Outer Limits 4x4 Board

hey
i put my sierra on the dyno the other day and it got 74.5 hp. does that sound good for a stock standard 1.6 vit efi.

me217

Mine got 51.5 bhp from a stock standard 1.3 G13A.

I reckon yours is a good rating. It makes sense for the larger capacity and EFI.

MF

ok cool.
anyone else gone on the dyno.

me217

That said, chassis dynos aren't a real accurate measure of power due to the many factors at play. You can get varying results by just strapping it down harder or moving the intake temp and ambient temp sensors. And when your talking about less than 100hp this becomes an even bigger deal. Always use the same dyno with the same operator exactly the same way and you'll get consistant results but realistically they are just a tuning tool.

Mike_1324 wrote:Mine got 51.5 bhp from a stock standard 1.3 G13A.

I reckon yours is a good rating. It makes sense for the larger capacity and EFI.

MF

Any chance i could get a copy of the the dyno slip, i just want it for the general curve over rev range

Yeah, i'll scan it and upload it.

Dynos are BS, it was just the novalty of putting it on, and it was a free run cos a mate owns the dyno. hp is not acurate from them as they are not calibrated (The shop versions) and as GRPABT1 said, they are just a tuning tool, but only to be used under the same conditions everytime.

MF

have u got ur slip ,me217?

this is mine - sierra with weber carby, vit 1.6, extractors and 2" pipe (stock cat in place), and 215/75r15's...



The guy calculated around 50% loss through the tcase/driveshaft though.
This was done in 4th gear at the rear wheels, not strapped down on the rollers, just chocked at the front end.

Works out around 51hp at the wheels.

I was more impressed with the top speed than anything =P haha proves i actually did do 160 in 5th with 1000rpm to spare before redline.. lol

Hang on..... thats 50.8 hp at the back wheels (To the rollers) by that chart is it???? With a 1.6 efi???

Mine was 51.5 hp at the back whells to the roller with a carby 1.3....



MF

Mine went 58 point somthing with the 1.3 turboed. I think I lost a fair bit through 35s and 40 odd degree tailshaft. And missing a piece of piston bout the size of a 10 cent coin

Hang on a minute there Mike_1324 - you can't have it both ways - you can't claim Dyno's are BS and then start comparing you car with others based on dyno figures without all the variables at hand.


Steve.

1.6 with a weber carby mate... was tuned and everything and the dyno itself had been calibrated the week before.

Notice though its not at redline there either... this was done ages ago, but from memory the back end was too light and the guy wasnt comfortable going much faster =) hehe

so one should sit on the rear with a full tank of petrol when performing a run...

Still it was Alien chart that made me ask for the dyno slip. I remember us all going 'Ohh' when we saw it

Gwagensteve wrote:Hang on a minute there Mike_1324 - you can't have it both ways - you can't claim Dyno's are BS and then start comparing you car with others based on dyno figures without all the variables at hand.


Steve.

Yeah, but thats a long way out! 4 or five horses maybe, but not a masiave span from a 1.3 carb to 1600 Efi (with a weber carb).....

Dynos are inaccurate but its still not making sense.

MF

ive had to sierra with 1.6efi vit motor and the both where very close on the dyno one was 79.6 the other was 82.8 both where on 235 and the same diff gears

how much difference does the bigger tyres make?

as i am now thinking of gettin mine done too for baseline and shits and giggles.

is it better to put my 225s or 205s or 31s on?

rest of driveline is stock NT gearing + 1.6 vit mpfi

Mike_1324 wrote:

Gwagensteve wrote:Hang on a minute there Mike_1324 - you can't have it both ways - you can't claim Dyno's are BS and then start comparing you car with others based on dyno figures without all the variables at hand.


Steve.

Yeah, but thats a long way out! 4 or five horses maybe, but not a masiave span from a 1.3 carb to 1600 Efi (with a weber carb).....

Dynos are inaccurate but its still not making sense.

MF

Im sure his 1.6 isn't EFI if its got a weber carb silly

Nic - go to West Racing in osborne park where i got mine done, they do a great job - and do it with your current running gear - ie: the 31's - then its accurate to your setup.

I'd be interested to see what mine does now its geared and on 31's - cos the gearing is slightly lower than it was on the 215/75's...

cut 4B wrote:ive had to sierra with 1.6efi vit motor and the both where very close on the dyno one was 79.6 the other was 82.8 both where on 235 and the same diff gears

Sounds about right, in comparison me lil webered 1.3 with 235s, 4:1's and 3.9's managed to pull roughly 46kw a smidge over 60hp. Std 1.3 on std zuk apparently runs 47rwkw from factory brand new yea?

Dan

GRPABT1 wrote:That said, chassis dynos aren't a real accurate measure of power due to the many factors at play. You can get varying results by just strapping it down harder or moving the intake temp and ambient temp sensors.

Care to explain these sensors on the chassis dyno?

can u dyno with a welded rear diff?

as long as both tyres are exactly the same size, might get a bit of chirping. Would be the same for someone running a lockrite too.

Yep. Don't think it's a problem at all.

Steve.

nicbeer wrote:can u dyno with a welded rear diff?

yes.


my sierra with twin cam engine made 78hp (58.2 kw) last friday. and (chassis) dynos are accurate, they have to be. but they will give a reading based on the health of the entire driveline. a engine dyno will tell you exactly what the engine is doing.

at least i have a baseline for when the turbo goes on.

interesting you did it in 3rd gear, whats the reason for that???

My guess it'd be to keep the speed down. 4WD's can get a bit squirrely at 160 on a dyno.

It does make a small difference to the recorded HP but it's not all that significant.

PS Alien - that's one weird looking dyno chart... had a little bit of tyre spin did we???


Steve.

well considering it wasnt strapped down and the guy was accelerating from outside the zuk (ie: no weight at all in it) it was a little, as you put it, squirrelly =) haha (hence not hitting redline).

Old mate not quite down with the spelling skills yet hey ..... SIERA.... lol

alien wrote:well considering it wasnt strapped down and the guy was accelerating from outside the zuk (ie: no weight at all in it) it was a little, as you put it, squirrelly =) haha (hence not hitting redline).

Not strapping any type of vehicle to a dyno is just stupidity.

Also taking the engine to redline wouldnt make a dick of difference , you will find the power curve will drop off before redline.

Nearly all reputable dyno shops these days use dyno dynamics dyno's and they are VERY accurate.

usually all dyno readouts are done in third gear .

nicbeer , most cars that get dyno'd will have welded or locked diffs in some way or another.

crackatinny , thats not a bad figure 78hp atw is what the motor made in its fwd relative with less drivetrain losses , nice work .

my jimny made 64.6hp at the wheels last time.stock g13bb with 215/75r15s. if i get some spare time i might try a few different tyre sizes just for a laugh (the weight will be what makes the difference in measured power)

alien that is a pretty funky dyno readout you have there??that dip is pretty odd (maybe an issue with the secondaries (A/F ratio readout instead of torque may tell the story)
very slack with the scaling on that printout.

crackatinny yours is actually reading lower than it should because the inlet temp is 5degrees lower than the ambient temp,compensations compare the 2 temps to give influence the readings.
ie(if the IT is more than 10 odd degrees hotter than the AT you can generally call BS)

nic the welded diff is fine.
Go see Mick at ovaboost he's a top bloke to deal with,i used his dyno once before to find a few bugs .the boys know him jas should have his details i think.

not everything needs to be strapped down on a dyno
chocking is fine for a lot of vehicles, ever tried to strap down a lowered car with IRS & a 3in exhaust at temp, not fun or even possible sometimes in the conventional way .
dyno's are callibrated new & normally rechecked when fitted.

theres more but we would be here for week.

Cheers Drew