Forums/Z31P/z31-performance-upgrade-forums engine-mechanical-aa/550cc good enough?
Imported from Z31Performance.com Forums{{#if:BarnFind_Z| — original post by BarnFind_Z}}{{#if:2019-09-08 22:49:54|, posted 2019-09-08 22:49:54}}{{#if:10| · 10 post{{#ifeq:10|1||s}}}}{{#if:/Z31performance_archive/forum/z31-performance-upgrade-forums/engine-mechanical-aa/544392-550cc-good-enough.html|
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BarnFind_Z: (2019-09-08 22:49:54)
So as of right now I have an 88t 300zx, I have 550cc injectors from the FC RX-7. I was wondering if I could up the boost to 20psi and run the injectors safely. Right now it's on 17psi on a really bad base tune. The tune is hot garbage and I want a friend of mine to use the Nistune that's on it.
Wilsonthesphere: (2019-09-09 14:28:48)
Do you have a inter-cooler? Are you on the stock T25 or T3 ?
mwolvinm: (2019-09-10 16:55:46)
Depends on your horsepower capabilities of your setup.... Fuel Injector clinic puts you maxing around 440 crank HP assuming stock fuel pressure.
https://fuelinjectorclinic.com/hp-calculator
my suggestion… get a good tune first, then check your actual duty cycle (if possible).
88sinZ: (2019-09-11 08:20:51)
im running 550CC Grams with vac/reference, they are around 60% duty cycle @ 400 WHP @ 17PSI on a hx35.
with goals i'd suggest at least 750 or 1000CC for head room and to keep duty cycle low. If you are not targeting over 400WHP 550CC is fine.
BarnFind_Z: (2019-09-12 01:28:52)
Now if I can't run a 420WHP setup on 550cc, I'd love for people to send me some links for bigger injectors, please and thank you!
88sinZ: (2019-09-13 06:49:52)
Injectors are less complicated than they appear
Replacing the original connector plugs is highly recommended as the original plastic plugs break down and crack.
Upgrade to the PastPowerPerformance O-ring rails, find a set of R32 skyline injectors, splice in ev-14 connectors, new gaskets… then do yourself a safety solid and convert your fittings to AN so you don't die in a fire.
before attempting start-up perform multiple leak checks.
550CC should safely get you over 400WHP, until duty cycle approaches 80% you're safe - this also relevant to you or your tuners comprehension
Wilsonthesphere: (2019-09-13 18:13:45)
Also remember if convert to E85 you need larger injectors compared to gasoline power goals.
dbruce: (2019-09-13 21:11:36)
Do you idle smooth with the large injectors ?.. just asking … . ( jwt 420cc on my t4/t3 turbo no problem ) but what about other larger injectors … ? do they pulse out small amounts at idle ? and then there's what cam is installed …
88sinZ: (2019-09-14 07:22:43)
Smooth idle is largely determined by your setup and tuning.
If you are competent with K values and idle/warm up trim you should be quite as a honda 4banger at idle
Wilsonthesphere: (2019-09-15 16:51:10)
im running E85 on 1200cc injector on nistune. Running a little rich 10-12.1 afr but holds a good idle at 900 rpm. I think 1200cc is already past the limit a little of E85 for decent idle. I had no problems with idle and afr with my previous 450cc dsm blue tops.