How much power ?
Discussion
A friend of mine had his Griff 500 rolling roaded at Austec a couple of months back and if my memory serves me correctly his stats were:
297 BHP and 340 lb/ft torque at the flywheel and
255 BHP and 302 ib/ft torque at the wheels.
His car is unmodified (it is a 1999 5.0 - not the HC version) and the guys at Austec did tell him his car was in the top 10%. Most impressive was the 340 lb/ft at the flywheel as his engine is only quoted at 320 lb/ft by TVR.
As far as I am aware, there are no differences in engine output between comparable 5.0 litre Griffs and Chims, so someone out there presumably should be able to quote similar stats for their Chim.
297 BHP and 340 lb/ft torque at the flywheel and
255 BHP and 302 ib/ft torque at the wheels.
His car is unmodified (it is a 1999 5.0 - not the HC version) and the guys at Austec did tell him his car was in the top 10%. Most impressive was the 340 lb/ft at the flywheel as his engine is only quoted at 320 lb/ft by TVR.
As far as I am aware, there are no differences in engine output between comparable 5.0 litre Griffs and Chims, so someone out there presumably should be able to quote similar stats for their Chim.
A friend of mine had his Griff 500 rolling roaded at Austec a couple of months back and if my memory serves me correctly his stats were:
297 BHP and 340 lb/ft torque at the flywheel and
255 BHP and 302 ib/ft torque at the wheels.
His car is unmodified (it is a 1999 5.0 - not the HC version) and the guys at Austec did tell him his car was in the top 10%. Most impressive was the 340 lb/ft at the flywheel as his engine is only quoted at 320 lb/ft by TVR.
As far as I am aware, there are no differences in engine output between comparable 5.0 litre Griffs and Chims, so someone out there presumably should be able to quote similar stats for their Chim.
297 BHP and 340 lb/ft torque at the flywheel and
255 BHP and 302 ib/ft torque at the wheels.
His car is unmodified (it is a 1999 5.0 - not the HC version) and the guys at Austec did tell him his car was in the top 10%. Most impressive was the 340 lb/ft at the flywheel as his engine is only quoted at 320 lb/ft by TVR.
As far as I am aware, there are no differences in engine output between comparable 5.0 litre Griffs and Chims, so someone out there presumably should be able to quote similar stats for their Chim.
Hi tim yeh i have been too busy and neglecting piston heads a bit what a crime! although i have been very busy working on the 5.5's so hopefully i will be let off!!
From what i worked on so far:
500's all the same
450 stock 4.6 range rover engine with a cam ported heads but standard valve
400 the same as 450 but a 4 litre short engine and not 4.6
Going back to the early 4.3 and 4.5 big valve etc you could have anything really compression and cam wise.
From what i worked on so far:
500's all the same
450 stock 4.6 range rover engine with a cam ported heads but standard valve
400 the same as 450 but a 4 litre short engine and not 4.6
Going back to the early 4.3 and 4.5 big valve etc you could have anything really compression and cam wise.
An update on my lost ponies.
I went for a second opinion today at Power Engineering (Uxbridge).
This car was tested there in Jun 2003:
Wheels: BHP 224@5897. Torque 226@4500
Fly: BHP 297@5459. Torque 300@4500.
It seems to me that something doesn't quite add up with those numbers. Maybe the Wheels and Fly charts were from different runs or something? Anyway....
Two years and 10,000 miles later on the same RR...
Wheels: BHP 212@5133. Torque 243@4100
Fly: BHP 256@5600. Torque 280@430.
So, worst case, I've lost 41BHP. Or, best case, I've gained some torque at the wheels. Surely something is not right?
Just as a quick check, we ran the test again with the air filter removed and the throttle cable tightened about 1/2 mm. Result? Absolutely exactly the same.
Clue #1: The exhaust system was coated *after* the original power run in 2003. Did the little gaskets go back in the right way round? (Just an idea I picked up from trawling the web)
Clue #2: The throttle pot was replaced about 6 months ago. Was the ECU somehow confused by this. (I'm probably talking cobblers here, but I have read about ECUs defaulting back to 'factory settings' under some circumstances).
Clue #3: The car is 'hesitant' when driving in low gear below 1500rpm. I have seen many references to this on the web with reports that an ECU change makes it better.
PLAN... Take the car for its scheduled service at the garage that did the mods (Tower View) and ask them to find out where the ponies have escaped to.
That won't be for another few weeks, but I'll report back.
BTW: The *wheel* figures from Surrey RR near enough match those from Power Engineering RR. The fly figures are a bit different though with Surrey reading 'high', not 'low' as I first thought.
I went for a second opinion today at Power Engineering (Uxbridge).
This car was tested there in Jun 2003:
Wheels: BHP 224@5897. Torque 226@4500
Fly: BHP 297@5459. Torque 300@4500.
It seems to me that something doesn't quite add up with those numbers. Maybe the Wheels and Fly charts were from different runs or something? Anyway....
Two years and 10,000 miles later on the same RR...
Wheels: BHP 212@5133. Torque 243@4100
Fly: BHP 256@5600. Torque 280@430.
So, worst case, I've lost 41BHP. Or, best case, I've gained some torque at the wheels. Surely something is not right?
Just as a quick check, we ran the test again with the air filter removed and the throttle cable tightened about 1/2 mm. Result? Absolutely exactly the same.
Clue #1: The exhaust system was coated *after* the original power run in 2003. Did the little gaskets go back in the right way round? (Just an idea I picked up from trawling the web)
Clue #2: The throttle pot was replaced about 6 months ago. Was the ECU somehow confused by this. (I'm probably talking cobblers here, but I have read about ECUs defaulting back to 'factory settings' under some circumstances).
Clue #3: The car is 'hesitant' when driving in low gear below 1500rpm. I have seen many references to this on the web with reports that an ECU change makes it better.
PLAN... Take the car for its scheduled service at the garage that did the mods (Tower View) and ask them to find out where the ponies have escaped to.
That won't be for another few weeks, but I'll report back.
BTW: The *wheel* figures from Surrey RR near enough match those from Power Engineering RR. The fly figures are a bit different though with Surrey reading 'high', not 'low' as I first thought.
leadfootlydon said:
BTW: The *wheel* figures from Surrey RR near enough match those from Power Engineering RR. The fly figures are a bit different though with Surrey reading 'high', not 'low' as I first thought.
Hi Andrew,
We use very different methods for estimating the flywheel figs so I would expect that.
However, from past experience I know that P/E and our road will read very similar at the wheels. In fact a recent experiment on the same day with the same car had the two roads read withing 1Hp of each other..
Which was nice
Cheers,
Charlie.
leadfootlydon said:
Wheels: BHP 212@5133. Torque 243@4100
Fly: BHP 256@5600. Torque 280@430.
The original readings had peak torque at 4500 rpm, now you're getting peak torque at 4100 rpm? The absolute numbers might not be identical, but having peak torque move by 400 rpm seems to suggest that the engine's torque characteristics have changed significantly. One possible explanation is that there is a significant restriction on the intake or exhaust, or perhaps a worn cam?
jellison said:
My God these figure are ALOTless than even V8 Developments dyno figure for an average 500 RV8 (275bhp) - TVR REALLY were taking the piss (320/340bhp). Yes they do go well though, before anyone has a pop at me - the pretty good torque and only weighing 1080kg.
Look Jon, I know you have an axe to grind on this, what with you having Corvette power in your Chimaera and all that, but TVR have only been playing a similar game to a lot of the other manufacturers - that is, measuring power on a bench dyno with no ancilliaries. We all know that, so why the need to bang on about it at every opportunity?
Edit: Although I should also point out that an LS6-powered Chimaera is waaay cool.
>> Edited by JonRB on Wednesday 4th May 22:12
GreenV8S said:
leadfootlydon said:
Wheels: BHP 212@5133. Torque 243@4100
Fly: BHP 256@5600. Torque 280@430.
The original readings had peak torque at 4500 rpm, now you're getting peak torque at 4100 rpm? The absolute numbers might not be identical, but having peak torque move by 400 rpm seems to suggest that the engine's torque characteristics have changed significantly. One possible explanation is that there is a significant restriction on the intake or exhaust, or perhaps a worn cam?
Saved me posting something similar. 
If you've not had the pre-cats removed previously it might be worth seeing if they are sitting on top of the main cat, not unheard of 
. Harry
Edited to add another simple check, if you have the original intake hoses is to make sure that the double skin has not blown on the inside causing an obstruction. >> Edited by HarryW on Wednesday 4th May 22:56
You could always put one of these in there - it would fit!
www.weberprecision.com/
www.weberprecision.com/
jellison said:
You could always put one of these in there - it would fit!
www.weberprecision.com/
That's what I'll end up with at this rate!
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