Thought I would get my 20vt dyno tested today.

Well it did pretty well I think, operator said it boosted well and was running at around 15psi (1 bar) with good fueling and he said it pulled all the way in all gears.

233.3 BHP / 229 lbs/ft Torque.

Here is a copy of the print out anyway...
http://i13.photobucket.com/albums/a259/overboostUK/P210608_171501.jpg

Looks like a great result

Nice spread of torque from 2,800rpm right across to 5,100rpm and bhp at around 5,850rpm near enough spot on for a standad car. I assume it is totally standard?

Although you've been told the fueling is OK, it would be nice to get the AFR on a graph too.


Why do some of these RRs plot BHP and torque on different ranges?

Yeah the car is standard all be it a new forge dump valve because the standard one was not working correctly, a new turbo fitted just before I bought the car and as far as I am aware thats all, although I do plan on changing the air filter but cant decide between a performance panel filter in the standard airbox or an induction kit mounted in the passenger wheel arch location.

Was good to see it running as it should though, always a worrying time dyno tests just in case its drastically lower then it should be which means the bank manager suddenly taking an interest in my car. lol

thats a cracking result for a standard car, considering that the car is probably 8 years old its making just as much power as it was when new, i am getting mine done in a couple of weeks would be delighted with those figures, especially the torque curve

The dyno operator did ask afterwards if it was chipped or had been re-mapped as the fueling he said was spot on as was the power/torque but as far as I am aware it is standard spec, just with a new turbo fitted.

you must be delighted with those results, must make the car really driveable with that spread of torque

Did they tell you how much wheel HP you have?

206.7bhp@ 5,921rpm according to the print out. Seems like the pflywheel figure may be a bit conservative. Mine made 220bhp@ 6,283rpm and only 175bhp @ the wheels as standard...

Even thought the guy said fueling was spot on, I'd still rather know what it actually is/was...

So do you think the flywheel figure should actually have been a bit higher?
It has standard wheels so gearing etc should all be correct too.

If it was a similar loss through transmission as yours was, then it could be closer 250bhp if I have worked it out correctly?

It is difficult to tell. If I look at my results;

Standard
220bhp @ 6,283rpm, 175bhp @ the wheels

Current
277bhp @ 6,840rpm*, 227 @ the wheels *(this rpm could be 6,440rpm)*

The first figures amount to 20.5% power loss, the second is 18% power loss. These are losses of 45bhp and 50bhp respectively.
Your figure is suggesting 11% and only 26bhp lost on the way to the ground.

I’m convinced that the bhp loss is not in fact a %, but a fixed amount that increases slightly as the power increases but I need to look into it a bit more. Taking my car as an example, this would suggest a ‘to the wheels loss’ of around 46-47bhp for your car, a flywheel figure of 253bhp ish. I don’t know how much boost you’re making at your peak rpm, but I wouldn’t think the standard turbo would be able to make that power if it only peaked at 1bar (around where your peak torque is). Again, without a boost/rpm printout, we don’t know what is going on…

Next time try to get all of the following plotted and printed on a graph against rpm (and check that rpm is properly calibrated, it appears mine wasn’t).
BHP
BHP@ wheels
Torque
AFR
Boost

Anyway 207bhp at the wheels is still 207bhp at the wheels, and a very nice amount of power for what is potentially a totally standard car.

sorry to butt in but when stats are given on a cars performance i.e. coupe 220 bhp or audi tt 225 bhp etc, this is the engine/flywheel power, not the wheel power?
and this is the same for all cars when they are tested?
cheers

Manufacturers measure the engines' power when they're out of the car on an engine dyno (or something like that). They don't have to worry about calculating BHP @ flywheel from the wheels figure But considering the differences between totally standard cars I wouldn't even trust these very much... Maybe they take an average themselves?

The trouble with RR places, is that they all come up differently... some types are notorious for giving higher @fly figures than others. Lots of Fccukers have seen wildly varying figures on different dynos, but the wheels figures are normally a lot closer. For this reason it is generally more accurate to simply go by the 'at wheels bhp' for comparative purposes and save the flywheel numbers for the pub

right and a standard coupe is 175 ish at the wheels?

Well, mine was but I have seen some come up at a lot closer to the flywheel 220 on different machines...

To be 100% sure, you really want to dyno an engine and then fit it to a car and do a RR run on the various different dynonometers, on the same furl, on in the same weather etc etc. Quite a tall order really...

I'm sure someone would have tried this before and it would be great to see the results if they have...