FFF Dyno Map (D18 MCA)

[Vixpy1]

I'm not entirely suprised with the figs, Not becuase of the engine but because those Daskek RR's don't half show some strange numbers sometimes.

Edited by Vixpy1 on Friday 20th November 10:14

[BGB autosport]

spitfire4v8 said:

BGB autosport said:

I cant really comment on the power but the AFR is all over the shop.

was that really post-mapping or was the AFR gauge fubared?

I presume that the afr plot is the same run as the peak power in which case it will be post mapping.

Also I would hope its not a duff sensor, else how would they reliably tune the fuel maps. If they knew the sensor was duff and used a stand alone then why use the dyno one at all? Seems odd, almost like a base map was chucked on there, bish bash bosh thats £££ please sir.

[tuscan_al]

Vixpy1 said:

I'm not entirely suprised with the figs, Not becuase of the engine but because those Daskek RR's don't half show some strange numbers sometimes.

Edited by Vixpy1 on Friday 20th November 10:14

So when are you going to get the boys along to your Dyno Charlie?

Dom I will happily run up to yours and leave my tuscan there and runa 4.3 down to Charlies

[d18mca]

Just to reply as to the driving of the car,yes I am very happy with its performance.
I can only judge it against cars it has run with whilst on our TVR outings.
Accelerating from 90 to 165 it stayed with a GTR ,which I thought was reasonably impressive.(3rd and 4th gears).
I enjoy the way it will pull from 1000rpm in 5th,and it's tractability in slow moving traffic.
Paul mentioned that the engine seemed extremely well balanced,.
I myself am not technically minded,so I have forwarded the charts to Racing Green .
The car was mapped when it was the standard engine and the figures on the same rolling road were 394 bhp and 340 torque,but at differing rpm to the present figures. A few club members have tried the car ,and without exeption,all prefer the way it drives now.
I know that figures may be available from another FFF engined car tested on a different rolling road in the near future,so it will be interesting to see any variations.

I will keep any developements posted,and in the meantime enjoy any dry roads we can get.
Happy motoring.
Davy

[tuscan_al]

So your saying you have lost 30 + bhp too since going FFF

OK it might drive slightly smoother, but for me and 10k it would have to be silk smooth and then I don't think the money would justify the power or smoothness, there must be more to these FFF's I really hope so. Like Racing Green and the guys there and there work is always of a good standard, but surely they would have hoped for more? Longevity issues seem to have been sorted on the std engines, and mine has done 30k on a top end 06 rebuild with no issues. So what more do these engines offer? Its hardly like the majority or TVR owners do more than 6k pa anyway.

[PascalBuyens]

d18mca said:

FFF Engine Map

Please see attached graphs from last weekend. Paul from austec racing organised the mapping. Very pleased with the result. It's very smooth and progressive power.

Please feel free to comment!

Davy

PS. Click on the link for a bigger picture.


http://www.blitter.co.uk/retro/new.jpg


Before you all jump on "breaking down the FFF", I've always been told this:

The simple formula for calculating bhp is based on 33,000ft lbs of work being done in one minute. This amount of work is regarded as one horsepower. The formula is: HP = Torque x rpm /5252 From this you can see that when the rpm is at 5252 the HP and the torque are the same. If the power and torque lines do not cross here on the graph then someone is telling you porkies!


It is NOT crossing at 5252 rpm, so if you ask me, there is something wrong with that graph.

Edited by d18mca on Thursday 19th November 17:49

[d18mca]

Sorry Pascal,but for my non technical non mathmatical brain,you would need to break it down .I don't know how the dynometers are calibrated etc.

[Vixpy1]

In order for the graphs to cross at 5252, both scales must be the same.

[s5tvr]

dvs_dave said:

Yes, bit baffled by the wheels/engine figures??? 360 bhp is what you'd expect from a standard 3.6 ltr, not a Sagaris/S spec. 4.0 ltr.

I don't think so. Standard 3.6 makes 350bhp (factory figures). Given that these are always a little on the optimistic side I would say a bog standard 3.6 makes more like 330-340bhp. 360bhp is what I'd expect a good standard 4.0 to make.

[s5tvr]

RM75 said:

Still 4 places here...

http://pistonheads.co.uk/gassing/topic.asp?h=0&amp...

Thurrock, Junction 30 M25.

Davy,

If I were you mate, I'd take that dyno read out with a pinch of salt and get yourself down to TDI (if you're close enough) at Lakeside. They are a very professional outfit and operate a very good hub dyno and have other SP6 dyno runs that you can compare yours to.

[dvs_dave]

s5tvr said:

RM75 said:

Still 4 places here...

http://pistonheads.co.uk/gassing/topic.asp?h=0&amp...

Thurrock, Junction 30 M25.

Davy,

If I were you mate, I'd take that dyno read out with a pinch of salt and get yourself down to TDI (if you're close enough) at Lakeside. They are a very professional outfit and operate a very good hub dyno and have other SP6 dyno runs that you can compare yours to.

Would be an idea....A few of us are heading down. I'll be waving the standard 4.0 ltr TVR Power flag. Got 340 at the wheels (400 fly) on the same dyno at this day last year.

[d18mca]

Thanks for the offer,but being in Belfast I'm unlikely to be in England until Chatsworth at the earliest,but I would be interested in meeting up to run it on a different setup and compare the results.
Cheers Davy

[mmspawn]

It would be interesting to hear which compression setup is fitted to this FFF engine. If the low compression setup (10:1) is fitted the results are O.K. in my opinion.

[Funky Jo]

Come on guys, stay reasonable. Nobody ever was complaining about the standard Speed Six engine not being powerful enough. Some mates might just be looking for better durability / reliability. Let`s do that comparison in 5 years from now...
The extra Power coming with the 4,3 l engine is just cream on top and helps to justify the fortune we are spending for rebuilds to keep our plastic toys on the road.

Edited by Funky Jo on Saturday 21st November 22:25

[JR]

tuscan_al said:

So your saying you have lost 30 + bhp too since going FFF

Why the surprise? The finger followers were in there for a reason. A loss of less than 10% for supposed improved reliability seems reasonable.

You pays your money ...

[Redmist336]

I can't believe the amount of negitive critisism based on figures that mean very little. Dyno's vary by huge amount between differing manufacturers, models, individual machines, even ambiant correction. Some have been known to even artifically inflate thier HP figures in order to attract business. "This tuner/dyno is the best as I produced the most HP on it" If anything I'd state that this dyno is probably more accurate than most of the others you gentlemen are comparing it against. The reason I state this is along with ambiant correction, they have completed a coast down in order to address drivetrain losses. Hence the differences between engine and wheel max HP RPM. Friction doesn't have a linea correlation with HP! You can't calculate flywheel hp simply by adding a percentage back.
You may also find that the reason the engine didn't run quite the HP others are expecting is it's a reasonably warm day (for UK) and I suspect dry? Both factors should drop HP (depending on how the ambiant correction is calculated)
Nice plot, although already stated your AFR is a bit all over the place. I suspect this to be causing the corresponding dips in your torque curve.
Dyno's are good for three things only.
1. Checking AFR's
2. Comparitive against the same engine, with modifications (without great accuracy)
3. Bullshyte stories to impress friends, scare fellow racing collegues.

Edited by Redmist336 on Saturday 21st November 23:25

Edited by Redmist336 on Saturday 21st November 23:34

[dvs_dave]

Redmist336 said:

.....they have completed a coast down in order to address drivetrain losses.

So you think performing a coast down with the clutch dipped gives an accurate measure of drivetrain losses? I'm afraid it doesn't. A fully loaded up drivetrain saps an awful lot more power than the same drivetrain does whilst free-wheeling. So much so, it's a waste of time doing it. Just a gimmick if you ask me.

The only useful measure for comparison is wheel horsepower. That's the power on the road and the power that moves the car. That's easily measured and can't be argued with.

[Redmist336]

I think performing a coast down is considerably more accurate at assessing flywheel hp than a % based on what someone’s dogs, sister's, brother in law posted to the web. However I do agree with your assessment that wheel HP is the only accurate way to measure HP. Given the same dyno, on the same day. Unfortunately almost all dyno readings I've had use SAE or estimated SAE HP as well as WHP. However I've only used 7 different dyno's so it's not a huge sample set. Everyone I’ve ever met also quotes the larger figure (the SAE HP). I always quote my 519HP at the wheels as nothing more than intimidation on some of the smaller engined racers. I know it'll vary by up to 20% given another dyno on another day so it means very little to me, my car, the performance, or the way my dog scratches itself.
For use as a comparative to another car, on another dyno, on another day, WHP or flywheel HP is completely and utterly useless.

[crimbo]

How come the torque curve is so different to that of other S6 engine dyno’s I have seen, they seem to have a flat curve consistent from 2,500rpm to around 6,500rpm where as this one seems to have a much sharper peak, I know that the scale of the graphs are slightly different but if they were the same it would still show a defining peak rather than a smooth curve?

[dvs_dave]

Redmist336 said:

....a % based on what someone’s dogs, sister's, brother in law posted to the web.

TVR Power (who incidentally used to be owned by TVR and was their engine shop) uses 15% for modern TVR's based on engine dyno figures cross-referenced with rolling road dyno figures. Given modern TVR drivetrains are all essentially the same (AP racing clutch, Tremec T5 gearbox, BTR diff, etc.), I'd say that in this instance it's a pretty accurate figure.

Unless you've done engine dyno/rolling road comparisons, transmission losses are very hard to accurately determine. Hence the reason a lot of guff and random numbers surrounding transmission losses.

I agree with you on the different dyno, different day stuff though.