Discussion
In the near future my T5 box is coming out for an S10 upgrade, coupled with an overhaul of the box to rectify some bearing noise and worn synchro on first.
While I was searching out bits for this job, I tripped over a web site which listed the different specs for the T5s fitted in various vehicles.
Which is where I became aware of the availability of a range of alternative 5th cog sets. So I made some enquiries and discovered that fitting a 0.63 fifth as opposed to the standard 0.73 is not that unusual a conversion on the continent, particularly in Germany, presumably for Chimaera/Griffith owners who clock up a lot of Autobahn miles.
With my current standard gear set, 4th will get me to around 107mph at 5000rpm and then when I change to 5th I drop back on about 3600rpm. With a 0.63 5th, this would reduce to 3150rpm - which according to the Lloyd’s dyno chart for my car is still around 220lbs/ft (peak is 232@4000rpm)
My current fifth ratio of 0.73 results in just over 2700 rpm at 80mph, whereas the 0.63 cogs would drop that to 2350rpm at a shade under 200lbs/ft - which is around 13% fewer revs and presumably quite a reduction in fuel consumption, wear and tear on the oily bits and overall noise on the boring straight straight stuff we have to endure on our way to TVR friendly roads.
I appreciate this would be a no-no for a track day car and probably also for those with more peaky engines but for a squirting and touring road car, I thought it might be worth considering.
Is it that simple? - keep the standard 1st, 2nd, 3rd and 4th for the fun stuff and then drop into a long 5th for the motorway. Has anybody done this?
The calculations make it look interesting - but I’m concerned I might be missing something.
If this is a goer, it would make a lot of sense to do it when the box comes out for its rebuild - but I don’t want to wind up with more relaxed cruising at the expense of needing to change down every time I come to a slight incline.
My engine is a bit more developed than a standard 400, putting out around 250bhp (flywheel) and this winter will get another boost when it gets a hotter cam and moves up to a 4.8 short stroke bottom end. I mention this in case it’s borderline with a standard 400, but do-able with a little bit more grunt.
Malcolm
While I was searching out bits for this job, I tripped over a web site which listed the different specs for the T5s fitted in various vehicles.
Which is where I became aware of the availability of a range of alternative 5th cog sets. So I made some enquiries and discovered that fitting a 0.63 fifth as opposed to the standard 0.73 is not that unusual a conversion on the continent, particularly in Germany, presumably for Chimaera/Griffith owners who clock up a lot of Autobahn miles.
With my current standard gear set, 4th will get me to around 107mph at 5000rpm and then when I change to 5th I drop back on about 3600rpm. With a 0.63 5th, this would reduce to 3150rpm - which according to the Lloyd’s dyno chart for my car is still around 220lbs/ft (peak is 232@4000rpm)
My current fifth ratio of 0.73 results in just over 2700 rpm at 80mph, whereas the 0.63 cogs would drop that to 2350rpm at a shade under 200lbs/ft - which is around 13% fewer revs and presumably quite a reduction in fuel consumption, wear and tear on the oily bits and overall noise on the boring straight straight stuff we have to endure on our way to TVR friendly roads.
I appreciate this would be a no-no for a track day car and probably also for those with more peaky engines but for a squirting and touring road car, I thought it might be worth considering.
Is it that simple? - keep the standard 1st, 2nd, 3rd and 4th for the fun stuff and then drop into a long 5th for the motorway. Has anybody done this?
The calculations make it look interesting - but I’m concerned I might be missing something.
If this is a goer, it would make a lot of sense to do it when the box comes out for its rebuild - but I don’t want to wind up with more relaxed cruising at the expense of needing to change down every time I come to a slight incline.
My engine is a bit more developed than a standard 400, putting out around 250bhp (flywheel) and this winter will get another boost when it gets a hotter cam and moves up to a 4.8 short stroke bottom end. I mention this in case it’s borderline with a standard 400, but do-able with a little bit more grunt.
Malcolm
Brerabit said:
In the near future my T5 box is coming out for an S10 upgrade, coupled with an overhaul of the box to rectify some bearing noise and worn synchro on first.
While I was searching out bits for this job, I tripped over a web site which listed the different specs for the T5s fitted in various vehicles.
Which is where I became aware of the availability of a range of alternative 5th cog sets. So I made some enquiries and discovered that fitting a 0.63 fifth as opposed to the standard 0.73 is not that unusual a conversion on the continent, particularly in Germany, presumably for Chimaera/Griffith owners who clock up a lot of Autobahn miles.
With my current standard gear set, 4th will get me to around 107mph at 5000rpm and then when I change to 5th I drop back on about 3600rpm. With a 0.63 5th, this would reduce to 3150rpm - which according to the Lloyd’s dyno chart for my car is still around 220lbs/ft (peak is 232@4000rpm)
My current fifth ratio of 0.73 results in just over 2700 rpm at 80mph, whereas the 0.63 cogs would drop that to 2350rpm at a shade under 200lbs/ft - which is around 13% fewer revs and presumably quite a reduction in fuel consumption, wear and tear on the oily bits and overall noise on the boring straight straight stuff we have to endure on our way to TVR friendly roads.
I appreciate this would be a no-no for a track day car and probably also for those with more peaky engines but for a squirting and touring road car, I thought it might be worth considering.
Is it that simple? - keep the standard 1st, 2nd, 3rd and 4th for the fun stuff and then drop into a long 5th for the motorway. Has anybody done this?
The calculations make it look interesting - but I’m concerned I might be missing something.
If this is a goer, it would make a lot of sense to do it when the box comes out for its rebuild - but I don’t want to wind up with more relaxed cruising at the expense of needing to change down every time I come to a slight incline.
My engine is a bit more developed than a standard 400, putting out around 250bhp (flywheel) and this winter will get another boost when it gets a hotter cam and moves up to a 4.8 short stroke bottom end. I mention this in case it’s borderline with a standard 400, but do-able with a little bit more grunt.
Malcolm
got a link to the website?While I was searching out bits for this job, I tripped over a web site which listed the different specs for the T5s fitted in various vehicles.
Which is where I became aware of the availability of a range of alternative 5th cog sets. So I made some enquiries and discovered that fitting a 0.63 fifth as opposed to the standard 0.73 is not that unusual a conversion on the continent, particularly in Germany, presumably for Chimaera/Griffith owners who clock up a lot of Autobahn miles.
With my current standard gear set, 4th will get me to around 107mph at 5000rpm and then when I change to 5th I drop back on about 3600rpm. With a 0.63 5th, this would reduce to 3150rpm - which according to the Lloyd’s dyno chart for my car is still around 220lbs/ft (peak is 232@4000rpm)
My current fifth ratio of 0.73 results in just over 2700 rpm at 80mph, whereas the 0.63 cogs would drop that to 2350rpm at a shade under 200lbs/ft - which is around 13% fewer revs and presumably quite a reduction in fuel consumption, wear and tear on the oily bits and overall noise on the boring straight straight stuff we have to endure on our way to TVR friendly roads.
I appreciate this would be a no-no for a track day car and probably also for those with more peaky engines but for a squirting and touring road car, I thought it might be worth considering.
Is it that simple? - keep the standard 1st, 2nd, 3rd and 4th for the fun stuff and then drop into a long 5th for the motorway. Has anybody done this?
The calculations make it look interesting - but I’m concerned I might be missing something.
If this is a goer, it would make a lot of sense to do it when the box comes out for its rebuild - but I don’t want to wind up with more relaxed cruising at the expense of needing to change down every time I come to a slight incline.
My engine is a bit more developed than a standard 400, putting out around 250bhp (flywheel) and this winter will get another boost when it gets a hotter cam and moves up to a 4.8 short stroke bottom end. I mention this in case it’s borderline with a standard 400, but do-able with a little bit more grunt.
Malcolm
You say it is a no-no for a track day car.....but there are not that many tracks where you use 5th gear, especially in a 4 litre (pardon me if I have read this wrong from your torque figures).
For me (5 litre and driven quite hard), Castle Combe maxes out at 120, which in my car is just under 6000 rpm in 4th, Cadwell Park is 115 mph, I can just about reach 135 mph at Snetterton at the end of the Bentley Straight, so am in 5th, but am only in 4th at the top of the pits straight (120 mph), I guess I might be in 5th at the end of the pits straight at Brands Hatch Indy, never managed to do a TD in the dry there. I did Hullavington the other day and maxed at 120 in 4th, etc etc. Frankly, it is not worth changing into 5th just before the end of the straight at most tracks - it just gives you two downshifts in the braking zone, unsettling the car before turning in.
Contrary to popular belief, you don't end up maxing the car at most race circuits, the interesting ones are those with bends!
For me (5 litre and driven quite hard), Castle Combe maxes out at 120, which in my car is just under 6000 rpm in 4th, Cadwell Park is 115 mph, I can just about reach 135 mph at Snetterton at the end of the Bentley Straight, so am in 5th, but am only in 4th at the top of the pits straight (120 mph), I guess I might be in 5th at the end of the pits straight at Brands Hatch Indy, never managed to do a TD in the dry there. I did Hullavington the other day and maxed at 120 in 4th, etc etc. Frankly, it is not worth changing into 5th just before the end of the straight at most tracks - it just gives you two downshifts in the braking zone, unsettling the car before turning in.
Contrary to popular belief, you don't end up maxing the car at most race circuits, the interesting ones are those with bends!
TBH I did look at this but concluded the following:
1. I feel my current T5 gear ratios are perfectly spaced as they are
2. I enjoy and use my 5th gear flexibility - Modulating speed between 45 & 145mph in 5th is a feature I love and really wouldn't want to lose
3. While I sometimes feel my current 5th gear could be taller I fear a bigger step between 4th & 5th could have a negative impact on my driving pleasure
For the above three reasons I dismissed the taller 5th gear idea fairly early on, as most will know good fuel economy is important to me but what probably gets misunderstood is my much stronger passion for enhancing the car's drivability and the tactile pleasure all the controls of this old school driver's car feed back to me the driver.
Anything that blunts these elements or dulls my pleasure is an absolute sin, on the other hand anything like a lighter flywheel, a better gearbox feel, a lighter clutch or the Holly Grail of throttle response that are throttle bodies must all be explored!
I've nailed the economy aspect and massively enhanced the car's drivability at the same time, so with an average petrol cost equivalent of 45mpg in the bag already my focus of attention becomes enhancing the feel of all the controls and developing the throttle response to give me that
feeling 
.
A taller 5th may give me the petrol cost equivalent of 50mpg, but at what cost just for that extra 5mpg?
The "cake & eat it" solution is clearly a six speed box, I concluded what I really want is the current T5's very well spaced five ratios with the addition of a double overdrive sixth gear that I would only use for high speed cruising.
But fitting a six speed box with perfectly spaced six ratios to a Rover V8 is an expensive business, an unjustifiably expensive business especially when I factored in how often that sixth cog would actually be used!
The next option after I'd dabbled in and rejected the old school idea of a Laycock type overdrive unit is just to effectively raise all five ratios by the same amount to keep their excellent spacing, the way to do this of course does not in fact involve the gearbox at all but the addition of a taller rear diff.
There are a number of guys on here who have done just this with their TVR, according to these chaps fitting a 3.08 diff apparently has no downsides... just benefits.
The Elephant in the room for 'Ol Gasbag' however is her modest output when compared with the guys running this taller diff, I concluded I need at least a 25% increase in power & torque to pull a taller diff, at which point a 3.08 crown wheel & pinion set becomes no brainer (perhaps even essential).
So with driving pleasure always at the forefront of my mind I parked the whole gear ratio project on the grounds of ratio spacing and lack of sufficient power to pull the taller diff, I decided to keep the box ratios and the rear end gears just as they are until I finally develop 'Ol Gasbag' into something that has the power to pull the taller diff.
What I still can't decide on is how I reach my minimum target of 320hp & 320 torques, do I fit the best heads I can and a set of throttle bodies for that delicious throttle response and that feeling .
Or do I fit some form compressor which may not give the yummy throttle response and free revving characteristics of throttle boddies, but would achieve the same or greater power hike for what will almost certainly be the same money (if I go supercharger)... or quite a bit less if I go turbo.
In the end I've decided the "cash for wider grin" ratio is becoming less and less cost effective. Sadly, throttle bodies, fancy heads, blowers and the diff upgrade that will likely need to follow.... are all very expensive things indeed
Then I took 'Ol Gasbag' out for a top down blast in the sun the other day which helped make my mind up on all this, well for a while at least. I pulled an easy 140 leptons on gas, accelerated past too many cars to count, sliced through the gears as I pressed on enjoying a lovely open winding road and even trickled through towns super smoothly modulating my speed between 20-30mph in third like I was driving an auto.
My grin was huge, the sound was glorious, the gear ratios were all absolutely perfect and 140 leptons excluded the 45mpg remained.
My mind was made up, leave her just as she is Dave and enjoy the
At which point I arrived home and immediately set about buying all the bits to complete my super duper dinner plate disc Brembo caliper big brake conversion
1. I feel my current T5 gear ratios are perfectly spaced as they are
2. I enjoy and use my 5th gear flexibility - Modulating speed between 45 & 145mph in 5th is a feature I love and really wouldn't want to lose
3. While I sometimes feel my current 5th gear could be taller I fear a bigger step between 4th & 5th could have a negative impact on my driving pleasure
For the above three reasons I dismissed the taller 5th gear idea fairly early on, as most will know good fuel economy is important to me but what probably gets misunderstood is my much stronger passion for enhancing the car's drivability and the tactile pleasure all the controls of this old school driver's car feed back to me the driver.
Anything that blunts these elements or dulls my pleasure is an absolute sin, on the other hand anything like a lighter flywheel, a better gearbox feel, a lighter clutch or the Holly Grail of throttle response that are throttle bodies must all be explored!
I've nailed the economy aspect and massively enhanced the car's drivability at the same time, so with an average petrol cost equivalent of 45mpg in the bag already my focus of attention becomes enhancing the feel of all the controls and developing the throttle response to give me that
feeling .A taller 5th may give me the petrol cost equivalent of 50mpg, but at what cost just for that extra 5mpg?
The "cake & eat it" solution is clearly a six speed box, I concluded what I really want is the current T5's very well spaced five ratios with the addition of a double overdrive sixth gear that I would only use for high speed cruising.
But fitting a six speed box with perfectly spaced six ratios to a Rover V8 is an expensive business, an unjustifiably expensive business especially when I factored in how often that sixth cog would actually be used!
The next option after I'd dabbled in and rejected the old school idea of a Laycock type overdrive unit is just to effectively raise all five ratios by the same amount to keep their excellent spacing, the way to do this of course does not in fact involve the gearbox at all but the addition of a taller rear diff.
There are a number of guys on here who have done just this with their TVR, according to these chaps fitting a 3.08 diff apparently has no downsides... just benefits.
The Elephant in the room for 'Ol Gasbag' however is her modest output when compared with the guys running this taller diff, I concluded I need at least a 25% increase in power & torque to pull a taller diff, at which point a 3.08 crown wheel & pinion set becomes no brainer (perhaps even essential).
So with driving pleasure always at the forefront of my mind I parked the whole gear ratio project on the grounds of ratio spacing and lack of sufficient power to pull the taller diff, I decided to keep the box ratios and the rear end gears just as they are until I finally develop 'Ol Gasbag' into something that has the power to pull the taller diff.
What I still can't decide on is how I reach my minimum target of 320hp & 320 torques, do I fit the best heads I can and a set of throttle bodies for that delicious throttle response and that
feeling .Or do I fit some form compressor which may not give the yummy throttle response and free revving characteristics of throttle boddies, but would achieve the same or greater power hike for what will almost certainly be the same money (if I go supercharger)... or quite a bit less if I go turbo.
In the end I've decided the "cash for wider grin" ratio is becoming less and less cost effective. Sadly, throttle bodies, fancy heads, blowers and the diff upgrade that will likely need to follow.... are all very expensive things indeed
Then I took 'Ol Gasbag' out for a top down blast in the sun the other day which helped make my mind up on all this, well for a while at least. I pulled an easy 140 leptons on gas, accelerated past too many cars to count, sliced through the gears as I pressed on enjoying a lovely open winding road and even trickled through towns super smoothly modulating my speed between 20-30mph in third like I was driving an auto.
My grin was huge, the sound was glorious, the gear ratios were all absolutely perfect and 140 leptons excluded the 45mpg remained.
My mind was made up, leave her just as she is Dave and enjoy the
At which point I arrived home and immediately set about buying all the bits to complete my super duper dinner plate disc Brembo caliper big brake conversion
Here's the link Discopotatoes
http://www.britishv8.org/Articles/Borg-Warner-T5-I...
If you want a copy of the spreadsheet I put together for calculating road speed against gear ratios at 100rpm intervals let me know and I’ll PM it to you. All you need to do then is change the variables such as tyre diameter and final drive to make it fit your car
http://www.britishv8.org/Articles/Borg-Warner-T5-I...
If you want a copy of the spreadsheet I put together for calculating road speed against gear ratios at 100rpm intervals let me know and I’ll PM it to you. All you need to do then is change the variables such as tyre diameter and final drive to make it fit your car
Some are 0.8 and some are 0.73 and I can't find a definitive answer as to which cars got what. My handbook says 0.73 with a 3.45 final drive. I know the final drive is correct because that's been confirmed on a Dynapack dynamometer which bolts directly on to the back axle.This eliminates any variables such as wheel spin, tyre growth etc. and calculates the ratio from the actual engine speed and the precise axle revs. In fact it calculates that the overall ratio in 4th is 3.46 which I presume factors in any rounding up or down with the real world gearbox and diff ratios. I'm fairly sure I read somewhere - don't ask me where - that our 4th isn't exactly 1:1 but is 1.01.
Forth gear simply locks the input shaft to the output shaft so it's exactly 1:1. In fact you could strip every gear in the box of its teeth and you would still have forth ( doesn't use any gearing at all) it's probably just rounding of the crown wheel to pinion ratio that you are seeing?
Thanks Neville
You’ve helped me on two scores:
First, I now understand a little bit more about the way gearboxes work, which although I understand the basic principles, still find worryingly complex.
…and secondly, I can stop racking my brains as to where I read about the 1.01 bo**ox.
Malcolm
You’ve helped me on two scores:
First, I now understand a little bit more about the way gearboxes work, which although I understand the basic principles, still find worryingly complex.
…and secondly, I can stop racking my brains as to where I read about the 1.01 bo**ox.
Malcolm
I agree with everything you said Dave… almost.
I think we’re both striving for a similar end result, that is to make our cars as efficient, entertaining and engaging as possible - even if we know, deep down, we’re never actually going to get there.
There’ll always be yet one more tweak that we need to make it perfect.
I started out thinking that I should be aiming for some some arbitrary bhp number. The trouble with that approach was - what was the number?
The more I thought about it, the bigger the number got - and what would be the trade-offs. Apart from the cost of the engine upgrade, what other upgrades would I need to support it? What would be the effect on drivability, reliability?
As you know, when I raised the subject on here it was Qbee who brought me up short by asking what I was going to do with tarmac shredding power and more to the point - where was I going to use it. So I started rethinking it.
Sure, I love the power to weight ratio I’ve got and the way it converts other cars to vibrating little dots in the rear view mirror. But I also love the other sensory pleasures like the noises (well, most of them) and all the other feedback. By going over to the CANEMS, upgrading the heads and induction, re-bushing all of the undercarriage, fitting Gaz Monos, SP12s and better brakes - all these have substantially and incrementally improved the immense pleasure I get from driving this car. Add to that the next jobs I’ve got planned over the next few weeks to improve the gearshift to make it more ‘snickety’ and precise, lightening the flywheel to improve throttle response and spin-up and I shall soon be getting close to chasing the laws of diminishing returns.
There is one more significant upgrade on the horizon but only because I feel that I will need to address the bottom end sooner or later from a reliability perspective. So I’ll probably make it sooner and at the same time move the capacity up with a short stroke 4.8 and possibly a slightly warmer cam. Not to achieve a specific bhp but simply to have a stronger, more reliable, more responsive engine - and yes, a little bit more grunt.
Love the idea of a Laycock overdrive. Had one on a ’68 SE4B Scimitar Coupe with a ‘breathed on’ 3 Litre Essex. The standard 4 speed box was a little widely spaced but with the optional Laycock overdrive on 2nd, 3rd, and 4th you effectively had three extra ‘half’ gears plus overdrive i.e. a close ratio seven speed box. Even better when I moved it from a column stalk to a Bond style ejector switch on the gear knob.
As for the longer 5th, I’m still undecided. A 3.08 diff is only fractionally shorter with the standard 5th than the 0.63 cogs option, I think there’s about 50rpm in it, so the overall result on cruising is fairly similar. The downside is that although going to the 3.08 diff keeps the ratio spread the same across all five gears, which is a good thing - unless you’ve got the mythical 300bhp+ to pull it through every gear, you’re knocking back your overall responsiveness. Whereas by only making 5th longer, you keep it all as it was, to well over 100mph - and even then, although it’s a bigger jump to 5th, you’re still dropping back nicely ’onto the cam’ at just over 3000rpm.
That’s the theory anyway - but am I missing something - does the theory pan out - or do I run the risk of spoiling something that was almost there but just a bit too busy on the motorway.
Malcolm
I think we’re both striving for a similar end result, that is to make our cars as efficient, entertaining and engaging as possible - even if we know, deep down, we’re never actually going to get there.
There’ll always be yet one more tweak that we need to make it perfect.
I started out thinking that I should be aiming for some some arbitrary bhp number. The trouble with that approach was - what was the number?
The more I thought about it, the bigger the number got - and what would be the trade-offs. Apart from the cost of the engine upgrade, what other upgrades would I need to support it? What would be the effect on drivability, reliability?
As you know, when I raised the subject on here it was Qbee who brought me up short by asking what I was going to do with tarmac shredding power and more to the point - where was I going to use it. So I started rethinking it.
Sure, I love the power to weight ratio I’ve got and the way it converts other cars to vibrating little dots in the rear view mirror. But I also love the other sensory pleasures like the noises (well, most of them) and all the other feedback. By going over to the CANEMS, upgrading the heads and induction, re-bushing all of the undercarriage, fitting Gaz Monos, SP12s and better brakes - all these have substantially and incrementally improved the immense pleasure I get from driving this car. Add to that the next jobs I’ve got planned over the next few weeks to improve the gearshift to make it more ‘snickety’ and precise, lightening the flywheel to improve throttle response and spin-up and I shall soon be getting close to chasing the laws of diminishing returns.
There is one more significant upgrade on the horizon but only because I feel that I will need to address the bottom end sooner or later from a reliability perspective. So I’ll probably make it sooner and at the same time move the capacity up with a short stroke 4.8 and possibly a slightly warmer cam. Not to achieve a specific bhp but simply to have a stronger, more reliable, more responsive engine - and yes, a little bit more grunt.
Love the idea of a Laycock overdrive. Had one on a ’68 SE4B Scimitar Coupe with a ‘breathed on’ 3 Litre Essex. The standard 4 speed box was a little widely spaced but with the optional Laycock overdrive on 2nd, 3rd, and 4th you effectively had three extra ‘half’ gears plus overdrive i.e. a close ratio seven speed box. Even better when I moved it from a column stalk to a Bond style ejector switch on the gear knob.
As for the longer 5th, I’m still undecided. A 3.08 diff is only fractionally shorter with the standard 5th than the 0.63 cogs option, I think there’s about 50rpm in it, so the overall result on cruising is fairly similar. The downside is that although going to the 3.08 diff keeps the ratio spread the same across all five gears, which is a good thing - unless you’ve got the mythical 300bhp+ to pull it through every gear, you’re knocking back your overall responsiveness. Whereas by only making 5th longer, you keep it all as it was, to well over 100mph - and even then, although it’s a bigger jump to 5th, you’re still dropping back nicely ’onto the cam’ at just over 3000rpm.
That’s the theory anyway - but am I missing something - does the theory pan out - or do I run the risk of spoiling something that was almost there but just a bit too busy on the motorway.
Malcolm
For road use, I keep wishing for a longer 5th gear, with no exceptions. Its the drone at motorway cruising speeds at around 2750-3000 rpm (73-80 mph) that is so dreary. My son-in-law's diseasel Saab 9-3 cruises at 85 mph at 2000 rpm, so much nicer. It's not as if you are trying for max acceleration at 70 in 5th - if you want to whip past someone you just drop down a gear or two and floor it. As already said, you rarely use 5th on a track.
Your comment about upgrading to a 4.8 tells me that you will have around 300 bhp normally arspirated. The single thing that has given me so much more pleasure from my 5 litre engine than from my old 4 litre is not the extra 100 bhp, strangely enough. It's the torque curve, well over 300 torques from 1500-5500 rpm. My car PULLS so well in all gears, pulls out of corners and has so much grunt. Ignore the BHP line, that gets you to the end of the straight slightly faster, but the torque curve gets you accelerating so much better out of the previous bend in the first place.
When I asked for more power, what I actually wanted but didn't realise it was more grunt, more torque, more pulling power (but not in a teenage t
t sort of way). Luckily I discussed my wishes with a talented TVR guy and also with a talented engine builder, and what I got was what I actually wanted. My 5 litre has a stealth cam , by the way, and was built by V8 Developments, so is cross bolted and internally balanced.
Here are the BHP and torque curves:
Try to aim for as wide a torque band as possible and you won't be disappointed.
Your comment about upgrading to a 4.8 tells me that you will have around 300 bhp normally arspirated. The single thing that has given me so much more pleasure from my 5 litre engine than from my old 4 litre is not the extra 100 bhp, strangely enough. It's the torque curve, well over 300 torques from 1500-5500 rpm. My car PULLS so well in all gears, pulls out of corners and has so much grunt. Ignore the BHP line, that gets you to the end of the straight slightly faster, but the torque curve gets you accelerating so much better out of the previous bend in the first place.
When I asked for more power, what I actually wanted but didn't realise it was more grunt, more torque, more pulling power (but not in a teenage t
t sort of way). Luckily I discussed my wishes with a talented TVR guy and also with a talented engine builder, and what I got was what I actually wanted. My 5 litre has a stealth cam , by the way, and was built by V8 Developments, so is cross bolted and internally balanced.Here are the BHP and torque curves:
Try to aim for as wide a torque band as possible and you won't be disappointed.
Brerabit said:
Malcolm speaks many wise words
As does Anthony...QBee said:
Try to aim for as wide a torque band as possible and you won't be disappointed.
In response to Anthony's intelligent observation I find myself once more magnetically drawn back to the almost irresistible pull of a lovely supercharger kit.But I'm just a humble salesman with a house inside the M25 and the matching mortgage to go with it, what with that and holidays with the wife plus trips to Le Mans with the boys, my poor little piggy bank tends to run and hide under the couch every time I utter the word "Rotrex ".
I'd always be fearful forced induction like drugs could deliver a short term high then leave me penniless in the gutter facing a big rehab bill, or in this case as I struggle to find the funds to rebuild my engine.
I'm then reminded what I have already is a rapid classic that serves up smiles like a school dinner lady serves up chips. Then I think back to the car I had most fun in all my life and always return to thoughts of twisty roads trying to tame the swing axle on my 948cc twin carb Herald convertible.
Laying it's mighty 45hp to the pavement this frisky little creature with a bite in it's tail gave me pleasure so beyond what the tiny power output suggested I can't begin to describe it. Or was the best car the 30hp Citroen Diane with it's rolly polly ways and quarter lights that stuck out like the ears of happy dog with his head out of the window of a moving car.
Actually I think is was the 37hp 850 Mini that ate exhaust valves like it was popping smarties, but when running on song would scurry about with such flat handling you could outpace most things twice its size and four times its power as it left a trail of burning engine oil smoke behind it.
So my top three owned cars of all time that I remember most fondly all had under 50hp, and here we are discussing how I just can't live without adding another 100 ponies to 'Ol Gasbag's' current corral of 250 prime stallions.
All I'm saying is sometimes less is more....
And sometimes we become gluttons and stuff our faces, only to find we really should have stayed at the salad bar.....
If you change just the fifth gear when you change from fourth two fifth the engine will not pick up quick enough ,a bit of a dead spot .
The only answer is slightly higher gears all the way through .. I would like to cruise around 70mph at around 2200rpm not 2700rpm which is ridiculous .
The only answer is slightly higher gears all the way through .. I would like to cruise around 70mph at around 2200rpm not 2700rpm which is ridiculous .
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