I have a MY95 WRX with a full decat and Samco turbo hoses, other than that the engine is std, i.e. fuel pump, fuel regulator, 380 injectors, TD05, slanty IC.

Always use Optimax and NF OB, also I am monitoring AFR, EGT, boost and knock (max sensitivity) - running 14.5 psi with a Dawes. At the moment the only yellow LED knock activity I see is at 5000+ rpm in top - and thats building up slowly i.e. one green, then two, one yellow then two then lift off the throttle! Not sure whether this is noise or det.

I am soon to junk the Dawes and get a remap to run 16.5 psi, hopefully to break the 300 bhp barrier (well at PE anyway ) so my questions are:

1. Will my current spec be able to run the extra boost?
2. I read the std fuel pump is near its limit for std boost, do I need to uprate it?
3. Will the std regulator handle an uprated pump?
4. Can the std regulator and 380's deliver enough fuel for my application?

I'm about to put the car in for its 60,000 mile service which includes a fuel filter change, so since the mechanic is in the region this would be a good time to change the pump if neccessary.

Thanks for any advice in advance

Justin

 

Justin,

All ide say about an uprated fuel pump is if you want to make full use of it, fit an uprated regulator.

I got my uprated pump and reg from Mark at Lateral Performance. Also with the package comes a guage to measure fuel pressure at the regulator. Very handy bit of equipment which will relieve any doubts you may have about not getting enough fuel

Mark

 

Sparkster, how much for the pump kit?

 

Leeroy,

I think the Walbro fuel pump with the guage is £120 + vat. Not 100% sure though.!!

 

"If I run an uprated regulator then would I be right in saying that the car would run rich if the map was based on the OE regulator?"

This is a good question and something i really would like to know. My thoughts are that the ECU will fuel the car based on the volume of air coming in past the MAF. Theoretically speaking, requests for fuel will remain the same and hence supplies will remain the same.

However, if the car runs higher boost for example and there is a request for large quantities of fuel made by the ECU. If your standard fuel pump and regulator are no good, the correct quantity of fuel will not be supplied (although requested)
and hence, your car will not run to optimum capabilities.

As far as i'm concerned, modifying an engine revolves around air and fuel. A good start is to make sure that the source of your modifications are strong. Its a good base to build on.

This is my understanding of the benefits of both uprated fuel pump and regulator - i certainly aint no expert.

Leeroy, ive misplaced the invoice for the pump kit. Mark at Lateral performance was able to supply an uprated FSE regulator with pressure guage and an uprated Walbro fuel pump posted and packaged including VAT for £234 (i think - give or take a couple of pounds - cant remember exactly)

Mark

 

I believe the answer there is yes and no! When the car is on low throttle positions, it would run with closed loop control off the lambda sensor (which effectively measures your AFR). Therefore, up to a certain amount, the ECU will alter the injector duty cycle to get the mixture right. When you open the throttle wide, the ECU goes into open loop mode, doesn't monitor the lamda, and just throws fuel in. At this stage, it could be running rich unless you have a remap.

Health warning: This is my understanding rather than fact. If someone like JB or Bob Rawle comes on and contradicts me, it'll be them that is right and not me!

 

Hades,

Do you think that the uprated fuel pump and reg might help to reduce my knocking probs

Mark

 

If you're detting at full throttle, particularly at high revs, then it ought to help; it will make the open loop mixture richer, which reduces in cylinder temps and should reduce det. However, there could be something else at the root of your problem - e.g. high charge temps - which should be put right. IMHO the best way to solve a knocking problem would be to get a proper re-map from someone who knows what they are doing; they should also be able to tell you if there are other problems to solve

 

thanks for that. Just trying to find a cheap and cheerful way.

 

"When you open the throttle wide, the ECU goes into open loop mode, doesn't monitor the lamda, and just throws fuel in."

Could you elaborate WRT throwing fuel in?

I believe it ignores the lambda and calculates fuelling based on rpm, tps and boost target, referencing pre-determined tables in the open loop section of the map - this map based on OE regulator and 380 injectors.

Elaborating on my question, assuming the remap allows boost targets of 16.5 psi and all relevent tables are in the map, bearing in mind the fuel pump is uprated - will the OE regulator and 380 injectors pass enough fuel for 16.5 psi with a RA TD05?

I think it will, just want to be sure. The worst case is I will find out once I get the remap, if I need a uprated regulator then I'll get it in due course.

Justin

 

Entirely true. "Just throwing fuel in" was a bit of an oversimplification, but it made my point!

I believe that 300bhp is nearing the limit of 380s with a standard regulator, although my MY02 WRX at 284bhp still had some injector duty cycle to spare on a standard fuel system. Hence, I agree with your "probably", but suggest to check with someone who knows more than me (Mark at lateral performance, Bob Rawle, John Banks or whoever is doing your map being prime candidates)

 

Jay,
The fuel filter is under the bonnet m8, next to the right strut as you look at it, whereas the pump is under the boot floor and is supplied with a new 'sock' filter to go over it.

You should be able to do the pump yourself. Run it pretty low on fuel first though. You can bend the pump bracket a little so it picks up lower in the tank, and this can help reduce fuel surge when you're running low.

The regulator is a different situation altogether. Its mounted down by the turbo and is a pig to get to. maybe best to get your mechanic to sort this for you.

I changed my pump and reg for the setup recommended by mark @ lateral, he was great and talked me through the tricky bits.

Since i fitted the new pump and reg, the knock link has been even quieter than it was before, and i have not seen any readings other than normal engine noise since.

hope this helps,
simon

 

Simon

Cheers for that, it does help

I saw a guide to fitting the pump, it mentioned a filter to which I assumed was THE fuel filter. Apparently not, its more of a strainer than the filter! So the pump isn't even approached during the 60,000 mile service, which means I don't have to fork out an extra £120+ on top of the service this month

So now there is no rush for the pump, as long as I get it before the remap. Which is rather handy this month.

Justin

 

Simon,

Just out of interest. What sort of performance improvement will i see after the fitting of my uprated pump + reg?

I wish i could find the time to get these fitted. I start work before garages open and after they close. My mods are just sitting gathering dust

Ta

Mark.

 

You probably won't notice too much of a performance gain.

What you will find, though, is that delivery is a lot smoother.

due to a ****-up on my part i did the regulator a couple of days before the pump, and the reg on its own made delivery quite a lot smoother.

My car always fuelled ok unless i was really nailing it, but the new pump and reg have completely eliminated det.

pump you can fit yourself really easily- shouldn't take more than an hour so don't let lack of time put you off. make sure you have the right tools (to work in a confined space) if you do the reg as well.

simon

ps. theres an FSE regulator in 'for sale' at the mo.

[Edited by RRH - 4/13/2003 11:06:52 PM]

 

If I run an uprated regulator then would I be right in saying that the car would run rich if the map was based on the OE regulator?

[Edited by Jay m A - 4/9/2003 5:38:47 PM]