6-spd conversion vs. 5-spd?

[Earthworm]

Originally Posted by Rotorflyr

other changes he has made kill the GT aspect of it reguardless

If you are referring to his suspension it can actually be quite comfortable when you adjust the Koni's to the softest setting. If the springs are too stiff for your liking there are definately alternatives.

As for cruising all day at high speeds, the WRX tranny will give you the lowest RPM's.

[mbtoloczko]

Originally Posted by Rotorflyr

For those running the 5mt, how much would you say it changes the GT nature of the SVX in comparison to the auto.
Jesse can sit this one out as I have seen his car, and cool as it is, other changes he has made kill the GT aspect of it reguardless

If by GT aspect, you mean long road trips at or above the speed limit, I'd say that the 5MT does diminish the GT aspect a bit. The car still cruises great on the highway, but it just doesn't have quite as nice of a feel as with the AT when it comes to opening it up on long stretches of empty highway. The 5MT does allow the car to work better in heavier two-way highway traffic on where lots of passing on two lane roads is required.

My feeling is the the 5MT also makes the car feel a little less "finished". This is due entirely to the minor glitches associated with the 5MT swap which include occasional stalling when slowing to a stop, the large tolerances in the rear diff support freeplay which make the car tend to jerk back and forth at low speeds in 1st and 2nd gear, and some odd behavior with the cruise control that I haven't yet figured out. In defense of the 5MT, not everyone seems to have all of these glitches with their 5MT swap, and some of these glitches I will eventually sort out.

Bottomline though is that even with the minor glitches, the 5MT is easily worth it. Not having to worry about when the AT is going to die, the improvement in acceleration, and the control over the power delivery and gear selection easily make it worth it.

[Rotorflyr]

Dave,
Actually I was refering to the "long road trip" aspect of the car as Mychailo talked about. The "finished"/"cruiser" feel of the car. While Im sure the koni's are nice, the stock suspension is fine for me (as I don't race/auto-x) though I do plan on doing Mychailo Type-A Drop Springs at some point in the future. Just thinking about when the time comes, if I want to do a 5MT swap or do an 4.11/4.44 auto (waffling back and forth between manual/auto)

[McTaff]

Originally Posted by mbtoloczko

If by GT aspect, you mean long road trips at or above the speed limit, I'd say that the 5MT does diminish the GT aspect a bit. The car still cruises great on the highway, but it just doesn't have quite as nice of a feel as with the AT when it comes to opening it up on long stretches of empty highway. The 5MT does allow the car to work better in heavier two-way highway traffic on where lots of passing on two lane roads is required.

My feeling is the the 5MT also makes the car feel a little less "finished". This is due entirely to the minor glitches associated with the 5MT swap which include occasional stalling when slowing to a stop, the large tolerances in the rear diff support freeplay which make the car tend to jerk back and forth at low speeds in 1st and 2nd gear, and some odd behavior with the cruise control that I haven't yet figured out. In defense of the 5MT, not everyone seems to have all of these glitches with their 5MT swap, and some of these glitches I will eventually sort out.

Bottomline though is that even with the minor glitches, the 5MT is easily worth it. Not having to worry about when the AT is going to die, the improvement in acceleration, and the control over the power delivery and gear selection easily make it worth it.

What kind of issues are you having with the cruise control?

Is there anything that can be done about the diff - would a diff rebuild help?

[mbtoloczko]

Originally Posted by McTaff

What kind of issues are you having with the cruise control?

Is there anything that can be done about the diff - would a diff rebuild help?

The cruise control is working perfectly except that its constantly making slight adjustments to the throttle position so as to make the car constantly accelerating slightly and then decelerating slightly. Its almost imperceptible, but its enough to drive me crazy. I think I may know the cause of it, but I haven't checked yet. Once I check this possible cause then I'll write about it.

The rear diff itself is ok. Its more that there is lots of freeplay in the rear subframe bushings that hold the rear diff to the chassis. Its just how Subaru made the SVX. The free play allows the diff to rotate some in the axis of the driveshaft when the throttle is pressed, and the bushings are fairly rubbery. Some people with older Imprezas and Legacys also have this problem. The solution is to remove the freeplay by inserting some firm rubber/plastic/urethane spacers into the subframe bushings. Impreza owners have had success with this, and Subafreak has also done this. So, this is just an additional step in the finishing-touches of a 5MT swap. It hasn't been done yet by many people though.

My feeling is that fixing these little glitches make the 5MT much more enjoyable for day-to-day commuting. I'd like to see the 5MT swap instructions updated to include fixes for these minor glitches when solutions are found.

[GreenMarine]

Just thought I would clear up something about where the 5MT actually tops out at.... Assuming that you have the "balls" to do this then the WRX 5MT swap will top out at around 168-174mph. How do I know? Because I saw 155mph about 2 years ago on stock wheels. I was sitting just above 6,000rpm's and the engine would have kept right on pulling.... But truthfully, I chickened out... If something had happened at that speed, I would have had almost no chance to walk away from it.... Honestly, I have no desire to ever go that fast again on any public road (Interstate Hwy). I truly scared myself that day.

The 2.5RS Tranny's probably only top out at around 140-145 or so. That is with the 4.11's or 4.44's...

The WRX Tranny provides the easiest swap with the best gearing (for me anyways) for crusing on the Highway. I still lost an average of about 2-3mpg after the 5MT swap though... Not sure if it is because the car is so much fun to drive now or if it is just that the engine is turning slightly higher RPM's...

[GreenMarine]

Originally Posted by mbtoloczko

.............occasional stalling when slowing to a stop,

.....................some odd behavior with the cruise control that I haven't yet figured out.

I have had the Same Stalling problem in the past man.... Ya know what it has to do with??? I am interested in troubleshooting it when I get my car back...


My cruise works just as it did origionally.... Porter did all the wiring for my cruise... Possibly ya should talk to him about it... I'm sure that he can help ya out with any issues on the cruise control

[McTaff]

Originally Posted by GreenMarineSVX

The 2.5RS Tranny's probably only top out at around 140-145 or so. That is with the 4.11's or 4.44's...

The WRX Tranny provides the easiest swap with the best gearing (for me anyways) for crusing on the Highway. I still lost an average of about 2-3mpg after the 5MT swap though... Not sure if it is because the car is so much fun to drive now or if it is just that the engine is turning slightly higher RPM's...

Ok, so the 4.11 / 4.44 swap is still an option for those with 5MT? Sorry if this is a dumb question, but I don't know about the final drives. I know that the WRX did have a 4.44 final - but you can still swap others in and out?

[SVXer95]

Originally Posted by McTaff

Ok, so the 4.11 / 4.44 swap is still an option for those with 5MT? Sorry if this is a dumb question, but I don't know about the final drives. I know that the WRX did have a 4.44 final - but you can still swap others in and out?

There is actually someone on Nasioc selling an STi ver 6 tranny with a 4.11 final drive..

USDM WRX has a 3.90 final drive.

[GreenMarine]

Originally Posted by SVXer95

There is actually someone on Nasioc selling an STi ver 6 tranny with a 4.11 final drive..

USDM WRX has a 3.90 final drive.

Correct.... The USDM WRX Tranny has a 3.90 front diff... However it also has a 1.1:1 Step up in the center Diff which makes the Rear Diff a 3.545. Just so happens that that is the SVX's Final Drive That is why a USDM WRX Tranny is the absolute easiest swap to complete. Ya don't have to mess around with the rear diff

[Earthworm]

Did Reading 5 with the 5MT (1600 miles each way) and with 2 passengers. the 5MT never caused an issue. In fact if you want you can get away with 30MPH (or even a little less) in 5th gear so you really don't have to shift if you don't want to.

Cruise issue: I noticed the cruise issue with my 4EAT with the TC locked up. The cruise issue never changed after the 5MT was installed. Actually now I notice it even less.

Rear diff mount issue: I'm currently working on a solution to the rear diff mount issue.

Mileage: highway mileage - almost the same. city mileage - improved. This is once you get over how much more fun the car is to drive with the stick.

Stalling issue: resolved after changing knock sensors and cleaning the throttle body (could be IAC related as well).

[McTaff]

Please keep us posted on these, and we look forward to seeing these in the SVXpedia.

In particular, can we see a little more info on the final drive, and why you'd need to change them, and all that jazz. So far I've heard a lot of stuff that I don't understand. I know they can be changed, but what EXACTLY are we changing? The rear diff? Or what? What changes from 'box to 'box, and if I have a 'box with a different final, what do I need to change to make the drive equal, for both directions (making one bigger or the other smaller to match).

I can't find a lot here that covers these points in one big go. The reasoning is what I'm after, as well as the how-to. I'm not a total n00b, but it could be extremely confusing for non-mech heads. My problem is that I need to explain this to other people, and having a nice definitive source would make my task a lot easier.

[Earthworm]

Basically you have 3 things you have to keep matched up:

1. front diff built into the transmission
2. center diff built into the transmission
3. rear diff

eg. USDM WRX has 3.90 front diff, 1.1:1 center diff and 3.545 rear diff
3.90/1.1 = 3.545

All the other trannies have a 1:1 center diff so both the front and rear diffs must match.

What's normally done with the SVX rear diff is that it's opened up to put in the correct gearing to match the transmission. The LSD from the SVX rear diff is kept for functionality.