Driving characteristics 4.0 v 4.5 v 5.0 - after 250-300bhp
Discussion
I am currently enjoying my fourth Chimaera and fifth TVR. All the Chimaeras have been 4.0 but I’m interested to know how the 4.5 and 5.0 compare. I realise there will be differences between individual cars, but do the characters differ between the engines? Ie do some rev more freely or higher? Any reliability issues as the capacity increases? I’m interested in either making my 4.0 faster or swapping for a larger capacity version. Would rather keep N/A but would ideally like a genuine 250-300bhp at flywheel...
By now each car will probably be different. (They are all old girls now).
I've had a bunch (see my car profile) and sampled each of the 3 in your list. I've had 1 very unreliable 5.0, but that was just that car. For me the 5.0 is the only one to have. Once you've had one anything else is just not the same.
But, as I say, by now it will vary car by car. Good luck!
I've had a bunch (see my car profile) and sampled each of the 3 in your list. I've had 1 very unreliable 5.0, but that was just that car. For me the 5.0 is the only one to have. Once you've had one anything else is just not the same.
But, as I say, by now it will vary car by car. Good luck!
You might squeeze 250 bhp out of a 4 litre. You won't get 300 bhp without spending the national debt on wildcat heads etc etc.
Turbocharging or supercharging will get you to 330 bhp with little difficulty. The 400 is a nice revvy engine, as was the 430 in the early cars.
The 450 and 500 are more grunty.
The 5 litre engines are about 280 bhp in factory guise, but can be improved to 300 to 360 bhp with liberal use of wallet. The most noticeable difference I found was the serious increase in torque over the 4 litre - they just have so much more grunt.
And that's your quandary - keep it standard at 280bhp or "improve" it, because none of the improvements are cheap, or if they are they add 2 bhp and you can't tell the difference. In my humble opinion, no improvement is worth the effort for less than 20 bhp minimum.
Can I just dispell one myth - "turbo lag". A TVR Rover V8 is not a 1980s Rally Audi Quatro. If you turbocharge your engine it will mostly feel like the normally aspirated engine, just a bit faster. At the low pressure levels we use, there is no turbo lag. The main difference is that the max torque is a much bigger number, but it has a much narrower band.
If you drive my car without knowing it is turbocharged I doubt you would actually know it was turbocharged, apart from the "pssst" on changing up a gear, as the dump valve dumps the excess pressure. It feels just like a normally aspirated car, but with the power and torque in a bit narrower band.
What I am saying is, if a turbocharged or supercharged 4 litre comes up for sale, don't turn your nose up with out trying it.
Turbocharging or supercharging will get you to 330 bhp with little difficulty. The 400 is a nice revvy engine, as was the 430 in the early cars.
The 450 and 500 are more grunty.
The 5 litre engines are about 280 bhp in factory guise, but can be improved to 300 to 360 bhp with liberal use of wallet. The most noticeable difference I found was the serious increase in torque over the 4 litre - they just have so much more grunt.
And that's your quandary - keep it standard at 280bhp or "improve" it, because none of the improvements are cheap, or if they are they add 2 bhp and you can't tell the difference. In my humble opinion, no improvement is worth the effort for less than 20 bhp minimum.
Can I just dispell one myth - "turbo lag". A TVR Rover V8 is not a 1980s Rally Audi Quatro. If you turbocharge your engine it will mostly feel like the normally aspirated engine, just a bit faster. At the low pressure levels we use, there is no turbo lag. The main difference is that the max torque is a much bigger number, but it has a much narrower band.
If you drive my car without knowing it is turbocharged I doubt you would actually know it was turbocharged, apart from the "pssst" on changing up a gear, as the dump valve dumps the excess pressure. It feels just like a normally aspirated car, but with the power and torque in a bit narrower band.
What I am saying is, if a turbocharged or supercharged 4 litre comes up for sale, don't turn your nose up with out trying it.
I carried out some mods to my 400, it started out as a basic cam swap as the car was on 78000 miles but escalated to some new heads and induction package.
I estimate I spent around £4000 doing this work, that included refreshing the crank bearings and the oil pump etc.
It made 260 bhp on the dyno and drives very well, it loves to rev!
If I were to do it again i would probably put the money toward a 4.6/5.0 build as for not much more than I spent you could get a freshly rebuilt motor.
Don’t discount the Supercharger route as it will still retain the driving characteristics of the Revvy 4.0 but give you a decent power upgrade, not a cheap option though as the management system should be upgraded too.
I estimated about £6500 to do the Supercharger conversion properly.
I estimate I spent around £4000 doing this work, that included refreshing the crank bearings and the oil pump etc.
It made 260 bhp on the dyno and drives very well, it loves to rev!
If I were to do it again i would probably put the money toward a 4.6/5.0 build as for not much more than I spent you could get a freshly rebuilt motor.
Don’t discount the Supercharger route as it will still retain the driving characteristics of the Revvy 4.0 but give you a decent power upgrade, not a cheap option though as the management system should be upgraded too.
I estimated about £6500 to do the Supercharger conversion properly.
Similar money for the turbo conversion - mine, including intercooler, oil cooler and installation was around £3,800, and you could run it on the 14 CUX, so add a bit for mapping. But it is much better with an aftermarket fuel and spark mapped ECU (I went Emerald), which will add a couple of grand installed and mapped to your bill.
Interesting topic. How is the low speed running with a supercharger or turbo fitted? Is it super smooth between 1 and 2k rpm? We all know the standard TVR V8s suffer a bit in this region. Come on, be honest. I'm tempted to fit a supercharger but the main reason is to make the car nice and smooth.
.....so you're not really interested in the extra 100 bhp? 
I believe it's the person mapping the aftermarket ECU that has made the difference, rather than the forced induction itself. Once you map both spark and fuel, and eliminate the distributor, things do tend to improve, but it is also possible to improve the 14 CUX mapping (see Joolz below)
My turbo is as smooth as a baby's bum at low revs, but I suspect that is down to the Emerald ECU and its mapping guru, Joolz of Kits and Classics.
A call to him (his number is on his website http://www.kitsandclassics.co.uk/) will tell you all you need to know. If he doesn't answer, leave a message, because he doesn't interrupt a mapping session for the phone, but he will get back to you when he takes a break.
I believe it's the person mapping the aftermarket ECU that has made the difference, rather than the forced induction itself. Once you map both spark and fuel, and eliminate the distributor, things do tend to improve, but it is also possible to improve the 14 CUX mapping (see Joolz below)
My turbo is as smooth as a baby's bum at low revs, but I suspect that is down to the Emerald ECU and its mapping guru, Joolz of Kits and Classics.
A call to him (his number is on his website http://www.kitsandclassics.co.uk/) will tell you all you need to know. If he doesn't answer, leave a message, because he doesn't interrupt a mapping session for the phone, but he will get back to you when he takes a break.
Sounds good. Id like a bit more power but my 5L is already 300 which is reasonable for the chassis. Fitting a supercharger to a 5L may result in uncontrollable power!!!! I already have the canems ECU which has improved things a bit in the low rpm area but like you say its probably in the mapping. I'm sure it could be better. Induction restrictions and camshaft are probably the main reasons why our TVRs are not super smooth below 2k rpm, but forced air could improve the induction bit.
Thanks for all the replies, the situation I have is that my latest Chimaera is very tidy, with a superb interior and chassis and I’ve just fitted Gaz Golds and upgraded the wheels. It’s a 1999 with 59k, so I would hope is worth around £15k. The car drives really well, but I would like more power. Question is do I upgrade it, or sell and buy a 4.5 or 5.0? My TVR mechanic prefers the 4.0 and 4.5 to the 5.0 from both a driving and reliability point of view based on his experiences. Interested to know what others have experienced.
I could get a really nice, late, low miles 4.5 or 5.0 for about £6k more than I guess mine would sell for. So the costs to upgrade or change seem similar. I would probably prefer staying N/A and getting a 4.6 built if I keep the car, I guess a turbo would muffle the lovely TVR noise and the supercharger may encourage me to turn up the wick more than I need resulting in the need to upgrade lots of other parts too...
I could get a really nice, late, low miles 4.5 or 5.0 for about £6k more than I guess mine would sell for. So the costs to upgrade or change seem similar. I would probably prefer staying N/A and getting a 4.6 built if I keep the car, I guess a turbo would muffle the lovely TVR noise and the supercharger may encourage me to turn up the wick more than I need resulting in the need to upgrade lots of other parts too...
The reason for your mechanic's preference is that the 4.6 is an engine constructed as God and range Rover intended it, whereas the TVR 5 litre engine has a small journal offset ground crank to get a longer stroke, which is inherently weaker - they have been known to break. In the case of my car my 5 litre engine must have been slightly unbalanced, because over 30,000 miles it wore out the front crank bearing.
The 5 litre is gruntier, the 4.6 revvier. I would suggest going and test driving a couple of each. Or you can drive my car if you like (4.6 turbo)
I will be at Burleigh TVRCC car show in less than five weeks time if that helps, and we can go for a drive locally (or up and down the A1) to give you a chance to see what it's like.
The 5 litre is gruntier, the 4.6 revvier. I would suggest going and test driving a couple of each. Or you can drive my car if you like (4.6 turbo)
I will be at Burleigh TVRCC car show in less than five weeks time if that helps, and we can go for a drive locally (or up and down the A1) to give you a chance to see what it's like.
notax said:
I could get a really nice, late, low miles 4.5 or 5.0 for about £6k more than I guess mine would sell for. So the costs to upgrade or change seem similar. I would probably prefer staying N/A and getting a 4.6 built if I keep the car, I guess a turbo would muffle the lovely TVR noise and the supercharger may encourage me to turn up the wick more than I need resulting in the need to upgrade lots of other parts too...
You would need to stop the wick turning around 400 bhp to avoid the need to upgrade the engine internals. All the same, you will probably need to upgrade injectors and fuel pump. In reality, number bragging rights are great fun, but there are not that many places where you can use much more than 400 bhp/tonneMy 450 runs 265.3BHP at the flywheel and is a very nice drive at all speeds and all traffic conditions. I have a new 885 cam, bigger plenum, ACT breathing kit including super flare trumpets, better injectors and a rolling road tune by Joolz but no major engine upgrades.
I can get to c300 with bigger heads and 330+ with bigger heads and an up rated management system according to Joolz but then would it make any difference to me? To be honest I think not as I drive 95% of the time on the road and the current set up is certainly powerful enough to keep up with most things on a B road in normal conditions.
The folks on here with much larger BHP figures have spent quite some money and quite a few do a lot of track days (QBee and Phazed for example) so I can appreciate why they wanted the extra power, both can pedal very well also
It is a very personal choice as to what you do to your TVR to make it "your" car whilst ensuring it is an easy drive in all traffic conditions.
I can get to c300 with bigger heads and 330+ with bigger heads and an up rated management system according to Joolz but then would it make any difference to me? To be honest I think not as I drive 95% of the time on the road and the current set up is certainly powerful enough to keep up with most things on a B road in normal conditions.
The folks on here with much larger BHP figures have spent quite some money and quite a few do a lot of track days (QBee and Phazed for example) so I can appreciate why they wanted the extra power, both can pedal very well also
It is a very personal choice as to what you do to your TVR to make it "your" car whilst ensuring it is an easy drive in all traffic conditions.
I guess it comes down to how you want the car to feel, as 300hp is do-able in all the formats, but the power delivery will be vastly different.
The larger the engine the more relaxed the power delivery will be, so ..
you could have a racey revvy screamy 4 litre, a less screamy 4.5 or a quite relaxed 5 litre.
Bottom line is nothing *feels* as fast as adding capacity, or a blower, so you might think going straight to a larger engine might be the best bet, and for 90 percent of people it is. But some others (maybe brought up on revvy 4-pots) might prefer the feel of a higher tune 4 litre.
Do you have a preference?
The larger the engine the more relaxed the power delivery will be, so ..
you could have a racey revvy screamy 4 litre, a less screamy 4.5 or a quite relaxed 5 litre.
Bottom line is nothing *feels* as fast as adding capacity, or a blower, so you might think going straight to a larger engine might be the best bet, and for 90 percent of people it is. But some others (maybe brought up on revvy 4-pots) might prefer the feel of a higher tune 4 litre.
Do you have a preference?
Not suggesting that it is what the OP needs per se but you guys need to drive a 4-litre Wildcat in a TVR Chimaera - a match made in heaven IMO. 350bhp and 7000rpm in a daily driver with low speed manners that are as good as any standard Chimaera (pulls along happily at 30mph in 5th gear, no surging, etc), more available bhp and rpm if you are willing to sacrifice some driveability. I am loving mine.
The UK national debt is about £2 trillion at the mo, every Rover V8 owner in existence could have a Wildcat conversion for that!
The UK national debt is about £2 trillion at the mo, every Rover V8 owner in existence could have a Wildcat conversion for that!
I used to have a 4.6l and it made 270bhp. It was a pleasure to drive plenty of grunt, more than enough for our roads. That said I was looking for 5.0l when I bought my current TVR however I bought a 4l as it was in excellent condition.
The 4l was a pleasure but I missed the power of the larger engine. So I turbo charged it.
A 4l turbo is sweet, nice and revvy with lots of power. Mine is at just over 360bhp. Sounds great too as I’ve got an ACT cherry bomb exhaust.
However I am having a new 4.6l engine built.
Power is addictive.
Driveability and power characteristics ,,,,,,, I’ve never driven a 5l
The 4l is a very nice engine with enough power for most.
The 4.3 is excellent I’m told but again never driven it, (no cat must be a positive).
4.6l better than the 4l I would say simply because of the extra grunt.
FI is different again and turbo seems to be the most popular choice.
So unless you are chasing bhp make the car you have the nicest place to be.
The 4l was a pleasure but I missed the power of the larger engine. So I turbo charged it.
A 4l turbo is sweet, nice and revvy with lots of power. Mine is at just over 360bhp. Sounds great too as I’ve got an ACT cherry bomb exhaust.
However I am having a new 4.6l engine built.
Power is addictive.
Driveability and power characteristics ,,,,,,, I’ve never driven a 5l
The 4l is a very nice engine with enough power for most.
The 4.3 is excellent I’m told but again never driven it, (no cat must be a positive).
4.6l better than the 4l I would say simply because of the extra grunt.
FI is different again and turbo seems to be the most popular choice.
So unless you are chasing bhp make the car you have the nicest place to be.
Edited by sapper on Wednesday 6th March 18:20
Horsepower chasing is addictive and I do sometimes wonder if I should have put a 4.8-litre in with the Wildcat conversion as it wouldnt have cost any more than the 4.1-litre. I would have had even more horsepower and torque (you definitely cannot beat more capacity for bottom end torque) but am getting a perverse pleasure out extracting maximum bhp per litre. I previously had 382bhp and 7500rpm with a different camshaft but have detuned it slightly for daily driving. Once the summer is out of the way our aim is to upgrade the conrods, fit a different camshaft and go for an 8000rpm redline! Even more power and it will sound unbelievable
You are right however, when chasing horsepower if is easy to end up making a car that is less enjoyable to drive. I suspect I will end up wishing that I left it in 350bhp/7000rpm format but do enjoy the development work
You are right however, when chasing horsepower if is easy to end up making a car that is less enjoyable to drive. I suspect I will end up wishing that I left it in 350bhp/7000rpm format but do enjoy the development work
notax said:
Thanks for all the replies, the situation I have is that my latest Chimaera is very tidy, with a superb interior and chassis and I’ve just fitted Gaz Golds and upgraded the wheels. It’s a 1999 with 59k, so I would hope is worth around £15k. The car drives really well, but I would like more power. Question is do I upgrade it, or sell and buy a 4.5 or 5.0? My TVR mechanic prefers the 4.0 and 4.5 to the 5.0 from both a driving and reliability point of view based on his experiences. Interested to know what others have experienced.
I could get a really nice, late, low miles 4.5 or 5.0 for about £6k more than I guess mine would sell for. So the costs to upgrade or change seem similar. I would probably prefer staying N/A and getting a 4.6 built if I keep the car, I guess a turbo would muffle the lovely TVR noise and the supercharger may encourage me to turn up the wick more than I need resulting in the need to upgrade lots of other parts too...
Like anything it all comes down to budget or what you deem reasonable to obtain your end purpose. I could get a really nice, late, low miles 4.5 or 5.0 for about £6k more than I guess mine would sell for. So the costs to upgrade or change seem similar. I would probably prefer staying N/A and getting a 4.6 built if I keep the car, I guess a turbo would muffle the lovely TVR noise and the supercharger may encourage me to turn up the wick more than I need resulting in the need to upgrade lots of other parts too...
I have a car that fits your criteria rather well.
Mk2/3 2000 year 4.6 engines car with cross bolted crank and the best heads Rover made.
Re built by Powers with 885 cam Mbe Ecu and new Dif.
Delivers around 300 bhp 345 torques mapped and dyno’d using catted Y so totally on par with most 5.0 engines unless they are tuned and being a 4.6 smooth as silk to drive. No shunt from 800 revs onwards so you can use the torque right down around town effortlessly and returns realistic fuel economy figures, upto 30 mpg on a run so the car is still a usable toy and touring vehicle as well as knock out a 12.60 on the drag strip which is faster than many 5.0 cars have managed including turbo driven motors.
It still retains its Tvr feel and look other than the dizzy missing which I like a lot.
Anything over 300 hp requires a brake upgrade imho, having had said upgrade to fantastic big disc 4 pot Brembo brakes i can say the car feels as good as it sounds.
It’s not the fastest by a long stroke but I care not one bit, it drives like a dream and is now the car Tvr might have sold us if they had access to decent easily mapped reliable Ecu systems that are designed for purpose rather than one designed for auto’s.
The throttle response both on and off is just superb with a good Ecu and mapping, really gives the engine a proper performance car feel and gives absolute control of engine revs, which is so important when controlling wheel spin and delivering the power at critical moments when grip changes.
It’s not just how fast it is it’s more how it feels when doing it which is why N/a will always deliver buckets loads of character no other form can create even though it’s not quite so fast.
Does it matter when your out on a brisk sunny day, there’s far more to the car than just its ultimate power curve.
The sound is really important to me for instance, not to loud but I love the deep induction roar i now have since AFM removal and Mbe installation, it all adds to the ore of it which is far more exciting than just another few hp.
It’s a compromise ultimately but one I’m very happy with overall as it’s fast but easy to repair and staying n/a retains the elements I like most which is character and loads of torque.
I’d decide how It will mostly be driven then chose what to do based on that and tune the car to match what your preferred options are or just buy one that’s got those options built in which will also be the cheapest way to attain them by far and a lot less hassle.
Trouble is there’s not that many cars out there with these levels of improvements and when they do come up get snapped up by savvy types pretty quickly because for 18/20k which is what I value mine at it would be impossible to do this to any car based on a purchase price of say 14k as a standard example. Mine probably cost 24k altogether incl car purchase price and that’s not including a 4K respray! 18k would clearly be a bargain as opposed to doing it all yourself via specialists.
drlloyd said:
Not suggesting that it is what the OP needs per se but you guys need to drive a 4-litre Wildcat in a TVR Chimaera - a match made in heaven IMO. 350bhp and 7000rpm in a daily driver with low speed manners that are as good as any standard Chimaera (pulls along happily at 30mph in 5th gear, no surging, etc), more available bhp and rpm if you are willing to sacrifice some driveability. I am loving mine.
The UK national debt is about £2 trillion at the mo, every Rover V8 owner in existence could have a Wildcat conversion for that!
I love the sound of this!! The UK national debt is about £2 trillion at the mo, every Rover V8 owner in existence could have a Wildcat conversion for that!
I adore the revvy nature of my 4.0 with an 885 camshaft, but i bet that is another level. Im a serial Honda Type R owner in a previous life so I like my revs
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