legacycentral bbs

First off, let me introduce myself, I'm Dan, a Newbie. I was a mustang guy until i owned one. I have a '93 automatic legacy turbo sedan converted to manual with a 4.11 transmission from a '98 2.5 RS, Lightweight fidenza flywheel or however you spell it, exedy stage 1 clutch, 3" stainless steel turbo back exhaust, Invidia wrx performance downpipe, modified snorkel and removed foglight covers. Recently i've been looking to upgrade the turbo on my car and install a front mount intercooler. I was wondering what is the best turbo upgrade for the money? I wanted to fit a VF22 but am told it wont fit. So if any of you have any thoughts or comments, I'd appreciate it.

Kelley installed a vf-23. He seems to like it. He gets great spool up and great gains, but part of that also comes from a new computer.

A lot of guys are going for the TD05-16G turbos that came on some of hte oversees subarus. You can buy one from the guys at DeadBoltEnterprises, they are in the vender section of the board.

They'll set it up so that it will be a pretty much direct bolt on.

dzx wrote:I have a '93 automatic legacy turbo sedan converted to manual with a 4.11 transmission from a '98 2.5 RS

sounds like my setup minus the turbo part. Are you afraid of doing damage to the transmission what with it being a push style instead of a pull style?

I'm not sure what i've done to the transmission but i dont have a third or fourth gear right now. Got pulled over for muffler being too loud but i was trying to get up to 55 in 2nd gear before switching to fifth. It used to go into third and fourth after some work but it seems like the more i used them, the worse they got, now its almost impossible to get into those gears. I've heard the turbo on the car now can get up to about 227 hp before it goes flat and that the overseas turbo can get up to about 280, is this correct?

Unless you're double-clutching it on the 2-5 shift, you're gonna wear out 5th's synchros as well.

You can hit 55 in 2nd with 4.11s? Not bad.

If he wiats for the revs to drop where they're supposed to be before shifting, why would that hurt the synchros?

Steve

i used be able to hit 75-80ish in 2nd

I can hit around 60 in mine before I start bouncing.

Steve - The synchros bring input shaft speed in line with road speed. Engine speed doesn't really have anything to do with it, except that it's the only way for the driver to control input shaft speed. With the clutch disengaged, you have no control over input shaft speed.

I hope that made sense.

So what's the difference between a 2-3 shift and a 2-5 shift? It should be the same thing as long as you wait longer between shifts, right? I thought I understood how this works, but maybe I'm wrong. I'm seldom sure until I rip something apart myself and I've never done a transmission.

Steve

dzx wrote:I was wondering what is the best turbo upgrade for the money? I wanted to fit a VF22 but am told it wont fit. So if any of you have any thoughts or comments, I'd appreciate it.

I just got a Monster Ported TD05H-16G with the 90 degree inlet, exhaust and compressor housing ceramic coating, from Deadbolt and it is sweet. I haven't gotten it installed yet but it should go pretty easy as the only thing I need to modify is my compressor outlet to TMIC inlet plumbing. For a NEW turbo, you can't beat the 16G that Deadbolt is offering because of the simplicity of installation, quality of the unit (most agree that Mistubishi turbos are better quality then IHI) and performance. You can also get 18G and 20G turbos with the 90 degree inlet from Deadbolt if you're after really big gains.

If you want to go through the trouble of adapting an aftermarket turbo that's for the WRX, like the IHI VF22, you can, it's just a lot more work. You can pick up used IHI turbo's (VF30, VF34, VF22, VF23 ect..) on NASIOC fairly cheap but I've always felt a little weary about how some of them may have been treated. There are really good deals out there but there are some stinkers too.

Another possibility is that you could maybe have a 16G with the 90 degree inlet that came off a 93-96 STI from Australia or New Zealand imported but I like the fact that my turbo is new and I will make sure to break it in right and not abuse it. I like that piece of mind.

does deadbolt have a website?

http://www.deadboltspeed.com/subaru/index.htm

http://bbs.legacycentral.org/viewtopic.php?t=15892

dzk, georryan is correct about the ecu, I would definately upgrade the ecu before a turbo upgrade.
yes the vf22 will work. there are other turbo's available as well.
feal free to give me a call if you are interested in any of the above products. we even have gear sets available if you need that.
once you do one or both of the mentioned, you will also need more fuel. we can supply those products as well.
the website should also be up by next monday with ecu information.

Steve - The difference is just the magnitude of the angular velocity difference. dzx is asking his 5th gear synchronizer to bring input shaft from ~6500 rpm down to ~1500 rpm.

Waiting longer gives the synchro longer to do its job, but it's still got to absorb all that kinetic energy.

vrg3 wrote:Unless you're double-clutching it on the 2-5 shift, you're gonna wear out 5th's synchros as well.

enlighten me, why would a person want to change from 2nd to 5th ?

Because on most cars, the top of 2nd gear is right around 60 mph, which is approximately cruising speed. So, to merge into traffic, you accelerate as hard as you can in 1st and 2nd, and then shift into 5th to cruise.

So how does it work in a dog box and why would double clutching be better than just going slow? I never feel anything stressful from my transmission from doing this.

Steve

From what I understand, most dog boxes don't have synchronizers. Either you have to double-clutch, or the interface between the gears and the collar teeth have play in them so you can slam them into gear. Boxes with that feature are called crashboxes because it's ridiculously loud when you shift that way.

Like I said, going slow just gives the synchro more time to absorb the speed difference. It still has to absorb it. Proper double clutching makes it so the speeds match up already.

Would it be useful for me to do a little high-level primer on how the internals of a manual transmission work?

Dog boxes have straight-cut gears. I would think if the speed differential was so great that you wouldn't be able to shift 2-5 without double declutching, but I've heard that only applies to downshifting.

Anyway, sorry to muddy up this guy's thread.

Steve

Thanks for the replies, i've found all of them to be quite informative, my car has an sti shifter, so that might have added a little more abuse by shifting gears faster. The third gear was the first to go a couple hrs after racing some honda civic hatchback, then a little while later 4th started to go. I've never had to deal with weak transmissions before, it was always parts of my unbuilt stock engine in my mustang that needed to be replaced.

I wasn't aware that our transmissions were weak at all... in fact I had thought they were pretty solid up until I read this thread.

That depends on whether or not your car is making stock power and the'yre not like the old 'rock crushers' no matter what so hamfistedness will take their toll. Of course a weak point for a Subaru means 150k mi at least before there will be a problem unless it's especially abused.

I'va always been wary of short throw shifters on these cars as I used to beat the synchros on shifts in my old transmission with the normal throw. This one I shift slower in and seems to be doing very well at around 130k (got int from a JY with ~70k).

Steve

Steve - I might be wrong about this, but I didn't think "dog" and "straight-cut" meant the same thing. In any case, the type of gears doesn't really have anything to do with how you shift as far as I can see...

Well, actually you're right - they're not one in the same, but more commonly they are. Back before synchros were common street cars would have dog boxes, but helical gears for quiet, but today I think it's only race cars with straight cut gears that have the dog change which is (I think) just these big teeth that fit into and out of corresponding slots when a gear is shifted. Sorry, I should've clarified more what I was thinking in my head. I have a tendency to do that as I'm always in such a hurry that I assume people know certain things they don't making me hard to follow occasionally and probably in the end taking me more time to say something.

Steve