Driving characteristics 4.0 v 4.5 v 5.0 - after 250-300bhp
Discussion
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!
Any idea of the weight of the Wildcat heads compared to the Rover ones? The stuff you put up top looks a bit weighty, too... The UK national debt is about £2 trillion at the mo, every Rover V8 owner in existence could have a Wildcat conversion for that!
How does the bottom end cope with 7K+ ? Any breakdown of what absolutely *needs* to be done, and what would be sensible precautions on top of that?
For our Speed Eight Performance builds, I'd be looking at an engine range of 4.6 GT (320 hp/ ca. 5700 rpm), 4.3 Speed (320 hp/6000 rpm) and 4.1 Supersports (Wildcat heads, 350 hp/7,000 rpm) but then the Wildcat-powered version should ideally be lighter than the other two (with ACT twin/triple throttle intakes) rather than heavier as 1) it would be mainly aimed at trackday regulars and mountain road carvers, and 2) there's more performance on tap but the chassis ain't getting any stiffer...
Would like to hear your thoughts
Edited by 900T-R on Thursday 7th March 08:57
V8 Developments do a 5L engine that apparently eliminates the problems of the original TVR 5L. I had mine rebuild recently and it has the dreaded 5L rattle on the overrun - something to do with the piston little ends apparently. The odd thing is it didn't have a rattle pre rebuild. 4.6 and supercharger sounds like the go.
I go to sleep at night dreaming of a V8D Stage 4 4.6 build which they sell as a crate engine inc. sexy heads, crossbolted, large journal crank, lightened and balanced internals, with JE crossover intake manifold and Clive F equal length exhaust manifolds, all managed by an intelligent and easily monitorable standalone ECU on coil packs and phat injectors. I can't picture a prettier engine bay or imagine a better noise.
Problem is that I know the square root of naff all about engine building, so I've no idea if these components would all play together nicely- but in my head it makes 350hp with perfect power delivery, torque of a 5l with 4l revs
Problem is that I know the square root of naff all about engine building, so I've no idea if these components would all play together nicely- but in my head it makes 350hp with perfect power delivery, torque of a 5l with 4l revs
CanoeSniffer said:
I go to sleep at night dreaming of a V8D Stage 4 4.6 build which they sell as a crate engine inc. sexy heads, crossbolted, large journal crank, lightened and balanced internals, with JE crossover intake manifold and Clive F equal length exhaust manifolds, all managed by an intelligent and easily monitorable standalone ECU on coil packs and phat injectors. I can't picture a prettier engine bay or imagine a better noise.
Problem is that I know the square root of naff all about engine building, so I've no idea if these components would all play together nicely- but in my head it makes 350hp with perfect power delivery, torque of a 5l with 4l revs
I did a quick guestimate tot up of that gorgeous list and reckon that the bits will cost in the region of £12,000, and the TVR gurus to install it all and map the ECU another £3,000 And it will sound lovely and go like rose fertiliser off a shovel.Problem is that I know the square root of naff all about engine building, so I've no idea if these components would all play together nicely- but in my head it makes 350hp with perfect power delivery, torque of a 5l with 4l revs
Supercharger or turbo will cost around 40% of that, including the ECU and injectors., and on a basic 4,6 will generate 400+ bhp and shed loads of torque.
Difficult choice, but you can see why a number of us have gone the farcical induction route.
QBee said:
CanoeSniffer said:
I go to sleep at night dreaming of a V8D Stage 4 4.6 build which they sell as a crate engine inc. sexy heads, crossbolted, large journal crank, lightened and balanced internals, with JE crossover intake manifold and Clive F equal length exhaust manifolds, all managed by an intelligent and easily monitorable standalone ECU on coil packs and phat injectors. I can't picture a prettier engine bay or imagine a better noise.
Problem is that I know the square root of naff all about engine building, so I've no idea if these components would all play together nicely- but in my head it makes 350hp with perfect power delivery, torque of a 5l with 4l revs
I did a quick guestimate tot up of that gorgeous list and reckon that the bits will cost in the region of £12,000, and the TVR gurus to install it all and map the ECU another £3,000 And it will sound lovely and go like rose fertiliser off a shovel.Problem is that I know the square root of naff all about engine building, so I've no idea if these components would all play together nicely- but in my head it makes 350hp with perfect power delivery, torque of a 5l with 4l revs
Supercharger or turbo will cost around 40% of that, including the ECU and injectors., and on a basic 4,6 will generate 400+ bhp and shed loads of torque.
Difficult choice, but you can see why a number of us have gone the farcical induction route.
The bottom line is that these engines are not efficiently modified to 300bhp+ in a wallet friendly manner without added woosh.
I originally had big plans for mine, but 12 months on from having the knackered camshaft in my 4.0hc replaced with an 885, I am still happy as the proverbial Larry in terms of performance. It willingly hits 6k rpm and provides more than enough oompf for road use. Realistically, if I had another 100bhp I think I would struggle to find opportunities on the road to enjoy the wonderful sound of the RV8 at full chat.
Although clearly it helps not having track-day bragging rights to worry about!
QBee said:
. In reality, number bragging rights are great fun, but there are not that many places where you can use much more than 400 bhp/tonne
Absolutely right.When I use mine on the roads I probably use 20% of the power most of the time. It is on the rare occasion that you can floor the throttle for a few seconds and that is it. A very good reason to do track days and other off-road events.
Unfortunately, most people live in suburban areas with countryside nearby which is full of the general public and in our overcrowded land there is little chance of putting the hammer down.
The faster the vehicle, the more pointless it seems.
On the other hand, we don't follow logic and therefore need the most horsepower that we can lay our hands on! Just use it wisely or you will end up in a hedge!
To the OP, more is better generally. Happy to give you a demonstration of 400 bhp and huge torque if you are ever in the area.
Other than big heads and a few other tasteful tuning aids I think anything else is overkill and only really necessary if you are a trackday guru.
I bet you a 240 hp 4.0 Chim in the hands of a driving god would whoop the ass off any Turbo or other tuned car around somewhere like Blyton park which is more like a short motorcycle circuit and virtually nowhere where the extra power could take over, it’s more about corner speed there, so what use is all that power even on many circuits let alone driving down the B4453
If money is no object which has to be a consideration as none of this is exactly cheap as it’s not just the cost of parts it’s then what else goes wrong until it’s fully developed on your car. Turbo’s and most proper tuning requires oil coolers etc etc so just adding more to fail is how I see it and for what exactly, other than QBee I know of few owners of highly tuned cars who drive them about to the shops!
If you are ok with this that’s fine but I’d you still want a failrly reliable economical car and you do put the miles on all this expense becomes a waste of money once it’s all worn off!
The accelerated engine wear from a tuned engine is fairly obvious and an accepted part of the game so even after tuning mods it can only wear and get slower which puts you off using it for cruising about, which is a very enjoyable experience in itself.
It’s not just the power that makes a good car great it’s it’s usability or we’d all own second hand F1 cars
I bet you a 240 hp 4.0 Chim in the hands of a driving god would whoop the ass off any Turbo or other tuned car around somewhere like Blyton park which is more like a short motorcycle circuit and virtually nowhere where the extra power could take over, it’s more about corner speed there, so what use is all that power even on many circuits let alone driving down the B4453
If money is no object which has to be a consideration as none of this is exactly cheap as it’s not just the cost of parts it’s then what else goes wrong until it’s fully developed on your car. Turbo’s and most proper tuning requires oil coolers etc etc so just adding more to fail is how I see it and for what exactly, other than QBee I know of few owners of highly tuned cars who drive them about to the shops!
If you are ok with this that’s fine but I’d you still want a failrly reliable economical car and you do put the miles on all this expense becomes a waste of money once it’s all worn off!
The accelerated engine wear from a tuned engine is fairly obvious and an accepted part of the game so even after tuning mods it can only wear and get slower which puts you off using it for cruising about, which is a very enjoyable experience in itself.
It’s not just the power that makes a good car great it’s it’s usability or we’d all own second hand F1 cars
OP, you can off set some of your cost by selling your good 4.0 engine as well remember.
For the record i have a 5L car that made 300 before getting an Emmerald upgrade and i think is now 321 from memory. The drive-ability is better for sure, but ECU and Guru aside, physics is physics. Tiny changes in throttle plate opening, injector spray pattern to name but 2 areas that impact the low revs transition, as you gain more BHP these become more of an issue to focus on finding a compromise for you.
I never drove a 4 or other engine, but i am not sure i could go smaller now.......but that wildcat one sounds like an idea though
For the record i have a 5L car that made 300 before getting an Emmerald upgrade and i think is now 321 from memory. The drive-ability is better for sure, but ECU and Guru aside, physics is physics. Tiny changes in throttle plate opening, injector spray pattern to name but 2 areas that impact the low revs transition, as you gain more BHP these become more of an issue to focus on finding a compromise for you.
I never drove a 4 or other engine, but i am not sure i could go smaller now.......but that wildcat one sounds like an idea though
Well, there's my V8D 4.6. SHINEY CF manifolds waiting in the wings and a gems ecu in the bedroom! Lol
It's got everything bar a JE or ACT manifolds.....I just could bush to them and so it's now 72mm plenum.
Mines a 450 and I looked at capacity increase including V8D 5 and 5.4 ltr option, but realised the fact that it'll only ever be a 80% + road car and I really didn't 'need' more than what my current spec would offer. I've driven 500+ bhp cars on the past and I never really got them....I always preferred a car with a balance of power, handling and most importantly CHARACTOR. After all, that's what comes as standard on our cars!
Also, I rather liked the idea of keeping my car a 450, and not a 450 with a bigger engine....draft train of thought, maybe.
As a number of people have already sited, if you take things too excessively then you're on a roller coaster of replacing and upgrading other components. I just wanted as factory production like as possible.
To sum up; decide what you want to achieve and how you'll actually use the car. It's all too easy to get carried away and ruin your pride and joy for its intended use!
The heads/valve sizes are the biggest single restriction on getting more power out of our RV8s.
It took me about 4 years and several wallet-emptyings to realise this.
Please sit up and take notice.
Yes, you can make loads of small improvements, but major horsepower increases are only available with serious capacity increases and/or finding a way of getting more air, and hence more fuel, into the engine. After V8D stage 4 heads, which with other mos can get you to 360 bhp, only Wildcat heads can take you further normally aspirated.
And to make a car feel any more than a just bit quicker, you have to defeat the law of diminishing returns and make seriously big power increases.
My car must get to 60 in about 4 seconds - you need getting on for 600 bhp to do it in 3.
Yes, my 395 bhp turbo is a bit quicker, but you do get used to it pretty quickly and it is not night and day quicker.
Back in the days of my five litre engine I had a mere 315 bhp and it was only a little slower than Phazed's 385bhp 5.5.
His is now 400 bhp, mine 395, and he is still just a tad quicker thanks to a broader torque/bhp band and better driving skills.
Before anyone starts on a project spending megabucks to get 350+bhp, please drop either of us an email and come and drive our cars (or be driven in them if you prefer). It might just save you some money.
Also, notax and anyone else, I can easily show you what 325 bhp feels like, using the lower boost map on my car.
For anyone fancying some passenger laps, Phazed and I will be joining all the other TVR nutters for the TVRCC track day at Cadwell Park on Friday 24th May. The track charges a nominal fee (around a tenner) and you need to have or hire a helmet.
It took me about 4 years and several wallet-emptyings to realise this.
Please sit up and take notice.
Yes, you can make loads of small improvements, but major horsepower increases are only available with serious capacity increases and/or finding a way of getting more air, and hence more fuel, into the engine. After V8D stage 4 heads, which with other mos can get you to 360 bhp, only Wildcat heads can take you further normally aspirated.
And to make a car feel any more than a just bit quicker, you have to defeat the law of diminishing returns and make seriously big power increases.
My car must get to 60 in about 4 seconds - you need getting on for 600 bhp to do it in 3.
Yes, my 395 bhp turbo is a bit quicker, but you do get used to it pretty quickly and it is not night and day quicker.
Back in the days of my five litre engine I had a mere 315 bhp and it was only a little slower than Phazed's 385bhp 5.5.
His is now 400 bhp, mine 395, and he is still just a tad quicker thanks to a broader torque/bhp band and better driving skills.
Before anyone starts on a project spending megabucks to get 350+bhp, please drop either of us an email and come and drive our cars (or be driven in them if you prefer). It might just save you some money.
Also, notax and anyone else, I can easily show you what 325 bhp feels like, using the lower boost map on my car.
For anyone fancying some passenger laps, Phazed and I will be joining all the other TVR nutters for the TVRCC track day at Cadwell Park on Friday 24th May. The track charges a nominal fee (around a tenner) and you need to have or hire a helmet.
spitfire4v8 said:
I like the way this thread has drifted from "i want 250-300hp" to "i will show you my 5.5 / 4.6 turbo / wildcat 4.1 / others" .. true tvr owners one and all! Why have less when you can have more more more!!
carry on!
Same thought crossed my mind - the OP didn't know what he was unleashing! carry on!
I blame you, Joolz, for making at all happen so relatively easily.
I’m more interested in making things smooth below 2k rpm. Shunting is the most complained about problem. Smooth running is the holy grail. 300bhp is enough. Mapping and ecu will help but are there any intake modifications that can be made? Different plenum design? Etc. Thor manifold has been mentioned but is that good for 300bhp? Gems has been mentioned but sounds like a big job and needs extra sensors installing.
QBee said:
CanoeSniffer said:
I go to sleep at night dreaming of a V8D Stage 4 4.6 build which they sell as a crate engine inc. sexy heads, crossbolted, large journal crank, lightened and balanced internals, with JE crossover intake manifold and Clive F equal length exhaust manifolds, all managed by an intelligent and easily monitorable standalone ECU on coil packs and phat injectors. I can't picture a prettier engine bay or imagine a better noise.
Problem is that I know the square root of naff all about engine building, so I've no idea if these components would all play together nicely- but in my head it makes 350hp with perfect power delivery, torque of a 5l with 4l revs
I did a quick guestimate tot up of that gorgeous list and reckon that the bits will cost in the region of £12,000, and the TVR gurus to install it all and map the ECU another £3,000 And it will sound lovely and go like rose fertiliser off a shovel.Problem is that I know the square root of naff all about engine building, so I've no idea if these components would all play together nicely- but in my head it makes 350hp with perfect power delivery, torque of a 5l with 4l revs
Supercharger or turbo will cost around 40% of that, including the ECU and injectors., and on a basic 4,6 will generate 400+ bhp and shed loads of torque.
Difficult choice, but you can see why a number of us have gone the farcical induction route.
I'm beginning to think along the lines that my car is a keeper, so I'm willing to dump the cash as it will be my DREAM build, mine forever and forever mine. An investment if you like (that's the man-maths talking). FI would be a far easier solution and may even produce results from my early 3.9, but the engine bay porn and the noise factor would really future-proof it for me, ticking all the boxes. But I could do with some seat time in Chims of different power outputs first to understand what I want a bit better, so I'll be blagging as many pax laps as possible at Cadwell.
You will always get more 'bang for buck' with forced induction, no denying that. Although we specialise in V8s, we tune a wide range of different engines (inc. 14,000rpm GSXR engines, turbocharged Jap stuff, etc) and we always find it ridiculously easy to make big power with turbos and superchargers, as long as the engine & drivetrain can take it. Worth remembering that one of the first ever turbocharged production cars was the 1962 Oldsmobile Jetfire, fitted with a 3.5-litre V8 that was the very close ancestor of the Rover V8 - so history is on your side with that one too. 
The Rover V8 must be one of the most cylinder head restricted engines still on the road today - the fact that we basically doubled Land Rover's 190bhp figure for a naturally aspirated 4-litre engine is proof of that! With most other naturally aspirated engines you have to do a hell of lot of work for a small gain in performance.
Forced induction is a completely valid way of overcoming the restrictive heads in the pursuit of performance but I do love the experience of the Rover V8 pulling hard to a 7,000+ rpm redline and am sure that the additional 1000rpm or more makes a significant difference to real-world performance. I do agree that it makes it a bit ridiculous on the road however - you only need two gears to easily exceed the speed limit on a dual carriage-way, leaving the other three gears as overdrive gears! Itching to get the car on track sooner rather than later.
900T-R - the Wildcat heads are heavier, the castings are more substantial than the Rover heads with much more material in the deck face. The intake manifolds we use are all aluminium, so not much weight difference there. I will weigh both the Rover and Wildcat heads to see what the weight difference is when I get a moment. Please get in touch if you want any application specific info
Back to the OP - the 4.6 or 4.8-litre engines will give you the smoothest running and most reliable engine for the lowest cost in the 250-300bhp range.
You would also need to decide whether you are happy with 250bhp or actually 'need' 300bhp as this will also guide your engine spec. If you wish to keep the 4-litre and will be content long-term with 250bhp, then a cam and aftermarket engine management will get you there. If you actually want 300bhp then a bigger engine, forced induction or aftermarket heads would be your realistic options.
The Rover V8 must be one of the most cylinder head restricted engines still on the road today - the fact that we basically doubled Land Rover's 190bhp figure for a naturally aspirated 4-litre engine is proof of that! With most other naturally aspirated engines you have to do a hell of lot of work for a small gain in performance.
Forced induction is a completely valid way of overcoming the restrictive heads in the pursuit of performance but I do love the experience of the Rover V8 pulling hard to a 7,000+ rpm redline and am sure that the additional 1000rpm or more makes a significant difference to real-world performance. I do agree that it makes it a bit ridiculous on the road however - you only need two gears to easily exceed the speed limit on a dual carriage-way, leaving the other three gears as overdrive gears! Itching to get the car on track sooner rather than later.
900T-R - the Wildcat heads are heavier, the castings are more substantial than the Rover heads with much more material in the deck face. The intake manifolds we use are all aluminium, so not much weight difference there. I will weigh both the Rover and Wildcat heads to see what the weight difference is when I get a moment. Please get in touch if you want any application specific info
Back to the OP - the 4.6 or 4.8-litre engines will give you the smoothest running and most reliable engine for the lowest cost in the 250-300bhp range.
You would also need to decide whether you are happy with 250bhp or actually 'need' 300bhp as this will also guide your engine spec. If you wish to keep the 4-litre and will be content long-term with 250bhp, then a cam and aftermarket engine management will get you there. If you actually want 300bhp then a bigger engine, forced induction or aftermarket heads would be your realistic options.
[quote=motul1974]
Back in the day I had a 4.5 TT and to top it off I 'acquired' a genuine land rover plenum with 4.5 cast into the lid. I can only assume it came from a development project before they settled on 4.6 engines.
Sadly, I had to sell it when my engine became a 5.0 TT. It forced me to make my own plenum for willy waving purposes.
Back in the day I had a 4.5 TT and to top it off I 'acquired' a genuine land rover plenum with 4.5 cast into the lid. I can only assume it came from a development project before they settled on 4.6 engines.
Sadly, I had to sell it when my engine became a 5.0 TT. It forced me to make my own plenum for willy waving purposes.
It would be interesting to see your 4.1 Wildcat at Cadwell Park for the TVR Car Club track day towards the end of May, and compare its performance with my 4.6T and Phazed's 5.5 NA. Though I guess you are nearer Castle Combe than Cadwell Park.
If you and Heath Briggs are there (he has threatened to come) I might even be able to get Mat Smith along in his S or his race car.
If you and Heath Briggs are there (he has threatened to come) I might even be able to get Mat Smith along in his S or his race car.
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