Dyno Disappointment

[Koo]

I have recently bought a new Cerbera 4.5 only find out today it only has 320 BHP and 328 LBS/FT Torque; what's up with that?

In my opinion that is grossly under powered as so far as the quotes from the manufacturers say. Is there something wrong with my car or is this standard? Nevertheless it’s not acceptable I feel cheated. I will be having some serious words with the dealer tomorrow. I'm severely p****d off!!! I can live with 10 or 20 BHP below but 100 less!!!!

[mudstud]

Demand your money back or get a 25% refund on account of the 25% power drop! I'll leave it to others to say if this is 'normal'.

[AJLintern]

I think the 420 BHP quoted is actually Blackpool Horse Power...
:justthoughti'dgetthatoneinbeforesomeoneelsedoes:

[Sparks]

Was that at the wheels or a corrected figure?

If it was an at the wheels value, then it could be 'corercted' by up to 25% to give the flywheel figure.

The TVR quoted value will be minus ancilaries (air con PAS) which will also make a difference.

Also search for previous threads on 'lack of power'

Sparks

[olly]

Question : At the end of the day, does your car out perform everything else on the road ?

Answer : Yes

Reply : Don't worry about the rolling road figure then ! It's still the same cracking car, and still 8100dy fast !

It's a well know fact on these forums that 4.5 Cerbera's are particularly bad at making their claimed BHP (for some reason 4.2's are better), but the speed 6 is pretty much bang on. But the 4.5 will still leave a speed 6 on an airfield day, so don't worry about it !

[dannylt]

Search for previous threads on the issue, but 320 does seem at the lowish end of normal. Might be worth taking to a specialist to make sure it's running properly. The highest unmodified cars (4.2 & 4.5) are around 350 to 360.

[tbloke99]

When I got my 2001 4.5 dyno'd 2 or 3 months ago, I also was very disapointed with the outcome. My figures were very similar to the ones you got. I know people say "could you use the full 420bhp everyday" but this is not the point. Blackpool should revise their figures to give people a true idea of what they are actually buying and to avoid disapointments like this when the dyno operator asks "what are you expecting?".

[jamer]

olly said:

Question : At the end of the day, does your car out perform everything else on the road ? Answer : Yes Reply : Don't worry about the rolling road figure then ! It's still the same cracking car, and still 8100dy fast ! It's a well know fact on these forums that 4.5 Cerbera's are particularly bad at making their claimed BHP (for some reason 4.2's are better), but the speed 6 is pretty much bang on. But the 4.5 will still leave a speed 6 on an airfield day, so don't worry about it !

Spot on

[jamie mackay]

olly said:

Question : At the end of the day, does your car out perform everything else on the road ? Answer : Yes Reply : Don't worry about the rolling road figure then ! It's still the same cracking car, and still 8100dy fast ! It's a well know fact on these forums that 4.5 Cerbera's are particularly bad at making their claimed BHP (for some reason 4.2's are better), but the speed 6 is pretty much bang on. But the 4.5 will still leave a speed 6 on an airfield day, so don't worry about it !

Olly, if the speed sixes are bang on (think they are meant to be 360bhp) and the 4.2's and 4.5's are not meeting there quoted outputs does it not mean the whole range of cerbies are outputing similar bhp's?????

[olly]

Correct ! ?????

BUT, that said, the 4.5 is quickest at airfield days, shortly followed by the 4.2, and then the speed 6, so they perform in real life, as the "paper power" suggests they should....

[alex200mph]

Just a question:
What standards do TVR quote their powers to?
DIN? which I believe is with ancilaries etc as it would be installed in the car with respect to exhaust etc.
SAE? the old yank standard which I belive meant that cars tested against this standard had inflated power outputs due to the fact that they were tested in ideal conditions without ancilaries.
Or no standard? just make the figues up...

Anyway whatever the arguments about the power of particular cars, provided they are running well they are always bloody fast.

Cheers
Alex

>> Edited by alex200mph on Wednesday 3rd September 12:59

[admiral]

This doesn't really stack up. The car's the same, the bhp/torque figures are the same. Why the difference then?

Gear ratios?

More torque throughout the rev range with the V8s?

[dannylt]

Ram air?

Personally, I believe it's because only a few of speed 6's have been tested. They might not have been representative.

[Koo]

Sparks... that was the corrected figure.

Olly... with respect, part of buying this car was the fact it had 420 or there abuts. Before this I had an M3 Evo the manufacturer states 321, I had it dyno’ed and I was getting 320 BHP, before that I had an Audi S2, manufacture states 220 BHP, it dyno’ed at 228 BHP.

Granted it is fast, and the debate is not the speed. The argument is: The consumer when buying a car is able to make an informed decision and not to be misled.

When I buy a six pack of beer I expect six cans not four, I don’t want to be told how great the beer is to compensate for the missing two.

However even the high 300 would have been more acceptable but low 3’s, that’s bs.

I am even thinking of handing the car back.

Thanks for everyone’s comments, much appreciated.

[gixxer1000]

Koo, I for one feel you have a good point. It's not about the extra speed/power that 420bhp would actually bring, it's rather disappointing to feel misled.

I have a 2000, Cerbera 4.5 LW, and had planned to put it on a Dyno. Was advised against it as I would only come away unhappy!

The car is fast, blisteringly fast, and in another world to the Chimaeras I had beforehand, but what gives with quoting 60-100BHP more than they actually produce?

Much of it stems from measurement techniques I would imagine, but if TVR can get the BHP figures more or less correct for the Speed 6, then what's the problem with the AJP8?

I also ride motorbikes and anyone who does will also recognise the large discrepancies often quoted for BHP on bikes. Pick up any 2 bike magazines and look at the new bikes section - I bet you'll struggle to find the same bike quoted with the same BHP in any 2 magazines. My own bike is usually listed as having something between 120-125bhp, whilst the manufacturer claims 141bhp! So it's not just a TVR thing.

[Tam Lin]

Koo said:

Sparks... that was the corrected figure. Before this I had an M3 Evo the manufacturer states 321, I had it dyno’ed and I was getting 320 BHP

Hi there:
1) You were lucky with the M3. One I've seen on a RR was 300 BHP & whilst that is close to the published figure, the car may weigh a little bit more than the published figure
2) FYI there's a great article in "Sprint", the TVR Club mag this month, on this very topic. Like you, the author was disappointed when he got a 4.5 which didn't outperform his earlier 4.2. He had the RedRose pack fitted (as had DannyLT, when he had his Cerb), and is now a happier bunny.

Don't give up on the car. We've got a 4.2 (336 bhp and 298 ft/lb corrected at PowerEngineering RR), and the more you get to know it, the better the Cerb seems. In the 4.5 you get better brakes than in the 4.2, and you get the option of upgrading to Red Rose spec, which I am led to believe is "difficult" for us 4.2 lot.
S

As regards the point why Speed 6's seem slower, doesn't the S6 engine weigh more than the AJP8?

[rjben]

Koo said:

Sparks... that was the corrected figure. Olly... with respect, part of buying this car was the fact it had 420 or there abuts. Before this I had an M3 Evo the manufacturer states 321, I had it dyno’ed and I was getting 320 BHP, before that I had an Audi S2, manufacture states 220 BHP, it dyno’ed at 228 BHP. Granted it is fast, and the debate is not the speed. The argument is: The consumer when buying a car is able to make an informed decision and not to be misled. When I buy a six pack of beer I expect six cans not four, I don’t want to be told how great the beer is to compensate for the missing two. However even the high 300 would have been more acceptable but low 3’s, that’s bs. I am even thinking of handing the car back. Thanks for everyone’s comments, much appreciated.

Dam right! I could not agree more with this. I'll agree that a cerbie is fast enough irrespective of 'claimed' power output, but I hate the way that most TVR owners seem to be prepared to accept sub standard quality of products and inaccurate claims just because it’s a TVR. IMHO this is why TVR seem slow to improve their general standards.

I may be wrong but I’m sure I’ve read somewhere that they are way off with their car’s weights as well. Yep, article in Evo comparing 4.5 LW against Brabus Merc,. They weighed LW and it was laughably off the claimed weight I think. Can anybody confirm this?

Don’t get me wrong, I love TVR’s more than any other marque and applaud PW’s power / weight /style / price philosophy. I think I would applaud it more if I didn’t have to provide explanations to others about power and reliability issues…….Hmmm, they all do that, it’s a TVR you know!

Sorry, rant over,

Rob

[Koo]

It seems unfair that I would have to spend an extra £2,350 or more to attain less BHP than I originally bargained for without the Red Rose option. With respect that’s a p*** take.

I know everyone in here is an avid TVR aficionado, Nevertheless a p*** take is a p*** take. And for me to get less than the bottom of the range Cerbera (no malice intended to the 4.0 & 4.2 owners) is a p*** take.

I just don’t think this is acceptable given the money I spent on a new car.

“Stand up for what you believe in, even if you’re standing alone.”

[FourWheelDrift]

Nothing new or unheard of I'm afraid.
These are results from a previous group rolling road.

Car Power Torque
Tuscan S6 358 291
Cerbie 4.5 349 301
Cerbie 4.2 340 308
Cerbie 4.5 338 298
Cerbie 4.5 335 304
Cerbie 4.2 333 305
Cerbie 4.5 333 288
Cerbie 4.2 332 309
Cerbie 4.5 319 295
Cerbie 4.5 315 292
Cerbie 4.5 313 308
Cerbie 4.2 310 285
Cerbie 4.2 281 227
Griffith 500 247 287

Remember power at the wheels will always be less than at the flywheel.

[sportie]

Surely this is against the Trades Description act and punishable in the court's.

I like the example bought a six pack and got four, but don't complain because the beers excelent.

Take them to court, make Mr Wheeler either deliver what he claims or stop lying about the BHP.