4.3 TVR Power speed 6

[DJR 7]

I was told on the phone that a 4.3 should give me around 420bhp at the flywheel!

[/quote]

Chris I've been told similar, I was told to expect 400bhp at the wheels from a good 4.3,
The information came from someone that builds a good 4.3 :-)

D

[chris watton]

Don1 said:

My Sag was a strong, good engine at 360 odd - RedSpikes is about the same as well. I have NEVER seen a standard engine over 390, let alone 400.

The Sagaris has a 4 litre and that is supposed to have 406bhp @7500rpm out of the box! The Tuscan S is supposed to have 390bhp. (I still have a lot of TVR books and brochures with all the details..)

So, the Sag never had 406bhp, but almost 50bhp less than advertised?

ETA - Still very much looking forward to having the 4.3, as I know it will transform the car and give me peace of mind - but when reading the earlier 2008/9 posts, you'd be forgiven for thinking the 4.3 gives an extra 50bhp approx., and not an extra 10 as others have stated...

Edited by chris watton on Thursday 23 January 09:33

[WolfyJones]

chris watton said:

Don1 said:

My Sag was a strong, good engine at 360 odd - RedSpikes is about the same as well. I have NEVER seen a standard engine over 390, let alone 400.

The Sagaris has a 4 litre and that is supposed to have 406bhp @7500rpm out of the box! The Tuscan S is supposed to have 390bhp. (I still have a lot of TVR books and brochures with all the details..)

So, the Sag never had 406bhp, but almost 50bhp less than advertised?

Yes less than advertised, very good standard engines around 370 bhp, the 4.3/4.5 deliver much improved lbft overstandard, if you want big Bhp you need extra work air box etc,

Only engine I have seen produce good figures without the extras is Deans 4.5SS Sag (just decatted) 420Bhp@7200 360 lbft (SRR)

Edited by WolfyJones on Thursday 23 January 09:37

[chris watton]

Well don't I look the fool! I have told everyone that my upgrade will give my Tam about 410/420bhp at the fly! In fairness to me, though, this is what I was told.....

If that is the true case, I can see why some go down the LS3/7 route, the former is 430 straight out of box, and 480 seems to be the norm - although having said that, I don't think it would suit the open topped Tamora so much - perhaps a little too much power...

ETA - Oh yes - If I wanted to eek out the full potential, I'd need that ACT carbon airbox with trumpets, a Tuscan S exhaust system and a very noisy and too antisocial decat?

But why was I told that with the 4.3, my Tam would have over 400bhp! The other mods weren't mentioned at all.

Edited by chris watton on Thursday 23 January 09:47

[Pursyluv]

Chris, I'm doing it the opposite way round, already got the ACT decat and Power sports exhaust, in the next few months I'm having the Brendan/Julian airbox and hopefully a Tuscan S exhaust modified to fit the Tam..........all I need then is for Dom to offer interest free credit and I'm sorted!

Edited by Pursyluv on Thursday 23 January 09:53

[WolfyJones]

chris watton said:

Well don't I look the fool! I

No, not at all, if a engine builder is telling you a standard 4.3 upgrade will give you 400 Bhp @ wheels he is a billy bullstter,

Loved to be proved wrong thou,

[chris watton]

WolfyJones said:

No, not at all, if a engine builder is telling you a standard 4.3 upgrade will give you 400 Bhp @ wheels he is a billy bullstter,

Loved to be proved wrong thou,

No - I have always assumed that would be the BHP at the flywheel - All of my figures are BHP at the fly, not the wheels. I am not silly enough to think that I'd ever get 400BHP at the wheels - you'd need a SC or souped up LS33 for that.

I just assumed, after what I was told, that my engine would produce around 350-360bhp at the wheels.

ETA - If the engine components are all balanced to much better tolerances than factory standard, shouldn't the engine be able, and more capable at even higher revs, say, 7600 - 7800rpm once run in properly?

Edited by chris watton on Thursday 23 January 10:16

[twold]

I'm new around here and am pretty new to Tuscan ownership.
Is it possible that when quoting BHP that either @fly/@wheels could always be included in any stated BHP figures to save thickos like me getting confused.

Also a question,do the major exotic car manufacturers(porsche,ferrari etc) generally state @Flywheel BHP figures or do they quote @wheels figures??

Regards

[TA14]

twold said:

Also a question,do the major exotic car manufacturers(porsche,ferrari etc) generally state @Flywheel BHP figures

Yes, evryone quotes at fly.

[m4tti]

chris watton said:

WolfyJones said:

No, not at all, if a engine builder is telling you a standard 4.3 upgrade will give you 400 Bhp @ wheels he is a billy bullstter,

Loved to be proved wrong thou,

No - I have always assumed that would be the BHP at the flywheel - All of my figures are BHP at the fly, not the wheels. I am not silly enough to think that I'd ever get 400BHP at the wheels - you'd need a SC or souped up LS33 for that.

I just assumed, after what I was told, that my engine would produce around 350-360bhp at the wheels.

ETA - If the engine components are all balanced to much better tolerances than factory standard, shouldn't the engine be able, and more capable at even higher revs, say, 7600 - 7800rpm once run in properly?

Edited by chris watton on Thursday 23 January 10:16

Are you doing a lot of track days... not sure on the public highway where you would drive one of these cars at 7800 rpm.

Part of the deal with the 4.3 isnt the headline bhp figure, its the tractability and the 5 year warranty.

[coetzeeh]

Reading all of this makes Clive's engine performance look even more impressive.

Feels like taking a standard 4.0 and adding GT cams + making it breathe & fuel better (in and out) gets you the same results and more as a larger capacity rebuild? Or am I missing something?

[DJR 7]

So in a nut shell what's a realistic rear wheel figure for a 4.3 ?
The 1st post shows 370 bhp, I'm assuming that was with a standard air box, exhaust etc.
How much more could you squeeze with an ACT air box, de cat and big bore.
I am looking at having the 4.3 and I'd like to know what to expect

[WolfyJones]

DJR 7 said:

So in a nut shell what's a realistic rear wheel figure for a 4.3 ?
The 1st post shows 370 bhp, I'm assuming that was with a standard air box, exhaust etc.
How much more could you squeeze with an ACT air box, de cat and big bore.
I am looking at having the 4.3 and I'd like to know what to expect

I would say a standard 4.3 gives around 370bhp but lots better lbft 330/340 @ fly, add airbox etc around 410Bhp@ fly

-15% for @ wheels

[chris watton]

m4tti said:

Are you doing a lot of track days... not sure on the public highway where you would drive one of these cars at 7800 rpm.

Part of the deal with the 4.3 isnt the headline bhp figure, its the tractability and the 5 year warranty.

I do plan to do track days, yes. I had a CR box on my first Tamora, and I always used to take it to the limit in 1st and 2nd gear, sometimes bouncing on the limiter - so, although I agree that 'bouncing off the limiter' in higher gears would be daft to say the least, especially on public roads, it is rather fun in the lower gears.

Now, I will have the 4.3, I am not put off one jot, the positives are simply too numerous to ignore - but my point is that, I was told that my engine would have about 420bhp with the upgrade, but other's on here are saying that's pie in the sky, expect about 50bhp less than advertised!

I certainly wasn't told that I'd need a new airbox, bigger exhaust system and no cats to get the figure! In any case, I cannot see another airbox, no matter how good or lovely to look at making an extra 40bhp over standard.

Edited by chris watton on Thursday 23 January 11:01

[TA14]

chris watton said:

I certainly wasn't told that I'd need a ..., bigger exhaust system

Note that within that statement you need the larger dia exhaust manifold.

[chris watton]

TA14 said:

chris watton said:

I certainly wasn't told that I'd need a ..., bigger exhaust system

Note that within that statement you need the larger dia exhaust manifold.

I know When I wrote 'exhaust system', it goes without saying that the whole lot would need to be changed, otherwise there'd be no point - manifolds, cats, pipes running to back box, and the back box itself - the whole caboodle!

That would cost, I am assuming, no less that £3k at a very conservative estimate (I still don't know why simple decat tubes are so expensive - almost as much as original cats!). Couple that with the airbox and trumpets, which is about £1k, and then setting the whole thing up, I would imagine you'd need to add about £5k at least to the original cost of the 4.3, in order to get the gains shown on the RR graph.

Edited by chris watton on Thursday 23 January 11:19

[twold]

TA14 said:

Yes, evryone quotes at fly.

Final dumb question ,would I be right in assuming that only car manufacturers can afford the necessary diagnostic rigs/equipment to bench test engine BHP figures @ flywheel,hence engine specialists eg TVR power/ Str8six etc etc use rolling roads as they are easier/cheaper to work with?

regards

[m4tti]

twold said:

TA14 said:

Yes, evryone quotes at fly.

Final dumb question ,would I be right in assuming that only car manufacturers can afford the necessary diagnostic rigs/equipment to bench test engine BHP figures @ flywheel,hence engine specialists eg TVR power/ Str8six etc etc use rolling roads as they are easier/cheaper to work with?

regards

An engine dyno isn't out of the realms of smaller outfits. I believe austec have one.

[m4tti]

TA14 said:

chris watton said:

I certainly wasn't told that I'd need a ..., bigger exhaust system

Note that within that statement you need the larger dia exhaust manifold.

Diameter changes at the output of the cat doesn't it?

[WolfyJones]

chris watton said:

I do plan to do track days, yes. I had a CR box on my first Tamora, and I always used to take it to the limit in 1st and 2nd gear, sometimes bouncing on the limiter - so, although I agree that 'bouncing off the limiter' in higher gears would be daft to say the least, especially on public roads, it is rather fun in the lower gears.

Now, I will have the 4.3, I am not put off one jot, the positives are simply too numerous to ignore - but my point is that, I was told that my engine would have about 420bhp with the upgrade, but other's on here are saying that's pie in the sky, expect about 50bhp less than advertised!

I certainly wasn't told that I'd need a new airbox, bigger exhaust system and no cats to get the figure! In any case, I cannot see another airbox, no matter how good or lovely to look at making an extra 40bhp over standard.

Edited by chris watton on Thursday 23 January 11:01

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

According to the above cats rob 50Bhp,