550 cc injectors pressure question????help

[wardog]

I just got my fully rebuilt and flow testes 87 rx7 turbo II injectors back and i want to run 18 psi with the followin mods were should the base fuel pressure in my AFPR be to run 18 psi??

mods:

ct26/60-1
k&n fipk
bic ddp + 3in exhaust no cats
spec stage 3
12 lbs flywheel
walbro 225lph
aeromotive afpr set at ?????????????????? with/ without vac
stock 440 s ----now 550
bypassed dampner with braided line
2.5 hardpipes to stock intercooler
greddy rs to the atmosphere
lexus afm
hks evc 4 set at .80/ 11-12 psi hehe soon 18-22 psi
safc 2
fresh rebuilt engine and head less than 2000 miles with cometic mhg and arp studs to 92 lbs


HELP PLEASE ill be installing them tomorrow afternoon im gettin ready for tx2008 dyno Im pretty sure wont be a dyno king but itll give me some tunning time with those 3 pulls:biglaugh:

 

[nosman4]

Check out this page from the TSRM.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/FI/FI_073.gif

 

[Nalleywhacker]

buy a wideband and figure it out for yourself.

 

[bountykilla0118]

buy a wideband and figure it out for yourself.

What he means is that there are variable that are different with each engine and “setups”. We could have the same exact mods but our settings are different and our power outputs are different. So you will only really know what you will need with a little bit of tuning. With the 550’s, Walbro, AFPR and Lex AFM you would decrease the fuel pressure a bit so that you can lean out the mixture but you wont know what your mixture is without a wideband. It should be one of the first things you buy once you start to mod and make changes with your SAFC II. Be careful once you start to tune with the SAFC dont go crazy with it without a wideband. I believe at 25% correction (+/-) you start to mess with your timing so you would do some base tuning with the AFPR.

 

[supra_ed]

take it from me(someone who loves to "learn" the hard way several times over)- never mess around with this stuff without a wideband. a must for any slightly modified turbo car, let alone one that has an upgraded turbo. narrowband doesnt cut it.

 

[buldozr]

the reason you go to the dyno, use their wideband

 

[jdub]

SP61 turbo at 18 psi, I run at 27 psi (vac line attached) base pressure on the AFPR.

 

[wardog]

thanks j dub that is the answer i wanted to hear and to you guys too. Im about to head out to College Station by were the Road Racing event was held at, just to check out some of the rides out there. Tomorrow I get out at 12 noon and im heading to the dyno hopefully i can get some of that dyno action so I can tune it and Ill post the numbers and if i can some videos for those who couldnt make it out.:evil2:

 

[ABQMK2]

SP61 turbo at 18 psi, I run at 27 psi (vac line attached) base pressure on the AFPR.

May I ask why youre runing you FPR that low? Do you get a CEL?

I have the same turbo and 550's and im having issues with it running richat idle...reads 10 on AFR and smokes big time! Fuel pressure on mine is Vac on at Idle 40psi and vac off at idle it only drops to 37psi. I have an AFPR/vpc/safc2/550's/sp61gt/ braided lines fuel lines(from driftmotion). Oh and a code 52(in the process of re-wiring with Shaeff's kit).

Ive been trying to figure out my rich issue for a week now..looking for vac leaks. Still no luck. Any ideas?

Sorry to threadjack.

 

[SMP142]

my friend has almost the same setup. he is running 25-30psi i am not sure what the exact number was. his seems real rich at idle but fine once in boost. i never knew guys out there ran without the vac line hooked up. what benefit does that have?

 

[jdub]

ABQ - No I do not get a CEL (why would you?). Base pressure is a "global" setting...using a Lex AFM, it is really the only way to get your AFRs close without an SAFC or other electonic piggyback. Typically guys run way too much pressure with the 550 injectors...it causes you to run very rich and can cause the engine to "studder" at higher rpm when the ECU adds fuel at boost.

The TSRM gives pressures with Vac line connected/disconnected. I usually give the Vac on setting because that is the one you run the motor with. You don't run the motor normally with the Vac line disconnected. The stock fuel pressure range still applies with the Lex/550 combo...33-40 psi w/ vac disconnected...23-30 with vac connected.