Dyno Run Gone Wrong?

[IRON8]

Hey,

I got my VP Calais (Buick 3800) tuned for the second time but got less power than the first time I tuned it with more mods?! SO:

For tune No. #1:

Wade 992a Cam, 1.8 YT High Rollers, Mahle Pistons, 2.5k Converter, Lukey Extractors + High Flow Cats + 2 1/2' Exhaust, Custom Rods, 40thou Oversized Rings, 10:1 Comp, Machined and Bored. Stage 2 Shift Kitted Auto - 4L60.

Power: 142rwkw @ 407nm Torque.

For tune No. #2:

Added Twin Throttle Body & 2x Brand New K&N Pods, Bosch Blue Top 775 Injectors 24lb & Freshened Up Motor a Little.

Power: 129rwkw @ 680nm Torque.

Has something gone wrong or is one of my mods robbing me of power. Can't work it out?

EDIT: After the second tune, it sounds a lot more 'droning' on low revs compared to the first one. Pulls very similar though.

Those figures arnt right, it would make more sence if it said 129rwkw @ 380nm. 129rwkw @ 680nm is like the results of a 4L diesel turbo. Thats massive torque.

 

[Cava454]

It's a dyno. It's a tuning tool and nothing more.

The black strip never lies. $800 each time u go on the dyno. Ur getting ripped.

It's only a touch up of the tune. Not another full tune. U shouldn't be paying that much.

Off note I have to laugh. All this money dropped into a Buick and ur making on par what a stock 304 makes.

 

[ari666]

useless figures are useless.

without the RPM of each result you are looking at random numbers you cant do anything with.

where is your chart?

just for shits n gigs i googled the magic number for KW which is 9550. i must remember that for the future, since all you kiddies work in KWs and not HP.

soooo:
Power (kW) = Torque (N.m) x Speed (RPM) / 9550

if you got 680NM and 129KWs that means your peak torque reading was at 1811rpm. so what you have effectively done by your additional mods is kill off top end torque. your original reading of 142kw and 407nm happened at at 3333RPM.

my suggestion is to kill off the twin throt because its looking like it wont flow past 2000rpm, its probably a bling bling piece of **** that belongs in the bin anyway. normally adding things like pod filters and gay arse twin throts kill off low and mid for a little bit more rpm, but it looks like yours has been killed off so badly down low that it cant climb up the rpm range and thus your **** power figure.

remember kids, there is no such thing as KW, its an imaginary number, there is only torque.

*another note, your stall converter will show a slightly lower reading to a standard torque converter, im not sure why exactly, but it just does.

 

[AirStrike]

Need to see the sheets to compare AT, IT, what gear was used, what mode the dyno was set in, etc

 

[IRON8]

HAHAHA Bling Bling piece of **** !!!! We deal in HP here in NZ, its Aussie lingo KW's. So he's reading his peak torque not hp ?

 

[ari666]

ah yes, please note:

my calculations are assuming all variables remain the same, ie. AFR's where they should be, tyre size and pressures remain the same, temps the same, bonnet closed each time etc.

 

[ari666]

We deal in HP here in NZ, its Aussie lingo KW's. So he's reading his peak torque not hp ?

que?

hp calulations are the same as KW but a different magic number is used for the metric system

HP= FtLbs x RPM / 5252
kw= NM x RPM / 9550

 

[IRON8]

que?

hp calulations are the same as KW but a different magic number is used for the metric system

HP= FtLbs x RPM / 5252
kw= NM x RPM / 9550

oh ok learn something new every day

 

[ari666]

and to delive a little deeper into the confines of scary mathematics. the reason i say "there is no such thing as KW, there is only torque" is because without NM, KWs cant exist. see, NM is the only real measure of force used on a dyno. kw is a calulation based on the force generated.

here is what wikipedia has to say:
A newton metre is a unit of torque (also called "moment") in the SI system. The symbolic form is N m or N·m,[1] and sometimes hyphenated newton-metre. One newton metre is equal to the torque resulting from a force of one newton applied perpendicularly to a moment arm which is one metre long.

and a fancy little picture:

so your wheels rotate the dyno rollers, the rollers measure the force applied to the rollers to get an NM reading, because they are linked to the ECU or dizzy they also take an RPM reading at the same time and spit out that magical non-existant KW number. which (as cava454 has already mentioned wisely) makes FK all difference to anything in real terms, other than bragging rights to a higher or lower number on a piece of paper.

the fastest car is the one that crosses the line first

 

[IRON8]

So torque is leverage? bigger stroke bigger torque?