Rover V8 and Gearboxes
Discussion
Ok Chaps, As far as I know I have 3 options for mating a gearbox to a Rover V8.
1) LT77 from an SD1
2) R380 from ?
3) A T5 from a Cosworth
The preference seems to be for a R380 as it is a better box and newer. The LT77 is a bit long in the tooth and has some problems one being they are starting to get a bit rare.
Don't know much about the T5
So I'd appreciate some opinions on which box and how much the current market rate is for a second hand unit.
I have seen new R380 for over a grand and more for the T5.
1) LT77 from an SD1
2) R380 from ?
3) A T5 from a Cosworth
The preference seems to be for a R380 as it is a better box and newer. The LT77 is a bit long in the tooth and has some problems one being they are starting to get a bit rare.
Don't know much about the T5
So I'd appreciate some opinions on which box and how much the current market rate is for a second hand unit.
I have seen new R380 for over a grand and more for the T5.
I had an lt77 rebuilt by Ken Tomlinson and powered it via a 5.0 rover with 9 psi of boost in a tr7. It never failed me and I sold it on along with the engine. Ok, so I lost traction in the lower gears and was carefull on launching but it never broke so any atmo engine using stock rpm's shouldn't hurt it.
markh said:
Doesn't the LT77 have a tendency to lose 5th gear?
I thoughtt that was the T 5?
I'm fairly sure it was the LT77 SD1 box; 5th gear was provided by a sort of overdrive bit hung on the back of the box, which was less robust than the rest of the box. Of course I could be getting terminally confused...
Not sure about what strengthening was done but both Peter Humphries and Steve Heath use LT77's in their respective tweeked sprinting Tivs. So can't be all that bad to mortals (that or its uneconomical to change them 
). In steves case I'm sure he's putting 450 ponies through it too 
Harry
). In steves case I'm sure he's putting 450 ponies through it too Harry
HarryW said:
Not sure about what strengthening was done but both Peter Humphries and Steve Heath use LT77's in their respective tweeked sprinting Tivs. So can't be all that bad to mortals (that or its uneconomical to change them
Harry
The LT77 I have was the original one fitted to my car in 1987. It has been rebuilt/strengthened to cope with the engine mods. The best upgrade is to declare the gearbox another consumable. Get it rebuilt every year ish for about £350 by Bernie the Box... Hasn't let me down yet.
The real issue is that to switch to another box would cost a fortune (new prop shaft, mounts, linkage etc) and I quite like the lower gearing that the LT77 offers. If I did change I would go sequential but that is silly money but I do still have one kidney left
I run a chevy TH350 gearbox on rover engine, it is an auto but i have installed a full manual valve body in the box so i have no choice but to use the manual gear change. It is perfect for my sport and i know it is not going to break as i know people that put around 700+bhp through them and have no problems. Al you need is a chevy-rover adaptor plate and with a quickshift kit in the it changes instant. It is just another option.
Boosted LS1 said:
T5 to rover usually means an expensive bell housing to suit. LT77 is a good box and common as was also used on tr7's and probably other cars as well. Supra 5 speed is also very good and bell housings come from Oz.
Hi Mike do you know any more on this Supra conversion, can you use the later 6 speed item as well?
timf said:
have a look at this lot in sheffield
www.classicconversions.co.uk/roverv8.htm
But for that sort of money you could buy a new R380 gearbox as used by morgan, TVR, etal
markh said:
T5 to rover usually means an expensive bell housing to suit. LT77 is a good box and common as was also used on tr7's and probably other cars as well. Supra 5 speed is also very good and bell housings come from Oz.
Hi Mike do you know any more on this Supra conversion, can you use the later 6 speed item as well?
I looked into it at one stage and iirc there are 3 versions of the 5 speed box. You pick the one that puts the gear stick where you want it. Bell housings come from dellow in Oz, Perth I think. Down under they like the 5 speed box a lot. Stevie turbo has abused one for several years with no real problems. He may chime in if he see's this thread and post up a link or 2
As for the toyota 6 speed, it big, heavy, strong and expensive. The T56 would be more suitable, it's all of the above but more available and probably cheaper. I've chosen the t56 for those reasons.
Ive broke a couple of Supra turbo boxes. But both were simply sec hand units.
Ive only stripped teeth once ( input shaft ), the other failure was very minor, with a thrust washer breaking up. It only broke a couple of teeth though when it did, after a boot in 3rd gear. It was still driving.
The 6 speed Supra box isnt an easy option, as it has an integral bellhousing, and is totally different to the 5 speed.
By comparison, I broke 3 rover gearboxes in under 3 weeks with less power than I have now before I finally decided it was time to change.
I have nothing but praise for the Supra box, it has lasted me very very well, including multiple 2nd gear launches at the dragstrip, with a fairly heavy car ( 1580kgs )
The ratios are also fairly good.
1st 3.30:1 = 6.4mph per 1000rpm
2nd 1.95:1 = 11 mph per 1000rpm
3rd 1.34:1 = 16 mph per 1000rpm
4th 1.00:1 = 21 mph per 1000rpm
5th 0.75:1 = 28 mph per 1000rpm
This is using my 245/45x16 with a 3.45 rear diff.
I dont believe a T5 would take the abuse and power I have put through the Supra box.
You can also buy the Supra boxes for sensible money compared to a T5. Shifter location in the R-154 turbo box is about 2" shorter than the normal rover one.
Overall cost may be similar for a complete conversion, but parts for the Supra box are also fairly cheap, as are the boxes. This was a deciding factor in my choice. T5's are even expensive for one that needs re-built.
http://gallery11536.fotopic.net/c29635.html
Of course, as much as I like the Supra box. The T56 appears to be the daddy, supporting much more power.
Ive only stripped teeth once ( input shaft ), the other failure was very minor, with a thrust washer breaking up. It only broke a couple of teeth though when it did, after a boot in 3rd gear. It was still driving.
The 6 speed Supra box isnt an easy option, as it has an integral bellhousing, and is totally different to the 5 speed.
By comparison, I broke 3 rover gearboxes in under 3 weeks with less power than I have now before I finally decided it was time to change.
I have nothing but praise for the Supra box, it has lasted me very very well, including multiple 2nd gear launches at the dragstrip, with a fairly heavy car ( 1580kgs )
The ratios are also fairly good.
1st 3.30:1 = 6.4mph per 1000rpm
2nd 1.95:1 = 11 mph per 1000rpm
3rd 1.34:1 = 16 mph per 1000rpm
4th 1.00:1 = 21 mph per 1000rpm
5th 0.75:1 = 28 mph per 1000rpm
This is using my 245/45x16 with a 3.45 rear diff.
I dont believe a T5 would take the abuse and power I have put through the Supra box.
You can also buy the Supra boxes for sensible money compared to a T5. Shifter location in the R-154 turbo box is about 2" shorter than the normal rover one.
Overall cost may be similar for a complete conversion, but parts for the Supra box are also fairly cheap, as are the boxes. This was a deciding factor in my choice. T5's are even expensive for one that needs re-built.
http://gallery11536.fotopic.net/c29635.html
Of course, as much as I like the Supra box. The T56 appears to be the daddy, supporting much more power.
stevieturbo said:
http://gallery11536.fotopic.net/c29635.html
Of course, as much as I like the Supra box. The T56 appears to be the daddy, supporting much more power.
The T56 is, after all, designed to cope with the ridiculous amounts of torque GM V8s pump out, being deployed mercilessly on the drag strip
I need one for my car
(well I don't really, but it would be nice 
)The T56 is only rated at 450lbft on most applications ( although some are only 400lbft ).
The Viper box is apparently rated at 550lbft, depending on who's specs you read.
Not too many standard engines will push this to the limit.
When I researched the Supra box, most said they were indestructable, and will take 500bhp all day long. While they are indeed very strong, I think this was being a tad optimistic.
Mine broke a couple of teeth on the input shaft exiting a roundabout in 3rd. After some moderate wheelspin, it got traction, when it broke the teeth. This box was in the car for about a year though.
Hopefully I'll see very soon how it copes with launching with some soft tyres and my new axle.
The Viper box is apparently rated at 550lbft, depending on who's specs you read.
Not too many standard engines will push this to the limit.
When I researched the Supra box, most said they were indestructable, and will take 500bhp all day long. While they are indeed very strong, I think this was being a tad optimistic.
Mine broke a couple of teeth on the input shaft exiting a roundabout in 3rd. After some moderate wheelspin, it got traction, when it broke the teeth. This box was in the car for about a year though.
Hopefully I'll see very soon how it copes with launching with some soft tyres and my new axle.
See the TREMEC website for a full applications, torque capacity and ratios list....
www.tremectransmissions.com/English/products/T-56.asp
Bear in mind their torque capacity takes into account general abuse and having to last 150,000 miles.
www.tremectransmissions.com/English/products/T-56.asp
Bear in mind their torque capacity takes into account general abuse and having to last 150,000 miles.
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