fpr

Fire & skill

Vintage member
looking to upgrade my R very soon and have been advised if i fit a z32 maf, 550cc injectors and new tubby that i will need a fuel pressure regulator.

can anyone tell me why i need one?
 
S

str_motorsport

Guest
hi mate, this is not 100% true.
for example i have an adjustable fuel pressure regulator fitted to my gtir with z32 maf and 550cc injectors, but it will work good even with the stock unit.
with an adjustable one you can do small fuel pressure changes to achieve a better a\f ratio...you can richen it a bit by rising pressure or lean it by reducing pressure....that is all...
hope this helps
David
 
E

EVOGUN

Guest
If you pull MS off the injectors you will pull timing same time. FPR you can change the whole curve with out affecting timing. SAFC is kinda made really for small ajustments on spike portions of you A/F curve.

Thanks :wink:
 
A

AJ4

Guest
An FPR is a good mod if its one with a guage on it for checking base pressure. The original one could be old and knackered and have low pressure ( running lean ) and you'd never know it.

Only really worth being adjustable if you want to keep the same injectors but run them at a higher rate. If you have 440's for example you can up the fuel pressure a bit and run them as if they were 550's.

You don't really need one for what your trying to do, but if you can get a hold of one anyway its a good mod and gives you good piece of mind ( like having an aftermarket boost guage instead of trying to rely on the standard one :D )
 
J

jiw

Guest
For what they cost its worth upgrading, i cant see the gauge lowering fuel poressure with age, it will only get higher as the spring relaxes, jeff.

P.S sard ones go for bargain prices on ebay :wink:
 

Fire & skill

Vintage member
jiw said:
For what they cost its worth upgrading, i cant see the gauge lowering fuel poressure with age, it will only get higher as the spring relaxes, jeff.

P.S sard ones go for bargain prices on ebay :wink:
it was the SARD one i was told to get :D

and before anyone asks - Simon Norris told me
 
A

AJ4

Guest
jiw said:
For what they cost its worth upgrading, i cant see the gauge lowering fuel poressure with age, it will only get higher as the spring relaxes, jeff.
I thought as the spring weakened more fuel would force its way past and back into the tank, making it lower pressure. I suppose it could work both ways though, interesting point.... 8)
 
J

jiw

Guest
No i think your rite mate, i forgot the regulator is on the return line, damn its been a long hard day lol, i must think more before replying :roll: :oops:
 
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