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View Full Version : just back from dyno......


Leasky
14-10-07, 02:16 PM
any guess to what hte zs made??
full exhuast and a filter.........


im off for a round of golf anwser wiil be up soon
have as many guess as you like
winner gets a pat on the back:smart:

stamford
14-10-07, 03:13 PM
Judging by the viewers on this post we are too scared to guess in case we are 'owned' :laugh:


My guess....................oh crap!.............191 @fly?

I am hoping for you btw :laugh:



*edit* I hope you mean the 180 ;)

sduk
14-10-07, 04:16 PM
now this i know nothing about, hope it was good :D looking forward to seeing the result!

stamford
14-10-07, 05:42 PM
How long is a round of golf? Come On! :laugh:

Mat C
14-10-07, 05:47 PM
177 at the flywheel

al_roverMG
14-10-07, 05:55 PM
Yah i would say about 175 at the flywheel. The 180 and 190 v6s are well known for being a bit short of the mark out of the box.

Mat C
14-10-07, 06:10 PM
Miserable little engines. I've just enjoyed a test drive in an 03 plate Alfa Romeo 156 GTA with the awesome 250bhp 3.2 V6. Wow, what an amazing car ! The power feels light years ahead of the ZS and it would blow it into the weeds ! Interior is stunning and there are so many nice toys and touches. It handles as good as if not better than the ZS too. Now if only i could find the £12,000 required to buy it !!

Shafz
14-10-07, 06:19 PM
186 :)

Leasky
14-10-07, 06:46 PM
results are in .......................

186.5BHP

good ? bad ? or respectable ?

Shafz
14-10-07, 06:54 PM
:rb::lttd::band::trampoline:

Mat C
14-10-07, 07:03 PM
I think that's a very good result ! Makes me wonder what mine would be with my twin Xpowers, induction and sports cat !

sduk
14-10-07, 09:09 PM
was that with the CAF and filter moved? or before mate?

arwilson80
14-10-07, 10:15 PM
I have no idea if that is good or bad, but it sounds OK to me.

stamford
14-10-07, 10:28 PM
Nice one Shafz :D

I have seen random bhp figures from various ZS's, not all give the same output from standard, so 186.5 isn't bad, but I have seen higher for the same mods, but again that is down to the rollers and engineer running the tests, they are not all the same.

Leasky
14-10-07, 10:32 PM
it was run with full exhaust and filter in wing
whats CAF?

KevG
14-10-07, 10:34 PM
CAF - Cold Air Feed

Gregor, what is the figure of 185.6 actually from the Wheels or Flywheel?

If 185.6 at the flywheel then, about 173 ish at the wheels

If 185.6 at the wheels then, about 198 ish at the fly

stamford
14-10-07, 10:39 PM
If that's wheels I'd be mighty impressed ;)

Leasky
15-10-07, 12:51 AM
140@wheels
186.5@fly

al_roverMG
15-10-07, 01:16 PM
If 185.6 at the flywheel then, about 173 ish at the wheels



Ummm kev 10bhp losses on the KV6 is a little bit optimistic isnt it?? I always thought it was generally accepted at around 25bhp?? (so around 15% on a standard engine)

At the end of the day WHP counts for nothing and is a complete nonsense. At the flywheel is where it counts and power is nothing without torque LOL

Very good result there as have seen KV6's with those sorts of mods make less than factory quoted figures.

RalphG
15-10-07, 01:33 PM
The power at the wheels for a standard ZS180 should be around 142BHP, if memory serves me correctly.

stamford
15-10-07, 01:54 PM
Something does not add up there then :huh:

Leasky
15-10-07, 04:51 PM
maybe a rubbish dyno

al_roverMG
15-10-07, 05:08 PM
See this is why at the wheels figures are nonsensical at best and a damm right lie at worst. The figure for the flywheel value will vary very little from one set of rollers to the next. The figure for the "at the wheels" (which is a nonsense in itself because it is actually the torque value measured at the rollers then calculated for the power figure at the flywheel and then the losses re-removed to give power at the rollers) will vary dependant on how long ago it was calibrated.

When a rolling road is calibrated the in built losses (ie the losses due to friction, inertia of the rollers etc) is taken into account but over time these change and so the "at the wheels" figure will have inaccuracies.

I spent a long time looking into this (call me sad or just curious to find out how things work) after 2 rolling road days at different places on following weekends with my CTR. Both gave me 238bhp at the flywheel but there was something in the order of 30bhp between the "a the wheels figures" and the second dyno was a brand new chassis dynamics setup which had been installed the weekend before while the other was an old sun rolling road which had been in since Jesus was a little boy. That is why i go into rant mode every time some spouts about "at the wheels" figures.

RalphG
15-10-07, 05:43 PM
The thing is though that rollers only measure the 'at the wheel' figure. They then use a formula to calculate the flywheel value. The better rolling roads calculate the transmission loss for the vehicle by unloading the engine and letting the rollers slow naturally and therefore find the resistance. Other rolling roads use a pre-calculated loss averaged for a sample set of cars of the type.

The only way to get a true flywheel value is to take the engine out of the car and connect it to a dyno. Rolling roads are not dynos.