RX7Club.com - Mazda RX7 Forum - running lean only at 3500 rpm?

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)

- 2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)

- - running lean only at 3500 rpm? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/running-lean-only-3500-rpm-1114466/)

fredrx7

05-15-17 02:29 PM

running lean only at 3500 rpm?

So my car is running lean as I said only at right around 35-4k. I have to get out my laptop to data log with my innovate motorsport af/boost gauge setup to be sure of the rpm when this occurs. I just havnt had the time yet to tune with my laptop since making a couple minor changes. Anyhow I am seeing around 11 for an afr right before and after this rpm range but for an instant it will drop to around 12.5 which in turn causes boost to cut via a safety feature in the boost controller. The lean spot lasts longer when in higher gears.
its an 87 t2 with a streetport, stock turbo,full exhaust, 680 secondaries, fcd, 255lph pump and a safc2. I am thinking maybe its due to a drop i pressure when the secondaries come on but its got a new stock fpr. Any ideas why this is happening? Thanks in advance

fredrx7

05-22-17 12:12 PM

for what its worth my safc is set around plus 20 above 2500 but from 3 til 4k is set to plus 30. I have richened it up in this range but had to go pretty high on the controller to do so. Should I be concerned about having to set this so high?

j9fd3s

05-22-17 07:20 PM

i think so, your setup should almost not even need the SAFC. how much boost are you trying to run?

12.5:1 AFR at 10psi or less should actually be ok, and 11:1 sounds rich to me. if you're over 12psi though, i think i'd want more fuel than 12.5:1

fredrx7

05-23-17 10:36 AM

cool thank you for the response. I am running between 10 and 11 pounds. So you suggest I aim for 12 for an afr huh?

rx7b13

05-24-17 08:36 PM

From a long time ago

Quote:

Originally Posted by Aaron Cake (Post 9037953)

Stock turbo?

13.5 at idle.

14.5 or so under light load out of closed loop.

Closed loop to 15.0 or there abouts.

Under moderate throttle, 13.5 out of boost.

At 0", go down to 12.5 and hold that number until about 4-5 PSI. Then go down to 12 until about 7-8 PSI. Now taper down to 11.5 to 10 PSI an run 11 exactly after that. Once you hit the 15 PSI area, 10.5.

Of course, without knowing how the car is configured, it's all a guess. And timing is rather important...

fredrx7

05-31-17 02:22 PM

thank you everyone this has been very very helpful :)

All times are GMT -5. The time now is 01:15 AM.