9 11-08-2006, 12:27 PM

I'm sorry. I didn't mean to start a big debate over shift points. To be honest I was trying to tell the topic host that the main advantage of manual shift comes into play during twisty roads. My bad for not being accurate over the rev limiter and shift points.

mikecg · #10 11-08-2006, 01:15 PM

If you have a stock ECU, your tranny will never shift at 7000rpms. Stock ecu cuts out lower then that. ECUTne ECU have a raise rev limit of something like 7200rpms at the request of the manual guys.

Ira Davis · #11 11-08-2006, 07:13 PM

Normally I don't tend to say much, I just sit back and take it all in; but this time I think I'll enter the fray.

First I see no reason why shifting gear to gear would harm any automatic transmission. It's designed to be able to do that; however if you don't have a manual valve body (a modified valve body, which allows the operator to determine shift points) I don't really see what the benefit would be. At this point I don't own an SVX (about to change) but I assume that the computer still controlls the shift points like in every other electronically controlled transmission.

Now as someone who has built and dynoed several automatic transmissions I would agree that power braking might not be the thing you want to do in a stock SVX.

These are just my opinions of course, so take it with a grain of salt.

Off subject (sort of) but has anyone thought of having an SVX automatic modified with a manual valve body? As I am about to buy a couple of SVXs I think that might be a project I am willing to take on. Never ripped apart a Subaru automatic before but it functions the same as any other automatic does, which means in theory it can be done. What would the benefit be? Manual shifting; of course!

Now out of curiosity where can I get a manual that details the rebuild of a 4EAT? Basically I need to have flow charts for the clutch packs etc.