Discussion
I'm getting to the stage in my project (1968 Volvo 142, 2.3l turbo 16v, lots of boost) where I need to be considering which gearbox to use.
The obvious choice to me initially was the T5 from a TVR (strongest T5 made, apparently). But talking to some American guys has got me thinking about a T56. I'm told that the prices you see on Ebay USA are ridiculously high and that most people don't pay much more than $500 for a gearbox. Obviously, in that situation I also have to consider shipping and duties.
I was thinking of the T56 for two reasons- torque handling and the 0.5:1 6th, which would let me run a lower ratio rear to help with launches at the strip. Stock diff in the 8.8" axle is 3.73:1 and I was thinking that the 6 speed would allow me to run a 4.10:1 and still have the car cruise nicely on the motorway.
Obviously the 6 speed box would have to be pretty cheap to justify it, but T5 boxes aren't exactly economy purchases either.
Ideas? Opinions?
The obvious choice to me initially was the T5 from a TVR (strongest T5 made, apparently). But talking to some American guys has got me thinking about a T56. I'm told that the prices you see on Ebay USA are ridiculously high and that most people don't pay much more than $500 for a gearbox. Obviously, in that situation I also have to consider shipping and duties.
I was thinking of the T56 for two reasons- torque handling and the 0.5:1 6th, which would let me run a lower ratio rear to help with launches at the strip. Stock diff in the 8.8" axle is 3.73:1 and I was thinking that the 6 speed would allow me to run a 4.10:1 and still have the car cruise nicely on the motorway.
Obviously the 6 speed box would have to be pretty cheap to justify it, but T5 boxes aren't exactly economy purchases either.
Ideas? Opinions?
Edited by BB-Q on Wednesday 28th November 23:47
Projected hp is about 550ish. Torque I haven't troubled to calculate. We're talking about a 2.3l 4 pot turbo lump. I'm being steered towards the T5 as it's available in this country for "reasonable" money and word is that they will take a lot more torque than they are rated for.
I've been told by the guys from TVR (I live in Blackpool) that they uprated the T5's as they came into the factory with stronger components.
I can make a T56 fit if needs be by cutting out the tunnel and making a new one, but the idea of something smaller definitely appeals.
My budget is severely limited as always, which is why the idea of a cheap T56 sounded so good.
The problem with the Getrag and Supra boxes is that they all have crap ratios compared to the 2.95:1, 1.94:1, 1.34:1, 1.00:1 and 0.83:1 of the T5 in Cosworth, V6 Camaro or TVR form.
I've been told by the guys from TVR (I live in Blackpool) that they uprated the T5's as they came into the factory with stronger components.
I can make a T56 fit if needs be by cutting out the tunnel and making a new one, but the idea of something smaller definitely appeals.
My budget is severely limited as always, which is why the idea of a cheap T56 sounded so good.
The problem with the Getrag and Supra boxes is that they all have crap ratios compared to the 2.95:1, 1.94:1, 1.34:1, 1.00:1 and 0.83:1 of the T5 in Cosworth, V6 Camaro or TVR form.
Boosted LS1 said:
Your cheapest option will be a yank World Class Mustang t5 from the States and they're quite strong as well.
Yes, but they have a nasty 3.35:1 1st gear. Well ok, not nasty, but nowhere near as tasty as the Ford based TVR T5 @ 2.95:1. Plus, there's plenty of TVRs in the breakers yards due to oh so many of their owners confusing their intentions with their abilities.My comments about the TVR box came from the guy who used to build them at the factory, so I'll take it as genuine.
Having spoken to guys who've run them behind stuff as big as BB Chevys I'm inclined to believe these boxes will take a hellava lot more torque than they are rated for. Also, some of the Cossie guys are putting bonkers power through them reliably.
Having spoken to guys who've run them behind stuff as big as BB Chevys I'm inclined to believe these boxes will take a hellava lot more torque than they are rated for. Also, some of the Cossie guys are putting bonkers power through them reliably.
Boosted LS1 said:
BB-Q said:
It was a random meeting when I was doing a breakdown, but the next time I come across anyone from the factory I'll ask them.
Could be interesting as lots of people have paid a premium price for a tvr box. Just like some people pay a price for a 24v ford with a cosworth badge on the plenum. The badge rocks if you get my drift.I found a place doing them for £350, but I've yet to call Douglas Valley Breakers and see how much they want. I'll do that in a minute but suspect they're going to be stupid money due to their "specialist" status.
I'm set on a T5 now (have you seen the gorgeous shifter kits you can get with the very weak dollar?!?!?!) unless a ridiculously cheap T56 comes along. Once I've got one (waiting for a small lump of cash that's coming my way) I'll measure it and report the differnces. There's a wealth of knowledge over on Turbobricks about the T5 ('cos they're all yanks) so the (external) differences can be noted. I think it uses the Ford input shaft and a different output shaft, but I'm not sure yet.
Edited by BB-Q on Saturday 1st December 09:14
GavinPearson said:
I think you need to be aware that the TVR transmissions have always been built in Tremec's factory in Queretaro, Mexico. How do I know? I asked the factory Manager when I went there.
That's fine- there seems to be no noticable difference between the Borg Warner and the Tremec that I know of anyway, unless someone would like to correct me. I'm just saying that I was told by someone from the factory that the new gearboxes were then stripped and rebuilt with stronger gears.
ridds said:
BB-Q would you mind letting me know where you found one for £350? I'm on the hunt for a replacement for my Cerb.
Andy Could mail me how much you are after for any of your many sets pretty please.
There are 2 variants of the T5 for TVR's, Std and Close Ratio. I believe the Tuscan RR cars had the CR boxes and yes I have seen one with my own eyes!
DV or Bell Hill can't remember who I phoned wanted about £650 ish all in. Also Tremecs UK supplier can supply them pretty much new off the shelf. Also there's a chap who makes T5's fit E type Jags and bought a lot of TVR's ex stock (had about 50) and he can supply, again not cheap though. Elite Transmissions I think.
What's a Tuscan RR?Andy Could mail me how much you are after for any of your many sets pretty please.
There are 2 variants of the T5 for TVR's, Std and Close Ratio. I believe the Tuscan RR cars had the CR boxes and yes I have seen one with my own eyes!
DV or Bell Hill can't remember who I phoned wanted about £650 ish all in. Also Tremecs UK supplier can supply them pretty much new off the shelf. Also there's a chap who makes T5's fit E type Jags and bought a lot of TVR's ex stock (had about 50) and he can supply, again not cheap though. Elite Transmissions I think.
I asked one of the local TVr garages for a gearbox supplier. I'll go ask them again and post up the number here.
shpub said:
Before going down the TVR T5 route bear in mind that the TVR T5 version has the gear lever in a different position compared to the RS500 and used a Chrysler (IIRC) output shaft spline. A Cosworth box might be a better fit for your application and save a lot of time and effort which can be spent on a CTS Quaife upgrade if needed.
The position of the lever isn't too important- I can get a mustang/camaro tail to change over for next to nothing. Besides, if I get a Cerbera box it has a reote on it already that can be kept, lenghtened, shortened or just removed as needed. 
No need to save up a small fortune for a quaife either, as the Ford 8.8" that's going in can be upgraded with genuine Ford Racing carbon clutch plates for $85 plus shipping and duties.
If I had a grand plus shipping and import duties to spend on a gearbox I'd agree with you whole heartedly!
Unofrtunately my budget for this build is only going to allow a T5- and I could break 4 or 5 of those for the cost of one TKO. With an annual mileage (mostly up and down Blackpool prom at 30mph) of about 3000 and probably a dozen or so runs down the strip a year, longevity can be compromised somewhat to make the budget more palateable.
Of course, if anyone wants to buy any of my kids I could stretch a bit further on the budget..........
Unofrtunately my budget for this build is only going to allow a T5- and I could break 4 or 5 of those for the cost of one TKO. With an annual mileage (mostly up and down Blackpool prom at 30mph) of about 3000 and probably a dozen or so runs down the strip a year, longevity can be compromised somewhat to make the budget more palateable.
Of course, if anyone wants to buy any of my kids I could stretch a bit further on the budget..........
I've got a 4.10:1 ring and pinion on the way over to replace the stock Explorer 3.73:1.
On a 26.5" tall tyre (295/50x15) a redline of 6k rpm would give me a maximum speed in each gear as follows:
1st (2.95:1)= 38.1mph. Changing to 2nd gives an rpm drop 2328, or 34%
2nd (1.94:1)= 57.9mph. Changing to 3rd gives an rpm drop 2103, or 31%
3rd (1.34:1)= 83.7mph. Changing to 4th gives an rpm drop 1725, or 25%
4th (1.00:1= 112.2mph. Changing to 5th gives an rpm drop 2516, or 37%
5th (0.63:1)= 177.9mph!
A 7k redline gives you another 12% on top of those speeds- 207.55mph in 5th! How fast do you want to go?
On a 26.5" tall tyre (295/50x15) a redline of 6k rpm would give me a maximum speed in each gear as follows:
1st (2.95:1)= 38.1mph. Changing to 2nd gives an rpm drop 2328, or 34%
2nd (1.94:1)= 57.9mph. Changing to 3rd gives an rpm drop 2103, or 31%
3rd (1.34:1)= 83.7mph. Changing to 4th gives an rpm drop 1725, or 25%
4th (1.00:1= 112.2mph. Changing to 5th gives an rpm drop 2516, or 37%
5th (0.63:1)= 177.9mph!
A 7k redline gives you another 12% on top of those speeds- 207.55mph in 5th! How fast do you want to go?
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