Need help choosing a transmission

[Zach]

Ok guys my little Astro a5 is starting to beg for some mercy, it's the 475 torque version and hasn't had to easy of a life In my heavy car. It hasn't let loose yet but really fusses after along pull in 3rd and I don't believe it will live very long when boost is introduced into the situation.

So I need help on deciding what way to go. My options are as follows, keeping the budget around 4K for the total swap.

-built the t-5 with the 575 upgrade and a gforce case.

Find a 3550-tko and slap it in.

Get a tko500/600 and go that route.

Find a low mileage t56 out of a cobra and use that.

Finally get the magnum t56 kit from d&d.

Pro's of keeping t5 would be cheapest and lightest.

Cons still probably the weakest.

Pro's of 3550-tko. Cheap if one can be found, easy to rebuild, and pretty robust.

Cons shift quality mainly.

Same applies for tko500/600 but they are a little more expensive and harder to find used.

Pros of cobra t56 can be had for reasonable price, it's a 6 speed and relatively strong.

Cons it's heavy, 2.66 first gear.

Pros of magnum t56, at my blocks power limits still will never be able to hurt it, again it's a 6 speed.

Cons it's heavy, and is the most expensive.

Ok so lots to think about I need yalls help haha; thanks in advance.

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[95riosnake]

My first choice would be the T56 magnum, but the price tag is a tough one to swallow for sure. The regular (terminator-spec) T56 would be good, but they don't actually have that high of a torque rating... would be fine with stock block limits, but in the interest of planning ahead, you may want to make more power someday, in which case you'd have to build or replace the T56 along with the new block to make more power.  I have no complaints with my 3550, it's built to the moon and will handle just about anything I'll ever throw at it. It's a tad bit notchy and I would have to say my #1 gripe is that reverse isn't synchronized. Sometimes I would forget and grind into reverse...somewhat embarrassing. You just have to push in the clutch, slip it into any gear, then pull it back out of gear and put it in reverse. Not intuitive but not too bad.

[Tabres]

It has been several years since I've looked it up so my memory may be foggy, but I want to say the T56 and the T45/3650/etc. are within like 20-30lbs of each other from the source I saw online.  The T45 was like 85 pounds and the T56 was listed as like 115?  I don't know if that was actually correct, but it was what I read...

 

Fwiw, I actually have in my car what could be considered the very first T56 magnum ever built.  I also have what is basically the prototype McLeod RXT twin disk clutch.  No bullshit.  I bought it used from the guy who worked with D&D on it as a test subject.  He had this crazy 1000rwhp twin turbo build in a white 03 Cobra that was running in KOTS several years ago.  I want to say it was like 2009 or 2010.  Bob Kurgan built, tuned and drove the car for him and worked with D&D and McLeod on it.  I actually confirmed the story with Bob before I bought everything.

 

I guess that was a long winded way to say this - I love it.  Shifts nice, takes all of the abuse (~790rwtq on drag radials), lighter than stock peddle feel, no chatter from the clutch, separable bellhousing with a T56 is super nice, and hasn't ever given me a single problem.  And the prices have come way down on them since I bought my setup.  I wouldn't hesitate to do it again.

[Zach]

Yea the magnum will be more than my car would ever need, and the price is high but not to bad. I was thinking though I could get a low mileage cobra t56 and upgrade the input shaft to 26 spline, but I just am not sure if the 2.66 first gear would be to tall for a pushrod with 3.73 gears; so I guess that's were I'm stuck at in that argument.

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[RedTwilight]

One more positive about the T-56's is the extra overdrive gear.  It gives better gas mileage.  So in the extremely long run it'll help pay for itself.

[95riosnake]

One more positive about the T-56's is the extra overdrive gear.  It gives better gas mileage.  So in the extremely long run it'll help pay for itself.

 

The stock 5th in a Cobra/GT T5 is .68, Terminator T56 6th is .63. At 70mph with 28.5" tall tires (guessing) and 3.73's the RPM difference would be 154rpm. 2093rpm (T5 - .68) vs. 1939rpm (T56 - .63)

 

Now if the T56 is rebuilt or ordered with a .50 6th, that would make a very noticeable cruising RPM difference. If I ever pull the trigger on a magnum, it will definitely have a .50 6th.

[410sn95]

T56 Magnum is my vote.  Just spend the money once.

 

Have a built G-force t-5 with all the tricks and after blowing it up several times, I have a lot more into it than a Magnum.  It was really the only thing available when I built my car unless I procured a Viper spec T56 which was BIG money at the time.

[Zach]

Looks like I have decided on the magnum, so we will see how much longer the t5 lives then I will begin the swap.[emoji106]

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[ttocs]

yea but the tranny isn't necessarily the spot you want to skimp too much.  I think its one of those spots I am just going to hurry up write the check(write really small) and then get it out of my mind so I can enjoy it.  Worked for the air ride, ignorance is bliss...

[RedTwilight]

Looks like I have decided on the magnum, so we will see how much longer the t5 lives then I will begin the swap.[emoji106]

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Though a little high in price, I believe you made the right choice!

[Yeahloh95]

yes do it right once and move on, doing it twice always cost ^more

[95opal]

Thats like asking what mufflers to choose lol. Everyone will have a different opinion. Do yourself a favor and talk with the big guys. Call Astro, D&D, promotion ect. They will go over your set up and recomend the best trans for your sitiuation. I agree with Troy... Do it once do it right. When i was on the hunt for a trans Bubba at gforce came highly recommended, so he was the first to get a shot. After speaking with him and going over options I wasnt 100% set on dumping 6k into a t56 so I called another guy who came highly recommended and picked his brain. After all was said and done and i talked to everyone who built high performance manual transmissions. I went with walt at promotion powertrain. Couldnt have been happier with the decision. Infact a year later he called me up to check in on the build to see how it was coming. Now thats customer service. Good luck with the decision.

[95opal]

Yes that's pretty much what gforce wanted for a built t56 and everything I needed to go with it. You do realize even a t56 is in need of upgrades when dealing with big numbers?.

[Zach]

Thats like asking what mufflers to choose lol. Everyone will have a different opinion. Do yourself a favor and talk with the big guys. Call Astro, D&D, promotion ect. They will go over your set up and recomend the best trans for your sitiuation. I agree with Troy... Do it once do it right. When i was on the hunt for a trans Bubba at gforce came highly recommended, so he was the first to get a shot. After speaking with him and going over options I wasnt 100% set on dumping 6k into a t56 so I called another guy who came highly recommended and picked his brain. After all was said and done and i talked to everyone who built high performance manual transmissions. I went with walt at promotion powertrain. Couldnt have been happier with the decision. Infact a year later he called me up to check in on the build to see how it was coming. Now thats customer service. Good luck with the decision.

. I understand what your saying, I do like to get it right the first time and be done. I still have some time since the t5 hasn't blown up yet; so I'll call around and pick a few brains to see what we come up with.

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[Tabres]

I can echo that Walt at Promotion is a hell of a good guy.  I've been on the phone with him for probably about an hour before when I was looking at what to do for my trans setup.