Wolf 3D V4 vs PowerFC

[Sydneykid]

Hi guys, I have done back to back on a Dyno Dynamics (roller) and a Dynojet (hub). No atmospheric corrections, on the same day, both calibrated, using the same car and the Dynojet was 14 kw (20 hp) higher.

So 431 to 411, sounds OK to me.

[GTS-t VSPEC]

When I looked yesterday just before the dyno comp it was 50psi at idle, I believe it increases fuel pressure by 1psi per 1psi of boost, but not 100% sure.

One of the GTR's there was running 80psi of fuel pressure on 1000cc injectors, and still ran lean on 652rwhp:D

[GTS-t VSPEC]

The Dynojet hub dyno's are very accurate for repeatability, my only comment about them is that the load the car up hard, as there is no slip, and this brought a couple engines unstuck, and they take a long time to setup the cars, which for a dyno comp can be a little be annoying.

[Sydneykid]

Thanks GTS-t Vpsec, I don't have my book in front of me (it's at the workshop), but if I remember rightly an R33 GTST RB25DET runs 36/38 psi standard.

Now 50 psi is 39% higher, 370 cc's plus 39% = 514 cc's

514 cc's = around 514 bhp

514 bhp - 80 hp (losses) = 434 rwhp

Now the 411 rwhp makes sense.

I am no longer perplexed.

PS, as I said in a previous post, I personally don't like "overdriving" an injector more than 10%, it can cause reliability issues.

[GTS-t VSPEC]

Cool, glad your no longer perplexed:D I'll let you know if I have any reliablity issues, but so far so good:D I'll put forgies in soon and try and squeeze some more power out.

[Sydneykid]

Well Steve-SST, you issued a challenge.

"Get a PFC on a standard BR25 motor and injectors to run these numbers Mr Sydneykid"

I wasn't worried about this challenge, other than previously posted standard injectors at 40 psi fuel pressure bit....

But since GTS-t Vspec confirmed you are using 50 psi fuel pressure, it's a piece of cake!

So what shall we bet on us achieving this? I was thinking of $1K, but cash is so passe. How about the looser flies to the others city and washes and polishes his car for him and then flies back, same day?

[GTS-t VSPEC]

Haha, we've already done it. All you have to do is match it then you have earnt our respect;) Which sucker are you going to find to volunteer for this abuse on there car?

[Sydneykid]

Hi GTS-t VSPEC, maybe I don't have to get a sucker? And why would you think that you were the first? I haven't lost a bet yet, 'cause I only bet when I know I can't loose.

All I needed was the missing bit of information, 50 psi.

This and its associates were all great threads, thanks for starting them and for putting up with my persistance.

[GTS-t VSPEC]

I've enjoyed the debate immeasureably too, always great to thrash things out, and hopefully we've given all of SAU some valuable info to make a decision with.

I look forward to when you post a thread saying "Sydneykid gets 400+rwhp on stock injectors":D

[rb20-calais]

it only took like 300-400 posts to thrash it out but it definately kept me and probably 100+ people very interested.

Well done and glad to see that its worked out.

Evan

[Sydneykid]

Hi GTS-t VSPEC, maybe you should check the archives, we did it in late 1999 / early 2000 with an R34 GTT. We had no choice as there weren't any aftermarket injectors available for GTT's then. We used a Malpassi rising rate regulator and just kept turning up the pressure until it had enough fuel.

As I posted previously, reliability when "overdriving" injectors this much is suspect, we had 2 fail a few weeks later.

So please be careful.

[the phantom]

Thanks for clarifying the dyno point GTS-t VSPEC...fair enough,

One query however that puzzles me. Perhaps its wrong and someone can correct me with their experience. I was under the belief that a pressure increase across an orifice such as an injector does not equate linearly to flow, i.e. there is a square root term in there. So for a 39% increase in flow you would need 1.39X1.39 = 1.93, which implies a 93% increase in pressure, i.e 69.5 PSI from 36, not the 50 PSI indicated???

Are you still running the standard exhaust manifold GTS-t VSPEC or do yo have a custom manifold???

[rb20-calais]

The Phantom,

I think the base pressure is 50psi and with the adjustable reg upping fuel pressure 1psi for every 1psi of boost means that the fuel pressure @ 18psi of boost is 68psi which is close to your estimation.

Evan

[Steve]

I was of the understanding that if its a rising rate regulator, it will increase more than 1 psi for every psi boost, hence the 'rising' rate.

Also, normal fuel pressure regs raise the pressure linearly, 1psi for every psi of boost, same as an adjustable fuel pressure reg, which just allows base pressure to be raised.

Is this right?

[the phantom]

hey rb20-calais,

I meant that the pressure by my calculation (rightly or wrongly) would need to be 69.5 + 18 = 87.5 total at 18 PSI boost. With boost fighting against the fuel as it tries to escape from the injector, at 68 PSI fuel pressure and 18 psi boost, the effective pressure across the injector is still only 50PSI...68-18. The regulators just try to maintain a constant pressure across the injector, unless you have a regulator that is greater than 1:1 when you will then add to the effective pressure.

[N I B]

Paul posted early that he had the pumps and reg fitted.Injector life? who knows but we have many GTSs every week in here running many different setups without injector problems.

I don't think any shop in OZ sees more Skylines than us as WA has the biggest import scene in Australia, Fly over and check it out.

[SHUTO-BOY]

WA's wildest supra with twin GT30's is also managed by wolf3d, u have to see it to believe it-its an absolute beast

[N I B]

WAs soon to be Fastest GTR will be on a GTR plugin Wolf but the Supra we had at the show was not the one with the Wolf the White monster with the Blue stripes and NOS etc has the Wolf.

The Twin GT30ed job is my Drift racing ride for next season and we fitted an SM2 Autronic because we did not have the V4 Wolf on sale when we first built this car.Its on its 2nd life now but as the current ECU is a good thing we will leave it in. Both Supras could not use a Power fc with their mods as theirs to many inputs and outputs needed plus PFC can not drive low impedance injectors without risistors( not a good thing to have to Ad)

or control the Nos that both have or the boost or run dual maps like the white one has.You could not risk tuning a 1000hp motor on a hand contoller as slow as the PFC one or any hand controller for that matter.Wolf ECUs can be reconfigured to most applications so this is were it runs away from the PFC but on a strong road car a PFC is fine.Pauls GTS can switch from 330 to 430 hp in a second so dual maps is a nice thing to have .

Pick your tool but don't bag the other as their is good in both.

[JimX]

Even though maximum power wasn't an initial concern of mine (since I'm not likely to ever to be able to afford a 1000hp+ car), would it be safe to say that at <1000hp the PowerFC is better, and at >1000hp the Wolf is better?

[Cubes]

I've heard of PowerFC's having no problems runing 1000hp in Japan. BUT they have laptop programmability.