411rwhp from stock internals

[Steve]

Interesting too that the power is better at lower boost than the XTR GT3040 fitted to Ben Ellis's R34 with cams. 11sec car there with the right rubber (and driver:D)

Would be interesting to see how much manifold back pressure there is with that turbine housing.

[Sydneykid]

Hi GTS-t VSPEC, you don't happen top have the A/F ratios from the dyno run by any chance?

[Steve]

didnt he say it was 11.5/1?

[Sydneykid]

Hi guys, it would be nice if just adding a plenum dramatically improved the efficiency of the engine. But it is well proven that RB's are over 90% standard, some measurements put them at 92%. There is no way any plenum can make a 370 cc injector flow 130% of its rated capacity.

It might improve the airflow, but that's not petrol. Remember there is only 8 to 10% efficiency left to get to 100% and there is no engine around that is 100% efficient. A Formula 1 engine is 97.2%, from memory.

So I'm still perplexed.............

[Guest RedLineGTR]

congrats man...very sweet power.

[Sydneykid]

Sorry Steve "about 11.5 to 1" isn't good enough for calculations. It also just makes it more difficult to understand, 370 bhp is based on 12 to 1. With 11.5 being 4% richer, that makes the max flow capacity 355 bhp.

mmmmmmmmmmmmm?

[raist60]

I think the answer was brought out when VSPEC said that other cars at his dyno are pulling 350horses with standard injectors. I think once again people are throwing blind faith at dynos being accurate. Not trying to detract from your car in anyway dude but its seriously baffling, but i think you'll find if more than 1 car with standard injectors are making magic pixie land kinda power on the same dyno then the dyno is not on par with other dynos.

my 2 cents sorry again if i seem to be raining on your results man.

[Steve]

There are more than just WA guys making over 260rwkw with stock injectors - unless you think all dyno dynamics dynos are out?

You would have to be winding in huge correction figures to be out by over 60 hp - it just isnt happening.

[Sydneykid]

Hi Steve, as I said before I am always suspicious when I see things that don't agree with the common laws of physics. Might I respectfully suggest that I see a lot of horsepower numbers out of WA that don't seem to be supported with track results. One example is the HPI Street Drag Challenge, out of the 50 cars listed (top 10 of each class) there is only 1 WA car on the list.

Maybe there are a whole pile of other reasons, but I see a huge number of very high powered WA cars in every magazine I pick up. But I don't see the track results that support it. Maybe I am not looking in the right places, it is just what I personally have observed.

Maybe it's just my sceptical nature.

[Steve]

Well, I can name a couple of guys here in SA off the top of my head, one making just under 350rwhp another over 350rwhp - that was on the morpowa dyno, tuned by martin donnon (in one case) - and he doesnt fudge figures to cater to anyones ego.

The problem I beleive is often people just dont want to believe that something is possible if it flies in the face of everything they have thought to be true.

As for dyno figures in WA, there is a dynojet dyno in Myaree (suburb of perth) that reads incredibly high - I had a mate in WA that had 298rwhp with a turbo back and 12psi of boost on an R33, alot of people who just want a figure to brag about use it, its one that is favoured I believe by X-speed, so you are quite right to think along those lines.

The dyno that Paul used isnt that dyno - its a dyno dynamics dyno. I have seen a handful of kw difference between dyno dynamics dynos, but not as much as people are suggesting.

I dont blame you for being sceptical, it is pretty bloody incredible - but maybe there is something new for people to learn here.

[rob77]

I'm making 339hp @ wheels (on 1bar) currently, but at the flow limits of the stock exhaust manifold, as we had to pull a reasonable amount of timing out of the top end to stop it from pinging. I also think its getting fairly hot in there now too, so I need to wrap my dump pipe and get a ceramic coated exhaust manifold to help keep it a bit cooler. I know I am definately running stock injectors I had them ripped out, cleaned and tested for flow. All were flowing well and had excellent spray patterns and I'm also at only just touching 70% duty cycle on them. It will be good when I finally replaced the stock manifold and find out what the turbo is capable of with perhaps 1.2bar on the dial, just to try it out and then do the pistons to make sure its going to hold together Nice figure paul... *sigh* I dont think I'll ever catch you.

[Guilt-Toy]

can you please list every mod done to the car. I am chasing 400rwhp also. very impressed that it can be done with STOCK injectors.

How much is your fuel pump worth ?

[Sydneykid]

Hi Steve.... This is not really an experience thing, this is simple mathematics. Fuel is calories, calories equal power. There is no substitute. You can stick more air in, you can do it more efficiently, you can do whatever you like, but in order to make more power, you need more fuel.

We have had 4 models of Dyno Dynamics, and I can tell you our operator got a reading 10 times that which the engine was possibly able to deliver. Just 'coz its a DD, doesn't mean its always perfectly accurate. The human element can over-ride the electronics in a multitude of ways.

If I wanna get a DD to read high, I can alter the "eletronic settings", but that shows up on the bottom of the screen in shootout mode. But, I can alter the "physical settings", and that shows up nowhere. It's as simple as popping the cover and standing on the load cell.

I assume the DynoJet is hub driven (no rollers). They obviously show higher readings because there are no tyre and roller losses. Our experience has been about half, this would be the equivalent to 190rwkw on a DD. Seems about right to me.

Hope that makes sense.

[Hicks]

The fuel pump is a bosch 910. You can pick em up for about $250.

[Hicks]

Answering Questions on behalf of Paul,

Mods,

GT30,

Custom exaust manifold,

Greddy plenum,

910 fuel pump,

Malpassi fuel reg,

Front mount,

twin plate clutch,

exaust,

blitz filter?,

Wolf ECU,

And a whole heap of stickers, and a BIG RICEY wing

Did I miss anything, Paul?? (hope you don't mind me givin away your secrets)

[Cubes]

When I had my Bosh 910 fuel pump fitted, I was told that it max's out around the mid 200's (rwkw). Or is that wrong?

I thought for 300rwkw or 402rwhp you need a Bosh040 pump which is nasty and loud.

[rev210]

I think maybe pointing the finger at the flow rating on side feed fuel injectors might be in order. I mean when people say 370cc or 550cc for any injector that rated delivery is particular to some kind of set pressure and fuel flow delivery. The fact that increasing the fuel line diameter from whatever to 1/2 inch can yeild additional headroom for fuel systems at the final delivery point speaks to some of this issue.

Simply 'flow testing' at your injector service center can't tell you the delivery potential of that injector in your vehicles enviroment. It is a fact conected to properly setting up the right fuel jet on a nitrous system. Each jet, although sized according to the hole diameter must be flow tested against the flow jet on the point of connection to the fuel system.

Anyway anyone like to have a go at the standard for injector sizing?

[rob77]

Doesnt appear so, I also have the bosch 910 pump. The DD dyno at SST reads low, we could go to another dyno if you want and it'd probably show 450hp or slightly more. There are a few large hearted dyno's here in Perth.

[Sydneykid]

Hi Guys. Injector flow benches have the capacity to alter flow rates and pressures. This is the same as larger fuel lines and a higher flow rate, pump. So on the flow bench, we can duplicate any condition. SO, lemme tell ya, increase the flow from the pump makes no difference to the flow rate of the injector, as long as the flow rate from the pump is GREATER, than the flow rate fron the injector. THE only thing that increases the flow rate from the injector, is increasing the pressure.

At 38 psi R33GTST injectors always flow 370cc's, + or - 2%. Increasing that by 2 psi increases the flow rate to around 380ccs.

Hi Rob77, I'll post the flow rates of all the fuel pumps tomorrow when I get to the shop.

Hope that helps.

[GTS-t VSPEC]

Sydneykid, I'll get the plot of power vs AFR's for you tommorow and then post it up, to see if that helps your calculations. The injectors are definately standard, as there the right colour, and if they were 550cc's then I'm sure the stock computer I had in there when I bought it would not have like it at all:D

As far as the dyno reading high: It was in shootout mode, so all the figures are there, all adjustable settings have been removed so no fudge factors can be entered. All cars dynoed on SST's read lower than most other dyno's in Perth, and Dyno Dynamics brought there car and tested it was accurate.

There are a number of other cars making around 350rwhp on stock injectors. Rob77 made 344rwhp (70% duty cycle) with stock injectors and no malpassi fuel reg., so I suggest that somewhere along the line the estimation that the stock injectors only flow 370cc might be wrong:D

Hicks, That's the majority of mods:D

Joel, Go the 910, nice and quite and flows heaps. I have my external, with the standard pump feeding the surge tank.