FATS - HP Converter

[ZeroK66]

Hi Guys,

Having got a FATS result now for my car... I am interested to see an estimated HP... does anyone have the excel spreadsheet that gives the estimated HP?

Cheers,
Leon

[CliveH]

The basic calculator is here Leon : http://www.vastperformance.com/faq.php (scroll about half way down...)

[ZeroK66]

Thanks clive...

I put in a weight of 4000lbs... that is Doug, Audio install ~50-100kg fuel etc... and I get 477BHP... probably got the weight wrong, but that is a good result!

[CliveH]

I put in a weight of 4000lbs... that is Doug, Audio install ~50-100kg fuel etc...

Wow! would never have said Doug weighed that much...

and I get 477BHP... probably got the weight wrong, but that is a good result!

Good result - maybe closer to 3,800lbs, but that's still well over 450bhp

So how does the car feel?

[ZeroK66]

Dont know... still not driven it :'( - my brother is on his way down at the moment. Should be here in the next 30 min... I will writeup tonight.

[S4TAN]

I have to ask: how on earth can your audio install weigh up to 100kgs???!!! That's 220lbs - the weight of a 15-3/4 stone man! Surely the door/shelf spreakers, head unit, cabling, amp and sub woofer(s) etc can't weigh THAT much can they?? Even at 50kgs that's still hugely heavy ... what's your system made out of - reinforced concrete and lead??!!

[stimp]

Just to understand this FATS timing, is it only a measurement then between 4200 and 6500 rpm then. Is there a measurement that gives a better indication of the power curve (apart from dyno)throughout the rev range as this is only measuring a spread of top end power.
Am I missing something or is this all a little pointless, I mainly drive <4000rpm in daily use so am more concerned about the power I get in the low end and midrange. Do we have to go to a calibrated hill, what tyre pressures are used etc.
Personally measuring the MAF (which I would think is function of boost pressure versus rpm and outlet restriction) and just the FATS times sounds like it gives you absolutley no idea on how well the car is performing throughout the majority of it's power curve. Something with a really good MAF reading and a great FATS time could be a really lacking engine below 4k and you would not know either way.
Get it to a dyno and find out what you've really got, not the ulitmate power figures but just to make sure the area under the curve is the best it can be, no nasty dips etc. Then post it so we can admire the beast.

[S2tuner]

Am I happy with 511 crank HP on a given dyno a given day with given (crap) fuel in the car? No. Am I happy with 350g/s, great midrange timing, 1.55 Bar peak boost in the midrange and 2.8 FATS on an RS4 gearbox? YES.

A dyno is good, but when cooling isn't adequate it can quickly lead to disappointment...

Just my 0.02.

Mihnea

[stimp]

On my 250 race bike am I happy I get 55hp equal to any of the 450 fourstrokes, damn right. When I have to accelerate from lower revs to get out of the corner and avoid an unneccessary shift then I want the best I can get throughout the range. My peak nuymbers and absolute accelaration down the straights say we are equal. Losing the first fifteen yards out of every corner says otherwise.
I personally also don't care for ulitmate numbers and have previously been happy with great plug colours, lack of detonation, positive swirl patterns on piston crowns etc but when I put it on a dyno I was able to see flat spots just not visible any other way. I know this is a different engine type but I still think it is relevant. A number that only impressive other pub users is I agree a bit pointless.
I am open to the fact that the S4 engine is a different beast and therefore it has unique tuning properties. I'm just suprised that you can predict best power torque by just measuring fueling inputs and timing. I've seen a few superbike engines tuned on the dyno where timing is advanced and retarded at many different point during the rpm range to get optimum results. The same applied to fuelling where some engines preferred a rich condition in the midrange before leaning out on top for example. Always interested to learn

[ZeroK66]

I will get the car on the dyno, be interesting to see how it performs with my exhaust then get decent downpipes & race cats on... should release the final few ponies I have under the lid. My peak maf is not far off Mihneas... apparently 347... which is odd with my restrictive exhaust. I bet Mihnea is running much better timing than me though. Cant wait to get that exhaust on.

Merry cristmas

[GrahamS4]

I will get the car on the dyno, be interesting to see how it performs with my exhaust then get decent downpipes & race cats on... should release the final few ponies I have under the lid. My peak maf is not far off Mihneas... apparently 347... which is odd with my restrictive exhaust. I bet Mihnea is running much better timing than me though. Cant wait to get that exhaust on.

Merry cristmas

If you can do it while visiting your brother, come to Aylesbury, you can use the same dyno KayGee and I used.

[flashyg]

What new results did you get on the fats and maf etc?
G
Hope all is well.