Dyno Tested Auto Vs Manual Driveline Loss

[FATAZZ]

So it lost ~36kW over the manual. What's that, nearly 50hp? That sounds about right to me but what auto/converter is in it?

Like 2rismo asked,,,,did it have a std converter in it? And would a higher stall converter make it read a lower overall rwkw?

[dangerman4]

when i got my trans built with high stall i also installed poncams , then re dynoed it and i lost 40 rwkws over standard torque convertor and standard cams, nothing else changed.

Mike at MV said the high stalls do suck power when run on a dyno, and if i wanted to be a dyno hero i should stick with the stock convertor as it will allways read a higher no.

but in a straight line the high stall will allways out perform the stocker.

Edited January 8, 2009 by dangerman4

[FATAZZ]

Cheers Darren

[Fastrotor]

Yeah i have found this too, going to a 2800 rpm converter dropped my mph from 118 to 113 ! , but ET dropped from mid 13's to 12.3 !

i now have a 3500 converter but yet to run strip.

I only show 250 rwkw's and can't seem to get past it..... however my 550cc nismos are maxxed at 6000 rpm, so this gives me more of an indication of where i am at relative to others on here. (740's arrive tomorrow!)

URAS, have you ever noticed on the R33 auto's, if you ramp them too slowly you get a big power dip just at the start of the run ??

The LINK i run has a rpm setting for cam on and cam off. I did notice if i turn it on to early it is noticibly harder to cruise up small hills, more throttle required, so i raised it to counter that, but the switch off has always been 6000, and i am ashamed to admit i haven't played with it yet when on dyno... will do now though as last run late last year i started noticing the top end dips !

Im chasing a problem of not being able to break thru 250rwkws. New larger turbo yeilded 250 same as previous, dropped exhaust BP from 7 to 3.2 (collapsed cat), nothing...250rwks....... its frustrating.

I often wondered if the auto comp was playing silly buggers....

Dyno opens again next week, so i'll be back on soon to try new options (HKS cast mani and replace turbine housing with proper .63 turbonetics, rather than bored out VG30 one. And Ext gate + full 4" inlet to 4" pod (yet to be shielded, but just going for best soloution on dyno with bonnet up for now, until problem/restriction is found then will box properly for cold air.).

Thanks for the info though, i really appreciate these posts where you guys show real data and measurements in your posts, great resource.

Gary

Edited January 8, 2009 by Fastrotor

[dangerman4]

Gary whats your fuel pump?

im also running 550 nismo's and im still below 90%

your fuel pressure must be very low to be maxing them at that power range.

i had a similar turbo and i got it to 270 but that was about the end of the vg30 housing.

im running a 044 intank with a FPR set at 43 psi base pressure.

[Fastrotor]

Oh i forgot to mention that in that spiel , thanks Darren.

Yes i now know pressure is a problem, i too run an 044 pump i bought off of "Pump Daddy" off the forums here, however i suspect its faulty.

The last dyno run i did last year when we discovered the new turbo and auto didn't add a kw extra, i had put a FP gague on and sure enough the FP topped out at 55psi on a 40 psi base, when running 20psi. So effectively have 35psi across injectors to your 43. which reduces there effective size to 496cc, plus it was running very rich, so that probably explains it..

When i got home, the pump was noisy as hell.... due to heat i assume , hasnt done it since.

I have a new walbro sitting here waiting for me to get around to throwing it in. Plus i have to sort out a dual volt setup that allows full volts when 'full on' , for guilt-toy.

I figured 550's should have been enough based on your results previously, and a few other guys around the 300 mark, however since i have sold my 550's (guys still isn't ready for them so i'm still running them) ,i figured i may as well buy some 740's.

I'll get the pump in this weekend, as with the 740's and should be on dyno next week.

I suspected the VG30 was out of puff, even with all the meat taken out of it, and hence why i went to a full turbonetics .63 housing.(and HKS cast mani) Time will tell i guess. I've got the option to go to the .8 later if this still isnt enough, however i sprint race the car mainly so i dont want to kill off bottom/mid any more as its already crap (full noise/boost at high 4000's)..

Gary

Edited January 8, 2009 by Fastrotor

[Bond]

So for us people with standard cams and a slightly bigger turbo what rpm should we hace it set to??

[VB-]

what auto/convertor was in the car? are they the same car, thats been converted auto/manual or 2 cars with the same setup?

[r33123]

i am making 240 rwkw with same setup on auto with stage 2 shift kit std convertor but as i change to mannual it gain power from 241 to 277 rwkw and torque from 381 to 430nm . thanks

[STATUS]

So for us people with standard cams and a slightly bigger turbo what rpm should we hace it set to??

i cant give a blanket answer as every setup is differrent, some need it dropped a few hundred some need it raised alot.

[satanic]

Interesting... was it the exact same car? Or just two cars of similar spec?

Has the auto box been touched at all bar the shift kit?

That's a 12.5% loss in your test; so an accurate 'window' would be between 10-15%? Wow... bringing that max % into my numbers, my car would have 450rwkw now if it was manual as opposed to 380rwkw? Mmmm, I think not.

[VB-]

i have heard someone say, autos will use up a given amount of power, not a given percentage, with a little allowance. dunno how true that is though

[R31Nismoid]

So it lost ~36kW over the manual. What's that, nearly 50hp? That sounds about right to me

Nissan from memory quote a 8kw or 9kw loss factory auto vs manual

So indeed, sound pretty right on

[STATUS]

Interesting... was it the exact same car? Or just two cars of similar spec?

Has the auto box been touched at all bar the shift kit?

That's a 12.5% loss in your test; so an accurate 'window' would be between 10-15%? Wow... bringing that max % into my numbers, my car would have 450rwkw now if it was manual as opposed to 380rwkw? Mmmm, I think not.

think kw loss not percentage as your car uses the same box.

[2rismo]

Nissan from memory quote a 8kw or 9kw loss factory auto vs manual

So indeed, sound pretty right on

I'm pretty sure Nissan's quoted kW figures are at the flywheel (187 vs. 184 for example) and as such, reflect different states of tune rather than different drivelines.

If you've seen another spec I'm unaware of then apologies in advance.

[satanic]

So as a realistic figure - what would be a ballpark on a manual version of my car now considering 380rwkw in the auto?

And Trent, could you please elaborate on your last reply to me - I kinda get it, but not really Are you saying that there is no magical %, it's purely a number?

[2rismo]

Stan, think about it like this:

You have a 100hp engine that makes 65hp at the wheels. That's 35% loss, yes?

Then you whack some gas on it and it now makes 150hp at the engine. Would you expect the wheel hp to be 97.5hp (35% loss) or more like 115hp (the same actual hp loss as the original scenario)?

Assuming the same driveline (flywheel/flexplate, clutch/converter, gearbox, tailshaft, diff, driveshafts/axles), why should there be significantly more (nearly 12% extra) drivetrain loss just because you upped the engine hp?

Sure there might be more heat/noise created (in the drivetrain) but sticking to an arbitrary and uniform drivetrain loss percentage or amount is ridiculous. Even so, I've heard some otherwise very switched on people suggest it as fact.

[R31Nismoid]

I'm pretty sure Nissan's quoted kW figures are at the flywheel (187 vs. 184 for example) and as such, reflect different states of tune rather than different drivelines.

If you've seen another spec I'm unaware of then apologies in advance.

Maybe it was a HR31 difference... bit vauge in my brain...

But would it be a state of tune or are they accounting for the loss?

Interesting as im not sure!

[2rismo]

They can't be accounting for a loss that hasn't happened yet.

[STATUS]

So as a realistic figure - what would be a ballpark on a manual version of my car now considering 380rwkw in the auto?

And Trent, could you please elaborate on your last reply to me - I kinda get it, but not really Are you saying that there is no magical %, it's purely a number?

410-415rwkw is realistic.