Speed Six Rebuild: Power 4.3 or 4.5?

[gacksen]

Incognegro said:

RESSURECTION!!

As a young TVR enthusiast/purest I nipped into see Dom today... After getting to know the brilliant bunch at Topcats Racing and hearing how brutally powerful and nice the LS conversions I wanted to hear even more about the 4.5 rebuild as for me a TVR has to keep its engine?

Dom has told me the 4.5SS will blow the 4.5AJP and to make the added torque and bhp useable and an enhancement of driving he can factor in switchable/adjustable TCS and N 8 stage launch control. So the 4.3 I have planned on has become a 4.5 just gotta get Brummie to ad a set of his rear discs to my set up.

I want 450bhp... Oh and a close ratio gearbox.

did you have your 4.0 already on the rollers ?

as a task on a budget i would aim for 400 horses with your current 4.0. new cams exhaust maybe manifolds and a remap should bring you there.

anything else will set you back in the region of min 15K pounds + to aim for 450 and above. as you mentioned 4.3 and 4.5 those engines are stroked so keep piston speed in mind if you aim for high horses.

if the previous owner would not have bought the 4.3 update i could have started working with i would have thrown out the engine and would have gone down the LS route. not the topcats one as the pricetag is out of this world.

Edited by gacksen on Tuesday 28th April 11:02

[chris watton]

I thought the MBE was more about drivability than extra BHP?

What would be needed to exploit the full potential of the 4.3/5 - the new manifolds, the MBE and perhaps CF airbox with trumpets? That is £7k for those three things.

I must admit, I have done well over 1k miles since the 4.3, and it doesn't feel like night and day compared to my 3.6 - but I am still in the running in period and keeping below 3.5k and still have the running in oil.

Am hoping that after a remap and a few more thousand miles, I will be able to feel more of a difference...

[gacksen]

chris watton said:

I thought the MBE was more about drivability than extra BHP?

What would be needed to exploit the full potential of the 4.3/5 - the new manifolds, the MBE and perhaps CF airbox with trumpets? That is £7k for those three things.

I must admit, I have done well over 1k miles since the 4.3, and it doesn't feel like night and day compared to my 3.6 - but I am still in the running in period and keeping below 3.5k and still have the running in oil.

Am hoping that after a remap and a few more thousand miles, I will be able to feel more of a difference...

i dont think spending 3K on manifolds is worth it. art of clive of course but 3k only worth if you are aiming for the last
horses. if you are happy with your 4.3 running why would you spent another 3 for a new ecu ? makes no sense. you only need
a new ecu if other things are modified e.g. cams manifolds etc. to gain the full benefit. as for the airbox save the money
as there is no gain to expect. if you want to have a high horses SP6 throw out the stroker get a regular one in make it durable
and rev to 8 safely. would be a different beast of engine compared to the 4.3 and with some bits and pieces you will see the
5xx horses....

chris watton said:

I must admit, I have done well over 1k miles since the 4.3, and it doesn't feel like night and day compared to my 3.6

how have you driven your 3.6 ? the 3.6 comes alive above 3.5K rpm and punches into redline. below that not that much happes....... the show is over with the 4.3 at around 4.5K with steady torque....

Edited by gacksen on Tuesday 28th April 11:40

[chris watton]

gacksen said:

how have you driven your 3.6 ? the 3.6 comes alive above 3.5K rpm and punches into redline. below that not that much happes....... the show is over with the 4.3 at around 4.5K with steady torque....

Edited by gacksen on Tuesday 28th April 11:40

Always like to rev to the limit, especially 1st and 2nd. I always loved the way it accelerated faster the higher up the rev range I went.

Hope you're wrong about the 4.5k limit for power tailing off!

I have no intention of having the MBE or manifolds - my last upgrade will be a CR box, stickier tyres and perhaps, just perhaps, the CF airbox - but for engine bay aesthetics only...

[gacksen]

had been the graph of my standard 4.3.

of course there happens something past 4.5rpm but thrill wise.... you wont be michael jackson

as for the CR box cant comment as i only have it in the chim but with the tyres i will change
to federal rsr too once i have the car back.

Edited by gacksen on Tuesday 28th April 12:15

[chris watton]

gacksen said:

had been the graph of my standard 4.3.

of course there happens something past 4.5rpm but thrill wise.... you wont be michael jackson

as for the CR box cant comment as i only have it in the chim but with the tyres i will change
to federal rsr too once i have the car back.

Edited by gacksen on Tuesday 28th April 12:15

That looks pretty good - if I get the same power, I'll be happy.

ETA - wonder what could be done to make the torque curve more linier, though..

Edited by chris watton on Tuesday 28th April 12:22

[gacksen]

you can almost be sure that it will have the same power. all the 4.3 cars have plus minus that figures.

[Lotus E300S]

billynobrakes said:

mine has 414BHP and 368lb/ft of torque

I drove a standard Sag and that span it's wheels in first second and third so what's that like?

Was told the Sag had a standard gearbox and 3.9 diff which is supposed to be the quickest set up?

[Don1]

Lotus E300S said:

I drove a standard Sag and that span it's wheels in first second and third so what's that like?

Was told the Sag had a standard gearbox and 3.9 diff which is supposed to be the quickest set up?

Depends how you drive it, and on what rubber....

Not sure about the gearbox, but the 3.9 diff is the fastest one they offered.

[Lotus E300S]

Don1 said:

Depends how you drive it, and on what rubber....

Not sure about the gearbox, but the 3.9 diff is the fastest one they offered.

Yes he did say he would be fitting track tyres next and that would help.

[billynobrakes]

Lotus E300S said:

I drove a standard Sag and that span it's wheels in first second and third so what's that like?

Was told the Sag had a standard gearbox and 3.9 diff which is supposed to be the quickest set up?

Its blooming fast and spins the wheels up through the gears, I cannot floor it or drop a gear and hit the loud pedal or the back will just squirm all over the place, what I love about the 4.5 is the torque, you don,t need to rev the nuts off it to get it going unlike the standard 3.6 and that is exactly what I wanted, you can poodle about and it drives just like a V8 and when you want it to go it flies, Chris Watton, have you had the 1000 miles service yet, wait till you feel the power after that

Here is my Dyno results no power drop off at 4500 revs, you can trust me on that, it really could do with Doms MBE for launch and traction control but I am trying to keep it a bit like a TVR no gadgets

[chris watton]

Billy - I have the post run-in service booked for the end of next month. Have already done well over 1000 miles since rebuild..

[glow worm]

gacksen said:

had been the graph of my standard 4.3.

of course there happens something past 4.5rpm but thrill wise.... you wont be michael jackson

as for the CR box cant comment as i only have it in the chim but with the tyres i will change
to federal rsr too once i have the car back.

Edited by gacksen on Tuesday 28th April 12:15

That looks poor to me ... The 4.5 has the torque at low revs and throughout the rev range and then peaks at 4500 revs.. your 4.3 appears to have very slowing increasing torque as you push the revs.... more like I'd expect from a 3.6.

Edited by glow worm on Tuesday 28th April 18:00

[Incognegro]

gacksen said:

did you have your 4.0 already on the rollers ?

as a task on a budget i would aim for 400 horses with your current 4.0. new cams exhaust maybe manifolds and a remap should bring you there.

anything else will set you back in the region of min 15K pounds + to aim for 450 and above. as you mentioned 4.3 and 4.5 those engines are stroked so keep piston speed in mind if you aim for high horses.

if the previous owner would not have bought the 4.3 update i could have started working with i would have thrown out the engine and would have gone down the LS route. not the topcats one as the pricetag is out of this world.

Edited by gacksen on Tuesday 28th April 11:02

Glad to have put life background in this one. I'm liking this response the most. Keeping standard 4.0 and hitting 400 sounds rather appealing. New cams good, I already have full act decat sport pipe so maybe I'll seek this out and a custom remap.

Big figures not my 1st want but drivability with the added grunt is key so it can be harnessed and used effectively.

Never going LS or any other engine, other than tvrs own for me, but I can see why others may have defected ;P

Keep all thoughts coming in, all that extra agro for launch... Maybe I'll just practice my starts more... Lol

Thanks for All thoughts gang!

[gacksen]

glow worm said:

That looks poor to me ... The 4.5 has the torque at low revs and throughout the rev range and then peaks at 4500 revs.. your 4.3 appears to have very slowing increasing torque as you push the revs.... more like I'd expect from a 3.6.

Edited by glow worm on Tuesday 28th April 18:00

not as extreme as of a 3.6.

after having the 4.3 for one week i didnt like the engine so things needed to change to end up there :

[Incognegro]

Gacksen, I may try to be at Doms when you go back... 416 from the 4.3 is good and that now looks nice however if 400bhp is achievable from the 4.0 (or effectively making it a 4.0S) I may run with that. The high Erving ballistic nature is what I love about the s6 so if it tails off like that I may not be so tempted. i love and hate how I finally decide what I want and then I hear more views and think again.

[HarryW]

chris watton said:

gacksen said:

had been the graph of my standard 4.3.

of course there happens something past 4.5rpm but thrill wise.... you wont be michael jackson

as for the CR box cant comment as i only have it in the chim but with the tyres i will change
to federal rsr too once i have the car back.

Edited by gacksen on Tuesday 28th April 12:15

That looks pretty good - if I get the same power, I'll be happy.

ETA - wonder what could be done to make the torque curve more linier, though..

Edited by chris watton on Tuesday 28th April 12:22

To be fair, look at the difference in scaling for Torque and power, the torque scaling amplifies what you are looking at. Transpose the torque figures onto the power scaling and it looks a lot more linear.

[m4tti]

Hi Gacksen Is your spark plug cover still in place or have apertures been machined in it for the cop. Are they weather proof themselves.

[gacksen]

Incognegro said:

Gacksen, I may try to be at Doms when you go back... 416 from the 4.3 is good and that now looks nice however if 400bhp is achievable from the 4.0 (or effectively making it a 4.0S) I may run with that. The high Erving ballistic nature is what I love about the s6 so if it tails off like that I may not be so tempted. i love and hate how I finally decide what I want and then I hear more views and think again.

my car had been at doms place with the previous owner before i bought it for the 4.3 upgrade.
anything else had been done after i had it by other companies like, Lloyds specilist developments, RND engineering etc.

just to clarify it is not there and wont go there as long as i own it

some people may start to say oh no how can you but why not speak to Dave of RND in regards of cams ?

@m4tti

regular carbon cover. no machine work had been done to that as far as i know.

Edited by gacksen on Tuesday 28th April 21:09

[Don1]

Lotus E300S said:

I drove a standard Sag and that span it's wheels in first second and third so what's that like?

Was told the Sag had a standard gearbox and 3.9 diff which is supposed to be the quickest set up?

Depends how you drive it, and on what rubber....

Not sure about the gearbox, but the 3.9 diff is the fastest one they offered.