Wideband Owners!!! A/F Ratio w/ Pump Gas??

[Mackzero]

I am just curious what A/F ratio you guys are running?? I know cars run better at slightly different A/F mixtures compared to each other, etc. I run 22 psi on 92 Chevron techron Pump. All mods are in my profile. Thanks in advance for any info. you guys can give me.

 

[yo2001]

On 93 octane, I see 11:1-10.5:1 on a good day with 7-10 knocks with 0-1 deg base timing. 20-22psi on a 50 trim with 680's

 

[Mackzero]

Yeah, I see only 1 count of knock pulling 1st and 2nd, but I'am getting from 4-12 counts through 3rd 4th and 5th gears. 5 BTDC stock base timing. Do you think I should advance the car to 2 BTDC to try to help it? Most guys on here just say to leave the car at the recommended base timing. Someone is burning me a custom eprom as soon as I get my spare chip sent to him to try and modify the timing maps a bit for my setup, but I am just trying to get it dialed in the best I can before I have him modify my setup for the logs I am sending him.

 

[eclipsegsx9797]

with 11.1 a/f on 93 octane at 21psi , see 1-2 counts of knock every so often. im going to try and run 23 psi her shortly and see what happends, with dsmlink it alows me to take timming away at that rpm that im knocking alowing me to run more boost but lower the timing. . now 110 is a way diffrent story hehe

 

[DSMJim]

I get my car to 11.5-11.8:1 with pump gas at 22-23psi of boost. I have no idea how many counts of knock I have but the car hauls ass and goes 12.1 so it musn't be much. When I go richer the car gets slower. I would not wanna see leaner than 12:1 on pump gas, really 11.5-11.8 is pretty well a good place to be at. Any richer then that and your just washing everything down and there is no need.

In the end it really depends on your car so you will have to see what your motor is happy with, not every car is the same. I found on my setup I was making optimal power at that level. Just experiment a bit between 11.0 and 12.0 and see what happens, your not going to blow anything up in that range. Get over the 12.0:1 range and your asking for it. I have seens cars go as lean as 12.5:1 on turbo with pump gas, but thats crazy.

 

[Mackzero]

Yeah, I am at around 11.5:1 when I just went out and drove it. It hauls ass, I can peg the speedo easy. But I am seeing too much knock. I can run 10.8:1 and I see the same knock numbers also. I think I might have to just buy the Link so I can get this ignition timing problem solved. My chip guy can do the same thing, just takes longer. And I save having to find someone to buy my logger, and chips, then having to drop a few hundred more for DSMLink, but I am sure it would be worth it. I hate the damn knock sensor I wish I could just unhook it.....

 

[NewB2dsm]

11.8:1 on pump gas at ~21psi on the small 16g with pump gas. No idea on knock but it made the most power and best torque and Hp curves at this setting.

Race gas im around 12.5:1 at 26psi falling fast.

 

[DBR01]

yeh, well I got some bad scoop and was told that 14.7:1 was perfect air/fuel.....lets just say my baby (97 GSX) didn't like that ratio too much..... imagine if you will, trying to stuff an elephant through a 747's rotory engine :thumbdown .....that's pretty much what my girl sounded like....I was pretty pissed if you know what I mean.....it turns out that the dyno tech I talked to forgot that my car had a turbo, wow big mistake,.... luckily nothing came through the side of my block.....just thought you guys would get a kick out of this....i'll tune to 12 and see where that puts me.....

 

[ITSME4G63]

I get my car to 11.5-11.8:1 with pump gas at 22-23psi of boost. I have no idea how many counts of knock I have but the car hauls ass and goes 12.1 so it musn't be much. When I go richer the car gets slower. I would not wanna see leaner than 12:1 on pump gas, really 11.5-11.8 is pretty well a good place to be at. Any richer then that and your just washing everything down and there is no need.

In the end it really depends on your car so you will have to see what your motor is happy with, not every car is the same. I found on my setup I was making optimal power at that level. Just experiment a bit between 11.0 and 12.0 and see what happens, your not going to blow anything up in that range. Get over the 12.0:1 range and your asking for it. I have seens cars go as lean as 12.5:1 on turbo with pump gas, but thats crazy.

Jim, I had my car wideband tuned to 11.6, up top about 7 k Im feeling a sort of hesitation, like as if you knew the car doesnt wanna go that high and will cut out. It cant be fuel cut, I have a tmo stage 3 chip in my rizzle. My friends tell me When I punch it, teh blackness smoke come out, how can I be running so rich if Im at 11.6? ANy other parmeters to worry about?

 

[DBR01]

...teh blackness smoke come out, how can I be running so rich if Im at 11.6? ANy other parmeters to worry about?

actually, black smoke = burning oil .....white smoke with a bluish tint is fuel or thick white smoke is coolant....the only way that that is fuel is if you are pouring fuel into your exhaust and it's cleaning out your pipes.....pull your plugs and see if any are wet, if none are wet you may have some fry'd rings.....

 

[GSX_RCR]

yeh, well I got some bad scoop and was told that 14.7:1 was perfect air/fuel.....

I'd kick that "dyno tech's" a$$, if I were you. Seriously.

14.7:1 is STOICH. Yes, it is the perfect air/fuel ratio in a perfect world with no knock or detonation. But things aren't always perfect. Even N/A motors like to get about 12.5.0:1-13.5:1. Anything more and you'll risk leaning it out, esp if it's a high rpm motor. Regardless, that "dyno tech" needs his a$$ kicked for even trying to shoot for 14.5. :laugh:

11.5:1 - 12.5:1 usually yields a safe and conservative performance on pump gas. Race gas can get away with a slightly leaner mixture (13:1 ish), but don't go overboard. You're also able to run slightly more timing due to the knock/detonation supression that a higher octane gas offers. The key is to tune it accordingly to your vehicle's preference and ability. One car might respond different than another with the same mods.

 

[Mackzero]

Jim, I had my car wideband tuned to 11.6, up top about 7 k Im feeling a sort of hesitation, like as if you knew the car doesnt wanna go that high and will cut out. It cant be fuel cut, I have a tmo stage 3 chip in my rizzle. My friends tell me When I punch it, teh blackness smoke come out, how can I be running so rich if Im at 11.6? ANy other parmeters to worry about?

If you are running stock cams, then you might actually be feeling the cams. They stop making power at around 6800 or so I thought.

 

[Skunked tsi]

actually, black smoke = burning oil .....white smoke with a bluish tint is fuel or thick white smoke is coolant....the only way that that is fuel is if you are pouring fuel into your exhaust and it's cleaning out your pipes.....pull your plugs and see if any are wet, if none are wet you may have some fry'd rings.....

Actually I am pretty sure you have the fuel and oil smoke switched. Fuel = Black smoke and oil= Blueish tint.

 

[ITSME4G63]

Actually I am pretty sure you have the fuel and oil smoke switched. Fuel = Black smoke and oil= Blueish tint.

Ok, When Im at idle, I have black shit jumping out the exhasut as well, The spot where I park my car at, there is a black line in back of where my exhaust would be.

 

[GSX_RCR]

Ok, When Im at idle, I have black shit jumping out the exhasut as well, The spot where I park my car at, there is a black line in back of where my exhaust would be.

Probably combination of both oil blow by and running rich. Are you running a catalytic converter, or straight pipe?

Check your intake piping for oil blow by. Check your compression for blown piston rings. If all fails, now's the time for a rebuild.

 

[ITSME4G63]

Probably combination of both oil blow by and running rich. Are you running a catalytic converter, or straight pipe?

Check your intake piping for oil blow by. Check your compression for blown piston rings. If all fails, now's the time for a rebuild.

its a straight pipe alright , 3" turbo back. But fawk Im really hoping its the head, because I have a head I just picked up from the shop. Got it from a friend who had a jdm motor on his car, rebuilt the head and his timimng belt tensioner failed and all the exhasut valves got bent, so i got it rebuilt and am planning to throw it on my car soon, lifter tick be-gone! But Yeah Im really hooping its the damned head leaking oil, my dsm is my only car, and I hate to have downtime on it.

 

[DSMJim]

My car puffs like a mofo at wot too, don't worry about it. Grey or grey/black smoke is just running rich. The problem is with the afc dumping fuel before your turbo is spooled up and it does it on throttle position, even though your at wot your not spooled but getting tones of fuel which = smoke...

http://www.etdracing.com/jim/1212vscobra.wmv - Puffy puffy, but almost 115mph
http://www.etdracing.com/jim/backfire.wmv - Now thats carbon...

Your gonna see that no matter what cause 11.6 is rich regardless, because it's turbo and your makin big power thats a lot of gas running through the engine at 11.6:1 air fuel ratio. Your now pumpin through twice the fuel you are stock so you can see the smoke coming out because you just doubled the amount of carbon your creating with burning more fuel at a richer state.

It's there so that when your whopin the cars ass behind you, not only do you get the satisfaction of seeing him in the rear view your also kicking a little "sand" in his face.

 

[ITSME4G63]

My car puffs like a mofo at wot too, don't worry about it. Grey or grey/black smoke is just running rich. The problem is with the afc dumping fuel before your turbo is spooled up and it does it on throttle position, even though your at wot your not spooled but getting tones of fuel which = smoke...

http://www.etdracing.com/jim/1212vscobra.wmv - Puffy puffy, but almost 115mph
http://www.etdracing.com/jim/backfire.wmv - Now thats carbon...

Your gonna see that no matter what cause 11.6 is rich regardless, because it's turbo and your makin big power thats a lot of gas running through the engine at 11.6:1 air fuel ratio. Your now pumpin through twice the fuel you are stock so you can see the smoke coming out because you just doubled the amount of carbon your creating with burning more fuel at a richer state.

It's there so that when your whopin the cars ass behind you, not only do you get the satisfaction of seeing him in the rear view your also kicking a little "sand" in his face.

what about the "hesitation towards redline" ? Must be knock?

 

[Mackzero]

Ok, When Im at idle, I have black shit jumping out the exhasut as well, The spot where I park my car at, there is a black line in back of where my exhaust would be.

So do I, and my head is completely rebuilt and the bottom end is good too. Just fuel that's all. The black crap is the fuel grabbing the black carbon, etc. that lines the exhaust, then flying out on the ground.

 

[pballernh]

yeh, well I got some bad scoop and was told that 14.7:1 was perfect air/fuel.....lets just say my baby (97 GSX) didn't like that ratio too much..... imagine if you will, trying to stuff an elephant through a 747's rotory engine :thumbdown .....that's pretty much what my girl sounded like....I was pretty pissed if you know what I mean.....it turns out that the dyno tech I talked to forgot that my car had a turbo, wow big mistake,.... luckily nothing came through the side of my block.....just thought you guys would get a kick out of this....i'll tune to 12 and see where that puts me.....

15:1 is perfect for an NA motor trying to get best fuel economy and best emissions at less than full throttle. For racing purposes you may be looking more at 11:1 - 11.5:1

When I hear 14.7 I think of the atmospheric pressure at sea level (1 Bar)

 

[DSMJim]

what about the "hesitation towards redline" ? Must be knock?

Either fuel pressure is dropping or your boost is dropping off, or your gettting really rich. Something is not quite right. Even with stock cams, my car pulls pretty well to 7500rpm with my 50trim. I can't wait to see what 9:1 and Comp 101200 (FPCams2) cams does to that mix.

Are you watching your air fuel ratio towards redline? Whats happening with it?

Here are some sample air fuel ratios I work with depending on the cars, just for the record...

Turbo 11.6-11.9
Nitrous (or Nitrous & Turbo) 11.0-11.3
All Motor 12.9-13.3

Those are all at WOT though the cams power band. 14.7 is idle and light part throttle driving only. Even part throttle with a few pounds of boost once it comes on is mid 13's because fuel pressure just got ramped up.

 

[GSX_RCR]

Here are some sample air fuel ratios I work with depending on the cars, just for the record...

Turbo 11.6-11.9
Nitrous (or Nitrous & Turbo) 11.0-11.3
All Motor 12.9-13.3

 

[dsm10sec]

When I first started tuning my car (without a wideband *shoots himself*) My car ran soooo incredibly rich at top end I had the hesitation you were feeling, just dial the fuel back alittle bit at a time and you'll notice a huge difference.