LS3 Chimaera

[stefan1200]

Hi all,

if everything goes as planned, I'll be going LS3 with TKO600 within the next few month. Loved these engines for a long time so I chose this way over upgrading the RV8. I know it has already been done by a few people on here who also might be able to answer some basic questions. I've also seen that Sportmotive and other specialists offer LS3 conversion up to 480hp, also for Chim and Griff.

Brake upgrade has already been done and Intrax 1K2 coilovers will be fitted after the engine conversion is finished.

So, considering spirited road driving and the occasional high speed blast on the autobahn, I'd like to know your opinion with these power levels on

a) chassis strength
b) diff (40k miles)
c) driveshafts (newish, about 6k miles.

Any thoughts highly appreciated.

Cheers,
Stefan

[Brummmie]

stefan1200 said:

Hi all,

if everything goes as planned, I'll be going LS3 with TKO600 within the next few month. Loved these engines for a long time so I chose this way over upgrading the RV8. I know it has already been done by a few people on here who also might be able to answer some basic questions. I've also seen that Sportmotive and other specialists offer LS3 conversion up to 480hp, also for Chim and Griff.

Brake upgrade has already been done and Intrax 1K2 coilovers will be fitted after the engine conversion is finished.

So, considering spirited road driving and the occasional high speed blast on the autobahn, I'd like to know your opinion with these power levels on

a) chassis strength
b) diff (40k miles)
c) driveshafts (newish, about 6k miles.

Any thoughts highly appreciated.

Cheers,
Stefan

Driveshafts snap like carrots, even the Raceprooved items.

But the Dave mac props ones i have fitted have lasted so far.
The Cerbera diff is different to the Chim one?
But i have gone for a 3.08 ratio change, i have broke one Crown wheel and pinion so far.
Chassis as far as its not rotten should be fine, although i thought my Chim was very nervous at high speed compared to the Cerbera, but i never had it set up.

HTH

[scotty_d]

Brummmie said:

Chassis as far as its not rotten should be fine, although i thought my Chim was very nervous at high speed compared to the Cerbera, but i never had it set up.

HTH

I had my chim well set up and it still felt scary at 120mph+ next to the cerb.

[flyingdutchie]

The Cerb is nice and steady at 160mph. With or without the LS engine. Well....my AJP went bang at that speed.

[stefan1200]

Brummmie said:

Driveshafts snap like carrots, even the Raceprooved items.

But the Dave mac props ones i have fitted have lasted so far.
The Cerbera diff is different to the Chim one?
But i have gone for a 3.08 ratio change, i have broke one Crown wheel and pinion so far.
Chassis as far as its not rotten should be fine, although i thought my Chim was very nervous at high speed compared to the Cerbera, but i never had it set up.

HTH

Paul,

from your profile your car puts out much more than to be expected with a 480 hp out of the box, given all the necessary compromises on intake and exhaust of LS in a Chim.

Will try with the stock driveshafts first and keep the Dave mac props in mind.

Chim/Cerb diff seem to be the same. For me it will be 3,45 and the long 5th on the TKO for quieter cruising. (normal road car, no track). Maybe 3,08 (than with the short 5th of course) at a later stage.


@scotty and flyingdutchie:

even with the standard suspension the car doesn't feel too nervous up to it's top speed of 160 mph. Standard splitter and closing the gap between rad and bodywork seem to do the trick with my car. This also effectively prevents any bonnet flapping or lifting, which I had experienced before.

Cheers,
Stefan

[Brummmie]

stefan1200 said:

Paul,

from your profile your car puts out much more than to be expected with a 480 hp out of the box, given all the necessary compromises on intake and exhaust of LS in a Chim.

Will try with the stock driveshafts first and keep the Dave mac props in mind.

Chim/Cerb diff seem to be the same. For me it will be 3,45 and the long 5th on the TKO for quieter cruising. (normal road car, no track). Maybe 3,08 (than with the short 5th of course) at a later stage.


@scotty and flyingdutchie:

even with the standard suspension the car doesn't feel too nervous up to it's top speed of 160 mph. Standard splitter and closing the gap between rad and bodywork seem to do the trick with my car. This also effectively prevents any bonnet flapping or lifting, which I had experienced before.

Cheers,
Stefan

DO NOT put that long 5th with the short diff, its sh!t!
I know because i had that at first and changed it.
Its shifting two gears in one, eg 4-6th or 3-5th on any other box, its rubbish.
This was with an engine with 150bhp less than i have now, an LS1 stroker, so more torque than bhp, trust me here...

[Omerta]

So Paul do you have the long 5th with the 3.08 now?

[Brummmie]

No short 5th, with 3.08 diff, that 4-5th shift was just to big of a jump.

[stefan1200]

After some more calculation I very much agree that short 5th and 3,08 diff is the best solution ratio-wise.

Who to turn to for a 3,08 in excellent condition? Or should I have the present one converted to 3,08? Still reluctant to have a my good 3,45 diff opened for conversion though.

Stefan

[Omerta]

http://www.ebay.com.au/itm/lsd-irs-diff-centre-com...

Holden have been selling their rebadged HSVs in the UK for a few years now so maybe you can find one closer....

[7 TVR]

I agree with Brummie, gun barrel drive shafts and thats with me running standard LS3, diff i put a reconditioned BTR H Coned 3.43, as for the chassis i strenghened the chassis with some extra support struts and more importantly a proper roll cage as you will start to see flex with the BHP figures your talking about, the griff and chim being convertable really benefit from any stiffening, you can really feel the differance between the Griff and my 350c when driven back to back. Good luck with your conversion and the best advice i would give is to try and get as much right as possible first time round, as compromises tend to come back and bite you in the arse!
You will not regret it i promise.

[stefan1200]

Thanks to everyone for pointing me in the right direction!

@7 TVR:
Christian, have already been watching pics and posts of yours and brummmies car very closely. Excellent reading on these conversions, do hope to be able to join the club soon! Must look into the rollcage thing; makes sense to me. And yes, I'm trying to cover as much as possible before really diving into it. Yours seems to be the only cars I came across so far which has the manifolds run downward. Is there enough space down there to place small cats or is it dual pipes from front to back? Would be interested in any pics if available.

Cheers,
Stefan

[7 TVR]

stefan1200 said:

Thanks to everyone for pointing me in the right direction!

@7 TVR:
Christian, have already been watching pics and posts of yours and brummmies car very closely. Excellent reading on these conversions, do hope to be able to join the club soon! Must look into the rollcage thing; makes sense to me. And yes, I'm trying to cover as much as possible before really diving into it. Yours seems to be the only cars I came across so far which has the manifolds run downward. Is there enough space down there to place small cats or is it dual pipes from front to back? Would be interested in any pics if available.

Cheers,
Stefan

Stefan, i have some pics from the development stage but none of the completed job and the car is not with me at the moment, you should get the idea though! Snug and tight just the way i like it!!

[stefan1200]

Wow, did not imagine it is that close to the chassis! Needs some stiff engine mounts then to stay clear, but IMO looks so much better than running the manifolds forward. Definitely worth a try!

Many thanks,
Stefan

[Omerta]

Certainly tidier, but there are reasons why others bring the pipes forward - for me it was to avoid having a tight bend at the exhaust port and to allow the engine to come back and down a bit more (cerb chassis) I'm not saying either way is right or wrong though and Brummie has proved this setup is no barrier to monster power. People have different objectives and approaches for getting what they want, but most decisions have a + and - side to them.

[stefan1200]

Good point.

Right now in the planning phase I'm gathering as much information as possible. If there's not enough space for cats with downrunning manifolds than it's ruled out for legal reasons anyway. And getting the engine as far back and down as possible is certainly a vital point for me too.

To my eye it looks very neat; but of course everything else must also be taken into account.

Cheers,
Stefan

[jellison]

Stefan

Why any sane person would "Butcher" a TVR in this way is Beyond me.

Back on topic though

a) chassis strength - fine if in good nick (took by body off to inspect it pre-swap - was only 6 years old I think).
b) diff (40k miles) - Did my swap at 27-8k mile and ragged the tits off it for about 18k miles over the next 4.5 years - never had an issue of any kind. Always used std sized tyre and not super grippy track stuff, SP9000, side ways = less load
c) driveshafts (newish, about 6k miles). Never had a problem.

7TVR

Those pipe bending so tight to get inside the chassis rail - hmm not sure on the logic of that!

Should just go forward with nice wide open bend for max power and any engine movement could crush the headers!

Both - make sure you use Racespec Poly SBC engine mounts, std stuff last 5 min.

Again - shocked that you could do this

[stefan1200]

jellison said:

Why any sane person would "Butcher" a TVR in this way is Beyond me.

Hi jellison,

well, you know, there once was this purple thing...;) Has been rather tempting when you put it up for sale, but I wanted to stay with LHD.

Thanks for the reassuring words concerning the drivetrain. It will be staying standard (except going 3.08 diff) initially and I'll see how things work out. Maybe stronger driveshafts at a later stage, time will tell.

Stefan

[jellison]

stefan1200 said:

jellison said:

Why any sane person would "Butcher" a TVR in this way is Beyond me.

Hi jellison,

well, you know, there once was this purple thing...;) Has been rather tempting when you put it up for sale, but I wanted to stay with LHD.

Thanks for the reassuring words concerning the drivetrain. It will be staying standard (except going 3.08 diff) initially and I'll see how things work out. Maybe stronger driveshafts at a later stage, time will tell.

Stefan

Anytime you need to run anything past me for an opinion just ask.

Oh the other thing - Really I would not go near a 3.08 diff, as the LS 2,6 and 3 have a much higher (real) Redline and rev limit (6500 for LS6 - maybe higher for the LS3 (LS7 was 7k)), you get way more revs and mph / kph in each gear and obviously top. Equates t about 10mph more max in 5th if on 3.45 std diff from and LS6 vs a 500 Rv8 limited to a sensible 6k.

Mine was lazy and turned very reasonable revs at all gear and nice for cruising. Go that much longer to 3.08 and it will really take the shine off the top acceleration, Ok you might end up with may 70-80bhp more than a properly mapped LS6 but that is a big lengthening of the final drive.

Is there a CWP in between 3.45 and 3.08 for the BTR diff - if so maybe go with that, otherwise, well as above. It would be different if like Brummie you end up with something over 550bhp then a 3.08 make sense.

I have a 3.31 in my Jag diff (tyres different size obviously but not going to be that much different 60 profile 225x15 vs something like 245x40x16 for the Chim) and I have similar top end Power to Brummie in my crazy pocket Rocket (under a ton ).

Any time you need anything - pictures opinion just ask.#

Jelly.

[macdeb]

Cool. What PH 'should' be about.