Trebor69

Hello all

I am currently running a MY93 WRX with following mods

HKS FMIC
HKS 3" Decat system
HKS powerflow air intake
HKS boost Gauge
VF34 Turbo -New
Walbro uprated fuel pump
Dawes Device at 1.1bar
Std Injectors...
Z4 ECU
4 pot fr calipers with grovved/vented discs (black diamond) with Tarox Pads
Steel brake hoses
17" kahn 5 spokes with F1's

Giving 285 BHP and 250LB torque

I am wondering what my next power upgrade would be..

I have the option of buying a set of STi V5/6 injectors (yellow), would these be a good set to fit.

I relaise I would then need to get an Ecu upgrade to run these injectors. I was thinking of a ScoobyECU..

Any advice or ideas will be greatly appreciated..

With running bigger injectors with ECU what benifits with tuning will these give me, Will I be able to run higher boost?

Could I run higer boost than 1.1 with my current setup?

What size are the yellow injectors?

Cheers

Rob

Johnny50

According to another thread, 440's are Yellow.

I'm running 440's on my 98UK car, with a VF30, and even then, i was advised to go to 550's, which i have.

Delboy2

Look HERE for info on injectors

Cheers

Trebor69

Ok...

So if I go for 550cc injectors what else will I need to do

Definately an ECU upgrade - Scooby ECU ok??

Will I need more fuel pressure, I am currently running a new Uprated Walbro pump.

What can i expect to gain with above mods?

Say 550cc injectors, ScoobyECU, VF34 Turbo, HKS FMIC, HKS Poweflow Air intake, HKS 3" De-cat Exhaust system?

Would I still run at 1.1 bar or could I hike this up?

Looking forward to your replies

Delboy2

I thought you were running a Unichip with your'e current setup? The Unichip is mappable?

Cheers

Trebor69

Hello M8

Yes I do have a Uni-chip fitted (currently disconneted as trying out Z4 ECU), but I was told some time back by somebody in the know, that a Uni-chip can't cope with Bigger injectors or it wont work for some reason... or is this Borrocks..... Anyone

Rob

RB5_245

I'd say go for 440's if you don't want to go for a bigger turbo in the future. Scoob 440's are 440cc @ 2.5bar, so if you up the fuel pressure, you up the flowrate of the injector.

440's should be good for 350bhp @ 4 bar, which is more than you'll get from a VF34.

The 550's suffer from a poor single nozzle set up IMHO, you'd get a far better idle and part throttle drive using 440's i'd say.

I use 550's but would upgrade to 740's even though i've not reached there limits, if i had the money at the moment.

Just my opinion, but i feel i suffer from a poor idle (has to be kept at 1k rpm) and some spluttery low rev action from these injectors.

Dave.

Trebor69

Cheers for info ....

One question I wish to ask.

So with upgraded injectors and ECU, How exactly is the extra power gained...

By running higher boost levels as we can fuel more.

Or same boost level as before but ???????

Would like to understand this area a bit more

Anyone?????? Bueller Bueller??

Erik

May I put 440 injectors into 98 car with standard ECU or is it a way to overfueled low and midrange only?
If I change my OE pump to Walbro is it enoguh to run up to 1,1bar with VF23?

Scoty

IMHO it's down to who maps the car.

Mines idles like a bog standard turbo (550's fitted)

Idle was crap when someone else mapped it with the same injectors.

Delboy2

Mine Idles pretty well on 550's with a custom mapped scoobyecu
You mention an uprated Fuel Pump but no FPR - It would be advisable to fit an uprated FPR as the Pump will easily be able to over-run the tiny stock item making mapping awkward
You should be able to run more boost with this setup but again its down to the mapper


Cheers

RB5_245

What you say about the mapping is quite possible, I would have thought the spluttery low revs were down to the injectors but it also could be that the ecu is having to stick too much timing on for idle stabilization and is not coming back perfect as you move up the load sites.

Erik, IIRC a 98uk car has 440's as standard. I assume the jap ones do to (wouldn't put to much money on it).

Trebor, it's all down to air fuel ratio. To simlify it greatly for 'x' mass of air you need 'y' mass of fuel. Therefor the injectors don't matter as you're only putting in enough fuel for the best combustion.

Manufacturers map rich anyways so if you changed the ecu and kept everything else including boost, standard you would actually reduce the amount of fuel going in. As you make mods to the car, de-cat, higher boost, bigger intercooler say, you would get more mass of air into the engine so up the fuelling.

Before anyone says I've not mentioned ignition advance on purpose.

Dave.

Johnny50

Dave.. 98Uk cars run 380cc as standard.

Trebor69

Ok then chaps......

So when I fit bigger injectors I need to get more air into engine so I can use the 'bigger injectors' otherwise I would only get same power as before but obviously the injectors not be working as hard as the 380cc ones.

So to get more air into the engine I would then turn up the boost pressure?, that way more is getting in and so more fuel with bigger injectors is more power... and torque....

Do I take it that the VF34 is a fairly big turbo? I am not fully conversent on how at same boost level some turbos push more air....

So if above is true, then I will be needing to up the Boost to make use of bigger injectors and ECU?

Will my Walbro fuel pump (from powerstation) be man enough to supply the amount of fuel pressure i will be needing or will I be needing something else on the fuel line?

Currently I am running 1.15 bar, with correct fueling with bigger injectors/ECU what boost could I safely run on a WRX Engine with FMIC etc etc?

I will be gettting a Lambalink and knocklink fitted before doing any of the above.

As I allready have a FMIC and Decat 3" system with HKS air intake and the VF34 turbo, could I maybe just take the car in to be mapped with Unichip and see how high I can get it with current setup? I.E try for 1.3/4 bar boost???

Thanks for listening

Again, looking foward to your replies.

P.S Delboy2 , If I remember right you went to biggers injectors and hence Scooby ECU.. How did this turn out, what gains do you achieve

Rob

RB5_245

Johnny50, I thought the 98uk was the same spec as the 99uk, which definetly has 440's? I may easily be wrong.

Trebor, I think 1.3 bar should sort you out just fine, the limiting factor here is that only the sti heads have sodium cooled exhaust valves, WRX does not. With your set up you should be able to push 340bhp if you upgrade the headers, otherwise i'd say you'd get around 320bhp @1.3bar which should be a nice set up.

With a bigger turbo and headers @say 1.4 bar you should be able to push on to around 400bhp

Dave

Johnny50

Dave, definately 380cc matey.
I changed mine up to 440's from a MY00 a month or so ago.
But seeing as i'm going for the bigger turbo, i'm going to 550's.

Trebor69

Dave are you saying 1.3 bar with current setup then? Without injectors/ECU?

Regarding the VF34 Turbo, what can I expect to go with this turbo?

Cheers
Rob

RB5_245

Actually for 1.3 Bar you would probably hit the limit on those injectors.

To calculate your fuel flow in cc's(roughly) use:

horsepower x 5.6 (which is a constant) then divide that by 4(the number of cylinders).

380's would flow about 450cc's @ 4bar, but bear in mind you don't want to go over about 85 per cent duty cycle on them IMHO. So 85 percent of 450 would be your max fuel flow on 380's.

Dave.

Scoty

Rob, get in touch with Andy F for an ECU upgrade and remap, I can highly recommend him.

andyf9000@hotmail.com

I have owned an Impreza for a few years now and had various different ECU's (Link/GEMS/Apexi) and remaps by different mappers, only the best mapper get's a mention
Andy fitted and mapped an Apexi Power FC, I also have a TD05/06 20G turbo fitted which Andy makes and supplies.

You have already got the most of the parts you need, the walbro pump will be fine if it's the 255 ltr one.
If it was me, and the money was there, I would be looking at a TD05/06 20G turbo, a set of 550's, and a Power FC and AVC-R boost controller.
With the adition of these mods, depending on what boost you run and how much your engine can be pushed during mapping, your looking anywhere between 375 and 425 bhp (roughly)
Boost target would probably be 1.3 - 1.4 bar on the 20G if you wanted to go that high.

DreXeL

I am in the middle of upgrading my UK MY97 to roughly the same spec as you Trebor, the difference being I have some Tony Law headers, and a Power FC which is being mapped by Andy F on thursday of next week. I'm also fitting 550cc injectors, and a Greddy e-01 boost controller. I intend to run 1.4bar midrange, tailing off to about 1.2bar at the top. I'm hoping for around 330-340bhp. The good thing is I will have everything in place for getting near 400bhp, I would just need to upgrade the VF34 to a TD05/06 20G (and get a further remap obviously).

My car will be finished next week, I'll post and let you know the outcome.

RB5_245

The Power FC if MAF based is it not? Maybe ok on the older cars But personally I'd be getting rid of that damn sensor soon as possible!

I think it mat be possible to convert the power fc to map based (IIRC) but if not link or gems would be the way to go imho.

Also with a decent ecu, using a £600 boost controller is a waste of money....... Although the profec e-01 may be the coolest thing i've ever seen in my life

Dave

Scoty

The Power FC uses the MAF unlike the GEMS or Link.

The GEMS mainly uses the MAP sensor and an airtemp sensor, but if the MAP sensor fails you can say by by to driving any further, at least you would be able to drive home on a faulty MAF off boost.

I havent had a MAF sensor fail yet, 4 different type's of filters later! (MY98)
Having the choice of being able to remove the MAF and get a Link or GEMS fitted again: or, keep Andy's map and Apexi Power FC, I'll be keeping the Apexi.
I have no intentions of removing it or having anyone else map it.
Bear in mind, I've had the Link and GEMS fitted, and removed them, which was probably due to my confidence in the mappers who mapped them more than anything else.

TBH as soon as I heard Andy was mapping I knew I would be paying him a visit.
I've watched the progress and pioneering development he has made with his own car over the past few years; which ended up holding the quickest quarter mile time in the UK for a 2 ltr.....even with standard internals!!

With the AVC-R you can set in gear boost targets, so there is instant advantages over the ECU controlling the boost straight away.
You should be able to pick up a used AVC-R for under £250, or keep the Dawes imho.
I had a GEMS controlling the ECU with a 3 port boost solendoid, decided to refit my Dawes just to see if there would be any difference.
The GEMS produced a nice flat boost control line, but imho it felt tame compaired to the Dawes, who cares what it looks like on paper it's how it feels and go's on the road that counts

DreXeL

Well, the Power FC is much less expensive than a Link or Gems, which is the main reason I went for one. With regards to boost control, you need some sort of controller with the Power FC, or get the boost control kit for it which is extra.

The Profec e-01 does indeed look utterly cool in the car, and I didn't pay £600 for it, it was £380 from GetGreddy.co.uk.

RB5_245

My Dislike of maf sensors comes from going through 3 of them since I owned the car. Could alway's carry a spare map sensor in the glovebox, I know if i still had a maf I'd be doing that.

May give it a shot with the Dawes back on though to see how it goes.

Dave

Andy.F

The Power FC _can_ control boost but only to the limit of the cars OE map sensor which varies by year. After that you would need either a boost control kit (which consists of a 3 bar map sensor and fast acting 3 port solenoid) or for a few pounds more, I'd recommend an AVC-R. This allows individual gear trimming of the boost ie full boost can be attained in 1st gear and then in 5th gear it can be tapered off to avoid high speed problems. The boost curve can also be set at 500 rpm intervals.

Strange how some cars suffer lots of MAF sensor failures and others of the same year take all sorts of abuse without issue.

For what it's worth, I'm looking at integrating the MAP conversion (that JB is working on) with the Power FC in the near future, although it is possible to retrofit either the earlier MAF or the Nissan version for piece of mind on 99/00 cars.

Andy

DreXeL

I stand corrected, I thought you needed the boost control kit for any kind of boost control.

So, do you think I'll get my 330-340bhp next week then Andy?

Andy.F

It depends on the rolling road you frequent ? It should be in that region, some rollers may be lower and some higher

Andy

DreXeL

I normally use Powerstation, notoriously low reading I know. I'd be happy with 320ish there to be honest.

Andy.F

The only problem with Powerstation is that they do not use the DIN correction for pressure and temperature. You only get P-eng, not P-norm which is what you get at any other fully functioning rolling road.
Atmospheric conditions can give rise to around 20% difference in figures, the purpose of the DIN correction is to allow warm/cold day or high atmo pressure/low atmo pressure day readings to be comparable.
Perhaps someone should suggest to them that they recomission their temp/pressure sensors for some realistic readings. (sorry for the rant !)

Andy

dougies549

Hi Scotty

Just the way i am reading this ,it's like Sam and Steve simpson are crap at Mapping and Andy is some kind of God.

Just wondering!!! Are you trying to compair your car now to when Sam mapped it??, if so i can't see how you can do that as it is Totally diffrent now to then!!!!!!. A whole load of diffrent component's

Dougie