Which Box?

[Robrover]

I’m looking at going 5.5 with well worked Buick 300 heads on my SD1. It should approach 380 - 400 ftlb of torque. What gearbox will fit the RV8 that’s man enough to handle the torque?

The Rover boxes are not up there.

Is the TVR 240 series T5 going to last long?

The Aussie T5 as fitted to the Falcon XR6s and many Commodores is supposedly rated at 265 ftlb,.

Gearboxman.com.uk do an uprated gearkit and selectors for the T5 but it costs.

Tremec TR3550 (now called TKO) is a tough box, fitted to some US muscle cars and will take well over 400 ftlb of punishment.

I know RPI do a kit that includes bellhousing to fit a Tremec to a Rover engine but this is a version of the Tremec T5 and is rated at 300 ftlb.

Tremec bought the rights to the T5 design. So the Tremec T5 is the same as the Borg Warner T5. But the T5 was an OEM box so its specs were changed to suit the application. And there are hundreds of applications (and hence variants of the T5).

Toyota Supra W57-58s reportedly can’t handle much beyond 330 ftlb (there are instances of them failing behind 5 litre Holden V8s). Dellow do an installation kit for the Rover that includes bellhousing, clutch, propshaft. Ok for most RV8 applications but maybe not a big torque 5.5.

The R154 Supra Turbo box will take a lot more but is much bigger and a bitch to install on anything other than a Toyota.

The BW factory T56 is pretty tough plus you get the whole 6 speed thing (plenty of these in Oz fitted to 6 litre Holden Commodores) however I’m not sure if it will fit under the SD1 too easily.

D&D Fabrications are now producing a few new bellhousing adaptors for the RV8 that allow a variety of boxes to be fitted (T5, T56, T10, Muncie, Saginaw, etc)

http://www.aluminumv8.com/index.htm

[SuperV8]

I am using a Tremec T5 out of a TVR. I believe all TVR's used the same gearbox either close ratio or standard. The Cerbra has (apparently!) 380Lb.ft.
I think generally the world class BW T5's were either rated at 300-330Lb.ft as are the later Tremec T5's. From what I have read that is conservative. I wouldn't use the none-world class T5.

Obviously how you use any gearbox will determine its life, lots of drag racing with sticky tyres in a heavy car will shorten any gearboxes life!

Personally I chose the T5 because they are light, small, cheap, there are upgradable gear sets to increase the torque capacity if required and the TVR belhousing bolts straight to the RV8, they have quite a high torque capacity and a good gear change. I have a supercharged 4.6 with potentially similar levels in torque but my car weights 700kg which will give the gearbox an easyer life!

Don't know if that's much help!

Tom.

[ChrisJC]

The other point is that the torque through the box is limited by the traction you have.

Chris.

[katanaman]

The 380 in the stock R380 is 380 ftlb. Not sure I would trust that but thats why it is called that. T5 should cope though but if you have big sticky tyres and a load of grip you might want to go one bigger. Trouble with that is the boxes physical size starts to get pretty big

[DaveEFI]

The other point is that the torque through the box is limited by the traction you have.

Chris.

That more applies to the final drive. The gearbox will still have to handle the peak torque in the higher gears - unless the traction is very poor. But if it can spin its wheels in top I'd say you've overdone the power.

[ChrisJC]

Hmm, in first, you've got a huge torque multiplication, so the output shaft has to deal with maybe 4x the input torque.

So I would argue it is down to traction still....

Chris.

[stevieturbo]

I’m looking at going 5.5 with well worked Buick 300 heads on my SD1. It should approach 380 - 400 ftlb of torque. What gearbox will fit the RV8 that’s man enough to handle the torque?

The Rover boxes are not up there.

Is the TVR 240 series T5 going to last long?

The Aussie T5 as fitted to the Falcon XR6s and many Commodores is supposedly rated at 265 ftlb,.

Gearboxman.com.uk do an uprated gearkit and selectors for the T5 but it costs.

Tremec TR3550 (now called TKO) is a tough box, fitted to some US muscle cars and will take well over 400 ftlb of punishment.

I know RPI do a kit that includes bellhousing to fit a Tremec to a Rover engine but this is a version of the Tremec T5 and is rated at 300 ftlb.

Tremec bought the rights to the T5 design. So the Tremec T5 is the same as the Borg Warner T5. But the T5 was an OEM box so its specs were changed to suit the application. And there are hundreds of applications (and hence variants of the T5).

Toyota Supra W57-58s reportedly can’t handle much beyond 330 ftlb (there are instances of them failing behind 5 litre Holden V8s). Dellow do an installation kit for the Rover that includes bellhousing, clutch, propshaft. Ok for most RV8 applications but maybe not a big torque 5.5.

The R154 Supra Turbo box will take a lot more but is much bigger and a bitch to install on anything other than a Toyota.

The BW factory T56 is pretty tough plus you get the whole 6 speed thing (plenty of these in Oz fitted to 6 litre Holden Commodores) however I’m not sure if it will fit under the SD1 too easily.

D&D Fabrications are now producing a few new bellhousing adaptors for the RV8 that allow a variety of boxes to be fitted (T5, T56, T10, Muncie, Saginaw, etc)

http://www.aluminumv8.com/index.htm

You're in Australia ?

R154 is easy, and a simple bolt in job with the right parts. And will work. And if you are in Oz, there are bellhousing kits readily available either in Oz, or NZ

Dont see why you would even consider anything else ? And why do you think its difficult ?

[russell_ram]

"The 380 in the stock R380 is 380 ftlb"

Unfortunately not - the R380 is rated at 380Nm (280ftlbs) - but it is rated at that for 4WD applications which don't (wheel spin) torque limit in low gears. Traction limit is hugely important in gearbox load capacity (as is vehicle inertia). Many current high performance cars have torque caps applied to the ecu maps in low gears to protect the gearbox, in higher gears this is removed as its not needed.

[katanaman]

"The 380 in the stock R380 is 380 ftlb"

Unfortunately not - the R380 is rated at 380Nm (280ftlbs) - but it is rated at that for 4WD applications which don't (wheel spin) torque limit in low gears. Traction limit is hugely important in gearbox load capacity (as is vehicle inertia). Many current high performance cars have torque caps applied to the ecu maps in low gears to protect the gearbox, in higher gears this is removed as its not needed.

Ah ok I stand corrected

[Robrover]

Thanks for these insights.

The R154 is the way to go I agree, they're virtually indestructable and a lot cheaper secondhand than the equivalent Tremec and stronger than most of the other T5 options.

Not sure about fitting it to an SD1 though.
.
Dellow Conversions in Sidney and Castlemaine Rod Shop out of Melbourne do kits to fit the W Series Toyota boxes to RV8s/ P76s but these boxes are smaller, narrower and lighter than the R Series. The bellhousing and clutch bits are the same I believe, but the extension housings are different and the rear mount may have to be fabricated (no big deal). The standard R154 extension doesn't line the gearlever up in the right place. Not sure about the rear yokes either.

Main issue is I'm not certain it'll fit width wise under the tunnel of an SD1.

I'll speak to Dellow to see if they have any knowledge of this being done before and if they can put a kit together. I know of quite a few Aussie SD1s with the W Series boxes in them, but not the R154.

[stevieturbo]

I went from an LT77 in my car when I had the RV8 to a R-154 with one of Colin's kits

http://www.conversioncomp.co.nz/

Although I used a different clutch purely down to the power/intended use.

All parts of his kit are very good quality, and it was a very smooth install. Shifter position is close enough to the LT77 that it really was no big deal at all.

In fact I can barely remember it being different. Speedo did require a little work though, but there are always options.

I thought I had some side by side pics, but cant find them

I have one photo that suggests the shifter is 20" from front of the box, but Ive no bellhousing height to add to that.

At a guess, I'd say the BH is a good 10-11" though, but that is a guess.

The R-154 bellhousing is unique to that box, and not the same as the non-turbo cars W-series.

Pretty sure in my first car, I really didnt need to cut anything at all, but it was many years ago and I have few photos. But from what I can tell I had to cut nothing over the previous LT77.

The majority of the bulk of the 154 is just that the body is much wider. It isnt any taller than the LT77.
The majority of the body along it's centreline is about 9" wide.

[Robrover]

Thanks mate.

Was your first car with the R154 fitted an SD1?

I'll need to measure the width of the transmission tunnel and that of a R154 box.

[stevieturbo]

Thanks mate.

Was your first car with the R154 fitted an SD1?

I'll need to measure the width of the transmission tunnel and that of a R154 box.

MK2 Ford Granada. SO it should never have had the LT77 either.

Surprisingly, with only the frame removed from the tunnel leaving it a single skin, the T56 fitted in no problem too !, and it's massive

I just welded flat bar around it to brace it and mounted the box off this flat bar via another bracket

[kokkolanpoika]

WC T5 Box is also rated at for 4WD applications. WC T5 300ftlbs -T5Z 330ftlbs/2500Kg

I have run many years my SD1 and LT77 with my 5.2litre engine witch has got +400ftlbs of torque. And box still work. Input shaft bearing is ultra slightly noisy and 3rd gear syncro is slightly worn. (I use same box with my old engine 4.6stage 3 approx 300hp/460Nm) Total approx +40000km without issue´s.

Now i made an upgrade for T5Z box. drived 2600km without issue´s. It is noisy box but ok..

[stevieturbo]

I was stripping LT77's at the tune of one a week before I finally got fed up.

Pretty cool



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