boost_its_what_for_dinner

i was wondering if someone knows?

under boost i have a afr of 10.0
im running 720/1000cc inj's @ 8-11 psi boost

i would like to have an afr of about 11.0 atleast so its not pig rich
i just wanna know how much percentage of fuel do i need to take out to achieve a 1 point afr lean out ?

thx

gxl90rx7

iTrader: (1)

its probably different for every setup, as well as for different injector sizes.. 10% of 1720cc (above staging, secondaries on) is alot more fuel than 10% of 720cc (below staging, secondaries off)

since you and me have similar injector setups (750cc/1000cc) ours may be close. for me i get about 1 point AFR difference at 10% fuel correction above staging

boost_its_what_for_dinner

thx ill try that. and yes i mean while in boost so secondaries staged

boost_its_what_for_dinner

just to bring this back up. im curious to what afrs are good for safety and reliablity (just asking?)

ive seen many guys on internet running like mid12's at 16+ boost,

reason im asking is my turbo doesnt wantto spool up fast enough around 3-5k rpm it stumble on building boost liike its fighting with to much fuel. but i might add my car pulls like a jet plane from 5.5k-redline @10-11.7psi @ 10's afr.

reasons?? plus this rtek forum is getting dull will no one ever talking about stuff....

gxl90rx7

iTrader: (1)

I believe a basic target for your fuel map would be something like this:

idle: mid 12s
vacuum: 13-14
0 psi: 13s
5 psi: 12s
10+ psi: mid 11s

but mine runs really rich in vacuum (when in open loop), like in the mid 12s, but only due to the cruising stumble problems. if i try to lean it out further, the cruising stumble gets worse. for example if i tune the vacuum to 13s, the stumble will be in the 17-18s. If i tune the vacuum for 12s, the stumbe will only be in the 15s, which is barely noticeable

as for timing, ive read that you want about 15 degrees at 15psi, then add a degree per psi boost, down to 0 psi. so at 10psi you would have 20 deg adv, 5 psi would be 25 deg adv. cruising you want mid 30's.

but those numbers are rough targets, if you really want to dial in your tune, get an EGT and/or get on a dyno. different setups will run better on different AFRs/timing

boost_its_what_for_dinner

hmm interesting? any idea on why my turbo stumbles though.

The Wankler

iTrader: (14)

Can you post a log so we can see the stumble area?

boost_its_what_for_dinner

hey wankler its not really a stumble... butit is its like the turbo wants to spool but cat do it fast enough?? mind you straight thru exhaust.. its like there is too much fuel and its booging out until 5k+ then it screams likea banshee. soim going to raise the staging pointto the max of 3800 and lean out the 3-5k region but i dont know which area to lean out(ie. 2-14 psi) also what loadis theidle affected by?

boost_its_what_for_dinner

this is all fixd now just needed to take some fuel out under boost, where before it was reading 10's i kept taking fuel out til it showed a 10.5afr at wot but it took almost 10% fuel taken out to get it up to a 10.5, now its safe and all good

marK's

did you fix your turbo stumble below 5.5k? i have the same problem. after 5.5k and above, it pulls hard, but anything other, it takes it awhile to accelerate.

boost_its_what_for_dinner

yes. but it was from too much fuel to soon and a pig rich tune... so until the turbo could clear out all the fuel it was boggy feeling, so i leaned it out and its all good

boost_its_what_for_dinner

so what was the fix for the cruise stumble?


and i just put my aeromotive fpr on and need to know what psi to set it near ?