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ATW Power for a STOCK RB20DET...???

rednut

By rednut,
in Engines & Forced Induction

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Cubes Grand Master

Cubes

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12.5psi & exhaust mine made 152rwkw with a little lean out via the fuel pressure reg.

Prior to the lean out it made ~140rwkw also.

Going from 12.5psi to 15psi didn't gain much. Only another 12rwkw. :P

Turbo's out of efficiency.

Bretto,

You are correct but dyno's do give a rough idea of the power it is making, especially if you have a base (stock) figure to work from.

rednut Collaborator

rednut

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I'm amazed at the different power figures everyone is getting off different dynos with different mods - its incredible!!! I might have to try a different dyno with a different tune and see what happens.

sxygtst - the power FC I've actually had in for a while now and on it's own, it made stuff all difference - even with a good tune. When you start doin other stuff, that's when the power FC really starts to make a difference over a stock ECU.

Bretto - you're absolutely right mate, I reckon a run down WSID will tell the whole story!!!

Cubes Grand Master

Cubes

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rednut,

What do you consider a really good tune? Was it done with the same tuner as previous tunes?

Different tuners lean on motors a little harder, spend a little more time getting the ignition timing near its limit. This is what makes good power or depending how carefull they are a broken motor. :P

Back in the Martin donnon days with Tilbrooks and their remaped ecu's the rb20det's used to run 1bar then drop back to ~13psi (nasty bleeders) by redline. ~13psi used to make around 170rwkw on their dyno.

rednut Collaborator

rednut

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rednut,

 

What do you consider a really good tune? Was it done with the same tuner as previous tunes?

 

Different tuners lean on motors a little harder, spend a little more time getting the ignition timing near its limit. This is what makes good power or depending how carefull they are a broken motor. :D

 

Back in the Martin donnon days with Tilbrooks and their remaped ecu's the rb20det's used to run 1bar then drop back to ~13psi (nasty bleeders) by redline. ~13psi used to make around 170rwkw on their dyno.

Thats just it mate - what is a good tune? I guess it depends on the tuner themselves and what you want it for. When I first got the power FC i took it to a guy in Sydney called Hitman, who is a gun tuner, but he mainly does rotary drag cars. I couldn't tell much difference then but my mate took his s6 RX7 there also and driving the rx7 after the tune, it would certainly be a handful on the track but the straight line speed is incredible. So once I got all this other work done, I took it to Unique Auto Sports instead, who specialise in Nissans. The bloke spent a couple of hours on the dyno then went for a short drive - a short time comparitively to re-tune a car. I guess the things i've learnt here is that tuning takes time to get it right for what you want and that a few tuning tweaks are needed.

bretto Proficient

bretto

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all i was trying to say sxygtst is that two different workshop dynos will almost definitely read differently. i have seen between two different workshops in brisbane a 35rwkw difference on an na car. so if your saying his is to low and he should be making an extra 10 - 15rwkw then its very possible that on another dyno he would easily make that. also different tuners will tune cars in different ways. depending on what the car is being tuned for there can be a significant difference in max power figures.

Roy Grand Master

Roy

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RB20s are completely different aninmals to RB25s.

On an RB25 you throw on some cam gears and make way more power. On an RB20 you dont get the same gain:(

Std RB25 ECUs suck, throw on some breathing mods and wind boost up and the ECUs does silly things with fuel and ignition. So once again a Power FC can make a big difference.

Now on an RB20, throw as many breathing mods as you like on your car, wind boost up to 14 psi and the thing will run pretty damn well. The ECU is much more flexible then the RB25ECU.

As for dyno figures...meh, ive discovered drag racing and i reckon mph is a more reliable way of comparing power...still nto fool proof , but better then this to that dyno.;)

rednut Collaborator

rednut

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So no real difference between the two tunes when driving?

Sorry dude - don't think I was quite clear...

Stock + Power FC = bugger all difference - a bit more responsive so I guess a few rwkw gain but hardly noticeble...

All mods I listed on first post = 166.3 rwkw and HEAPS of difference...

And that's just it, it feels faster than 166.3 rwkw - I can now easily keep up with my mates s6 rx7 which has 188 rwkw - yeah I know rotaries and RB's are like apples and oranges but then all the debate over dynos and shit is kinda proving to me that the drag strip is the best "real world" way to guage performance improvements. Watch this space for a time slip :)

Cubes Grand Master

Cubes

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ahh yes.. My misunderstanding.. :)

It would be nice to see a dyno graph scan. :)

166rwkw is where the turbo is fairly maxed out. Airflow is airflow and a turbo can only supply so much of it.

Mid range is where gains can be had, which is what you stated. ;)

I really would like to see the dyno graph scan as I have mine here making 164rwkw on 1bar with the stock ecu.

At 164rwkw it appeared to flatten out a little in the lower of mid range.

rednut Collaborator

rednut

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Roy - yeah i've heard RB25 ecu's are basically a paperweight once you start modifying them. And i'm subscribed to the "top RB20 club..." thread also and it seems you're having heaps of success by running yours down Calder and adjusting / tweaking stuff from there...definitely sounds like the way to go :)

Cubes - once i can be arsed to get to my mates place i'll definitely put up the dyno graph - and your exactly right, mid range is where all the fun (read:gain!) is, there's a massive power lump right up to about 6000 rpm and then it drops. And that's how I drive it now, short shifting!

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