Jimmy2222

iTrader: (3)

Been looking around the past few days (manual browsing and search) and I have yet to come across a thread giving me specific numbers. I've heard "14.7:1" a lot and "10's-11's"
My question is, for an S5 T2 (pretty much stock) where should my AFRs be? What are some good threads/websites to look over?

RotaryEvolution

iTrader: (30)

20-0" Hg - 13:1 AFR
0-5 PSI - 12:1 AFR
5-10 PSI - 11:1 AFR
10-15 PSI - 10.5:1 AFR


you get the picture..

n/a can be a little richer(ideally) during WOT than 13:1, generally about 11.5:1 under heavy loads and high RPMs.

Jimmy2222

iTrader: (3)

Thank you, getting some solid numbers is good.

KhanArtisT

iTrader: (2)

Can you list your setup and what AFR's you're seeing? I'm curious to compare to mine.

Aaron Cake

iTrader: (1)

Do you have some way of tuning this car, or are you just curious? A number of things effect AFRs so you might not see the numbers mentioned above.

Additionally, every tuner has their own method. For example, I tune low load for 14.0, then taper to 13.5 approaching atmospheric. 12.5 at atmospheric, 12.0 to about 4-5 PSI, 11.5 thereafter until about 14-15 PSI where I drop into the high 10s. Closed loop should be around 15.0.

BDC

That's not bad although it may run a bit funny in swinging vacuum ranges that lean. Also a bit stout for 1bar of boost.

B

RotaryEvolution

iTrader: (30)

richer is safer, since i tune cars that i don't drive daily and don't monitor my own AFRs with my wideband(i use it to tune other people's cars) then a point richer is a safety buffer and better anyways since fuel systems won't always be 100%.

steve kan tunes at least 1 point richer than i do and he is the most well known rotary tuner.

1 point won't make a world of difference in the vacuum ranges for response nor will it really kill economy that much, i actually notice if you try to push these cars too lean then you will lose economy rapidly. it really all just depends on climate and health of the motor, not all tunes will be equal nor will they be wrong.

most of the figures mentioned are just basic figures and any will be close to where you should be anyways with relative safety, just keep in mind that porting and your climate will determine how the car acts under those perameters. a full bridgeport for example, an aggressive one, needs 11.5AFR even idling and cruising or it will start to hiccup and fall on it's ***.

BDC

Richer isn't always safer. Don't allow yourself to fall into that belief. Try running a high load too rich, blow the spark out, and see what happens.

B

RotaryEvolution

iTrader: (30)

i'm not advocating running your car in the 8's under a load, but what does any tuner do when they are tuning a car? yep, they start at the rich end and work their way leaner, not the other way around. so yep, i stand by what i said 100%

never seen a motor pop running too much fuel, it is generally a timing issue or something else that i'd like to see proven.

Aaron Cake

iTrader: (1)

Oops, I typed 45 PSI in my post above when I meant to say 4-5 PSI. I wouldn't suggest running 12s at 45 PSI as I posted by mistake.

I don't agree with the richness stated for a bridgeport. Mine idles great in the high 13s, cruises around 15.0 and loves 13.0-13.5 under moderate throttle in vacuum. I'm at around 12.5 crossing the zero vacuum point, 12 until until 3 PSI or so, then down to 11.4-11.7 and that carries 14 PSI where I try to hold 11.0 - 10.8 or so to 16 PSI.

I totally agree with tuning to where the car is happy. So many people get hung up on ratios that they tune their car into crappyness. I've seen this with very well known tuners who many describe as "rotary gods" as well as newbies alike.

therotaryrocket

I've got a question about something I've read. I've heard that you can get detonation even if your AFRs are right on target. I read that if you were to also monitor your EGTs than you would know better if it was running dangerously, but what does it mean is happening when the EGT is really high? I would think your EGT would go up if you go lean, but if your AFR was fine, than would it be a matter of your ignition timing? What other factors affect that? Yesterday after running my car hard I got out and popped the hood only to find a glowing red turbine housing, well it wasn't bright red, but it was glowing red.

RotaryEvolution

iTrader: (30)

second and third paragraph correlation, all porting needs it's own tuning. i did say an aggressive bridgeport, meaning i did cut back the rotor housings about 3.5mm just to give you an idea. high compression rotors also allow the bridge to run leaner AFRs than a lower compression stock rotor T2, climate also plays a part as well. as we all have said, the car needs to be tuned to how it wants to be tuned, all we can do is post figures that are ballpark.

i most certainly would also sacrifice ~3% WHP to be 3/4 point rich and have peace of mind that if the fuel filter gets crappy gas that it has that much more of a chance to survive without me staring at my wideband without blinking, partly because i don't have my wideband in my car at all. i tuned it over 2 years ago and haven't touched it since, daily driven and never worried about.


otane of fuel can cause detonation without showing anything abnormally wrong except slightly higher EGTs. 87 octane tends to detonate around 9 PSI and 91 octane tends to detonate around 18 PSI (as tested in an S4 T2)just to give you an idea of the difference. a glowing turbine after a hard run isn't abnormal.

Jimmy2222

iTrader: (3)

I'm just curious as of now, just researching before I get started, but I'll be buying a Zeitronix Zt-2 WB and an Rtek 2.X. Car is an S5 T2 and I'm not planning to run more than 12 psi for a long time (that won't even come for a while). The engine will have 9.4 rotors and a street port, I'll also be using a BNR turbo 720/1000's and a denso pump is what I'm planning for but we'll see where every thing goes. Gonna fab up a cold air box over winter also.

Frostycrowd

iTrader: (9)

That seems like a good guidline to follow.

In high vacum I run a bit leaner, and up top at at 10-15 psi if i run anything richer then 10.5:1 AFR my car begins to hesitate and will have intermitent rich missfires. so I try to keep it at 10.8-11 AFR at 10-15 psi.

I wonder how some people can get low 10 afr to ignite consistently while I can't.

RotaryEvolution

iTrader: (30)

hotter plugs

some AFR gauges also aren't accurate to others, mine does read a little on lean side as well.

arghx

iTrader: (3)

Under WOT boost, I prefer a little leaner mixture but then less aggressive timing. At about 16.5psi I run about 10 degrees of timing advance (8.5:1 rotors) in the more detonation-prone rpms. AFR is between 11.2:1 and 11.5:1 . Wideband readings do vary though. They are sensitive to exhaust temperature and pressure, which is a function of the sensor's location.

Lately I've been running 15 degrees trailing split over 12psi, especially after seeing that the Rx-8's do this stock. I've been pretty happy with it. I've never been able to pick up much power from advancing the trailing timing (reducing split) by a couple degrees.

For cruising AFR's on a stock ECU you are going to see it vary between 14-15:1 a lot. Idle AFR will show up as very lean if your airpump is still on.

Frostycrowd

iTrader: (9)

For plugs I have always ran 8's all around, never anything colder. I wonder exactly how accurate my wideband is, I guess it is possible its not at all.

Jimmy2222

iTrader: (3)

Thanks for the help guys, really useful stuff here. I'll be sure to keep all this in mind.

Aaron Cake

iTrader: (1)

In my case, I have a Crane HI-6 on the leading coil. While the stock coils are very good, spark will blow out with excessively rich mixtures. With the Crane box I've found that my car will run fine even with the wideband showing 10 flat. Though obviously with a dramatic reduction in power.

Molotovman

iTrader: (49)

Alright, I'm bumping this instead of making a new thread. I just installed a used Innovate LC-1 on my 91' Turbo with the help of Pele.
Yes, the sensor is used as well.
The ECU is stock w/ an RTEK 1.5 chip.
The Exhaust is a 3" turboback w/ a cat.
Stock eveything else.

The AFR's I'm getting are crazy. between aroudn 10.5 at WOT to between 17 and 21 at Idle.
When I boost it seems like it's working right according to the mentioned above(even though I don;t have a boost gauge yet), but cruising etc. it's around 16.
We calibrated it properly, in Free air, then installed. All connections are soldered, and grounds are soldered to one wire which is grounded on the UIM.
From what I've been reading here it sounds like it's reading way too lean. Will a bad sensor do that? Is it bad even though it seems to be reading accurately under boost?

I'm almost done installing my boost gauge so I should be able to get corresponding PSI's to AFR's soon.

This is the First Turbo Rotary I've owned. I'm just tryng to get my head straight.

Black Knight RX7 FC3S

iTrader: (7)

wow
17-21 at idle?
My car dies out by the time it hits around 14.5 at idle...

HAILERS

Because the ACV routes airpump air to the exhaust ports which are located where???????????????????????

And the 02 sensor is located where in relation to the exhaust ports??????????????????

Yes. That is the reason you read numerically high numbers when at idle (and other given times when driving).

Pele

iTrader: (28)

Pwnt!

Ian, we need to delete your emissions gear and throw the air pump into the woods.

I can't believe it was that simple.

HAILERS

On a TURBO car this can be overcome just by removing a single small vacuum hose located on the ACV itself.

Idle the engine til the engine is fully warmed up. Then go to the ACV. There is ONE small hose that sticks straight up. Look at the afr on the gauge then pull that hose off and plug the hose with a small bolt or something similar. The afr gauge will now read a much smaller figure, most likely a figure close to 13afr which is the true engine afr.

If it were a non turbo engine you'd just pull the blue plug off the relief solenod and get the same result. Pulling the blue plug off the relief solenoid will not work on a TURBO car for this application. ON a turbo car you have to pull the vacuum line on the ACV that sticks straight up.

The other two vacuum lines on the ACV stick straight out towards the fender and you don't do a thing to them.

arghx

iTrader: (3)

Just leave the ACV working for now. What's the point? The car's idling fine, might as well keep the cat working efficiently so it doesn't smell.