Like the thread name says, whats the best AF ratio to have on an S5 Turbo....

I'm more concerned with reliability then performance.... i dont want to take the risk of leaning out....



Mods:

- S4 Block with S5 Externals
- 3" Racing Beat Turbo-Back Exhaust
- Blitz SS BOV
- Coilovers ( Tein rear, Ground Control front )
- Centerforce Dual-Friction clutch
- HKS PFC F-Con
- HKS GCC
- Knights Turbo-Timer
- Knights FCD
- FD Flywheel
- JDM Brake Balancer
- Stainless-Steel Braded Brake Lines
- Autometer boost and A/F guages
- MazdaSpeed steering wheel
- MazdaSpeed racing pedels
- Manaray 6spoke 16" rims
- K&N Filter on 3Inch TID
- Yokohama AVS ES100 Z-Rated rubber
- Greddy ProfecB SpecII Boost controller
- Walbro 255lph Fuel Pump
- SAFC-II ( Need Install )
- Greddy Vspec FMIC
- MSD 8.5cm Race-Wires
- Megan Strut-Tower Bar
- Denso 720cc Secondary's



http://www.cardomain.com/ride/828726


thanx....

 

id try to keep it around 11's-12's, thats what ill be aiming for then i get my wideband.

 

We need more info - i.e. how much boost you're planning to run, etc.

I'll assume you're running 12 psi on the stock turbo, in which case mid to low 11s would be safe.

 

on 93 Octane.... and a good intercooler (intakes BELOW 125 degrees at full boost)

5" vac to 0....... 13.5
From 0-5 PSI... 12.5
From 5-10 PSI... 12.0
10-15 PSI..... 11.75

Thats where my schnitz been dialed in for the past year... no complaints..... no blammo!!!

In my experience.. Power drops of DRAMATICALLY the lower into the 11's you go.... so invest in a good IC!!!! (edit) if appears you have one!!!!!!!

 

Good call, didn't see that he had an FMIC. You can def tune a little leaner once you get rid of the stock interheater.

 

keep the AFR's at 11.5:1 in boost.

 

Personally, I stay mid 11s, even with the Alchy injection and an FMIC... But I like a conservative tune. If you want to run the ragged edge of detonation, thats all you!

 

heeeeeeelllllllll no, i want to make sure this thing doesent crater on me from leaning out!...

yep i definitly got a good intercooler....

i will be running approx 10-12psi on stock turbo for now....

 

11.5:1 then.

dont push it

i ran in the high 10's low 11's, i just wanted to keep it a tad more safe due to the heat that the stock turbine causes.

 

Although i will be waking the dead, ( somewhat literally ) i just wanted to confirm which AF mixture would be best suited for my setup....

i will be running 13-14psi on a stock S5 turbo with the mods above, i'm tuning with an FCON and GCC on a mustang dyno that reads the AF through a probe in the exhaust, and i was thinking of tuning @ 11.5:1 on boost on 91octane and run 94octane daily, i say that because i may not have 94octane in some places if i decide to go to edmonton and medicine hat to race....

 

11:1 is a general safe range but widebands still are not an accurate tool for tuning, to know if you are really running safe you need to run it on a dyno. even most out of spec widebands it should still be safe at 11:1 unless it is really fubared.

 

How accurate is the Tech Edge wideband?

 

Why would a wideband be innacurate (assuming it is installed correctly)? We have a DynoJet dyno at work and the sniffer pump has a wideband installed in it to take the A/F reading. The exhaust is still cherry hot coming out of the tailpipe.

 

Hmm with the A/F ratios I'm seeing in this thread, it's no wonder people keep blowing engines here. Some of you guys aren't leaving enough margin for error in case of slight fuel starvation. With your A/F ratios in the miid to high 11's at say 15psi on 93 octane, just imagine how lean you will really get once your secondary injectors start to clog (and they will without you even knowing it). Guys just remember, a perfect tune can't always prevent detonation from happening from some other cause.

Personally I would run no higher than 11s at 15psi on 93 which is safer.

 

i'll be tuning on a dyno and nothing else, i was wondering where in the 11's would be safest....

i have brand new injectors and the works....

are mid 11's alright for 13psi on 91octane gas?...