Type 9 gearbox fitted to a 4.6 stage III v8

[sidecar]

Hi
Not sure of the TVR straight 6 bolt pattern, but as it was an in house design I would see if it is Buick V8 anyway, might well be, if nit it isnt rocket science to make up an adaptor.
The Quaif box will be pretty strong, they have a reputation for making boxes that do not blow up and are pretty keen to keep it, what BHP is your engine, cant be much more unless you have merlin/TA (if they exist) or Buick 300 heads.
Best regards
Mike

Hi Mike,

The last time my car was on the rollers it made 285 at the fly. It runs stage III V8Dev heads along with other stuff. Since then I have discovered that it was running lean above 5000 RPM, basically it did not want to rev past that figure. Once I found this out and richened the mixture up the power above 5k improved quite alot. I also then fitted an MSD ignition system and that improved the BHP again.

So I reckon that it is about 300 BHP now. Oh and I run an 85 BHP NOS shot now and again just to help me get away from the traffic lights.

Therefore the total BHP is quite a bit above 250 but the car is light and does not have a massive amount of rear end grip (The tyres are too wide for the weight of the car so they tend to spin up but they do look 'right').

Cheers,

Pete

[SuperV8]

The Rover V8 tvr bellhousing will fit the T5, got mine new for £150.
I think the close ratio box was fitted on the tuscan s and some sagaris's.

Tom.

[kiwicar]

Hi
If you hadn't mentioned the Nos I would have said you would be fine with the type 9 and 285 - 300 bhp mention the Nos and I am inclined to think that a Close Ratio T5 would be a much better idea. Too much power and particulally torque (as Dave points out) will wear out a box quickly. Shock loading brakes them, the Nos will give you big of shock loads, especially where the rear grip may be a bit on/off.
Best regards
Mike

[sidecar]

Thanks guys, looking at the TVR boxes is looks like the gear lever position is wrong for my car, its too far forward.

At least I know what bellhousing to go for if I end up with a T5 box, I have found a chap (Gearboxman) that does do close ratio T5 gear sets for both the TVR and Ford version of the box but first is still a bit high at 2.5:1. I'll work out what the road speed will be for that ratio when I get home.

Cheers,

Pete

[kiwicar]

I am pretty sure the TVR gear knob position is by virtue of a horribly crude bodge linkage fitted to the box . . throw it away and fit a standard leaver and the knob will be about 8" to 10" further back.
Best regards
Mike

[sidecar]

Hi Guys,

Right I've got fed up with this so I took my gearbox out of my car tonight.

I've just spent a good hour working out the ratios that are in the box by spinning the output shaft whilst counting the turns on the input shaft. Fifth gear was the worst to work out, it took 5 complete turns of the output shaft before I got a complete number of turns of the input shaft, (6 turns).

Anyway I'll be having a word with the bloke that I got the R380 box from, (TM Transmissions) because the box ain't from a Morgan with a 4:1 first gear!

The ratios are 4:1, 2.5:1, 1.5:1, 1:1, 0.83:1

No bloody wonder first gear is useless and no wonder second gear is OK to pull away with. With my box as it is now the gear calculator reckons that at 5.5K RPM the speed in each gear is:-

31, 49, 82, 123, 149

The close ratio T5 box has the following ratios:-

2.572:1, 1.675:1, 1.259, 1:1, 0.87:1

The above ratios give a max speed in each gear at 5.5k RPM of:-

49, 74, 98, 123, 142.

The top speed has dropped a little but I'm not bothered about that, infact the engine will rev to 6K which will add around 13 MPH to the max speed so I'm going to order up a Close ratio T5 box from 'gearboxman'

Good job I did not order up a box with a 2:1 first gear!

[ged]

That is a low first. The lt77 I'm using is 3.321-1

Regards Ged

[unstable load]

With 4:1 in first it sounds like a commercial vehicle box.

[minorv8]

I bought a R380 box from Ebay and turns out it had the same ratios than yours. Good thing is that you can get parts to convert it to better ratios. Well you can guess the bad news...

Anyway, that´s what I did. I got the gears from Ashcroft Transmissions and converted the box to same ratios that LT77 has i.e. 3,321 first. to be honest the parts were not that expensive but some bearings did not survive the disassembly so that needs to be added to the total cost. Fifth gear nut was fastened by some 500 lb giant and even a 5 ft extension did not break the nut loose. I finally had to grind the blo**y nut in pieces.

That 3,321 ratio is more than enough for road use. Sure a first gear ratio of 2,7 - 2,9 would most likely allow more acceleration and less wheel spin but I you need to crawl in traffic then the 3,32 is better. But it´s a matter of personal opinion.

[sidecar]

I bought a R380 box from Ebay and turns out it had the same ratios than yours. Good thing is that you can get parts to convert it to better ratios. Well you can guess the bad news...

Anyway, that´s what I did. I got the gears from Ashcroft Transmissions and converted the box to same ratios that LT77 has i.e. 3,321 first. to be honest the parts were not that expensive but some bearings did not survive the disassembly so that needs to be added to the total cost. Fifth gear nut was fastened by some 500 lb giant and even a 5 ft extension did not break the nut loose. I finally had to grind the blo**y nut in pieces.

That 3,321 ratio is more than enough for road use. Sure a first gear ratio of 2,7 - 2,9 would most likely allow more acceleration and less wheel spin but I you need to crawl in traffic then the 3,32 is better. But it´s a matter of personal opinion.

Hi MinorV8,

I've decided to bite the bullet, I'm going for a T5 box, I'm really quite pissed of with TM Transmissions over my R380.

I've had an email back from Gearboxman regarding the T5, it ain't going to be cheap, the close ratio box is 1760+vat, the bellhousing is 420, it comes with a concentric slave which I don't like at all. I could get my bellhousing cut and welded to take the T5 but I'm not sure if I want all the agro'. They also reckon that the gears and other components should be peened due to the NOS shock load....425 quid. I'll also need to sort out the rear support and the propshaft.

With regards to first gear I now know for a fact that my second gear is 2.5:1 which just happens to be the first gear ratio of the close ratio T5. My current second gear works very well as a first gear, I can crawl in traffic but it also has some 'legs' allowing me to get up to a decent speed before changing gear.

I'm going to get the flywheel lightend whilst I'm at it, the car should go 'quite well' after all of this stuff has been done!

Cheers,

Pete

[ian.stewart]

BHP is pretty irrelevant to a gearbox. It's peak torque which matters.

By the way I bet Ians picture is the result of a high speed Yump in third on a tarmac rally again shock loading of the box (and probably a bit of a suprise to the driver.
Mmmmmmm straight cut gears good way to save weight, no point in fitting a radio, you will never hear it!
Best regards
Mike

the gearbox breakage was a 2nd to 3rd at SantaPod, the bottom half of the casing slid up the track quite a distance, and it was only behind a pinto, so that broke with possibly no more than 200, hp Max and 150 ftlbs,

[kiwicar]

OK Ian
Bad guess. . .
I must confess though I have seen a few boxes in rally cars do that, saw the remains of a mini box where the diff exited teh bottom of the back of the case, didn't leave much behind it. . . like the drive shafts and saw the remains of an Alpha sud case that shoved the first motion shaft sideways through the case. It always happened after getting airborn at full throttle and not dipping the clutch before landing, though I suspect in the case of the 'Sud the quality of casting might have been an issue.
Best regards
Mike

[SuperV8]

Cricky, sounds more like a 4x4 ratio!

Sounds like a lot for the bellhousing! Mine was more like £150-200. Personally I would just use the standard TVR setup, similar to the SD1, with slave and pushrod, works great and if it does start leaking you don't have to take the whole engine/gearbox out! also a lot cheaper than a concentric.

I had a custom prop made and they had the correct output adaptor on the shelf. I think somewhere arround £100.

Tom.

[minorv8]

I have also thought about the T5 box since my LT77 box is from 4-pot TR7 which is not supposed to be the strongest one built. I am not sure if it is same as A suffix boxes. However, it has not broken down, I now have a rebuilt R380 waiting for that to happen (which most likely does not happen since I have another box). T5 conversion was so expensive even if the parts would have been sourced s/h that I stuck with Rover box.

Ýes that concentric slave has been a problem in many cases, mate´s new slave leaked from day one. PITA to replace

Your box is probably from a Sherpa or LDV or whatever they are called, i would be very surprised if Morgan used such ratios.

[Cobratone]

With 4:1 in first it sounds like a commercial vehicle.

Fixed it for you, mind you, Pete's engine sounds like a commercial vehicle in any gear