Uprating fuel system
01 July 2007, 05:44 PM
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Uprating fuel system
Advice please, before I part with more of my 'hard earned'
I have just fitted an EJ25 to my '93 JDM WRX (std Heads ported/polished/matched, Apexi Power FC, FMIC, std TD05, 3'' de-cat, blah, blah)
Looking for advice re: choice of: a) injectors (apexi, Sard, Nismo.. 550? 650? ??. b) fuel pump (walbro 255, Twin inline Bosch? with swirl pot, without??. c) pressure reg?.
Perhaps leaving scope for future upgrade.
Interested in anyone having anything suitable for sale
I am looking for a conservative? 350+BHP (which will no doubt trash the standard transmission)
I have just fitted an EJ25 to my '93 JDM WRX (std Heads ported/polished/matched, Apexi Power FC, FMIC, std TD05, 3'' de-cat, blah, blah)
Looking for advice re: choice of: a) injectors (apexi, Sard, Nismo.. 550? 650? ??. b) fuel pump (walbro 255, Twin inline Bosch? with swirl pot, without??. c) pressure reg?.
Perhaps leaving scope for future upgrade.
Interested in anyone having anything suitable for sale
I am looking for a conservative? 350+BHP (which will no doubt trash the standard transmission)
Last edited by E46_M3; 01 July 2007 at 07:40 PM.
05 July 2007, 12:20 AM
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255 Walbro and regulator are almost certainly going to be my choice. What make of regulator are others using, or maybe more importantly NOT using? SX/Fuel Labs has been highly recommended. (I have access to a proper fuel pressure gauge so shall be avoiding those with integral gauge)
I think the choice of injectors will be Apexi. (any yey's or ney's?)
My first thought was toward 550cc, however I have had more than one source recommend larger.
My concern is if I were to go larger, say 650, or even 740 will there be a risk of having too large an injector with a possibility of low engine speed drivability issues?. I understand that the larger injectors will ensure high engine speed fuel demand is met, but wouldn't want to discover a lack of controll over the low engine speed fuelling.
From advice I have had thus far I am quite confident that 550's should suffice, but wouldn't going 740 now ensure that the fuelling requirements of any future mods can be catered for?
What injectors are others using, and with what results?
I should point out that I am very much a novice re- fuel mapping and the relationship of injector size to drivability.. I am merely appling logic(?)
<considers flipping a coin to decide> 
I think the choice of injectors will be Apexi. (any yey's or ney's?)
My first thought was toward 550cc, however I have had more than one source recommend larger.
My concern is if I were to go larger, say 650, or even 740 will there be a risk of having too large an injector with a possibility of low engine speed drivability issues?. I understand that the larger injectors will ensure high engine speed fuel demand is met, but wouldn't want to discover a lack of controll over the low engine speed fuelling.
From advice I have had thus far I am quite confident that 550's should suffice, but wouldn't going 740 now ensure that the fuelling requirements of any future mods can be catered for?
What injectors are others using, and with what results?
I should point out that I am very much a novice re- fuel mapping and the relationship of injector size to drivability.. I am merely appling logic(?)
<considers flipping a coin to decide>
Last edited by E46_M3; 05 July 2007 at 12:23 AM.
07 July 2007, 11:39 PM
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For the fuel regulator Sx or the fuel lab are both very popular and reliable.
Injectors i would stick with 550cc, there is no need to go bigger for the set up you have. I would only consider this if you are planning more changes in the near future that may warrant larger injectors...
Injectors i would stick with 550cc, there is no need to go bigger for the set up you have. I would only consider this if you are planning more changes in the near future that may warrant larger injectors...
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