Fuel Pressure question

[samiam3356]

Was reading in the Bentley where fuel pressure on x50 motors are 43.5 ~2.9 and fuel pressure on the x52 blocks are 51 +- 2.9.

When converting to OBD1 and using the m50 fuel rail, wouldn't you be lowering the fuel pressure on a motor that was designed for a higher pressure. Or does the software compensate for this?

Was wondering if it would be better to have an adjustable FPR to get the pressure back where it should be?

Sorry if its been discussed. Haven't seen it on here before and running into an issue on my car with the fuel pump that has had me in the Bentley for a bit now.

[Adrian_Visser]

That's interesting now that you mention it. I thought all were 3.5 bar.

[crazyvwobie]

Was reading in the Bentley where fuel pressure on x50 motors are 43.5 ~2.9 and fuel pressure on the x52 blocks are 51 +- 2.9.

When converting to OBD1 and using the m50 fuel rail, wouldn't you be lowering the fuel pressure on a motor that was designed for a higher pressure. Or does the software compensate for this?

Was wondering if it would be better to have an adjustable FPR to get the pressure back where it should be?

Sorry if its been discussed. Haven't seen it on here before and running into an issue on my car with the fuel pump that has had me in the Bentley for a bit now.

seems to me you should be running what ever fuel pressure is required for obd1 which I believe is 3 bar.I would not think it matters on what size engine because the software should be giving the correct amount of air and fuel ,as long as the chip matches your setup.I just installed a fuel pressure gauge on my obd1 s52 and it reads 40psi at idle and 43 if I rev it.

[Adrian_Visser]

Hmm this made me realize something. I think I have the wrong fuel injectors, I'm sure I did the flow calculation using 3.5 Bars pressure. Guess I better get some cams and use my 24lb'ers right quick eh?

[328ijunkie]

The OBD2 regulator is mounted under the drivers feet on E36s and XXX

[AlpineS50E30]

i'm running about 58#ish on idle and 62 at WOT on my s50...used to run at 50#ish but bumped it up and made a WORLD of difference on how the car ran... don't go higher than that or you'll be running too rich throwing black smoke on WOT lol

[samiam3356]

What is your setup? Adj FPR obviously but which one? injector size? Chip programmed for what?

Thanks BTW

[AlpineS50E30]

What is your setup? Adj FPR obviously but which one? injector size? Chip programmed for what?

Thanks BTW

no problem, i'm running an aeromotive FPR with 21.5# injectors and my software is Active Autowerke Tune, i'm changing to a TRM tune very soon, my father has Turner Chip in his car with 24# software(s52) and is also running the same FPR with the same fuel pressure i am, i've seen guys bump it even higher, but i think it runs too rich if you bump it any higher, if you don't wanna go that high for whatever reason then i'd say just leave it at 55, but at least try it, car runs great when it's bumped up....pull the vacuum hose and adjust it to 45#...drive it then try it at 60...you'll notice a difference...:)

p.s.: my old m42 pump couldn't handle the pressure/volume, so i'm running a 255lph walbro...

[samiam3356]

This the one you used?

http://www.shopatron.com/products/productdetail/part_number=AER13129/415.0

Also, what fuel rail are you using? OBD2?

[AlpineS50E30]

This the one you used?

http://www.shopatron.com/products/productdetail/part_number=AER13129/415.0

Also, what fuel rail are you using? OBD2?

OBD1, this is the regulator i'm using:http://www.summitracing.com/parts/AEI-13101/?rtype=10

[328ijunkie]

Theyre all 3.5 bar.

[samiam3356]

[328ijunkie]

Well i have two OBD1 fuel rails sitting in front of me both say 3.5 bar and this:

http://www.pelicanparts.com/bmw/catalog/shopcart/BE36/POR_BE36_FULful_pg3.htm#item20

[AlpineS50E30]

mehh. for ///M motors you bump it up =p, for example the s54 runs at 5 bar.(stock btw)

[matt]

[IMG]http://i106.photobucket.com/albums/m261/srainey1/fpr.jpg

Not the first time the bentley is wrong.