My 4.0 has 279 bhp? Great but why?
Discussion
Hi,
I bought a 4.0 last week and when going through the recipts etc the other night there was a slip in there from when it had been on a rolling road and tested. It seems its 279 bhp. I know its not a HC, anything else it could be down to.
It does have a little sticker on the back with gt performance parts on it, however the web link doesnt work - I wonder if its been played with.
It certainly feels quicker than 4.0s I have driven before, I just cant nail what it might be.
any suggestions?
I bought a 4.0 last week and when going through the recipts etc the other night there was a slip in there from when it had been on a rolling road and tested. It seems its 279 bhp. I know its not a HC, anything else it could be down to.
It does have a little sticker on the back with gt performance parts on it, however the web link doesnt work - I wonder if its been played with.
It certainly feels quicker than 4.0s I have driven before, I just cant nail what it might be.
any suggestions?
obiwonkeyblokey said:
Hi,
I bought a 4.0 last week and when going through the recipts etc the other night there was a slip in there from when it had been on a rolling road and tested. It seems its 279 bhp. I know its not a HC, anything else it could be down to.
It does have a little sticker on the back with gt performance parts on it, however the web link doesnt work - I wonder if its been played with.
It certainly feels quicker than 4.0s I have driven before, I just cant nail what it might be.
any suggestions?
sure its not 219,if as you say its 279 its had some serious work done,any outward signs,i.e carbon plenhum or receipts for parts/work done
Like I say - Its gpt the " GT Performance Parts" Sticker on the back which leads me to believe something may have been done.
I knew that they are supposed to kick out 240 ( so really prob kick out a little less) and the HC was 270.
Its got some very purple HT leads....mmmmm. I think I will have to do some investigation with previous owners etc.
Still, Im not complaining!!
I knew that they are supposed to kick out 240 ( so really prob kick out a little less) and the HC was 270.
Its got some very purple HT leads....mmmmm. I think I will have to do some investigation with previous owners etc.
Still, Im not complaining!!
I've got a '98 4.0ltr that was chipped by Mark Adams in December last year. Now he said mine was running pretty good to start with. After the event it only achieved 197bhp at the wheels. Some argue that the rolling road used runs about 10% lighter than it should - even so I was disappointed with the figures. Yours must have some significant tweaking going on somewhere.
What does the torque and power curve look like?
My standard 400 has an almost flat torque curve from 190lb/ft at 2000rpm to 216 at about 4500rpm, power was 130bhp at 3000rpm and was still rising when it hit the rev limiter at 210bhp at 5775rpm.
If it's not got much at the bottom end chances are it's been cammed. Other than that it's had some sort of machining/major change done somewhere, because a chip won't make that much difference (40-60 bhp) at the top end.
Paul
My standard 400 has an almost flat torque curve from 190lb/ft at 2000rpm to 216 at about 4500rpm, power was 130bhp at 3000rpm and was still rising when it hit the rev limiter at 210bhp at 5775rpm.
If it's not got much at the bottom end chances are it's been cammed. Other than that it's had some sort of machining/major change done somewhere, because a chip won't make that much difference (40-60 bhp) at the top end.
Paul
How can previous owners "forget" that the car was modified? If it is putting out that kind of power quite a lot of work must have been done which is going to have cost someone a _lot_ of money. Also, surely the insurance situation is a bit dubious if this info dissapears into the ether?
Sounds like it's time to go on a voyage of discovery under your bonnet!
Sounds like it's time to go on a voyage of discovery under your bonnet!
Obviously and without question, a load of bollix.
I would just ignore that receipt (are you sure it was for your car?). Which dyno was it from (so we can avoid it)?
If it genuinely feels good/better than others then get it R/R'd at a known place if you really want to know the figure (for comparative purposes only
)
I would just ignore that receipt (are you sure it was for your car?). Which dyno was it from (so we can avoid it)?
If it genuinely feels good/better than others then get it R/R'd at a known place if you really want to know the figure (for comparative purposes only
) Quinny - the Mech Repairs dyno does read differently to V8D, Austec, and Power Engineering, which are all in the same ballpark.
I have taken a car from Power Engineering straight to Mech Repairs to find the difference. The car showed 266BHP at Power, and 223BHP at Mech. This difference has always been there in the 15 years I have been dyno'ing things, and has been totally consistant for all this time.
The actual numbers don't really matter that much - it is consistancy that counts. Different dynos mostly seem to give different answers! If you look for a place that gives the highest numbers only, then you are rather missing the point (unless you are a MaxxyP Boy).
So if you want figures on the same basis that everyone else uses, then you just add about 20%, which makes yours about 279BHP. This is a very good result for a 5.0 Litre.
Kev (KTG1000) - your 197BHP at the back wheels is a very good result for a 4.0 Litre - do you remember what the flywheel figure was? I can get a printout for you if you didn't get one? (I thought you were selling it?)
I have taken a car from Power Engineering straight to Mech Repairs to find the difference. The car showed 266BHP at Power, and 223BHP at Mech. This difference has always been there in the 15 years I have been dyno'ing things, and has been totally consistant for all this time.
The actual numbers don't really matter that much - it is consistancy that counts. Different dynos mostly seem to give different answers! If you look for a place that gives the highest numbers only, then you are rather missing the point (unless you are a MaxxyP Boy).
So if you want figures on the same basis that everyone else uses, then you just add about 20%, which makes yours about 279BHP. This is a very good result for a 5.0 Litre.
Kev (KTG1000) - your 197BHP at the back wheels is a very good result for a 4.0 Litre - do you remember what the flywheel figure was? I can get a printout for you if you didn't get one? (I thought you were selling it?)
Quinny said:
Edited to add, guess which dyno sheet I'd show a prospective buyer if I ever came to sell?
You never know if he, she were niave enough I might even get away with it as well
For sale. Griff 500, geniune 339bhp, dyno sheet to prove, 50,000 quid ovno
>> Edited by Quinny on Tuesday 20th July 00:12
I Better clarify.
I only found the receipt after purchasing the car and driving it, thats what raised the question. I certainly wouldnt buy a car on its Max Power potential. I take the point though that many RRs can be massively different, I need to dig it out again to see where it was done but Bosch does ring a bell.
Out of interest what would you expect the difference to be (roughly) between the wheels and the flywheel?
Anyway - I better stop talking about it and go and drive the bloody thing
>> Edited by obiwonkeyblokey on Tuesday 20th July 08:39
Mark Adams said:
Quinny - the Mech Repairs dyno does read differently to V8D, Austec, and Power Engineering, which are all in the same ballpark.
I have taken a car from Power Engineering straight to Mech Repairs to find the difference. The car showed 266BHP at Power, and 223BHP at Mech. This difference has always been there in the 15 years I have been dyno'ing things, and has been totally consistant for all this time.
The actual numbers don't really matter that much - it is consistancy that counts. Different dynos mostly seem to give different answers! If you look for a place that gives the highest numbers only, then you are rather missing the point (unless you are a MaxxyP Boy).
So if you want figures on the same basis that everyone else uses, then you just add about 20%, which makes yours about 279BHP. This is a very good result for a 5.0 Litre.
Kev (KTG1000) - your 197BHP at the back wheels is a very good result for a 4.0 Litre - do you remember what the flywheel figure was? I can get a printout for you if you didn't get one? (I thought you were selling it?)
Hi Mark,
I don't recall talking about flywheel figures with you on the day. I'd love to know though, do you still have the data? I would really appreciate a copy of the results. As for selling, well the phone did not ring and I'm greatful. I can't bear to part with it. Please email me direct and I'll send you my address if you no longer have it. Cheers Kev Gill
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