Will this AFPR be OK?

[khartley]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=5514546687&ssPageName=STRK:MEWA:IT

Is this one OK or is there a better one out there for less? Let me know.

 

[TimG]

Are you going to try to raise the fuel pressure or lower it?

 

[khartley]

Well, I haven't got the Walbro 255 on yet, but when I do I figured that I'm going to need some way to keep it from running lean, so raise the fuel pressure I guess.

 

[spendone]

Yea Im looking for one myself but the ad does say it allows you to adjust from 25-60 psi. I dont think Im pushing 60 psi of fuel anytime soon.

 

[khartley]

Yea Im looking for one myself but the ad does say it allows you to adjust from 25-60 psi. I dont think Im pushing 60 psi of fuel anytime soon.

So, how about you buy it and then tell me how it works, then maybe I'll get one too! j/k

 

[dsmtrance]

The B&M I would'nt recommend. You can only raise FP w/ it. The problem most run into w/ the 255 is overrunning the stock reg. at idle causing a lousy idle. Many need to LOWER their FP at idle w/ the 255. Not raise. Under boost the stock reg. is ok. It is a 1:1 regulator. Don't believe me. Well, how's about 482whp. STOCK FPR. And that's still what I'm running to this day. I get about 38-39psi at idle. Works in my case. Eventually I am going w/ the Buschur SX kit just so that I can have more flexibility if/when needed.

 

[TimG]

You have to cut and add this to your existing FPR. You drive a 1G so your base fuel pressure is 28psi. You won't be able to adjust it any lower then 28psi. With a 255lph, you probably won't ever run lean unless your injectors are way too small for your turbo/boost levels. I'd suggest a SAFC or MAFT.

 

[khartley]

Ok, so your saying I might not even need a regulator? I have 550cc injectors. But if you don't think I will be running lean, then I probably just won't worry about it.

 

[spendone]

Im looking to get a fpr to use the full potential of my 550's. I am about 85% duty cycle on them as of now with my mods currently :::I believe they are all in my profile, might have updatd 1-2 things::: I was told my 550's would last me a long ways if I had a fpr.

 

[TimG]

If you can tune for no knock using your SAFC or MAF-T, then don't worry about a AFPR. If you tune for no knock but hit an early fuel cut, you better get an adjustable FPR or at least one that will allow you to flow more fuel into your engine. The non-turbo 90-94 FPR will allow you to do this (42psi base).

If you notice your idle is rough because your FPR is being over-run by your high flowing fuel pump, you need to lower your fuel pressure. At this time, an adjustable FPR would be ideal.

 

[khartley]

If you can tune for no knock using your SAFC or MAF-T, then don't worry about a AFPR. If you tune for no knock but hit an early fuel cut, you better get an adjustable FPR or at least one that will allow you to flow more fuel into your engine. The non-turbo 90-94 FPR will allow you to do this (42psi base).

If you notice your idle is rough because your FPR is being over-run by your high flowing fuel pump, you need to lower your fuel pressure. At this time, an adjustable FPR would be ideal.

So, you are saying that if I do need one, I can get it from a n/t 1G?

 

[boostedinaz]

So many weierd answers.

If you get a 255 then you will need a regulator to LOWER your fuel pressure. The 255 will ovwer run the stock FPR and that B&M can not go lower than the stock pressure and will not work for what you want. Get a good FPR and you will have not only an easier time tunning your car but the drivabiltiy will be nicer also.

As far as tunning goes an FPR is just used to stabalize the fuel pressure so that tunning can be accurate. It is not a tunning tune by anymeans. If you are running out of injector then you need to steup to the next size. Running more fuel pressure is just a bandaid for the wrong size injectors.

 

[SpoolnTsi]

You have to have a FPR for proper tuning regardless whether your running a maft or not. You could get by without one but thats just going to cause nothing but problems and headaches. You have to be able to control your FP for what you want/need. And to be honest, i currently have the b&m FPR and from my experience, ive never had a problem with it. No you cant lower it past the stock FP which is 38 but y would you? I have 40 psi at idle with no affect. I know the price seems to good to be true but believe it or not it works. I cant compare it to the other ones like aeromotive and so forth cuz i dont have much experience with them but for me the b&m gets the job done

 

[Spellmen]

I can tell you from experience that tuning with a MAFT on a 255 with stock regulator is just asking for headaches. Without the MAFT you are running rich, so you lean it out with the MAFT, but you go out the next day and your car is now lean because the fuel pressure changed. Get something like the Aeromotive or the Buschur SX and be done with it. I have an aeromotive on now at 38psi and can't describe how much nicer the tune is now.

 

[steve]

It should be clear by now that the B&M isn't the way to go.

Here's the deal with it. It reuses the base of the stock regulator.
That very same part that's too small to deal with larger fuel pumps.
I've see fuel pressure overrun with pumps as small as the 180 lph 3kVR4 pump, there is no question a walbro 255 will overrun it.

So why is FPR overrun a problem? The FPRs job is to maintain a constant pressure difference between the fuel inlet and the outlet of the injector so that it delivers the same amount of fuel for a given unit of time regardless of the pressure in the intake manifold.
Stock that difference is 36.3 psi on a 1G MT-Turbo. If you graph fuel pressure vs manifold pressure you have a straight line with a slope of 1. When you have overrun the FPR can no longer control the fuel pressure due to excess fuel volume and your pressure rises causing a bump in the bottom end of that graph. This causes your injectors to deliver more fuel than the ECU is expecting and you run rich until the ECU adjusts by lowering the fuel trim. As soon as your engine "eats" the excess fuel the FPR starts regulating again, the pressure goes back to the stock line, the injectors start delivering less fuel that they did a second ago causing you to go lean because the ECU had compensated. The nasty part is the switchover point isn't fixed, it's load based not rpm based so you can't really tune around it. The easiest thing to do is avoid the problem to begin with.

Steve

 

[khartley]

So what would happen if I just backed down to a Walbro 190, or whatever the next size smaller is. Then I should be OK with the stock FPR, right? I've just decided I don't want to go any higher with performance, and I definitely don't want to get different injectors. So will the 550cc injectors and a smaller Walbro with the stock FPR be okay? Because the 255 and the 550cc just won't work without a good FPR, correct?

 

[Raph]

^^^^ somebody please answer this question..i wanna know too^^^^

 

[SpoolnTsi]

So what would happen if I just backed down to a Walbro 190, or whatever the next size smaller is. Then I should be OK with the stock FPR, right? I've just decided I don't want to go any higher with performance, and I definitely don't want to get different injectors. So will the 550cc injectors and a smaller Walbro with the stock FPR be okay? Because the 255 and the 550cc just won't work without a good FPR, correct?

To do it right, your going to need a FPR. My other car with a s16gb@18lbs, 550 injectors and stock FPR..................with the 255 walbro i ran rich, with the 190 i ran lean. So i went and got a FPR and it solved the problem. I currently have the 190 but i might switch back to the 255. Both my cars have the b&m FPR with the one having 650's

 

[boostedinaz]

If you are going to run an 18G there are certain thngs you are going to need to run it safely. First being the right size injectors. 550's are a bit small for an 18G so I bet you will max those out fairly quick. If you get bigger you will probably need a 255 pump, but you may be able to get away with a 190 only a logger can tell you that.

A 190 will not "need" an AFPR, btu it would be a good thing to have for tunning. The B&M regulator is crap and other than being cheap there is no reason to get it. Since you will be using the guts of a 1G regulator that was over run in the first place, what makes anyone think that just becasue you but a new tiop on it it wont be over run this now??

 

[SpoolnTsi]

True true. With an 18g your going to need bigger injectors

 

[khartley]

Alright, well there is NO WAY I can afford bigger injectors for a while...so what's the best way to do this...keep my 255 and get the FPR, or get the 190.

Which will I have the least problems with until I can get the injectors?

 

[9d2TSi]

The Buschur/SX unit is very nice and it will keep your fuel pressure right where you want it. It's not cheap, but good quality usually isn't. It also bolts right to your rail. Truly bolt on and comes with everything that you need.

 

[SpoolnTsi]

Well, like boostedinaz said, you might be able to get away with a 190 but you could only know for sure with a logger. Id hate for you to buy a 190 than have to upgrade to the 255 cuz it wasnt sufficient enough. Your best bet, in my opinion, is to get the 255 and FPR. Then you know you will be set. I think you would appreciate it more in the future

 

[khartley]

Is there a color code for the injectors? I'm pretty sure mine are 550cc's, but I don't know for a fact. Anyone know?

 

[4geze63]

i got the b&m, then took it back in favour of an aeromotive