Feel dumb, but PowerFC Boost question
04-12-18, 11:02 PM
#1
Full Member
Thread Starter
Feel dumb, but PowerFC Boost question
I've had this car for about 9 years now and never touched the PowerFC setting wise. The previous owner mentioned putting it in a lower boost mode for the drive home because it was during a blizzard, and I started navigating around the menus and found where these two settings are but know nothing beyond that. Here is a picture of the one I've been running and the second profile that I've never used, what exactly do the numbers mean and should I try the second profile? Still on stock engine, turbos, about 70k miles and just got a clean bill of health compression wise and everything from Speed1 last year.
EDIT: Ok, so looks like the first profile has a PSI of around 13/11.3 for primary/secondary and the high setting is at 14.2/15.6? Am I reading that right?
EDIT: Ok, so looks like the first profile has a PSI of around 13/11.3 for primary/secondary and the high setting is at 14.2/15.6? Am I reading that right?
Last edited by berfles; 04-12-18 at 11:06 PM.
04-13-18, 08:33 AM
#2
RX-7 Bad Ass
iTrader: (55)
Yep, the 1 and 2 are 2 different boost settings you can switch between. Each setting shows the boost setting for the primary and secondary turbo (Pr and Sc) and the percentage is the gain adjustment - how fast the boost comes up. If the gain is too low the response will take forever, if it's too high it will overshoot and boost creep.
Going from .8 to 1.0 is a bigger step than it seems. On the twins you will definitely need more fuel and proper tune to support it.
Dale
Going from .8 to 1.0 is a bigger step than it seems. On the twins you will definitely need more fuel and proper tune to support it.
Dale
04-13-18, 10:14 AM
#3
Full Member
Thread Starter
Ah, the percentages make sense. I drove it to work today with the second profile and did notice it seems to spool up faster, and I easily his 1.1bar as well. I know the previous owner used to run it on this mode exclusively though, and it was tuned for it as far as I know. What would be some things to watch out for while driving in this mode? I didn't do any super hard pulls but nothing seems different other than having more boost and it coming on a little sooner.
The following users liked this post:
alexdimen (04-13-18)
04-13-18, 01:57 PM
#5
You might want to stop while you're ahead. Go back to your first boost profile until you get some things sorted and do some research.
Unless you know what your AFR and injector duty is at .8 bar / 12 psi there is no way to predict if the fuel system will keep up with 1.1 bar / 16 psi.
What is your current max injector duty? Were you getting any high knock readings?
I'm not even sure the stock fuel system (is yours stock?) is capable of keeping up with 16 psi. Banzai racing just did a thread where they took the injectors to 91% at 14.5 psi with an upgraded walbro pump and considered that a safe limit. https://www.rx7club.com/3rd-generati...1104322/page2/
Also, I would take anything a previous owner said with a grain of salt unless there is documentation.
Unless you know what your AFR and injector duty is at .8 bar / 12 psi there is no way to predict if the fuel system will keep up with 1.1 bar / 16 psi.
What is your current max injector duty? Were you getting any high knock readings?
I'm not even sure the stock fuel system (is yours stock?) is capable of keeping up with 16 psi. Banzai racing just did a thread where they took the injectors to 91% at 14.5 psi with an upgraded walbro pump and considered that a safe limit. https://www.rx7club.com/3rd-generati...1104322/page2/
Also, I would take anything a previous owner said with a grain of salt unless there is documentation.
04-13-18, 02:16 PM
#6
Full Member
Thread Starter
You might want to stop while you're ahead. Go back to your first boost profile until you get some things sorted and do some research.
Unless you know what your AFR and injector duty is at .8 bar / 12 psi there is no way to predict if the fuel system will keep up with 1.1 bar / 16 psi.
What is your current max injector duty? Were you getting any high knock readings?
I'm not even sure the stock fuel system (is yours stock?) is capable of keeping up with 16 psi. Banzai racing just did a thread where they took the injectors to 91% at 14.5 psi with an upgraded walbro pump and considered that a safe limit. https://www.rx7club.com/3rd-generati...1104322/page2/
Also, I would take anything a previous owner said with a grain of salt unless there is documentation.
Unless you know what your AFR and injector duty is at .8 bar / 12 psi there is no way to predict if the fuel system will keep up with 1.1 bar / 16 psi.
What is your current max injector duty? Were you getting any high knock readings?
I'm not even sure the stock fuel system (is yours stock?) is capable of keeping up with 16 psi. Banzai racing just did a thread where they took the injectors to 91% at 14.5 psi with an upgraded walbro pump and considered that a safe limit. https://www.rx7club.com/3rd-generati...1104322/page2/
Also, I would take anything a previous owner said with a grain of salt unless there is documentation.
https://www.rx7club.com/time-slips-d...-today-415983/
It has an upgraded fuel system, I just don't know the specifics. To be honest I haven't really touched the car mechanically since I bought it from him because it was set up so well and needed nothing, so I never really dove in and learned the technical stuff. I've just never had a problem with it all these years. I'll search his old posts and see what I can find out about it again. I just know he said he was running it on this other map for years and that's what his numbers and tune were based off of.
EDIT: I knew I saw something about injectors and fuel pump before:
m2 intake, full exhaust, supra pump, 1300cc injectors, power fc, light weight flywheel, koni yellows with eibach spring, stiffer front anti roll bar, hks twin power, short throw shift, and the m2 med ic.
Last edited by berfles; 04-13-18 at 02:25 PM.
04-13-18, 02:41 PM
#7
Well, if it helps, this car was matty's car here:
https://www.rx7club.com/time-slips-d...-today-415983/
It has an upgraded fuel system, I just don't know the specifics. To be honest I haven't really touched the car mechanically since I bought it from him because it was set up so well and needed nothing, so I never really dove in and learned the technical stuff. I've just never had a problem with it all these years. I'll search his old posts and see what I can find out about it again. I just know he said he was running it on this other map for years and that's what his numbers and tune were based off of.
EDIT: I knew I saw something about injectors and fuel pump before:
https://www.rx7club.com/time-slips-d...-today-415983/
It has an upgraded fuel system, I just don't know the specifics. To be honest I haven't really touched the car mechanically since I bought it from him because it was set up so well and needed nothing, so I never really dove in and learned the technical stuff. I've just never had a problem with it all these years. I'll search his old posts and see what I can find out about it again. I just know he said he was running it on this other map for years and that's what his numbers and tune were based off of.
EDIT: I knew I saw something about injectors and fuel pump before:
I assumed everything was stock and got worried for you!
The only complication I could imagine is the spinny bits of the fuel system aging after 9 years.
Trending Topics
The following users liked this post:
Project88Turbo (12-14-19)
04-13-18, 06:01 PM
#10
RX-7 Bad Ass
iTrader: (55)
You just arrow to either the number one or number two so it's highlighted then go back to the previous screen. That's it.
Dale
Dale
The following users liked this post:
oppa637 (04-13-18)
12-13-19, 10:52 AM
#11
Eats, Sleeps, Dreams Rotary
Love it! my old car still ripping hard after 20 years. Fyi I ran the higher setting of 15psi literally everyday. @berfles
People will try to say no more than 13-14psi. As long as the car is setup correctly 15psi is great!
What a great car this is. stock motor stock twins. pushed to max for two decades.
People will try to say no more than 13-14psi. As long as the car is setup correctly 15psi is great!
What a great car this is. stock motor stock twins. pushed to max for two decades.
Thread
Thread Starter
Forum
Replies
Last Post
Buzzardsluck
3rd Generation Specific (1993-2002)
21
01-31-06 07:36 PM
Yelow RX-7
2nd Generation Specific (1986-1992)
3
11-27-01 07:25 PM