Strange Dyno Results???

[mr_rbman]

OK, had my car dynoed yesterday and i got some strange results i THINK, its a 1992 R32 GTS-T manual with what i presume is an RB20DET ECCS!

The only mods i have are:

Full 3" mandrel bent exhaust

Hot air pod

11 PSI and 13PSI (dual stage boost controller0

now i made 149rwkw's on 11 PSI and 159rwkw's on 13 PSI but the strange thing was the amount of torque i made. I made 417.2NM of max Torque at 11 PSI @ 127 kph and 435.0NM of max torque at @94kph.

Now i'm no expert but isn't that a lot more torque than what they are supposed to be putting out?

Anyone with similair mods can you please tell me how much torque you have?

[strutto]

tractive effort... not torque...

[silver gts-t]

tractive effort... not torque...

can you explain this for the not so dyno smart people

[strutto]

can you explain this for the not so dyno smart people

Nup... Too hard for me too explain...

Have a read here: http://www.skylinesaustralia.com/forums/sh...ead.php?t=49383

And then try a search here on SAU, it's been discussed a few times...

[silver gts-t]

i aint reading that!!!!

lol

[mr_rbman]

this aint helping me!

Whats the impressive part strutto?

[NA_R33]

tractive effort is whats read on a dyno, it is relative to things like the gear ur in, ur diff ratio and other things, in first gear im sure ur car will make over a 1000nm's on a dyno, u cant measure torque on a chassis dyno, only an engine dyno.

[silver gts-t]

thats better

[mr_rbman]

so over 400 max NM of torque is about right then at the wheels? i read that link and still very confused!

[NA_R33]

it varies hugely between dynos gear ratios diff ratios lots of things, had this argument with an idiot telling me my car wasnt capable of making the torque (tractive effort in this case) that i claimed. I cant say wether or not its right as im not hugely familiar with rb20's and dont know what gear you were in, basically dont concern urself with it, only use it as an indicator next time u have ur car on the dyno if say u have done mods...

[NA_R33]

another interesting point, two identical engines but one auto and one manual, the auto will make more torque/tractive effort on a dyno with less power but the manual will make less torque with more power...

[bootlegapparel]

basically, forget torque on a dyno, power at the wheels and torque at the engine are what you should only care about.

things like tyre profile change at the wheel torque, so it's pretty pointless

[strutto]

Whats the impressive part strutto?

NFI... You tell me...

Dynos are a tuning tool... Fullstop... The numbers don't mean shit unless your comparing apples with apples...

[mr_rbman]

now i understand, thanx NA_33

[Cubes]

I'm more interested at the RPM or km/h that the peak torque was made.

It may be that on 11psi boost holds constant through the rev range allowing peak torque to be made higher in the rpm.

On 13psi the boost may peak up then being to taper off maybe half a psi to 12.5psi. This will cause torque to drop slightly in the higher rpm as boost has dropped slightly. Or it may have spiked to say 14psi then settled on 13psi giving the higher peak torque at a lower rpm.

Reason I speculate is this is what mine did with a bleeder.

I fitted an EBC and boost was held at what it was set to right until thr 7500rpm cut. No matter how much boost I pumped in to it 15-16psi it would still drop to 12.5psi over 5500rpm.

I later sold the EBC and modified the wastegate actuator's bracket so I could reduce the travel which forces boost to be held in the higher rpm's, just like an adjustable rod.

159rwkw is a good result for 13psi.

I would assume your AFR's are fairly sorted, which means your fuel pump is near its limit.

[silver gts-t]

just curious, would simply changing his fuel pump cure his running lean???

and if so would running a lil richer decrease the kw?????

[Cubes]

Running richer definitely drops power.

Mine went from around 153rwkw on 12.5psi with an afr of 11.8 to 135rwkw on 12.5psi by simply dropping in a new fuel pump.

It ran hell rich and blew a bit of black smoke on the dyno.

So the fuel pressure was played with and power came back up.

On 1bar with the new fuel pump & standard fuel pressure the car made 150rwkw.

With fuel pressure adjusted to lean out the afr's power came up to 164rwkw.

[silver gts-t]

though so, i ran 150rwkw on 9psi, modes were just exhaust.

ive put in a new fuel pump but yet to b dynoed

[Cubes]

9psi? How did you manage that?

I was only able to get 9psi with the stock exhaust & stock fist sized cat.

Once the 3" went on boost goes no lower than 11psi.

[silver gts-t]

i dunno, just the 3"turbo back and a pod also, but that wont make any differance.

just hope the power dosnt drop off too much after i put the fuel pump, the power loss is not noticable when driving.

i got room to boost to make up the power