550's get into high duty cycles when reaching 400 bhp.
Looking for a comfort zone and thinking about 850's, but would have to run them at about 55%.

Will that be safe and easy to map?

 

850 x 4 / 5.5 x 0.55 x 1.15 = 391 ?

 

Overkill IMHO. You may have a crap idle depending on the granularity of the ECU injector pulse widths.

650s would be about right.

 

That's why I dont want your 850's windows.
Still holding out for Pat to come up Trumps on the 740's

Andy

 

LOL @ Andy

Thanks John, looks like I've bought injectors that are not suitable for my engine's spec, ****

If anyone wants to buy them or swap for 650's (750's?)get in touch.

Would I get away with 750's John if I cant get 650's?

 

740s would be fine, still very underutilised. 850s probably would as well, but some are getting 440 BHP out of 550s so you are mega overkill!

 

550s at what pressure? Idle's beginning to get 'interesting' at 4 bar I'm getting a jump from 13.2AFR to a not very happy 16.5 with the tiddliest fuel change I can do.
My rather iffy calcs suggest that 550s should be fine at 420ish - for rather brief periods - at 3.8 bar. But I'm not convinced, as I have no idea what pressure the 550s are usually measured at as being at 550...

 

I ran my 550's at 3.8 bar and made 440 bhp.
I could still hold a nice rich AFR of 10.8:1 whilst running flat out at over 170 mph at Elvington last weekend.

Depending on the actual efficiency of your engine, you could use much more fuel and achieve less power output.
The biggest players in this equation on the Subaru are the turbo and exhaust system.
For example if your turbo is innefficient, you will build a high exhaust backpressure. This will reduce the engine output but will still require fuel and air to overcome the pumping losses.

It's not so easy as saying xxx injectors are good for yyy bhp

Andy

 

Could possibly lay my hands on a set of 550's
Don't know why I never went for them to start with

If anyones interested in the 850's drop me an e-mail.
£350, they are cleaned and tested with new o-rings and pintle caps.

Or will swap for 550's, 650's or 740's

 

Brought the price of them down to £300 for a quick sale

At this rate they will be free by the morning

 

Phase 1 or phase 2 550's needed?

[Edited by AlanG - 7/21/2003 10:44:01 AM]

 

Thanks for the info on your findings, Andy.
I think I have something quite similar going on, so will give 3.8 bar a whirl & see what happens

 

Phase 1 550's if you have some please?

 

We only use 850's when at the drag strip, at 24-27PSI boost.

 

Pity.

Only got drop in phase II 550's.

Worth a try though

Alan

 

alan; are you selling your phase 2 "drop ins" ?
let me know mate..

[Edited by chrome - 7/22/2003 12:35:18 PM]

 

An e-mail is winding it's way to you as we speak....

Alan