21 replies to this topic

[MRLXSS]

Hey Guys,

I'm tossing up what to bolt up behind my new motor.

Currently I'm running a Trimatic with a 2500 Stall... It seems like a pretty tight box, shifts well and all. But i'm worried that it won't hold up to a 400hp+ 355.

So I'm now thinking about other options. Here is a list i've been thinking in my head of each box.

Trimatic - (Beef mine up, or buy a better one)

• Can keep my tailshaft, crossmember etc. Easy fit
• Just need to have block re-drilled to suit Trimatic Pattern

TH350 - (Buy one)

• Fairly cheap to come across, and seem to handle power easier
• No Need to re-drill the block
  
• Need to buy new Crossmember, Tailshaft, Stall, shifter brackets etc

TH700 - (Buy one - Out of a VN V8)

• Overdrive! Would be great for cruising an could mean i could get some 4.11's in the future.
  
• No Need to re-drill the block
  
• Need to buy new Crossmember, Tailshaft, Stall, shifter brackets etc
• Heard they can't withstand heaps of horsepower
• Bit of Tunnel Massaging required?

Maybe a Manual? T5?

• Enjoy driving a manual again!!
  
• No Need to re-drill the block
  
• Need to buy new Crossmember, Tailshaft, and everything associated with the manual conversion.
  
• Lots more hassles getting the clutch etc all working perfectly
  
• Bit of Tunnel Massaging required?
• Not sure if the pipes i already bought will fit or not.

What do people think? I'm open to suggestions and opinions... My budget is already stretched going the stroker, so trying to do everything on an ok budget,

[rexy]

Although its potentially cheapest to keep your trimatic for now, once you break it or go to yet more hp in the future you will be screwed for stronger choices without a fair bit of rooting around. You should be able to source most of the stuff or modify your own to fit a proper strength auto without spending too much. I of course mean t350 or t400. If you want a strong t700 you will need to spend a fair bit more money.
R

[wot179]

MAYBE a manual?

C'mon Matt........You KNOW you want to.

Think about it like this.
You wont have to worry about getting your skirt caught on that great big brake pedal anymore.

[MRLXSS]

If you are considering staying auto why not beef up the Tri-matic? I ran one in my last LH which had a smaller stroker combo similar to the mumbo torana and it shifted hard and held up no problem, i think the mumbo car also runs a Tri-matic? either way its going to cost you to build it up but at least you have a good starting point with your current box if its in good condition. A built Tri-matic can be good for up to 500HP.

If the block was a Trimatic pattern, i wouldn't consider anything else, i'd just put a beefed up Trimatic behind. I know they can be build to withstand good power.

t700 not been able to be beefed up?
um you do work for street machine mag don't you?
corvette servos and they can handle more power
or you could go with the 4180 out of the states
the trimatic is the cheapest option but it is your car
and in the end your choice and will be governed by that and your budget
and if you want more than 450+ horses then i'd steer clear of the t5

I didnt say you can't beef them up, but you spend 2k on a T700 and 2k on a T350, and the 350 will handle more power... If the T700 was just as tough, there'd be more of them. I have heard people say they are limited to around the 500hp mark... Is this true?

I'll check out the 4180. The Aussie dollar is looking good too!

By the sounds of it the T5 and the T700 seem to handle similar horsepower, and if i had to choose either, i'd probably go the T700..

Although its potentially cheapest to keep your trimatic for now, once you break it or go to yet more hp in the future you will be screwed for stronger choices without a fair bit of rooting around. You should be able to source most of the stuff or modify your own to fit a proper strength auto without spending too much. I of course mean t350 or t400. If you want a strong t700 you will need to spend a fair bit more money.
R

Yeh, thats exactly how im currently thinking... If i get the block re-drilled for Trimatic pattern, im stuck with that.

[MRLXSS]

i have had a t700 box beefed up for my 5ltr , costed me 500 bucks to get the corvette servo pistons and stage 2 shift kit. My mate who did it says they are a good strong box unless you downshift with them . He tells me if you are comming into a corner and you shift hard down a gear like you would in a manual they break something in the planetary gears? (i think he said). Apparently police cars were breaking them all the time. His words to me were "dont downshift it period " .

Thats interesting to hear... I don't really slam in back gears in auto's anyway... I know unless they are built for it, not many boxes like it...

TH350 gets my vote, great box, stronger than a Trimatic to start with, plus a easy fit.


Dont worry about the t5, unless you dont care about breakin more stuff ,oh and that autos with the same RWHP will be faster (ha-ha)




MT

HAHA! Yeah, I like to go fast at the track! Thats another reason why i'm swaying towards the auto... Big Stall and im set! HAHA!

TH350 gets my vote too, i run a properly built one behind the 355 in my SLR which has put out 450bhp on an engine dyno & has run an easy 11.9 on it's third pass at WSID with 3.5s in the diff. You might remember the car, it was the one with the crap silver paint & primer patches.

Yep! I know your car.... We are pretty much going to have identical driveline when i'm done! I have a few friends with T350's and with not big bucks spent on them, they have handled many 11 second passes.

[Statler]

You should probably leave it auto.... Maddy might want to drive it.

[yel327]

4L80 is just a 4spd version of the old 3L80 (otherwise known as a TH400). If you want to go down that path a TH400 would be easier and cheaper! Plus it'll be manual shift only in 4L80. Both 3L80 and 4L80 are very tough boxes, but they are big mothers. For a light car like a Torana i'd stick with a TH350 or a trimatic.

[Stedz_lc]

T350 gets my vote too! Ive failed in breaking mine so far! And ive hit it with nitrous and all sorts of torture!!
stil like new!

[76lxhatch]

T10

The TH350 is the best all round option in terms of budget and performance if you're happy to stay auto

[gtrboyy]

A well built rimatic will take 450hp
A good th350 will take it easily
Dont rate th700 as I've never had much luyck with them...2 rebuilds was enough.

T5 will eventually blow apart unless you baby it...

[LXCHEV]

Whatever option you decide on Matty will be fine, assuming it's BUILT RIGHT! Unfortunately it all just comes down to cold hard cash.

Personally, I also vote for a 'built' TH350. They are such a good all-rounder, and have proven to withstand big HP, without costing mega bucks. For a mild budget, you can't go wrong. The ratio's of the TH350 are also great (and slightly better than a T400) for a tough streeter come drag car.

TH700's do sound nice. But I've heard the same thing... to make them reliable, you need to spend some serious coin. I have a few mates running them behind SBC's, and I'm not sure if it's just their setups or not, but they just don't feel as nice shifting through the gears.

Manual would be great fun, but in my opinion will tend to require more maintenance if you treat it mean with some serious HP... auto's tend to be more 'set and forget'. Just make sure you buy a top of the range trans cooler. Buy a good brand name stally, and you'll never look back. (Once again, more bucks!!!)

[dirtbag]

Just get a T56 and be done with it. Leave the autos for nannas camry : )