as title, anyone know?

will be replacing injectors soon when ive found some decent ones, but just wondered the above for the time being.

cheers
ian :)

Thats a very good question. Anybody in the know about it? I know that I'm crazy with my boost (1.3-1.5 bar) but I can't be sure about it being safe. I think the problem is more when you're using part throttle (closed loop) where it relies on you MAF to sort the fueling out. But you have the SAFC so you could easily adjust that.

yeah ive got the s-afc, and a walbro 255ltr pump, however, its the max flow rate of the injectors thats the problem :(

ian :)

My MY94 STI is running 19PSI at the moment, on a TD05, and seems to be more than happy with it. As an STI, it may have the 440cc injectors, it's unknown at the moment, but the engine is standard and showing 282BHP/272LB, but I do run it on a rich fuel mixture.

measure afr and inlet temps and work it out for yourself...

my std td05 runs 22psi but Ive got 550's

David

My MY94 WRX was running a TD05 and with 380 injectors I was getting 294 bhp at 1.2 bar peak and 1.1 held, but that was at 100% IDC (standard fuel pump though).

Oops, that was using the 7000 rpm limit. I now have STi V heads, PACE FMIC and 550 injectors and uprated fuel pump and run 330 bhp, still at 1.2 peak 1.1 held, and have a 7500 red line.

Paul, I think the STi V1/2 has 380cc Injectors.

I am also interested in this question as I will be fitting a f/e TD05 in the new year, I was thinking of keeping the boost fairly sane, around 1.2bar, but I am still concerned about how hard this will be working the std injectors.

Andrew...

Is Andy.F still using his standard injectors? I'm just too lazy to do some more calcs as its the christmas holiday now for me. :D

I'm running 1.4 bar tailing to around 1.25 bar on 380's but i have an uprated regulator and fmic :)

My MD304 tails off to 1.3 bar at the top and runs 80% IDC at 11.4:1 at std fuel pressure on 550cc injectors. Seems to flow similar to a TD05? Check with a wideband - if not you could well be a LOT leaner than you think and have nightmares with ignition timing.

John, my car was checked on Sam's wideband and everything was ok, however this is the upper limit and have now begun a quest for bigger injectors :D

AndrewC - You could well be right ! :D Would be interesting to check what my injector duty is doing, if they are 380cc's then I must be getting close to 100% I would of thought, especially with the high inlet temps I'll be getting with my battered TMIC.

JB - Could you confirm who this comment is for ? You've got me worried now....

I'm still running rich at the top end (11.4, John! Wow! Still, guess the WB helps) with a front entry td05. 18psi at the redline is just hitting 95% idc with 440's. Just over 19psi is no problem through the mid-range (but I've leaned it a bit there :)).

Mine is around 10.6 from 6k on...if the OE lambda is to be believed (and I don't think it can be :)).

With 380's you need to be v.v.v.v.careful I'd say! Drop boost above 6k, taper it to 14 or 15 psi. You really need some way of monitoring fuelling, and be exceedingly safe until a WB can confirm whatever your stock lambda is telling you.

If you're not planning on remapping then talk to Mark about a rising rate regulator - will take some time with a WB to set up optimally, but it should solve short term problems.

Richard

Here's the equations form 'Maximum Boost - Corkey bell' :

Cubic centimeters/min = pounds of fuel/hour * 10.5

Pounds of fuel/hour = bhp * 0.55 / no. of injectors

So for 380cc injectors this works out at about 265 bhp. At bit conservative maybe but if i go past 16.5 psi boost (probably about 275-280 bhp) i'd definately want to get bigger injectors. I'd say that if you pushed your luck then 300bhp may be possible. Definately need Mark's famous fuel pump tho.

Tony.

Then again Andy F has 360 ish with 380cc injectors :confused:

Was running 1.18bar on 330's with std pump and remap..
317bhp - 290lb/ft
How lean was i running though!!!!!!!
Now have fmic, pump and rising rate reg...
Still on baby injectors though... but down to 1.1bar now...
Tried the car at 1.2bar with current set up and its gotta be running lean still, it feels much quicker than before!!!!!!
Good AFR readings but not sure about EGT's YET...
Rob.
p.s. no knock display at 1.2bar... maybe a green every now and then.

Tony - I think you'll find Andy doesn't play by the rules, his charge is not entirely composed of flammable contents via the 4 stock injectors...or the 5th useless one :D

Richard

Why did they put the 5th injector on the car in the first place again? I keep hearing that it doesn't work!

The injector was there so the rally cars could use it.... no other reason.

Tony.

This thread is making interesting reading - I was wondering after my third Well Lane result why with the boost I was reaching why my power output seemed low, and suspected the fuelling/injectors to be the limiting factor. Also made me reconsider my second results at Well Lane, where in warmer air temperatures than Run 1 and 3 the power figures were down to 254BHP, and encountering some detting as well. At the time, I put it down to trying Optimax with octane booster, but now I'm wondering if because of the cooler ambient temperatures I'm simply putting slightly less stress on the fuelling system of my car.

Well, I think the answer to the original question seems to be around the 280-300BHP mark : my plans are to go to 550cc injectors, with upgraded fuel pump. Although I have my own source for these items, other than Mark .... :D As for intercooler, I can't decide wether to try out an uprated TMIC, or go the whole hog and plump for the FMIC. I know it makes more sense, the FMIC, but the TMIC option is so much more simpler to install.

Of course, I could be completly wrong about all this....

[Edited by BoxerFlat4 - 12/13/2002 6:32:30 PM]

Tone, there must be a way to make it work. I mean, its even plumbed in right?

Anyway Boxer, get a FMIC. Its like choosing between a 16" alloy and a 17". You'd soon get bored of the 16"s..

To be honest i always thought it actually worked.... it's only thru' Andy looking in to it that it seems it does diddly squat. It must be able to work some how.... the group a rally cars had to use the standard ecu. This of course was remapped tho.... even so there must be a way of getting it to work.

Tony.

Can the 5th injector inject water instead??
Could be a cheap way forward regarding DIY water injection..
Rob

Tell me when you find out mate as you guys are the masters of mapping. Saves me money from buying a set of new injectors. :D

Tony -

Problem is, as been "hinted" by others, that the early standard ECU is capable of many things, even ALS. May not be true, but....
Wouldn't suprise me to find some sort of control system for a 5th injector in there somewhere.

There's no doubt in my mind that ALS and 5th injector control is possible.... the rally cars did it and they just has remapped Jecs ECUs (or so the rules said but i think i've been a bit naive when it comes to interpreting the rules ;) ).

Tony.

Chances are that it can be turned on, but its not worth it... just go with 550's or 850s I use an aquamist 1s kit on mine :D

works well..

David

I'd rather use my 5th injector as this was the reason why I sold my old car and got an RA, not a newer WRX which I could've. I only found out that it was a dud a few days after I bought this car when Andy did his experiment. :(

If you can find a way David to use your chip and activate the fifth injector, you'll be my hero forever. Besides, I keep forgetting to put water in the water spray container, imagine runnign out of water for a water injection kit.

thats the only reason you bought an ra??

If your basing your mods on the fact it has a 5th injector then you've got problems :D

I wont be looking for the 5th injector value, as I cant be arsed :D

David

I don't think it's worth making the 5th injector work:

4 * 440 = 1760cc/min
5 * 380 = 1900cc/min
4 * 550 = 2200cc/min

For the cost of 550's I'd go with them, interesting thread though, there seems to be quite a wide range of power @ boost v IDC which don't all seem to match, proving yet again that there are many other factors to take into consideration and that boost isn't everything.

Andrew...