Chim 450 Dyno Results
Discussion
Does the output depend on whos rolling road you use ? I was down at Austec with my 450 last week, and came up with 231BHP peak at 5200RPM and peak torque of 248 at 4000RPM - They told me that this is right on the money for a stock 450 thats running well - figures are at the flywheel. Watched them also run up a 400 which was being tornado chipped and that peaked at about 175BHP , again apparently right on the money for a chipped 400. So is their road reading low, are the other roads reading high or what ? Confused thats me !
>> Edited by bigdods on Saturday 30th July 18:44
>> Edited by bigdods on Saturday 30th July 18:44
Power is a function of torque - they are not separate entities. Typically, the higher in the rev range you produce your max torque, and the longer that torque is sustained, the higher your peak power.
That is why my old Honda S2000 produced 237bhp (from 2 litres). From memory, peak torque was in the region of 150lbft, but was produced at 6700rpm (there being another 2000rpm+ in the available rev-range!
Your car is producing higher than average power for 450 - in fact you are in the mid-range for a stock 500. The torque figure, on the other hand looks lowish. BUT the curve appears nice and smooth and torque is sustained well up the rev-range, which is why power is good.
The print-out on my 500 shows a much higher peak torque of 298 lbft, but reached at only 3800 rpm. It then tails off, until at 5000rpm it's developing much the same torque as yours, about 260-odd lb. Which is why my peak power is 268bhp at 5553rpm, in spitting distance of yours.
Just shows the different characteristics of the cars - driven back to back, I suspect yours would feel much more "revvy" than mine, but performance would be near-identical.
That is why my old Honda S2000 produced 237bhp (from 2 litres). From memory, peak torque was in the region of 150lbft, but was produced at 6700rpm (there being another 2000rpm+ in the available rev-range!
Your car is producing higher than average power for 450 - in fact you are in the mid-range for a stock 500. The torque figure, on the other hand looks lowish. BUT the curve appears nice and smooth and torque is sustained well up the rev-range, which is why power is good.
The print-out on my 500 shows a much higher peak torque of 298 lbft, but reached at only 3800 rpm. It then tails off, until at 5000rpm it's developing much the same torque as yours, about 260-odd lb. Which is why my peak power is 268bhp at 5553rpm, in spitting distance of yours.
Just shows the different characteristics of the cars - driven back to back, I suspect yours would feel much more "revvy" than mine, but performance would be near-identical.
SharkyTVR said:
Power is a function of torque - they are not separate entities. Typically, the higher in the rev range you produce your max torque, and the longer that torque is sustained, the higher your peak power.
That is why my old Honda S2000 produced 237bhp (from 2 litres). From memory, peak torque was in the region of 150lbft, but was produced at 6700rpm (there being another 2000rpm+ in the available rev-range!
Your car is producing higher than average power for 450 - in fact you are in the mid-range for a stock 500. The torque figure, on the other hand looks lowish. BUT the curve appears nice and smooth and torque is sustained well up the rev-range, which is why power is good.
The print-out on my 500 shows a much higher peak torque of 298 lbft, but reached at only 3800 rpm. It then tails off, until at 5000rpm it's developing much the same torque as yours, about 260-odd lb. Which is why my peak power is 268bhp at 5553rpm, in spitting distance of yours.
Just shows the different characteristics of the cars - driven back to back, I suspect yours would feel much more "revvy" than mine, but performance would be near-identical.
Bloody good explaination that sharky!
Their have been a couple of mods carried out over the last few months:
Removal of pre cats and installation of sport free flow main cat.
224 cam fitted.
TVR Power Eprom chip.
ACT induction kit with K&N filter.
Magnacore 8.5mm leads.
Flame Thower coil.
daxtojeiro said:
NTEL,
do you have the readout of the lambda for that run? Id love to see what AFR its running at if youve got that info, its on the graph but I cant see the line for it,
Phil
No, sorry. The mechanic who did the run said the fueling was spot on all the way through the range if that helps.
Those figures are incredibly close to what the std car did on Noble's and as i said earlier I suspect they're reading slightly higher now that they've been recalibrated .. so I'd be very disappointed with those figures bearing in mind the mods on your car.
Of course we don't know what the figures were for your car pre-tuning, but if the fuelling is bang on there's precious little else to do except go mapped ignition if you want better hp in this engine spec.
If you were to ask me what i thought of the power in value for money terms based on what you'd got now I'd say it was very poor value for money .. cam / induction / leads etc must be close to 1500 pounds? and it's still only about what a good standard car will make
Of course we don't know what the figures were for your car pre-tuning, but if the fuelling is bang on there's precious little else to do except go mapped ignition if you want better hp in this engine spec.
If you were to ask me what i thought of the power in value for money terms based on what you'd got now I'd say it was very poor value for money .. cam / induction / leads etc must be close to 1500 pounds? and it's still only about what a good standard car will make
trackcar said:
Those figures are incredibly close to what the std car did on Noble's and as i said earlier I suspect they're reading slightly higher now that they've been recalibrated .. so I'd be very disappointed with those figures bearing in mind the mods on your car.
it's still only about what a good standard car will make
Really? Based on my research, this is plumb in healthy 500 territory, not standard 450 territory...
Sharkytvr said:
Those figures are incredibly close to what the std car did on Noble's and as i said earlier I suspect they're reading slightly higher now that they've been recalibrated .. so I'd be very disappointed with those figures bearing in mind the mods on your car.
it's still only about what a good standard car will make
Really? Based on my research, this is plumb in healthy 500 territory, not standard 450 territory...
the hp is what you'd expect forn an average 500, 280ish for a healthy one, but as we know the extra ccs doesn't increase the top end hp much at all anyway .. the midrange on a 500 would hopefully be stronger though .. what would you expect teh cam change / induction to add to an otherwise std 450 then? .. fact is this car only made the same hp as the std 450 on these rollers, that you can't argue?
*have to say though that 260lbs/hp does make for a fast car so i'm sure there's no worries on the performance front.
gerjo said:
If the RR is accurate, which is the big question here since it's very hard to compare between different RR's, I'd say 262 bhp and 266 lbs is pretty good for a 4.5. A good standard 500 would do about 275 bhp and 300 lbs at Austec's.
it's the same rolling road, so a comparison is valid.
Never mind then, it's a good output for sure, just not very good for a tuned engine was what i was saying.
Can't comment on the absolute numbers because I don't know how that RR compares to the ones where mine has been measured, but just looking at the shape of the power curve it looks as if it has a fairly long cam in it. A typical standard power curve for these engines would have slightly more torque than power, and the torque would peak relatively early. Yours seems to be pulling well at the top end, which is consistent with the induction work you've done. For comparision, my Stage III 4.6 with an early ACT induction kit measured 265 bhp / 280 lb-ft with a 218 (a fairly mild fast road cam). Don't read too much into the absolute numbers, but you can see that even here there was more torque than power.
trackcar said:
If you were to ask me what i thought of the power in value for money terms based on what you'd got now I'd say it was very poor value for money .. cam / induction / leads etc must be close to 1500 pounds? and it's still only about what a good standard car will make
£1500? You are miles out mate. The cam was replaced as part of an engine rebuild at TVR Power so the difference between the cost of a standard cam and a performance cam is next to bugger all. Even including the induction kit, leads, coil, and the new CAT it only came to about £600.00.
>> Edited by ntel on Sunday 31st July 16:51
>> Edited by ntel on Sunday 31st July 16:58
yes indeedy mate, if you get it upgraded as part of another cost then it's cheaper .. i just don't see that you've gained anything that's all. You yourself say you're disappointed with the torque and asked for opinions...
Most people pay about 700-800 pounds for a cam change, add the vat and you've spent 1000 pounds, dunno how much the induction pipes are but a few hundred pounds i would think, leads are 80 odd pounds? so it would have cost 1500 pounds ish had you paid for it .. that was the point .. obviously if you have a worn cam you have to change anyway .. what was wrong with the engine that you needed to have it rebuilt?
>> Edited by trackcar on Sunday 31st July 17:07
Most people pay about 700-800 pounds for a cam change, add the vat and you've spent 1000 pounds, dunno how much the induction pipes are but a few hundred pounds i would think, leads are 80 odd pounds? so it would have cost 1500 pounds ish had you paid for it .. that was the point .. obviously if you have a worn cam you have to change anyway .. what was wrong with the engine that you needed to have it rebuilt?
>> Edited by trackcar on Sunday 31st July 17:07
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