Transmission spline count?

[Beretta1234567]

I'm not sure.

[Rettax3]

I do eventually plan on finding a newer turbo that can handle higher boost and buying the tuner/emulator from Moates.net. But I am not there yet. So the trans will have to handle a good amount of torque.

The T-25 on your LG5 can crank out 12 psi or more through midrange RPM, if the waste-gate is set for it. Not sure how long it will like doing that, but it certainly can produce it -mine did, and mine was shot already.

The issue is that the T-25 is undersized, even if everything else is stock. Unfortunately, I went too far in the other direction with my car, and the 60-trim T-4 takes too long to spool up (but it can swallow a pop-can, if need be ). I am consoling myself on that however, that I don't have a lot of boost at low RPMs when detonation would be more likely on my almost 10:1 CR engine. And no, I NEVER want to see 12 psi on my 3.4! I will probably swap-over the K-3 turbo I have eventually though, since I don't take my car out to the track.

Since you are looking for track-times rather than stop-light brawls, you should definitely keep going with that turbo upgrade -you need the top-end boost rather than quicker spool-up times.

Edit: Oops, my T-4 is not a 60-trim, it is a .60 A/R -I don't recall the trim size on it...

[Beretta1234567]

Someone said it can handle it, I dont know.

[Rettax3]

Be careful with what you buy -for instance, "T-3" and "T-4" refer to a specific flange type for mounting the turbo to the exhaust, not necessarily a specific capacity for boost pressure or volume. Generally, the T-4s are bigger, but the A/R and "trim" numbers tell much more. There are people here that know more about this than I do too. T-3s and T-4s are very interchangeable too, and are easy to hybrid. I almost did that with mine, using my T-4's huge .60 A/R compressor section with the turbine and liquid-cooled body from a T-3 I had "lying around", but opted not to restrict my exhaust that much. As a result, I have (because if the specific options on my T-4) an oil-cooled body (sucks), a gargantuan turbine section (I want to say .87 A/R?) that matches my compressor nicely and doesn't restrict exhaust-flow from my balanced headers but also takes forever to spool, and an external waste-gate, which while controlling the boost better than an internal WG was far more complicated to plumb and required the room for the soft-ball sized WG.

If you are having that cross-over pipe built for you, you might want to have a T-3 or T-4 mounting flange made for it instead of the stock T-25 flange...

[Slinky]

Pick your intended HP at an intended RPM goal and than take each turbo you are considering and read the effiency map to find out which is right.

Stock for stock yes the 4t60e-hd is better than the 4t60-e, but without an LSD, upgraded clutches, huge trans cooler and hardened parts one won't last much longer than the other since its only the diff as Jon said that is different..

[Beretta1234567]

its the 4t60, not the 4t60e. Has a TV cable.

[3X00-Modified]

Its a 4T60-HD, no 'e'. Its got a kick back cable.
There are not many of the non electronic 4t60's from what i read.

Honestly doesn't matter... The difference between a 4t60 and 4t60-HD will still probably only be the diff... so every and all pitfalls that everyone bitches about with the 4t60e will be there since they are pretty similar just one shifts half electronically vs manually like a 3t40 does.

[Beretta1234567]

Its a 4T60-HD, no 'e'. Its got a kick back cable.
There are not many of the non electronic 4t60's from what i read.

Honestly doesn't matter... The difference between a 4t60 and 4t60-HD will still probably only be the diff... so every and all pitfalls that everyone bitches about with the 4t60e will be there since they are pretty similar just one shifts half electronically vs manually like a 3t40 does.

Yah, I'm not sure what all is changed between a regular and an HD version. I assume its enough to allow for the higher hp.

Yep, the 3T40 I took out was cable control with TCC. This 4T60-HD is cable and vacuum.
I was considering the 4T60e but I do not feel like switching to an OBD2 setup when I have a working OBD1 setup ready to plug and play with.

[3X00-Modified]

Your not reading... THE ONLY CHANGE BETWEEN THE 4t60 AND 4T60-HD IS THE DIFFERENTIAL. Nothing else inside the trans is any different. Same clutches, same 4th gear hub, same reverse shell, same chain, same valve body... Need I go further?

[Beretta1234567]

Your not reading... THE ONLY CHANGE BETWEEN THE 4t60 AND 4T60-HD IS THE DIFFERENTIAL. Nothing else inside the trans is any different. Same clutches, same 4th gear hub, same reverse shell, same chain, same valve body... Need I go further?

Yes I read it, you said "probably".
I do not want to rely on any assumptions and risk damage to anything. I am assuming its able to handle the engines factory ratings, but for any extra boosting I plan to check the book and see what all exactly is different and the ratings of the parts.

[3X00-Modified]

suite yourself...

[Beretta1234567]

Hey Rettax3, What are your thoughts on this:
http://www.turbobygarrett.com/turbobyga ... %20%284%29

[Slinky]

Hey Rettax3, What are your thoughts on this:
http://www.turbobygarrett.com/turbobyga ... %20%284%29
I kept thinking about turbo's since it was brought up and decided to try and compare a few on the manufacturers web page.
I'm not sure what I am looking at here as far as spooling up time and boost capabilities.
Says T25 inlet and 5 bolt outlet; Sounds right to me but I'm not sure if that is the same as what I have on my current T28 turbo.

If you plan on making over 250-300hp MAX efficiently, than that's a good turbo for you, IMHO that turbo is still a little small and you may choke out the hot side with to much air flow, i would use a turbo with a minimum of 35-45lb/minute, but that's just me.

[Beretta1234567]

Hey Rettax3, What are your thoughts on this:
http://www.turbobygarrett.com/turbobyga ... %20%284%29
I kept thinking about turbo's since it was brought up and decided to try and compare a few on the manufacturers web page.
I'm not sure what I am looking at here as far as spooling up time and boost capabilities.
Says T25 inlet and 5 bolt outlet; Sounds right to me but I'm not sure if that is the same as what I have on my current T28 turbo.

If you plan on making over 250-300hp MAX efficiently, than that's a good turbo for you, IMHO that turbo is still a little small and you may choke out the hot side with to much air flow, i would use a turbo with a minimum of 35-45lb/minute, but that's just me.

Thats why I asked, because I'm not sure what to pick. lol
I will look through the listings for a 35-45 lb/minute range turbo.

[themixer]

suite yourself...

Would recommend at least listening to this dude, he is pretty knowledgeable. Don't know many on here rebuilding automagic transmissions in their garages