BHP per ltr. – normally aspirated engine
Discussion
With the current trend for BHP per litre to be at or above the 100 mark -think 500bhp from the 5.0ltr Lamborghini Gallardo 100bhp per ltr, 911 GT3 (new version) 3.6 with 381bhp, 105bhp per ltr. While BMW are always getting the flags waved for their 3.3 engine fitted to amongst other things the M3 with 106 bhp per ltr I’m sure you’ve got the idea by now
In the post TVR haven’t gone mad with the tuning of horse power from their Rover soured V8’s 220-240 from a 4.0ltr-4.5ltr engine isn’t phenomenal (torque is being specifically excluded in this thread. As I know that these engines have bucket loads) now however………… (see I was getting to the point
) TVR are offering their 3.6 Spd 6 engine fitted to the T350C with 400bhp oh dear mrs that’ll be 111bhp per ltr. More than the M3, the GT3 and the Gallardo which displaces 1.4ltrs more and has 4 extra cylinders !!
Why is it that TVR a small British company building their own engines (think Morgan who have postituted themselves to BMW for their engine) never even get a mention for producing an inhouse engine with more bhp per ltr than any VTEC offering from Japan from any double VANOS BMW engine etc…. surely this is something to be shouted from the rooftops by the cloth headed singled celled imbeciles known as the motor journalist
Am now going to climb down slowly from my
In the post TVR haven’t gone mad with the tuning of horse power from their Rover soured V8’s 220-240 from a 4.0ltr-4.5ltr engine isn’t phenomenal (torque is being specifically excluded in this thread. As I know that these engines have bucket loads) now however………… (see I was getting to the point
) TVR are offering their 3.6 Spd 6 engine fitted to the T350C with 400bhp oh dear mrs that’ll be 111bhp per ltr. More than the M3, the GT3 and the Gallardo which displaces 1.4ltrs more and has 4 extra cylinders !! Why is it that TVR a small British company building their own engines (think Morgan who have postituted themselves to BMW for their engine) never even get a mention for producing an inhouse engine with more bhp per ltr than any VTEC offering from Japan from any double VANOS BMW engine etc…. surely this is something to be shouted from the rooftops by the cloth headed singled celled imbeciles known as the motor journalist
Am now going to climb down slowly from my
No, it's true there is now a 400bhp option for the 3.6 Speed 6 engine.
Thing is these things aren't black and white, take the M3 engine. It produces less specific BHP then the BMW Williams F1 engine (obviously) but it'll last 100,000 trouble free miles (ot there abouts), whereas the F1 engine will last what 500 miles? Opposite ends of the scale I know but the question is where does the Speed 6 sit in this range? TVR tweek it for more power but I bet it won't last as well as the M3
Thing is these things aren't black and white, take the M3 engine. It produces less specific BHP then the BMW Williams F1 engine (obviously) but it'll last 100,000 trouble free miles (ot there abouts), whereas the F1 engine will last what 500 miles? Opposite ends of the scale I know but the question is where does the Speed 6 sit in this range? TVR tweek it for more power but I bet it won't last as well as the M3
I think that this is a valid point, but is to a degree a given. The Mitsubishi EVO 7 pushing a standard 276bhp from it’s 2.0ltrs requires servicing every 5,000 or 7,000 miles (it’s one of the two but am not sure exactly) the Caterham R500 requires servicing every 5,000 miles (this is Caterham’s quoted figure I don’t own one so stand to be corrected) point being, getting high BHP from an engine generally requires regular care and attention (yes I know the VTEC maybe different and that Honda says it has never had a VTEC warranty claim) otherwise things do go pete tong.
I still think that given the output and that the engine is made by a small company rather than using an engine supplied (albeit tweaked) by a large company with a significant R&D budget – Honda, BMW etc.
TVR’s BHP figures are allegedly getting closer to the quoted outputs, but I’m not going to open that can of worms again. barefoot has had this conversion on his T350C for £4,000 I think he might be able to answer the ‘is this a real figure’ better than me
I still think that given the output and that the engine is made by a small company rather than using an engine supplied (albeit tweaked) by a large company with a significant R&D budget – Honda, BMW etc.
TVR’s BHP figures are allegedly getting closer to the quoted outputs, but I’m not going to open that can of worms again. barefoot has had this conversion on his T350C for £4,000 I think he might be able to answer the ‘is this a real figure’ better than me
MikeE said: No, it's true there is now a 400bhp option for the 3.6 Speed 6 engine.
I thought that was the 4.0 speed six as opposed to the 3.6. If they are claimimg 400 from 3.6 litres I'd be surprised, but not immensely!
The 4.0 in the Tuscan S produces a claimed 390 and from what I've heard that is a more realistic figure than the 420 you are supposed to get from the 4.5 AJP V8.
Even the factory admit that claimed outputs for Rover and Cerbie V8 units are optimistic (see threads on how much a 5 litre Rover produces - 300 is very good), but no-one denies the Speed 6 has the power. See how a Tuscan S pulls from 120mph plus and it's evident.
I'm with MikeE on this one. Just what kind of a service life was the Speed 6 designed for.
The other thing that should be mentioned is that these figures are peak figures. You only get these figures when the engine is at full throttle at its peak RPM.
For 99% of the time you won't be at these conditions (cos you'll be lower down the rev range) and therefore won't be getting this.
One thing that does annoy me is the amount of servicing that these high specific power engines need. Its largly cos they've got twin overhead camshafts and therefore need the shims/tappets adjusting every once in a while. Which is expensive simply cos of the time involved.
Pushrod engines may not be great but look at the Corvette V8 (LS1). 5.7 litres but can be tuned to 400hp (with a bit of cash) and you'll only need to look at the camshaft every 100000 miles. Now thats what I call and engine.
That said I'm hoping to buy a motorbike with and engine that redlines at 14000 rpm and no power under about 6000rpm. I must be mad. oh and 60hp from 400cc makes for 150hp/litre. Beat that.
Andy
The other thing that should be mentioned is that these figures are peak figures. You only get these figures when the engine is at full throttle at its peak RPM.
For 99% of the time you won't be at these conditions (cos you'll be lower down the rev range) and therefore won't be getting this.
One thing that does annoy me is the amount of servicing that these high specific power engines need. Its largly cos they've got twin overhead camshafts and therefore need the shims/tappets adjusting every once in a while. Which is expensive simply cos of the time involved.
Pushrod engines may not be great but look at the Corvette V8 (LS1). 5.7 litres but can be tuned to 400hp (with a bit of cash) and you'll only need to look at the camshaft every 100000 miles. Now thats what I call and engine.
That said I'm hoping to buy a motorbike with and engine that redlines at 14000 rpm and no power under about 6000rpm. I must be mad. oh and 60hp from 400cc makes for 150hp/litre. Beat that.
Andy
When I read the reports about the GT3 engine they go on about more torque over a wider rev range as well as more peak power. Just read EVO this month to see what they had to do to achieve these figures.
I guess Porsche do not push the performance envelope right to the edge- I bet they could also get 400bhp + from the engine but would it compromise driveability/reliability/longevity?
I suspect TVR push towards the edge of this envelope a little harder.
With the 3.6ltr 400bhp from TVR I understand the low / mid range torque has been significantly improved not just peak power. Cylinder head and exhaust plus different cats but with the same cams I believe.
It will be interesting to hear barefoots opinions running his car in although is it so that it does not yet have the full 400bhp exhaust system?
Barefoot - What is the story? When will you have driven the ca 1000 miles that the final `chip´ and exhausts can be fitted? You have got Tuscan S brakes as well if I understand correctly?
I guess Porsche do not push the performance envelope right to the edge- I bet they could also get 400bhp + from the engine but would it compromise driveability/reliability/longevity?
I suspect TVR push towards the edge of this envelope a little harder.
With the 3.6ltr 400bhp from TVR I understand the low / mid range torque has been significantly improved not just peak power. Cylinder head and exhaust plus different cats but with the same cams I believe.
It will be interesting to hear barefoots opinions running his car in although is it so that it does not yet have the full 400bhp exhaust system?
Barefoot - What is the story? When will you have driven the ca 1000 miles that the final `chip´ and exhausts can be fitted? You have got Tuscan S brakes as well if I understand correctly?
Barefoot-what do they reckon you have without exhaust and final chip?
What will you have with the full kit and chip?
I understand that it is 400bhp even with 95 octane although I guess most people take optimax or 98.
I think if the low/midrange claims are true it should transform the Speed 6 driving experience.
Look forward to hearing your impressions and please complete the 1000 miles quickly.
What will you have with the full kit and chip?
I understand that it is 400bhp even with 95 octane although I guess most people take optimax or 98.
I think if the low/midrange claims are true it should transform the Speed 6 driving experience.
Look forward to hearing your impressions and please complete the 1000 miles quickly.
Barefoot,my car is currently in Blackpool having some major work done on it and in the course of my chats with J.Oxley/A. Mimms/P. Forrest I picked up some info on the engine uprates and dyno work.
It all sounds really good and at 4000 quid inc brakes it has to be interesting if albeit quite expensive.
Do you know anything about further uprates like for example full sequential fuel injection etc?
It all sounds really good and at 4000 quid inc brakes it has to be interesting if albeit quite expensive.
Do you know anything about further uprates like for example full sequential fuel injection etc?
pddmac said: Andytk - that's a 2 stroke i presume. What is it? sounds interesting....
Nope its a 4 stroke. A V4 400cc four stroke engine. 60hp at about 13500rpm. Small engines can make loadsa power for such small capacity cos they can rev so high. They can rev cos small light components means low inertia so they don't have to worry about conrods coming through the crankcase wall
Oh and the bike is a honda RVF 400 (NC35)
very very similar to the VFR400 (NC30)
Andy
Gassing Station | General TVR Stuff & Gossip | Top of Page | What's New | My Stuff