How much power is enough?
Discussion
ClassiChimi said:
^^^^^^ hahah,, ain't that a fact!
I've been trying to reason it,,
If your going on track then there's never enough power,,,
If your a road driver like most of us,,,
I can only go by my car and I've got just about 300 Bhp at the wheels from my 4.6 ,,,
In my humble view it's close to being perfect for road use,,,
Hit a bump in 1st to 4th when hard at it on a road and mine will spin wheels at will,,
350 ft lbs torque when kept in the right rev range is fooking quick
Unless I had a need to run my car hard and time it I don't think FI would do anything for me that a fast N/A doesn't already do,,,
It's not just about ultimate power either to my mind,, you have to enjoy your car,, mine sounds just fantastic,,
The idea of effecting the induction roar or noises that the beast snorts out on over run,,
The best Tvr being a reliable Tvr can't be understated,,
After market Ecu and fine tuning of what you have,, especially if you use the 4.6 will give you real usable big power,,,
Run hard tyres like me and it feels like 500 hp,,,
in the real world we have no choice but to drive at sensible speeds,, I'm getting 28 mpg from my Tvr all day long,,,
Drove down to the Ace Cafe on Saturday evening to have coffee with an old mate,, 190 mile round trip,, just a cruise,, I probably got nearer 30 mpg,, the cars got 300 Bhp at the wheels FFS if I had to sacrifice those figures just so I had another 20% power of which I couldn't have used on any of that journey and stays hidden 90% of the time,,, it's totally unnecessary unless you have a private road,,
The question also revolves around the handling of the car,, my gut feeing is FI is another level,, surely your gonna need the highest spec suspension/brake set up, clutch, drive shafts ,,,,,
That's all money,,,
I'm personally really glad to have stayed N/A and my engine figures are in line with what I think can still retain reliability and most importantly use ability
300 at the wheels is 340 engine hp Alun, how did you manage that? Got the paper to prove it I've been trying to reason it,,
If your going on track then there's never enough power,,,
If your a road driver like most of us,,,
I can only go by my car and I've got just about 300 Bhp at the wheels from my 4.6 ,,,
In my humble view it's close to being perfect for road use,,,
Hit a bump in 1st to 4th when hard at it on a road and mine will spin wheels at will,,
350 ft lbs torque when kept in the right rev range is fooking quick
Unless I had a need to run my car hard and time it I don't think FI would do anything for me that a fast N/A doesn't already do,,,
It's not just about ultimate power either to my mind,, you have to enjoy your car,, mine sounds just fantastic,,
The idea of effecting the induction roar or noises that the beast snorts out on over run,,
The best Tvr being a reliable Tvr can't be understated,,
After market Ecu and fine tuning of what you have,, especially if you use the 4.6 will give you real usable big power,,,
Run hard tyres like me and it feels like 500 hp,,,
in the real world we have no choice but to drive at sensible speeds,, I'm getting 28 mpg from my Tvr all day long,,,
Drove down to the Ace Cafe on Saturday evening to have coffee with an old mate,, 190 mile round trip,, just a cruise,, I probably got nearer 30 mpg,, the cars got 300 Bhp at the wheels FFS
if I had to sacrifice those figures just so I had another 20% power of which I couldn't have used on any of that journey and stays hidden 90% of the time,,, it's totally unnecessary unless you have a private road,, The question also revolves around the handling of the car,, my gut feeing is FI is another level,, surely your gonna need the highest spec suspension/brake set up, clutch, drive shafts ,,,,,
That's all money,,,
I'm personally really glad to have stayed N/A and my engine figures are in line with what I think can still retain reliability and most importantly use ability
?300@ wheels would be nice 
the last horses you try to chase are anytime the most expensive ones
and sooner or later going the blower router seems to be the only option.
i am often thinking of putting a different cam in the 4.6 xbolted but what
do you guys think how high can you rev that thing without further mods
and no forged internal ? 5500 6000 6500 rpm ?
the last horses you try to chase are anytime the most expensive ones
and sooner or later going the blower router seems to be the only option.
i am often thinking of putting a different cam in the 4.6 xbolted but what
do you guys think how high can you rev that thing without further mods
and no forged internal ? 5500 6000 6500 rpm ?
gacksen said:
300@ wheels would be nice
To be honest 300hp at the wheels has always been my goal and translates to 354hp at the crank if you're using the 18% drive train loss rule, I just wanted to achieve it while still delivering reasonable levels of fuel economy that keep the car practical to use.To achieve 354hp you basically have three options:
1. Spend close on £10k building a full house naturally aspirated Rover V8.
2. Spend a lot less adding a low pressure turbo kit from Eann Whalley to a stock 4.0 litre (requires an ECU upgrade).
3. Take the middle ground on price and fit Rotrex supercharger kit from SC-Power that also requires an ECU upgrade.
If you already have the ECU upgrade the whole forced induction project (turbo or supercharger) becomes a lot less expensive, but I cant help feeling the process of suddenly adding over 100hp to a well used engine is always going to come with risks.
The right way to do it of course is to follow Mac's lead and build a fresh engine that's been specified from the outset to be compatible with forced induction, but you're really getting into big bucks now.
If like me your pockets aren't endless and there's a likelihood of a chassis restoration to pay for at some point in the next few years (and maybe even an engine refresh too), is it really wise to bolt a blower on your current engine?
This is the dilemma I'm in, if I pull the trigger on a blower only to get another 3,000 miles out of the engine before I need to pull the lump and spend a similar amount on rebuilding it I can see that extra 100 ponies costing me at lest £10k in total in a very short time frame.
Worst of all the car will likely be off the road for 6-8 months while everything gets sorted and I'd be left will a bank balance that leaves me no funds for a chassis restoration. I have to ask myself if I want all that grief just for 100hp?
I guess I could get lucky, the engine could do another 40,000 miles with a blower on it, but my gut feeling is it won't and I'll be faced with big round of spending just to get my TVR back on the rod again, all this kind of makes me think 250hp & 260ft/lbs is perfectly adequate right now.
Running a hobby car is a luxury that inevitably comes with regular but manageable everyday maintenance costs... Tax, Insurance, fuel, servicing, consumables, general repairs ect ect, I can handle all that but I'm not sure playing financial Russian Roulette with forced induction would be a sensible move for me right now.
It will come though, but I want to know if it all goes Pete Tong I've got the bank balance to support it!
In the mean time I'll continue with my epic European tours with the wife and trips to Le Mans with my good mates, safe in the knowledge I have a reliable and economical British classic that's still capable of 150mph and gets me from rest to 60mph in around five seconds flat
I fully appreciate this is a rather sensible and unfashionable point of view, but my 50mpg and 250hp 'Gas Bag' TVR still excites and is still a long long way off being sensible.
Sure as hell works for me
macdeb said:
I now have 500 At the Wheels! 
thats quite a number i am always tempted in doing things but work commitments slow me down.
my wallet likes that and havent done many miles in the chim this year.
the compromise in going for boost would be to get a more radical cam in it
and leave it NA but i am lacking experience in how high a RV8 can safely rev
keeping the hyrdraulic followers and the rest of the valvetrain is as.
i could imagine around 6000rpm with cast pistons is the max that is possible.
Edited by gacksen on Tuesday 1st December 14:51
I have to agree with Peter, over 400bhp on the road is maybe a little pointless, in the dry it will spin in 1st + 2nd, we have 375BHP from a Supercharged 4.0 and because the blower is belt driven, you do get instant and constantly power identical to a N/A, and although more expensive than a Turbo still a lot cheaper than getting to a similar figure going the N/A route.
That said, I would always say to put the same £££ you are planning in to the engine into the rest of the car, especially brakes + suspension.
That said, I would always say to put the same £££ you are planning in to the engine into the rest of the car, especially brakes + suspension.
I have a little over 300 bhp at around 5000 rpm, and around 350 torques from 1500 rpm to 5200 rpm.
The torque is what makes the car so much fun for me.
I don't want any more power on the public road.
I don't want any more power or torque on track day corners - the car is already faster than its handling or my ability.
I wouldn't say no to being faster between corners.
So rather than spending money on a turbo, I am going to buy some new track tyres and invest in some driver training to get me out of the corners faster. Get out faster and you get to the next one faster. On an average track in Norfolk I can presently just about make 135mph on the straight. If I get onto the Bentley straight faste,r then maybe I will end up faster.
With an airfield runway available it only makes around 150 mph anyway. Gearing, aerodynamics and wind resistance determine that.
But then, it depends on what you want to do with your car. The above is what I want to do with mine.
The torque is what makes the car so much fun for me.
I don't want any more power on the public road.
I don't want any more power or torque on track day corners - the car is already faster than its handling or my ability.
I wouldn't say no to being faster between corners.
So rather than spending money on a turbo, I am going to buy some new track tyres and invest in some driver training to get me out of the corners faster. Get out faster and you get to the next one faster. On an average track in Norfolk I can presently just about make 135mph on the straight. If I get onto the Bentley straight faste,r then maybe I will end up faster.
With an airfield runway available it only makes around 150 mph anyway. Gearing, aerodynamics and wind resistance determine that.
But then, it depends on what you want to do with your car. The above is what I want to do with mine.
Nice one Anthony,, getting the best shocks you can lay your hands on wont do any harm,,, big investment but huge return,,
It's simply not possible to compete against a similar car if it's got so much more power/Torque,,,, especially if Peters built it,,
Ultimately driver training should get you going in faster, rotating with control, maintaining mid corner speed and hence getting to the next corner faster,,, yeah spend the money on the nut behind the wheel,,,that's what I've always been told !
Personally it's about skid control, get that together and your on it regardless of what power you have,
Sliding is where the buzz is anyway, it's all very well getting all hooked up and that's faster but controlling a slide and slight slip angle is what I think makes these cars come alive, and what any great driver must be able to do,,
Skid pan,, teach you a million things and not wear out the tyres,, going around circles in a great broadie controlling it with the throttle,, deliberatly provoking understeer and getting it back again,, you'll have an infanatly better feel for the cars abilities,,
Sorry for the rant,
Power,,, that figure of 300 Bhp at the wheels,, seems about right,, that would make our cars feel proper fast but still drivable on the bumpy roads,, jeez I feel a new target for my car coming on
It's simply not possible to compete against a similar car if it's got so much more power/Torque,,,, especially if Peters built it,,
Ultimately driver training should get you going in faster, rotating with control, maintaining mid corner speed and hence getting to the next corner faster,,, yeah spend the money on the nut behind the wheel,,,that's what I've always been told !
Personally it's about skid control, get that together and your on it regardless of what power you have,
Sliding is where the buzz is anyway, it's all very well getting all hooked up and that's faster but controlling a slide and slight slip angle is what I think makes these cars come alive, and what any great driver must be able to do,,
Skid pan,, teach you a million things and not wear out the tyres,, going around circles in a great broadie controlling it with the throttle,, deliberatly provoking understeer and getting it back again,, you'll have an infanatly better feel for the cars abilities,,
Sorry for the rant,
Power,,, that figure of 300 Bhp at the wheels,, seems about right,, that would make our cars feel proper fast but still drivable on the bumpy roads,, jeez I feel a new target for my car coming on
gacksen said:
i am often thinking of putting a different cam in the 4.6 xbolted but what
do you guys think how high can you rev that thing without further mods
and no forged internal ? 5500 6000 6500 rpm ?
Revs are not generally a problem to the Rover block (piston speeds and rod loadings etc are actually pretty low if you do the calcs), a decently balanced 4.6 with its better piston design especially will easily handle being buzzed from a mechanical point of view although the valve gear will definitely need bolstering (outriggers and roller rockers a good bet). do you guys think how high can you rev that thing without further mods
and no forged internal ? 5500 6000 6500 rpm ?
The difficulties actually come from running a cam with the right grind to enable high rpm breathing assuming the heads can support that (look at the torque drop off from 5krpm or less on most dyno traces you see posted to see where even 'sports' cammed cars typically live) - this needs loads of overlap, which will impact low speed running and manners (chronically with a single plenum). The charge robbing and cross-contamination that causes this will also make for a dirty engine internally, which can be dispiriting.
That apart, a screamer coming on cam with a bit of boost behind it is pretty addictive
Pupp said:
Revs are not generally a problem to the Rover block (piston speeds and rod loadings etc are actually pretty low if you do the calcs), a decently balanced 4.6 with its better piston design especially will easily handle being buzzed from a mechanical point of view although the valve gear will definitely need bolstering (outriggers and roller rockers a good bet).
This ^ 
I am not sure what the answer to the question is at the moment.
My car has been sat in the garage for a month unused.
Too busy and rubbish weather has curtailed fun but I am keen for a run out tomorrow.
After the last 10 days wafting in an oil burner Vel Satis it will come as a shock I'm sure, bring it on!
I have never left the car for so long before but maybe that's a sign of the times, get older and work more.
Next year will be different, so I hope anyhow.
Hope I don't bin it
My car has been sat in the garage for a month unused.
Too busy and rubbish weather has curtailed fun but I am keen for a run out tomorrow.
After the last 10 days wafting in an oil burner Vel Satis it will come as a shock I'm sure, bring it on!
I have never left the car for so long before but maybe that's a sign of the times, get older and work more.
Next year will be different, so I hope anyhow.
Hope I don't bin it
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