Beefing up T5

[2Munkys]

O.k, it aint gonna happen this year but for the next I'm kinda toying with the idea of cobbling a bit of SC Power onto the 5.4:

I know people are putting up to 400 lb/ft through the T5 with some measure of reliablity. But, let's assume I wanted it to handle more and with a bit of a safety margin, say 500 lb/ft. Is this possible? What would it need (would it just be changes to 5th)? Who should I entrust this to (could it be DIY; doesn't Matt350 do this kinda work)? Any idea of cost? Don't wanna go TKO 600.

[Boosted LS1]

Whats the tq rating of the WC box? Maybe one of those from the States would be viable. I bought a load of them a few years ago (mustang iirc) but they were hard to sell at the time.

[RichardD]

I know shpub likes T5 rebuilds done by Competition Transmission Services.

http://www.gearboxman.co.uk/psgearkits.html

[rev-erend]

RichardD said:

I know shpub likes T5 rebuilds done by Competition Transmission Services.

http://www.gearboxman.co.uk/psgearkits.html

I talked to CTS about this .. it's quaife internals .. quite pricey at about £1300 but very strong.

[2Munkys]

Boosted LS1 said:

Whats the tq rating of the WC box? Maybe one of those from the States would be viable. I bought a load of them a few years ago (mustang iirc) but they were hard to sell at the time.

Ah, by that I guess the T5 in the Griff isn't WC; for some reason I thought it was.

Ideally I'd drop the box off someplace where it'd be freshened-up and returned with any necessaries to take the extra loads. That route, it'd go back where it belongs without any spline/clearance/other issues. Kinda looks like it could be costly which is why it all needs factoring in with other foreseeables: milder cam, heads with larger combustion chambers, uprated half-shafts etc, etc . . . .

[RichardD]

rev-erend said:

RichardD said:

I know shpub likes T5 rebuilds done by Competition Transmission Services.
http://www.gearboxman.co.uk/psgearkits.html

I talked to CTS about this .. it's quaife internals .. quite pricey at about £1300 but very strong.

I would have been interested in this (depending on future plans), but given I'm starting with a LT77 making the jump to TKO600 would be slightly less work as far as I can tell!

I am saying this after reading info from Quinny how he had changed a LT77 to T5 in the past which I thought was rather not straightforward !

[2Munkys]

RichardD said:

I'm starting with a LT77 making the jump to TKO600 would be slightly less work as far as I can tell!

IIRC from a couple of years back, Austec were doin the TKO for around £1100; does that sound right?! There were some incompatibilities with coupling the input/output if it was to replace the T5 I seem to recall. Not sure about the LT77 splining.

[RichardD]

2Munkys said:

...IIRC from a couple of years back, Austec were doin the TKO for around £1100; does that sound right?! There were some incompatibilities with coupling the input/output if it was to replace the T5 I seem to recall. Not sure about the LT77 splining.

IMHO that price seems on the low side of do-able if it was based on $2 per £1. I've not seen less than £2k recently, but then I've not looked properly.

From all the Major Mods type topics I've read on PH it does seem that if you have a T5 then the CTS / Quaife option is the most straightforward.

The TKO box seems to have been done mainly by people doing Chevy transplants. There is however one Speed Six car out there with a TKO600. Done since it was supercharged!

[rev-erend]

Main drawback of TKO seems to be it's hugh size and the huge weight..

[Guillotine]

Hi Bruce,

Chris at Dulfords should be able to build you what you need.
The TKO as stated is effin huge and effun heavy. I know you are mainly concerned with handling the power, but those would knock serious holes in any plusses.

The T5 can run to 500 with higher spec internals, I've heard tell of 600, but it will get noisier. Mine have all been fine with 400lb/ft and the transmission shock of jumping kerbs, and my brutal clutch must take it to 500lb/ft I'd have thought.

Generally the diff is considered to be the weak point, followed by driveshafts. I've done my original diff, but the others have quaife internals and touch wood....

The easiest way to contol driveline torque is via they tyres. Keeping 245s on the rear will allow wheelspin on serious right foot action taking the shock out of the drivetrain until they hook up and feed the power in.

Andy

BTW T5 to my spec a Dulford was about £500

[shpub]

The CTS box is actually quieter than the original. Also has the shortest sweetest change on a T5 I have ever experienced. The uprated gears are semhelical and don't have the whine that is associated with straight cut.

Its expensive but and this is the big but, drop out box out, drop new box in. No worrying about mounts/remotes/bellhousing/clutch slave etc etc which can easily add another £2k to the cost.

Stu at CTS reckones the box is stronger than a TKO600 and having seen the remains of a 600 at the workshops I can see where he is coming from. They have customers using them with 800bhp Cossies, V12 twin turbo jags and a road legal Lister Storm LeMans car.

The nice thing is also gives you the option of doing nothing. Many Cerberas are running 420-450 bhp through the T5. A lot will depend on how it is used. So try it and if your T5 goes bang, swap it for a CTS version.

Oh and its about 25lb lighter than a TKO.

I went CTS after an uprated "600bhp" non-CTS T5 box broke an internal shaft on my Wedge. I was only putting 530 bhp through it at the time.

[2Munkys]

Guillotine said:

Hi Bruce,

Chris at Dulfords should be able to build you what you need.
The TKO as stated is effin huge and effun heavy. I know you are mainly concerned with handling the power, but those would knock serious holes in any plusses.

The T5 can run to 500 with higher spec internals, I've heard tell of 600, but it will get noisier. Mine have all been fine with 400lb/ft and the transmission shock of jumping kerbs, and my brutal clutch must take it to 500lb/ft I'd have thought.

Generally the diff is considered to be the weak point, followed by driveshafts. I've done my original diff, but the others have quaife internals and touch wood....

The easiest way to contol driveline torque is via they tyres. Keeping 245s on the rear will allow wheelspin on serious right foot action taking the shock out of the drivetrain until they hook up and feed the power in.

Andy

BTW T5 to my spec a Dulford was about £500

Thanks for that Andy. I'm in Filton tomorrow and was intending to pop into Dulfords on the return so I'll have a word with Chris; he does seem to know his stuff.

Ref' the Diff, I have a BTR and thought they were pretty darned robust.

And these are the people I spoke to last year about the half-shafts; I use 'em for my CV joints:

http://www.prolinx.biz/driveshaft_components.htm

Edited by 2Munkys on Wednesday 10th June 09:08

[2Munkys]

shpub said:

The CTS box is actually quieter than the original. Also has the shortest sweetest change on a T5 I have ever experienced. The uprated gears are semhelical and don't have the whine that is associated with straight cut.

Its expensive but and this is the big but, drop out box out, drop new box in. No worrying about mounts/remotes/bellhousing/clutch slave etc etc which can easily add another £2k to the cost.

Stu at CTS reckones the box is stronger than a TKO600 and having seen the remains of a 600 at the workshops I can see where he is coming from. They have customers using them with 800bhp Cossies, V12 twin turbo jags and a road legal Lister Storm LeMans car.

The nice thing is also gives you the option of doing nothing. Many Cerberas are running 420-450 bhp through the T5. A lot will depend on how it is used. So try it and if your T5 goes bang, swap it for a CTS version.

Oh and its about 25lb lighter than a TKO.

I went CTS after an uprated "600bhp" non-CTS T5 box broke an internal shaft on my Wedge. I was only putting 530 bhp through it at the time.

Thanks Steve; this would be my optimum solution as I know that the box will go straight back where it came from. Don't wanna take short cuts and would rather have the assurance of not bending shafts or leaving teeth at the bottom of the casing. And if I'm some place remote from home then the recovery after it has 'gone bang' is both embarrassing and inconvenient, plus there's the expense of the rebuild that should have been done in the first place. But, as you say, 'it's expensive'. All needs a good considering.

[shpub]

To be honest, it's expensive as in it's over £1000 but it's cheap in comparison to other solutions. A lot depends on how much power/torque you want to put through it. If its about 400 lb/ft and the car is essentially for road use then I suspect the standard box will be fine as the gearbox won't see that level of torque. When was the last time you rev'ed to 5000+ rpm and dumped the clutch? The other safety solution are the tyres. Wheel spin has saved many a transmission because it takes the pressure off. Sticky tyres, dump clutch starts and general abuse will increase the stress on the box and transmission though.

Don't underestimate the work and costs involved in changing to a different box. It cost me around £1000 in parts excluding the gearbox to go from the LT77 to a T5. Fortunately I could reuse the clutch and the remote didn't need any mods or changes but I had to get a new bellhousing, clutch slave, release bearing, propshaft, gearbox mounts, hydraulic pipe work so that is another major factor in the calculations. Then there was all the effort to do it. In my case I had no choice as the LT77s were breaking shafts with 400+ bhp.

If you want it a bullet proof T5 that doesn't whine, then the CTS solution is the way to go.

In terms of how strong they are, I did this to a diff mount. I also did the same thing to its steel replacement. I then had to redesign the diff mounts completely and they have been fine. As for the box... no problems at all. Not a bit of broken metal when I drained the oil.

[RichardD]

shpub said:

...Don't underestimate the work and costs involved in changing to a different box. ...

Given a starting point as per the Wedge with a LT77 box (pre Serp Griff 500 with Rover box), do you think that going :-

LT77 -> T5 (CTS) would be less work than
LT77 -> TKO600?

I do half expect an answer here of sell the car to one with a T5 box, but currently I have a rolling chassis which I intend to protect far far better than per the original coating.

There would (eventually) be enough power to justify one of these options, so a LT77 rebuild would not be suitable.

All I know is that the T5 change is a big job (from you/Quinny) and hence wondering if the TKO (which I know is strong enough given Brummie hasn't killed his yet) would be a bit more straightforward...........?

[shpub]

The advantage is that with a T5 swap for a Griff, TVR actually made all the parts you need and I suspect you would be able to reuse most of what you already have. i.e. clutch slave etc. That wasn't an option for me and the Wedge as the Griff T5 has the remote in the wrong position, different splines to what I am using and so on. Propshaft can be modded as it will need a different coupling. There are other things to sort out like speedo sensors etc but that will be true for them all.

Also don't forget that the TKO600 is huge compared to the T5 and there are the questions of what else needs to be moved/modified to accomdate its bulk. Also bear in mind the question of maintainability. Is the TKO install an engine out job if there is ever a need to drop the box? The T5 is a tight fit but it is a lot smaller than the TKO600. All things to consider.

T5 swap is a known quantity - TVR did it for a start - with parts available. TK0600 swap is an unknown with the need for more custom work parts. As the T5 is around the same price as the TKO600, its really a question of evaluating the cost/difficulty of the swap. I'd say in this area, the T5 wins hands down.

[oblio]

Bruce

Dont you think at your age you should be thinking about slowing down and taking it easy?

[2Munkys]

I put the question to Gearboxman and with their 'o.k' here's an extract:

Staying with the original T5 from your car, the best you can get it is to go for the heavy duty gear kit (preferable treated to a shot peen and super finish).
This would certainly be in the ball park though with high power longevity is always a question and the gearbox may need servicing, time scale for servicing will depend on the usage and mileage involved.
We can build a big tooth T5 for you (using your gearbox as the donor) for £1342.00+VAT (OEM selector forks) or £1825.00+VAT (heavy duty selector forks) but we'd strongly recommend spending the extra £425.00+VAT having the gear set treated, think of it as insurance on your investment in the gearbox.
Going this way you'd be looking at either £1767.00+VAT (using the standard selector forks) or £2250.00+VAT for the same but fitted with the ali bronze heavy duty selector forks.
This is certainly the simplest answer as it'll not involve cutting about or adapting anything else to fit, just pull it out and put it back in a week later, other than that you'll be looking at a bespoke conversion of some description and that's where it starts to get expensive.
Having just taken a look at the Pistonheads thread we'd say the big tooth T5 would be the way to go, it's just so much easier than a full conversion and you're not really into the power level that will dictate a full conversion.

[2Munkys]

oblio said:

Bruce

Dont you think at your age you should be thinking about slowing down and taking it easy?

Hehe, you're probably right, but then again at my age I forget . . . . . erm, things, erm . . . that I should be doing. Whatever they were . . .

[RichardD]

2Munkys said:

I put the question to Gearboxman and with their 'o.k' here's an extract:

Staying with the original T5 from your car, the best you can get it is to go for the heavy duty gear kit (preferable treated to a shot peen and super finish).
This would certainly be in the ball park though with high power longevity is always a question and the gearbox may need servicing, time scale for servicing will depend on the usage and mileage involved.
We can build a big tooth T5 for you (using your gearbox as the donor) for £1342.00+VAT (OEM selector forks) or £1825.00+VAT (heavy duty selector forks) but we'd strongly recommend spending the extra £425.00+VAT having the gear set treated, think of it as insurance on your investment in the gearbox.
Going this way you'd be looking at either £1767.00+VAT (using the standard selector forks) or £2250.00+VAT for the same but fitted with the ali bronze heavy duty selector forks.
This is certainly the simplest answer as it'll not involve cutting about or adapting anything else to fit, just pull it out and put it back in a week later, other than that you'll be looking at a bespoke conversion of some description and that's where it starts to get expensive.
Having just taken a look at the Pistonheads thread we'd say the big tooth T5 would be the way to go, it's just so much easier than a full conversion and you're not really into the power level that will dictate a full conversion.

A great detailed response but reading it - by "full conversion" do they mean an upgraded T5 without the treating?