Discussion
A lot of us this forum have the 400 and a very fine vehicle it is.
However - and I know I’m not alone here - some of us have a hankering for the sheer grunt of the 500 and sooner or later start considering an upgrade - by one means or another - to get us up to that unholy grail of 300BHP - and beyond.
As I understand it - and I’ll be the first to admit that I don’t understand all of it - there are two basic approaches.
Normally aspirated, whereby with capacity increase, improved breathing, valve timing etc. we build an engine capable of sucking enough of the banging mixture in, to produce the power output we’re looking for
Alternatively, there’s forced induction using either a supercharger or turbo-charger to force feed it with air and kid the engine that it’s a lot bigger than it really is.
A tad simplistic I know but it captures the essence of it.
My problem is which way to go and if i’m honest I’m starting out a bit biased - there is a certain purity about ‘naturally aspirated’ that appeals to me - and blowing always strikes me as bit like a boob job - it might get the results but you just ‘feel’ there’s been a bit of cheating going on…
So come on guys put me straight…
I’ve got a new stock cam, fancy top end with Stage III heads, SC Power plenum mods, 71mm throttle and ACT smooth bore, managed very nicely via a CANEMS ECU and according to the Lloyds Dyno is putting out around 250BHP at the flywheel. The engine has done 85k but showing no obvious signs of bottom end wear.
I was seriously considering an ACR short stroke 4.8 bottom end with forged pocketed pistons and a hotter cam but am now wavering - to blow or not to blow- that is the question?
However - and I know I’m not alone here - some of us have a hankering for the sheer grunt of the 500 and sooner or later start considering an upgrade - by one means or another - to get us up to that unholy grail of 300BHP - and beyond.
As I understand it - and I’ll be the first to admit that I don’t understand all of it - there are two basic approaches.
Normally aspirated, whereby with capacity increase, improved breathing, valve timing etc. we build an engine capable of sucking enough of the banging mixture in, to produce the power output we’re looking for
Alternatively, there’s forced induction using either a supercharger or turbo-charger to force feed it with air and kid the engine that it’s a lot bigger than it really is.
A tad simplistic I know but it captures the essence of it.
My problem is which way to go and if i’m honest I’m starting out a bit biased - there is a certain purity about ‘naturally aspirated’ that appeals to me - and blowing always strikes me as bit like a boob job - it might get the results but you just ‘feel’ there’s been a bit of cheating going on…
So come on guys put me straight…
I’ve got a new stock cam, fancy top end with Stage III heads, SC Power plenum mods, 71mm throttle and ACT smooth bore, managed very nicely via a CANEMS ECU and according to the Lloyds Dyno is putting out around 250BHP at the flywheel. The engine has done 85k but showing no obvious signs of bottom end wear.
I was seriously considering an ACR short stroke 4.8 bottom end with forged pocketed pistons and a hotter cam but am now wavering - to blow or not to blow- that is the question?
Unless you really need 350 Bhp etc then keeping it N/A is to my mind far more satisfying, bloody quick but also retains the sound that only a great sucking monster can give,
Mines a deep deep noise when opened up, I wouldn't want to change that for the world,
Unless I want to prove something or really need 400bhp then I'm more than happy with the power in my 4.6,
The fact it's N/A is even better, I don't disagree with blowers etc, love them in fact but for me I'd never really use its potential, I barely do with a very Torqy engine as it is,, get a big bottom end and keep the essence and purity of line yet give it s
t loads more torque, with your heads etc, should be a beaut. If it's blown it's like oh well the engine just relies on that,,
It's a more interesting car N/A I feel.
Mines a deep deep noise when opened up, I wouldn't want to change that for the world,
Unless I want to prove something or really need 400bhp then I'm more than happy with the power in my 4.6,
The fact it's N/A is even better, I don't disagree with blowers etc, love them in fact but for me I'd never really use its potential, I barely do with a very Torqy engine as it is,, get a big bottom end and keep the essence and purity of line yet give it s
t loads more torque, with your heads etc, should be a beaut. If it's blown it's like oh well the engine just relies on that,, It's a more interesting car N/A I feel.
When I was looking for my Chimaera I drove 4, 4.5 & 5 litre. I wanted a TVR so that I could hold my head up in the sportscar world. It didn't matter which engine it had, it only mattered that it was a TVR and a good one to boot. I've owned my 4lt for nearly 14 years and it has served me well, I have never hankered for more. Well maybe for a Sag but that's just a pipe dream
Haha, I've been reading your very interesting points on Chimpongas thread with some amusement Brerabit so I was hoping to provoke some level of reality. 
It's not just when you floor it, it's just there all the time, deep menace, utterly thrilling and points to facts,,,,, power
When blowers take over its all whoosh and smooth a silk but whoosh rather than roar ya fker,,,
Each to there own but I like simple, I like to see the ground in the engine bay,, it's just so much extra stuff and other considerations,, but hey if you want to develop your car then FI isn't a bad thing now is it.
It's not just when you floor it, it's just there all the time, deep menace, utterly thrilling and points to facts,,,,, power
When blowers take over its all whoosh and smooth a silk but whoosh rather than roar ya f
ker,,, Each to there own but I like simple, I like to see the ground in the engine bay,, it's just so much extra stuff and other considerations,, but hey if you want to develop your car then FI isn't a bad thing now is it.
Edited by ClassiChimi on Tuesday 8th March 23:05
It depends on how deep are your pockets and how far you want to go! Bang for your bucks has to be FI and if it's ultimate power you are after FI is the only way! I went the n/a route with my 500 and once your chasing over 300 at the wheels it's very expensive. I would probably recommend FI as it's tried and tested and cheaper but when I had to decide I went n/a because it felt the right way to go!
It's a slippery slope to financial ruin coming on here for advice, piston heads membership should carry a financial health warning. That reminds me, I need to speak with Dom regarding next steps.......
It's a slippery slope to financial ruin coming on here for advice, piston heads membership should carry a financial health warning. That reminds me, I need to speak with Dom regarding next steps.......
To add some numbers to this, to get to a 5 litre NA with your present car and get over 300 BHP will cost you around £7000.
To supercharge the car and get 330-350 BHP will cost you around £3500. Both numbers variable, but the relative proportions are correct.
You are welcome to drive my 5 litre, 315 BHP, 350 torques car if it will help, but my suggestion is ask why you need more power first. I will be using all of it on track on Friday.
To supercharge the car and get 330-350 BHP will cost you around £3500. Both numbers variable, but the relative proportions are correct.
You are welcome to drive my 5 litre, 315 BHP, 350 torques car if it will help, but my suggestion is ask why you need more power first. I will be using all of it on track on Friday.
Very good question Qbee - and I’m struggling for a good answer.
The glib one would be - because I can - in that these cars are so up for it, it’s almost irresistible.
But you make a very good point - why do we do it - and more to the point when do we stop.
In my case I think I was resigned to the fact that sooner or later the bottom end was going to need sorting and that would be an ideal opportunity to up the ante with a capacity increase, warmer cam, etc.. and then, being resigned to that, I was quite prepared to pre-empt the need and do it next winter.
This is all Dave’s fault with his talk about VVT blowers - I’ve been radicalised - I would have been quite content with a solid bottom end and a few extra horses - the man’s a menace.
The glib one would be - because I can - in that these cars are so up for it, it’s almost irresistible.
But you make a very good point - why do we do it - and more to the point when do we stop.
In my case I think I was resigned to the fact that sooner or later the bottom end was going to need sorting and that would be an ideal opportunity to up the ante with a capacity increase, warmer cam, etc.. and then, being resigned to that, I was quite prepared to pre-empt the need and do it next winter.
This is all Dave’s fault with his talk about VVT blowers - I’ve been radicalised - I would have been quite content with a solid bottom end and a few extra horses - the man’s a menace.
You are far from alone in this desire for more "because you can". There are a whole raft of cars out there with super chargers, turbochargers, bigger engines, LS engines etc, some with over 500 BHP and 500 torques.
The most many of those see is a quick burst on a relatively straight bit of A road when PC49 is looking the other way, or the odd continental road trip. Or possibly one trip to the drag strip to see how washable the seats are.
Some do make it to a race track, and give the owner a chance to enjoy the awesome power or break the drive shafts/gearbox/clutch (delete as appropriate). But even with standard power output, that's the only place to spend a day at a time enjoying the power of the car to the full.
Get onto that slippery slope and your cash will go on bigger brakes, rollover protection, better seats and harnesses, track tyres, baffled sump, racing oil, racing brake fluid, oil cooler and then rebuilding the parts of the transmission that go "ouch" at the repeated extra strain.
And then a bigger engine, super charger, turbo charger, LS engine etc.
The most many of those see is a quick burst on a relatively straight bit of A road when PC49 is looking the other way, or the odd continental road trip. Or possibly one trip to the drag strip to see how washable the seats are.
Some do make it to a race track, and give the owner a chance to enjoy the awesome power or break the drive shafts/gearbox/clutch (delete as appropriate). But even with standard power output, that's the only place to spend a day at a time enjoying the power of the car to the full.
Get onto that slippery slope and your cash will go on bigger brakes, rollover protection, better seats and harnesses, track tyres, baffled sump, racing oil, racing brake fluid, oil cooler and then rebuilding the parts of the transmission that go "ouch" at the repeated extra strain.
And then a bigger engine, super charger, turbo charger, LS engine etc.
HEALTH WARNING - forced induction will empty your wallet.
I too had the standard 4 litre but had planned a turbo. That's easy, just find a low mileage car, send it to Powers and there you go. Wrong!!!
You just cannot fit a turbo unless the engine has been stripped and checked or the bearings will dissolve first time you boot it. It is absolutely essential to rebuild the engine if you want it to last more than a lap chasing Qbee. My 50,000 mile engine which seemed perfectly okay was badly worn and the rebuild doubles the cost. The total for my turbo is more than the car cost.
I have not driven a 300+ normally aspirated but, for me at any rate, that kick up the arse when you hit 3,000 rpm is absolutely epic. Contrary to what has been said, I use this to overtake all the time despite my other half's (nickname Handbrake) orders.
This is the seductive Powers turbo upgrade story: http://www.powersperformance.co.uk/upgrades/rv8-tu...
I too had the standard 4 litre but had planned a turbo. That's easy, just find a low mileage car, send it to Powers and there you go. Wrong!!!
You just cannot fit a turbo unless the engine has been stripped and checked or the bearings will dissolve first time you boot it. It is absolutely essential to rebuild the engine if you want it to last more than a lap chasing Qbee. My 50,000 mile engine which seemed perfectly okay was badly worn and the rebuild doubles the cost. The total for my turbo is more than the car cost.
I have not driven a 300+ normally aspirated but, for me at any rate, that kick up the arse when you hit 3,000 rpm is absolutely epic. Contrary to what has been said, I use this to overtake all the time despite my other half's (nickname Handbrake) orders.
This is the seductive Powers turbo upgrade story: http://www.powersperformance.co.uk/upgrades/rv8-tu...
Don't be put off by ''do I need FI if I'm not going to use it all of the time?' The benefits are more far reaching than that. We have no interest in track days, our car is for touring and fast road use and is blown to 450 bhp. So the chances of using all that on a public road are slim (though very tempting) but the benefits are always apparent. The car has so much urge, it pulls from any speed in any gear and with MBE management has a smoothness that would put some moderns to shame. And if you're not in a rush on a motorway 27mpg too, saving fuel for those glorious A roads. It's also very stable on wet roads (as far as any chim is anyway) and I can honestly say it's the best version of this car we've ever had. Not decrying NA obviously but you shouldn't be put off by thoughts of 'it's only of benefit flat out and balls out'.
That's one of the things I love about this forum - people feeling free to express different views on a question like this, without feeling the need to resort to childish abuse of any point of view that doesn't match entirely with their own.
It's your car, OP. Open your wallet, sell the children, remortgage the wife and do to it exactly what floats your boat and have fun. It's a good part of the joy of TVRs.
It's your car, OP. Open your wallet, sell the children, remortgage the wife and do to it exactly what floats your boat and have fun. It's a good part of the joy of TVRs.
lots of good advise...especially the eye watering, wallet weeping route of F.I.
you need to think about the journey as much as the end goal? What i mean by this is do you want a drive in, drive out solution or, do want to progress their?
The progressive modding route is by for the more affordable route although ultimately the most expensive.
Reading your OP, you have already done much of the progressive route (head work and induction mods). The next step is the internals, whether you go N/A or F.I. this needs to happen (F.I. will require a rebuild/refresh if you want it to last long enough to enjoy) and its at this point you need to decide "all in", or "progressive". When budget is limited i would split it into two stages and buy a bespoke "short" engine from V8D or J.E. (other providers are available) as you have good heads. otherwise you will be going down the 4ltr refresh and F.I. package and always wishing you went 5ltr.
Spec- 5.2 litre, have everything balanced internals and externals and install forged pistons and H beam rods. with this package and your existing modified top end its going to be a great N/A engine with MC1 or Stealth cam. (C.R. is the only caveat to this and you will need to know the cc of your heads (10:1 max if you intend F.I. later although 9.35:1 seems to be the sweet spot for F.I. its too low for N/A)
Enjoy and wait for wallet to recover...Now you can go F.I. and the only engine work required is a new cam for F.I.
just my tupence worth
you need to think about the journey as much as the end goal? What i mean by this is do you want a drive in, drive out solution or, do want to progress their?
The progressive modding route is by for the more affordable route although ultimately the most expensive.
Reading your OP, you have already done much of the progressive route (head work and induction mods). The next step is the internals, whether you go N/A or F.I. this needs to happen (F.I. will require a rebuild/refresh if you want it to last long enough to enjoy) and its at this point you need to decide "all in", or "progressive". When budget is limited i would split it into two stages and buy a bespoke "short" engine from V8D or J.E. (other providers are available) as you have good heads. otherwise you will be going down the 4ltr refresh and F.I. package and always wishing you went 5ltr.
Spec- 5.2 litre, have everything balanced internals and externals and install forged pistons and H beam rods. with this package and your existing modified top end its going to be a great N/A engine with MC1 or Stealth cam. (C.R. is the only caveat to this and you will need to know the cc of your heads (10:1 max if you intend F.I. later although 9.35:1 seems to be the sweet spot for F.I. its too low for N/A)
Enjoy and wait for wallet to recover...Now you can go F.I. and the only engine work required is a new cam for F.I.
just my tupence worth
There's something very appealing in a car that can go in so many different directions based on the indervidual owners likes,,,
I realised early on in my Tvr ownership that no car is standard, all are bespoke even from the factory so all we are doing is carrying on the design curve and natural path cars like these would naturally take,
In time we'll have so many indervidual Tvr's with someone's own concepts put to good use, better cars and enhancing the future reputation of the Now Classic Tvr range in the publics mind. Yes the very original cars will be worth a quid but so will the cars that have been developed using known respected tech, it's not rocket science and we are the boys future proofing the Mark.
If I sold my car now to a 1st time Tvr owner,,, he'd have a reliable car for years, he'd have no knowledge or history of the car other than his experience,, which I hope would be second to non,, many cars are at my cars level and far higher so the owners of the future should be very happy indeed.
Slowly the dogs will get re built and turned into good cars,,, but this all costs money, the values now are getting somewhere near what it should be so these mods are feasible to more and more of us,, it's also because with these mods the car should take on a new lease of life and modern science helping out really changes the game.
I dunno about the new Tvr company but we are certainly gaining respect for the mark with our hard work so keep up your responsibility as a Tvr owner to enhance your cars for yourself and the future. We are custodians of very special cars,,
Like an original 3 Wheel Morgan, our cars are funky like few others.
I realised early on in my Tvr ownership that no car is standard, all are bespoke even from the factory so all we are doing is carrying on the design curve and natural path cars like these would naturally take,
In time we'll have so many indervidual Tvr's with someone's own concepts put to good use, better cars and enhancing the future reputation of the Now Classic Tvr range in the publics mind. Yes the very original cars will be worth a quid but so will the cars that have been developed using known respected tech, it's not rocket science and we are the boys future proofing the Mark.
If I sold my car now to a 1st time Tvr owner,,, he'd have a reliable car for years, he'd have no knowledge or history of the car other than his experience,, which I hope would be second to non,, many cars are at my cars level and far higher so the owners of the future should be very happy indeed.
Slowly the dogs will get re built and turned into good cars,,, but this all costs money, the values now are getting somewhere near what it should be so these mods are feasible to more and more of us,, it's also because with these mods the car should take on a new lease of life and modern science helping out really changes the game.
I dunno about the new Tvr company but we are certainly gaining respect for the mark with our hard work so keep up your responsibility as a Tvr owner to enhance your cars for yourself and the future. We are custodians of very special cars,,
Like an original 3 Wheel Morgan, our cars are funky like few others.
vinnie01 said:
Probably sacrilege but, if you get to the stage where chasing numbers is going to be quantities of money with three or more zeros is it cheaper to start looking at other engines LS chevrolet for example or going FI? Not trying to kick the nest just genuinely curious.
I've often asked myself that same question, If you're looking for 450-500 bhp the overall cost is almost identical. And many a time i have regretted my decision to stay RV8 with all the grief it has given me getting there, LSxx would have been so much easier in hind sight. But, now its all working I'm kinda glad i endured the pain cos its still got a Blackpool heart and its STILL a British underdog biting at the heels of the established power units 
........having said which the LS engines and appropriate gearboxes are awesome, rumble along like a V8 should, give huge power and still return decent mpg and long service intervals.
You can get a suitable engine and gearbox for the same as an RV8 engine upgrade.......but by the time you have done all the other mods (exhaust, drive shafts, prop shaft, clutch etc etc etc) and had the whole thing installed and set up, you will be well over £10k out of pocket I believe.
Correct me if I am wrong.
You can get a suitable engine and gearbox for the same as an RV8 engine upgrade.......but by the time you have done all the other mods (exhaust, drive shafts, prop shaft, clutch etc etc etc) and had the whole thing installed and set up, you will be well over £10k out of pocket I believe.
Correct me if I am wrong.
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