Dyno Test - low on power, what next..?

[DazN]

Hi,

I had my car on a dyno today with Unit 20 / Dyno Demon and the results are a bit disapppointing...

At the crank = 338.6, at the wheels = 260.8.

Grizz from Unit 20 said I should take the car in and leave it for a couple of days so it's booked it.

Question is, is it really worth it? I'm going to spend a few hundred £'s getting it 'sorted', then it'll have another 40-50 BHP at the most. I drove an M5 for a year or so and there wasn't a massive amount of difference between normal 400 and sport mode with 507.

On the other hand I know I shouldn't be driving a car that's not running right?

Thanks

[sonny]

Did he say what the possible problems are?

[HYFR]

get it on another dyno, or run it against another RS 4 or similar 400ps car

[sonny]

get it on another dyno, or run it against another RS 4 or similar 400ps car

Good point Dave.

[Steve_C]

Have you done the rolling 3k - 8k test?

[DazN]

He basically said he'd need 3 hours to check it out and then let me know. He said he'd check the service history and see if things had been done right and then went into the air intake and something about flaps opening and closing, I'm no mechanic tho, I just drive it!!!!

There doesn't feel to be much wrong when I drive it tho, I only took it out of interest.

I could take it to awesome gti for a 2nd opinion?

[sonny]

Well Unit 20 are a respected garage in the Audi community, so I very much doubt his trying to pull the wool over your eyes. I would go to Awesome GTI for a second re-run and opinion. May I ask what few you was using?

Does your "S" button work when you press it?

[DazN]

Fuel? The last few times it's been either V-power or Tesco momentum but on a regular basis I just use a regular fuel, either Shell or BP.

Yes the S button works, I can hear the flaps move in the exhaust and the engine drops a note.

He was talking more about the valves in the engine and pressure created, I understand engines but not in that detail.

I didn't think he'd be trying to pull the wool over my eyes, as you say he's respected on here and he was a really nice bloke, certainly knows his stuff and he had a really nice RS6 there.

I'll try this rolling 3k - 8k test (if I can find out what it is on here) and will take it back to Unit 20 as I've already arranged it.

Let's face it, a few hundred £'s for an expert to look at my car isn't going to be a bad thing!

Thanks all

[kiwi_mtm]

Spend the money, the increased power will bring a smile to your face.

[PJC]

I was told to use Super Unleaded only unless in an emergency, not sure how much difference that makes though.

[lengster1]

Yes its worth it,you have "s" power not "RS" power,if you dont drive the car how its meant to be driven regulaly then i probably wouldnt bother,its nice to floor it coming out of tight slow corners and it pin you in the seat,std there so so and with issues plain boring,unit 20s rolling road may differ slightly to mrc in terms of figures,has grizz got a decent database of other b7 rs4 runs to compare to? I guess you suspected something wasnt right to take it for a dyno run in the first place?

[lengster1]

Did he run it in 3rd or 4th? Did he check the airbox flap was opening fully after 5k?

[PetrolDave]

on a regular basis I just use a regular fuel, either Shell or BP.

That could explain a loss of up to 50bhp.

This engine NEEDS at least 98RON to generate the specified power.

[DazN]

Did he run it in 3rd or 4th? Did he check the airbox flap was opening fully after 5k?

The run was done in 3rd gear and I was a bit disappointed that it was only actually done once, it was on the rolling road for about 5 minutes.

Nothing was really 'checked' on the car, the did the run, gave me a print off and then back up to Unit 20 to book it in.

I'm going to keep filling with V-power fuel between now and the 3rd June (when it's going in), then see what happens, if the difference is noticeable and
it makes an already great car even better then it's worth it.

[PJC]

on a regular basis I just use a regular fuel, either Shell or BP.

That could explain a loss of up to 50bhp.

This engine NEEDS at least 98RON to generate the specified power.

I didn't realise it made that much difference.