Mate! Where has this beast been on all the cruises in S.A.??!

instead of using two bosch 044 pumps which will draw heaps of current, why not use a MSD voltage booster. What I have done is that on cruise and low load the pump runs normal voltage, but on high demand the voltage booster is switched by the EMS via a relay to put around 16-17 volts to the pump. There is plenty of fuel there for 700hp with less noise and less hassle. Also you 72lb injectors should be OK for 400rwkw.

There is also one bigger bosch pump than the 044. its B261205413. It flows 200l/hr at 8bar whilst the 044 flows 200@5bar. But last time I checked they were around $800

have you actually measured the available fuel flow at say 62psi rail pressure??

as for my 72's being good for 400rwkw, the problem i have at the minute is i dont know exactly how much power i am making... i may be somewhere near 400 now? but i doubt it...

what i do know for sure is.. right now, my 72s are seeing 92% duty cycle.. which i am uncomfortable with. who here has seen the effects of running such massive duty cycle???? with the autronic, it gives you a graph of the injector open time over the 4 cycles. ive had to adjust my injector end angle a fair bit to stop the inlet charge getting hit with two injector events..... THIS WOULD NOT HAPPEN WITH BIGGER INJECTORS. which is why i want them, if you have an onboard a/f meter running on datalogger at 20 samples/sec you can see what happens to the mixture stability when this starts happening, mine starts going bad at 90% (note: you cannot see this happening from the tailpipe mounted a/f meter, it needs to be in the dump pipe)

ill try draw it for those who are wondering what on earth the problem with duty cycles over 85% is


before someone points it out, i need to make a small correction here^^^^ the exhaust opening point in my diagram got moved when copy and pasting, its meant to be just to the left of the power/exhaust cycle marker

ok, by that, you see the issues, if you follow it along from say, compression, the injector is open all the way until into the start of the inlet by about 30-40deg depending on valve timing. what happens, the inlet opens, draws in all the charge mix sitting in the inlet tract... thats fine, however towards the end of the inlet event, you see the injector re-opens sometime before the inlet valve shuts... so you have a fresh fuel squirt entering in with the premixed lot.. 360 works out about the best compromise, i did start with 330, but that gives an even larger amount squirted in just before the inlet closes

ideally, most engines run best with ALL the injection squirted in BEFORE the valve even opens

hope someone can learn something from this brief lesson

cheers, brad

Last edited by ebs_4l on Thu Jan 17, 2008 4:48 pm, edited 1 time in total.

ye I learnt something from that. We mostly talk about injector duty cycle and how much the injector will cope with till it does not function but the point you raised is very important also.

You work it out with these figures that I did with a measured container a few years back

52psi @ 15v 2.5-2.6L per 30 sec
76psi @15v 2.5L per 30 sec
94 psi @15v 2.4 L per 30 sec

On this test I only ran at 15volts. At 17volts about 6l per min. Do your calcs from here.
The thing with the bosch pump was that flow did not decrease that much with increased pressure

I couldn't get much more than 13 to 13.5 volts at the pump without the booster. The booster will give a constant output voltage regardless of the input down to about 10volts.

slight improvement to my plans... they now include gt4294r and new split pulse exhaust manifold... my aim here is to lower the exhaust backpressure as much as possible

Good stuff. It will interesting to see the difference in power and spool time.

Have you had you car on the dyno in its current state of tune? Sorry if its been mentioned and I missed it.

nah havent had a run recently... next problem is fitting at gt42 in the engine bay

been a while since my last update... doesnt mean things havent progressed. Now I need to come up with a nice heat exchanger and pump system.. ive got some things in mind for this.. but i also want to incorporate a system for special occasions. eg, dyno comp

Hey,

Looking pretty good there. Where did you get the core for the W2A??? Wouldnt mind making my own.

Cheers

Daz

Ive got a garrett supplier in the U.S.. Ive settled on a turbo that i now want, a gt4202r 1.15 turbine 0.6 comp.. whether or not i can justify spending any more money on my car is a different story though

after ive got the w2a system under control, the plenum will be coming off for some reworking

What kind of power are you chasing? Thats a 1000hp turbo isnt it?

Cant wait to see the results.

don't snort do a liquid/air intercooler kit??

where you are going to mount that is going to restrict air flow to the radiator..

nice, but wat about air flow throu the radiator?

y the upgrade to bigger turbo?

its to mounted where ive shown it.. i cant see airflow being a problem. we'll see. It will have a small air gap between the cooler and the a/c condensor, and then, there is a bit of a gap between the a/c and the radiator, i think it will breathe enough in and around that area to work good enough.. the falcon fans do a great job. If i have issues, i may make a nice ally radiator with a racing spec core

Why the bigger turbo? because i personally beleive that at near 400kw, the gt35 is well past its best effiency.. sure, 450kw is achieveable if you squeeze the thing hard. but, why not achieve the figures you want with a turbo thats exactly in the best part of its intended effiency?? remember, the 1000hp figure is a MAX figure, not the BEST figure for the turbo... also, the exhaust side flows 31% better, so im hoping for very little exhaust backpressure... should go well with a 3.5in system

and, if later down the track i want to build a forged bottom end, then there is the option of winding the gt42 up