I give up... so which TKO?

[Ffirg 005]

I've given up on the T56 for my LS6 Cerb - it fills the tunnel at the narrowest point leaving enough room for about a .5" exhaust. There are workarounds like side exit exhaust, widening the tunnel, squeezing the pipes into an oval but they all involve compromises that I don't like. The kiwi $ is at an all time high against the US $ so I'm going to bite the bullet and go for a TKO instead.

So what spec: I'm thinking close ratio 1st. I'm told the .64 final drive is too big a gap from 4th to 5th and it'll never get used on track like the .82 would, but I like the idea of having a lazy cruising gear for road use. Comments...?

Also can anyone recommend a US source that I could get a quote direct from?

Don

[brummiewedge]

Don, i had the big 5th gear, it sits at 100mph @3000rpm, the jump from 4th to 5th is big, so you have to rev the t@ts off it to shift into the power, if your GOING for it. 4th is 140mph at 6200rpm,( thats where my rev limit is ) but that does work. If its a track car then go for the small 5th, if a road car then the big 5th. Ideally about a 0.70ish would be best. 6200rpm with the small 5th is "only" 169mph. But its still not exactly slow on pick up even with the tall gear!

[RichardD]

Ffirg 005 said:

...
So what spec: ...

Ideally a taller diff would spread out the gearing better and still allow a normal 5th ratio as with mega grunt first gear can be a waste of time!
Back in reality, what Paul has just put is of course spot on, he's got the power to hit redline in that tall 5th too

Send me a PM if you want, I can create a Cartest2000 model of your car so see how a LS6 Cerb would compare with different gearing options (as per Paul, Jellison, the SBC Tuscan etc )

[Ffirg 005]

brummiewedge said:

Don, i had the big 5th gear, it sits at 100mph @3000rpm, the jump from 4th to 5th is big, so you have to rev the t@ts off it to shift into the power, if your GOING for it. 4th is 140mph at 6200rpm,( thats where my rev limit is ) but that does work. If its a track car then go for the small 5th, if a road car then the big 5th. Ideally about a 0.70ish would be best. 6200rpm with the small 5th is "only" 169mph. But its still not exactly slow on pick up even with the tall gear!

So at a license-keeping in NZ speed of 110kph (65mph) the .82 5th will be turning over at 2400rpm. Higher than I'd like, but more than acceptable trade-off for having a usable 5th gear on the back straights!

Richard - thanks for that, look forward to hearing what my 0-60 target is

Cheers

[jellison]

Ffirg 005 said:

brummiewedge said:

Don, i had the big 5th gear, it sits at 100mph @3000rpm, the jump from 4th to 5th is big, so you have to rev the t@ts off it to shift into the power, if your GOING for it. 4th is 140mph at 6200rpm,( thats where my rev limit is ) but that does work. If its a track car then go for the small 5th, if a road car then the big 5th. Ideally about a 0.70ish would be best. 6200rpm with the small 5th is "only" 169mph. But its still not exactly slow on pick up even with the tall gear!

So at a license-keeping in NZ speed of 110kph (65mph) the .82 5th will be turning over at 2400rpm. Higher than I'd like, but more than acceptable trade-off for having a usable 5th gear on the back straights!

Richard - thanks for that, look forward to hearing what my 0-60 target is

Cheers

Told you you need a TKO Just hit the tremec site or ebay for a new / new'ish one. In NZ and UK for that matter, the short 5th for me is best, almost identical to 5th in chim / griff (.80 I think). That is 175 for me with LS6 6500rpm limit (have ARP rod bolts, so could go higher - but no point).

[Ffirg 005]

Didn't think I'd have to wait a whole 3 weeks for the I Told You So line Jon.... Personally, I blame Paul for throwing it in with the LS6 sale.

Yes I'll be going for the .82 ratio.

Edited by Ffirg 005 on Wednesday 8th August 22:36

[jellison]

Ffirg 005 said:

Didn't think I'd have to wait a whole 3 weeks for the I Told You So line Jon.... Personally, I blame Paul for throwing it in with the LS6 sale.

Yes I'll be going for the .82 ratio.

Edited by Ffirg 005 on Wednesday 8th August 22:36

Hmm - yes very odd for me - been lurking in the Motorsports forms alot lately - most thing about TVR's have been said (several times) unless it is a heavy mod

175mph should be enough.

[Ffirg 005]

Hey Brummie, Jon, anyone... can someone tell me what the part number is for a McLeod bellhousing to suit LSx/TKO? Or Lakewood... whatever fits!

[tvrolet]

Ffirg 005 said:

Hey Brummie, Jon, anyone... can someone tell me what the part number is for a McLeod bellhousing to suit LSx/TKO? Or Lakewood... whatever fits!

The lakewood bellhousing for the TKO is huuuuuge; I have one. Not only is it wide and deep, there's a flange that goes under the bellhousing to bolt up to a back plate to complete the scatter shield, so that loses another inch or so of ground clearance (unless you've the world's deepest sump, in which case it may not be as deep as that). I ground off the flange at the bottom (oh err) and had to do some other surgery with an angle grinder to make it all fit. If I was doing it again I'd be looking more closely at the dimensions and trying to get something lots smaller than the Lakewood.

[jellison]

tvrolet said:

Ffirg 005 said:

Hey Brummie, Jon, anyone... can someone tell me what the part number is for a McLeod bellhousing to suit LSx/TKO? Or Lakewood... whatever fits!

The lakewood bellhousing for the TKO is huuuuuge; I have one. Not only is it wide and deep, there's a flange that goes under the bellhousing to bolt up to a back plate to complete the scatter shield, so that loses another inch or so of ground clearance (unless you've the world's deepest sump, in which case it may not be as deep as that). I ground off the flange at the bottom (oh err) and had to do some other surgery with an angle grinder to make it all fit. If I was doing it again I'd be looking more closely at the dimensions and trying to get something lots smaller than the Lakewood.

It is simpler that that - all parts avalible from tremec - tr56 bellhousing and a special adaptor plate - call transmission components (no on tremec site unnder distributors).

Jelly

[Ffirg 005]

OK, so better the McLeod than the Lakewood - thanks for that tip.

Jon - you meant 'T56'? I have got an LS/T56 bellhousing so you reckon it's just an adaptor plate needed at the TKO end then? I'm in New Zealand, not UK so will import from the US directly if I can get a part number.

Per Terje used a McLeod bellhousing in his LS2 Griff and looks pretty tidy, can't find him on PH though. Anyone got an email address for him?

Edited by Ffirg 005 on Thursday 4th October 10:15

[jellison]

Ffirg 005 said:

OK, so better the McLeod than the Lakewood - thanks for that tip.

Jon - you meant 'T56'? I have got an LS/T56 bellhousing so you reckon it's just an adaptor plate needed at the TKO end then? I'm in New Zealand, not UK so will import from the US directly if I can get a part number.

Per Terje used a McLeod bellhousing in his LS2 Griff and looks pretty tidy, can't find him on PH though. Anyone got an email address for him?

Edited by Ffirg 005 on Thursday 4th October 10:15

It is all of the shelf - forget the McLeod / Lakewood stuff - call you nearest dealer and order it for thr t56 bellhousing it bolts directly between the two - it is a Tremec part. Have the number somewhere - just tell them what you are doing and they will say Ahhhhrr yes you need the............

jelly

[Pete500]

Hi, here I am, Per Terje. Yes I used a McLeod Scattershield between a LS2 and a TKO600, bought it from classicchevy5speed.com. Had to cut some clearings against tubular frame and exhaust on both sides, and I cuttet away some in the bottom to get enough ground clearance.See pics here: http://www.thegriffithpages.com/modifications/engi...

Jeff Mortenson wrote this in a mail for me:
We have recently found that using the McLeod 8630 bellhousing on an LS motor is a better solution than using the modular McLeod unit. The 8630 has less external flanges/obstructions that can interfere with clutch forks. Additionally the 8630 is a less complex, easier to install piece.
When using the 8630 scattershield behind an LS motor, the only thing that changes is that we use a different pilot bearing (part #12557583) which we will send to you with your kit. In fact if you were to buy a brand new LS crate motor from GM, their instructions call for using a stock bellhousing, or a scattershield like the 8630, and to use the #12557583 pilot bearing that we will send to you.

[Ffirg 005]

Per, thanks very much for that information - just in time as my US order is going in today. The 8630 is half the price of the modular one too (US$430 vs $850)

Very nice job on the Griff, have you had it on track? How have you found the handling?

Cheers!

[brummiewedge]

I've took my diff to have the Diff ratio swapped from the 3.45 to a 3.08 this morning, he's going to shim the planets etc if there is any slop. I am going to retro fit the 0.80 5th gear too. You should be able to get a crown and pinioin easy in your kneck of the woods!

[Ffirg 005]

Cool... Have you got some numbers on the difference 3.08 will make through the gears. Cruising speed in 5th?

[brummiewedge]

According to RichardD i think 188mph@6200rpm. I've asked him to run the figures through the magic box for an overall picture.

[Ffirg 005]

Ffirg 005 said:

Cruising speed in 5th?

brummiewedge said:

According to RichardD i think 188mph@6200rpm.

[RichardD]

brummiewedge said:

According to RichardD i think 188mph@6200rpm. I've asked him to run the figures through the magic box for an overall picture.

In gear speeds (6200 redline) for 3.45 diff and tall 5th (mph):-

46,71,105,135,193

In gear speeds (6200 redline) for 3.08 diff and normal 5th (mph) :-

52,79,118,152,186.

(with 500bhp, 100-110 in 3rd in 1.13 secs )

[brummiewedge]

Hmmm...not quite how i meant it!