Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   DIY Turbo Discussion (https://www.miataturbo.net/diy-turbo-discussion-14/)
-   -   do I really need bigger injectors? (https://www.miataturbo.net/diy-turbo-discussion-14/do-i-really-need-bigger-injectors-76494/)

90R 12-11-2013 02:25 PM

do I really need bigger injectors?
 
2 Attachment(s)
I'm having a hard time seeing how.
It's a 1.6 @ 15psi, on MS1. Currently there are 550cc RC EV1 style injectors in the car. My last datalog of a 3rd gear pull to 7500 showed the DC at 98% with an AFR of 11.7 @ 192kpa. DC crossed 80% around 170kpa. This is a 40psi system.

Is this tuning or hardware issue?

pdexta 12-11-2013 03:34 PM

No idea how useless and potentially devastating this advise will be, but I've been in the exact same situation and just ignored it. My first miata ran RC550 injectors on a MS1, I didn't really pay much attention to injector duty because I knew I had plenty of headroom. When I was going through a log I noticed it recorded over 100% duty cycle. I asked about it on the forum at the time, but never really got a clear cut answer. I just ran it like that until I ended up parting the car out and never had any issues.

I just kept a close eye on AFR's and on my fuel map. I never saw the upper right of my fuel map increasing abnormally in an attempt to compensate for the injectors being too small so I just kind of ignored it.

Here's the thread I made at the time: https://www.miataturbo.net/megasquir...y-cycle-35394/

18psi 12-11-2013 03:34 PM


Originally Posted by 90R (Post 1081707)
I'm having a hard time seeing how.
It's a 1.6 @ 15psi, on MS1. Currently there are 550cc RC EV1 style injectors in the car. My last datalog of a 3rd gear pull to 7500 showed the DC at 98% with an AFR of 11.7 @ 192kpa. DC crossed 80% around 170kpa. This is a 40psi system.

Is this tuning or hardware issue?

found the problem

another thing to keep in mind is that the ecu calculates idc based on what you tell it about the injectors its running

concealer404 12-11-2013 03:36 PM

15psi on what turbo, exactly? Shitty old injectors or not, i can't think of any reason why a sane-sized turbo on a 1.6 @ 15psi would result in enough power that you'd max out 550cc injectors.

90R 12-11-2013 03:41 PM


Originally Posted by concealer404 (Post 1081761)
15psi on what turbo, exactly? Shitty old injectors or not, i can't think of any reason why a sane-sized turbo on a 1.6 @ 15psi would result in enough power that you'd max out 550cc injectors.

It's a VJ11 turbine bolted to a VF30 compressor.

concealer404 12-11-2013 03:42 PM

I mean... i'm never one to say "Oh no, don't buy some modern EV14 injectors, upgrades SUCK!" but there's no reason why you should be maxing those injectors out.

90R 12-11-2013 03:47 PM


Originally Posted by concealer404 (Post 1081767)
I mean... i'm never one to say "Oh no, don't buy some modern EV14 injectors, upgrades SUCK!" but there's no reason why you should be maxing those injectors out.

The cost of set of injectors could be better spent on tires!

That's why I'm asking. I know it's a tiny turbo and should only be 200-ish. So I'm confused why I'm getting this DC

concealer404 12-11-2013 03:49 PM

Hard to tell without knowing how it's tuned. Is your fuel pump healthy?

90R 12-11-2013 04:03 PM

1 Attachment(s)
Fuel pump is good, the filters been replaced.
Heres the latest msq. It's fat up top. But when I run VE analyze. It's pulling fuel if I get up there.

90R 12-11-2013 04:06 PM


Originally Posted by 18psi (Post 1081760)
another thing to keep in mind is that the ecu calculates idc based on what you tell it about the injectors its running

isn't that info taken from the REQFUEL info?
I know thats correct.


All times are GMT -4. The time now is 11:20 PM.


© 2024 MH Sub I, LLC dba Internet Brands