Is my 450 slow ?
Discussion
Took delivery of a 2015 Jaguar XFS last weekend. It has a 3.0 supercharged V6, with a 0-60 time quoted as 5.9secs.
It is quick....very quick. It pulls and pulls and just keeps pulling and doesn't seem to let up, even on a steep hill. Very impressive.
Took it for a run along a route I use regularly in the TVR and from a standing start at a junction, it reached the same speed before braking for the first corner (in the region of 60) as the TVR would.
This begs the question, how can that happen when the TVR is supposed to have a 0-60 time of around 4.7secs ?
Is the 0-60 time quoted completely unrealistic or is my Chimaera down on power ?
It is quick....very quick. It pulls and pulls and just keeps pulling and doesn't seem to let up, even on a steep hill. Very impressive.
Took it for a run along a route I use regularly in the TVR and from a standing start at a junction, it reached the same speed before braking for the first corner (in the region of 60) as the TVR would.
This begs the question, how can that happen when the TVR is supposed to have a 0-60 time of around 4.7secs ?
Is the 0-60 time quoted completely unrealistic or is my Chimaera down on power ?
Difficult to say, as a number of factors would come into play aside from simple power - traction, gearing, final drive ratios, manual vs. auto box (gear change speed), what revs torque is being produced, etc etc.
If you are serious about finding out, a good start would be a power run to help assess engines character and provide clues if there are any issues - obviously to find out the power figure itself, but also max torque, width of torque band, where torque band is in rev range, possibly AFR ratio's if provided etc etc...
HTH,
Dom
If you are serious about finding out, a good start would be a power run to help assess engines character and provide clues if there are any issues - obviously to find out the power figure itself, but also max torque, width of torque band, where torque band is in rev range, possibly AFR ratio's if provided etc etc...
HTH,
Dom
Is yours the Diesel? Otherwise it'll do 0 - 60 in 4.9 not 5.9. Then you have to ask, is my XX yr old chimaera still keeping up with a New Jag with a Supercharged engine? Also the Jag is more powerful overall, so weight will give the chim the initial advantage, but absolute power will make the Jag catch up at higher speeds. Also gear changes, you'll lose pace in the chim if the Jag is Auto. So no the chim isn't slow, the Jag is fast.
Yes it is the diesel and is an auto and it's the older XF (2015) not the newer one, which is slightly quicker.
All good arguments and things like weight and gear changes etc but my thinking was that both cars are reaching around 60 in the same distance and it's a relatively short distance so should both take approximately the same time.
If the TVR was over a second quicker to 60, I would have expected it to be at a higher speed by the corner than the Jag was. No ?
I have had the car on a dyno twice in the 15 years I have had it. The latter time (2015 ish) it had a few runs and the peak bhp results were quite variable so I wasn't sure how reliable they were but the top figure was around 250bhp from memory. I could post the curve if you are able to comment on it for me ?
All good arguments and things like weight and gear changes etc but my thinking was that both cars are reaching around 60 in the same distance and it's a relatively short distance so should both take approximately the same time.
If the TVR was over a second quicker to 60, I would have expected it to be at a higher speed by the corner than the Jag was. No ?
I have had the car on a dyno twice in the 15 years I have had it. The latter time (2015 ish) it had a few runs and the peak bhp results were quite variable so I wasn't sure how reliable they were but the top figure was around 250bhp from memory. I could post the curve if you are able to comment on it for me ?
Edited by taylormj4 on Monday 19th September 14:43
Race them on an open stretch of dual carriage way or something? You and other driver both doing say 30 mph and floor them at the same time to 70mph (Keeping it legal) 
, you just need another driver and a quiet stretch. Then you'll see is there is a difference.
I've only got a 400 and I drove a 650i BMW (2008) 2 days ago and that felt slower (0 - 60 5.2) (Yet effortless) to me, but without being alongside one another it would be hard to tell.
, you just need another driver and a quiet stretch. Then you'll see is there is a difference. I've only got a 400 and I drove a 650i BMW (2008) 2 days ago and that felt slower (0 - 60 5.2) (Yet effortless) to me, but without being alongside one another it would be hard to tell.
Edited by Danattheopticians on Monday 19th September 14:59
s p a c e m a n said:
Tried downloading one of those gps 0-60 app things on your phone and comparing the two cars that way, no idea how accurate they are..
I didn't know these existed? But Sat Nav is a second or 2 behind ie still say 3 - 4 mph when stopped for a bit, so I'd doubt the accuracy, however, the same phone doing the comparisons would still be a fair test even if not the true figures.I've got the torque pro app on my phone for obd2 error codes and it has a gps speed timer, some g force thing and an economy thing where you can make all of the leaves fall off of a picture of a tree if you drive fast enough (don't think that's what you're supposed to do though 
)
No idea if they're accurate because I've never really used them, but there's loads of free drag race timer things in the play store.
)No idea if they're accurate because I've never really used them, but there's loads of free drag race timer things in the play store.
i think the difference is in the launch, when I've seen how they get a manual car off the line to get these 0-60 times, it's pretty brutal where as an auto is just floor it ... I remember reading in autocar that they used to bring up the revs to 4k and sidestep the clutch etc, I've always got my rolling a bit before I give it the beans ..mainly because mine is an old girl .. there must be a bit of time lost if you're showing a bit of sympathy in the launch phase 
With the auto you just floor it, it'll (I guess) manage its own traction and the gear change is probably much quicker than you'll manage on your T5, so.. If you're not getting an optimum start in the TVR (how often do you practice standing starts with it?) and your gear changing isn't as quick as it might be you could easily be leaving a second and a half or so on the table.... (i.e. operator error not quicker/slower car )
)My old 4.6, (275bhp) was I thought, quite fast, in fact it was averagely fast.
5.0's are instantly fast, (torque) then run out of steam.
4.0's really aren't fast. They are moderately quick, smooth and a fun drive. Noticeably slower then the 5.0's, or a good 4.5, (or 4.6).
The gearing on a modern slush box is so low in the lower gears that very respectful 0-60s are easy.
Sooooo, the jag is probably deceptively fast, especially when you take the slow T5 gear changes into consideration.
5.0's are instantly fast, (torque) then run out of steam.
4.0's really aren't fast. They are moderately quick, smooth and a fun drive. Noticeably slower then the 5.0's, or a good 4.5, (or 4.6).
The gearing on a modern slush box is so low in the lower gears that very respectful 0-60s are easy.
Sooooo, the jag is probably deceptively fast, especially when you take the slow T5 gear changes into consideration.
phazed said:
Danattheopticians said:
Phazed: Don't wanna point this one out but BMW 435d is quicker (Slightly) than the 435i.
I actually love a fast diesel, will I go to hell?4.0's are fast - Compared to it's similar competition at least - Honda S2000's, Audi TT's, Porsche Boxster's and Nissan 350z etc
4.5's a little faster than a 4.0
5.0 a noticeable bit quicker than a 4.5.
But also peoples idea of what is fast is subjective and down to experience, so my 4.0 feels very quick to me as it's the only performance car I've owned. Other fast thing I've driven are 0 - 60 in the 6's and been driven in Jaguar XKR 4.2 and that was only quicker than my (Not fast) 4.0 above 85 mph or so. I think that's not bad really.
I will admit I'm used to the speed now but I don't feel I NEED more power but would like to (In a while) have a bit more. But then it becomes addictive.
Iis your 450 slow,,, hmm. Get your phones video camera out, do some 0-60 mph drag starts and then get your stop watch out and check the footage. That will give you an indication of how yours performs.
I've done this in the past and I manage 60 mph in 4.5 seconds but it is a very rough guess.
To get a fast time in the Tvr you've got to be prepared to control wheel spin etc and that's where you loose time, that and gear changes compared to a modern car.
If you've engines done 50,000 + miles then your cam may well be worn thus losing some power.
My 450 with a new cam and Ecu produces around 300 bhp and is almost as fast as a decent standard 500,,, faster actually but a re built 500 will just have the edge on me, we're talking a few yards at the very best over this short distance,
Regardless of the numbers my 450 revs it's tits off very easily at high revs, smoother and less vibration than a 500 (generally) speaking so again probably just as fast, what my 450 lacks is that instant torque low down compared to the 500, this is obvious when pulling out of a slow speed corner in say 3rd gear, the 500 jumps ahead by about a metre then it all levels out again,
The heads on the 500 are probably the biggest advantage, get you 450 heads ported and it should be just about on par, that's assuming your 450 is in good health.
Comparing your Tvr against these modern cars is a little unfair to the Tvr in my opinion, it may not be any faster/ slower but will feel way better in its own way.
The question was is my 450 down on power, what mileage is your 450 at, what air filter and cam etc,
The only way to be sure would be a recent power run on a dyno ( not that cheap)
Or a few timed runs up a drag strip ( cheap) in comparison and a lot more fun.
There's another thread on here about a get together of Tvr boys at Shakespeare raceway near Stratford (Warwickshire)
That would be a perfect opportunity to test your cars speed in safety,,
You'll also have plenty of time to discuss your car with other Tvr nutters who know these engines inside out.
Just a thought
I've done this in the past and I manage 60 mph in 4.5 seconds but it is a very rough guess.
To get a fast time in the Tvr you've got to be prepared to control wheel spin etc and that's where you loose time, that and gear changes compared to a modern car.
If you've engines done 50,000 + miles then your cam may well be worn thus losing some power.
My 450 with a new cam and Ecu produces around 300 bhp and is almost as fast as a decent standard 500,,, faster actually but a re built 500 will just have the edge on me, we're talking a few yards at the very best over this short distance,
Regardless of the numbers my 450 revs it's tits off very easily at high revs, smoother and less vibration than a 500 (generally) speaking so again probably just as fast, what my 450 lacks is that instant torque low down compared to the 500, this is obvious when pulling out of a slow speed corner in say 3rd gear, the 500 jumps ahead by about a metre then it all levels out again,
The heads on the 500 are probably the biggest advantage, get you 450 heads ported and it should be just about on par, that's assuming your 450 is in good health.
Comparing your Tvr against these modern cars is a little unfair to the Tvr in my opinion, it may not be any faster/ slower but will feel way better in its own way.
The question was is my 450 down on power, what mileage is your 450 at, what air filter and cam etc,
The only way to be sure would be a recent power run on a dyno ( not that cheap)
Or a few timed runs up a drag strip ( cheap) in comparison and a lot more fun.
There's another thread on here about a get together of Tvr boys at Shakespeare raceway near Stratford (Warwickshire)
That would be a perfect opportunity to test your cars speed in safety,,
You'll also have plenty of time to discuss your car with other Tvr nutters who know these engines inside out.
Just a thought
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