what a/f are you tuning for on pure pump gas?

[Mellon]

what a/f ratio are wideband users tuning for on pure pump gas 93 octane? (no alky, propane etc..)

I've been experimenteng and it seems

11.7 is too lean to be reliable
11.5 is about right up to 5000 rpm
11.1 is good after 5000 rpm

so mine tapers off from 11.7 initially to 11.5 by 4000 rpm and on down to 11.1 by 5000 rpm

what are you guys doing on pump gas?

 

[Rob Rohr]

what a/f ratio are wideband users tuning for on pure pump gas 93 octane? (no alky, propane etc..)


what are you guys doing on pump gas?

I am tuning for 10.5 to 11 on my 1G. Leaner might be good for max power on short runs (15sec or less) but I am convinced that the lean A/Fs aren't good for extended runs (60sec +).

 

[ryanman]

I tuned my Talon to 12:1, I have no knock, car runs awesome, plugs look good, made 302hp and 345 TQ on a 2.3 with a 14b. I drive the crap outta the car and have no problems. I think 90% of the people who tune cars tune a little too much on the rich side.

 

[nazthug]

what a/f ratio are wideband users tuning for on pure pump gas 93 octane? (no alky, propane etc..)

I've been experimenteng and it seems

11.7 is too lean to be reliable
11.5 is about right up to 5000 rpm
11.1 is good after 5000 rpm

so mine tapers off from 11.7 initially to 11.5 by 4000 rpm and on down to 11.1 by 5000 rpm

what are you guys doing on pump gas?

some of you guys have it kinda backwards

you want it RICHER through your torque peak, making it richer on the topend doesnt really do anything

The torque peak is the hardest stage on the car, not the peak rpm, they dont need fuel as much as torque does

You want the car slightly richer through the torque peak, as it fades out and you get more rpm, you can lean it out slightly

Any experienced tuner will tell you this...

 

[Mellon]

well in a 3rd gear pull from 2000 to 7000 tuned for 11.7 worked out fine but in a drag race I would knock at 5500 every time.. I might experiment with pulling more timing instead of drowning the cylinders

 

[Mellon]

ok I made the a/f curve much flatter and closer to 11.7 and so far it's working out ok.. it's pulling harder now that it's not bogged with fuel but when I shift the fuel doesn't come on instantly and it's a bit lean setting off a few counts of knock

I wonder if anyone else is lean right after a shift.

for instance I'll be tuned for 11.7 in a 3rd gear pull but lets say I take it to 7000 in 2nd then shift to 3rd it'll be lean ~5000 (12.0) and eventually start getting richer but often very slowly kicking off knock.

 

[Ronin17]

22 psi on the GT30r on 93 octane. I tune for a 10.6:1 A/F Ratio, this is with timing at 16* at redline and flowing 39 lb/min according to DSMLink.

Anything leaner than 11.0:1 and I have to reduce timing to keep the knock down.

 

[nanokpsi]

Have you noticed any boost spiking after the shift? Tuned leaner for pump a few psi spike might cause a little knock.

 

[Violater101]

22 psi on the GT30r on 93 octane. I tune for a 10.6:1 A/F Ratio, this is with timing at 16* at redline and flowing 39 lb/min according to DSMLink.

Anything leaner than 11.0:1 and I have to reduce timing to keep the knock down.

Don't you find it amusing that people who aren't running something like DSMLink on pumpgas with a 2g always get crazy timing (well above stock). That tells me onething..they are really knocking and they just don't realize it because of the false airflow signal. When I dyno'd during the heat of the day (99F), I actually had to retard timing by 2 degrees (14 degrees from 5k up). I was flowing around 41.5 lbs/min @21-22psi. Car made 340 SAE. THis was with an A/F of 10.9 to 11.1:1 on 93 Octane.

 

[NewB2dsm]

22 psi on the GT30r on 93 octane. I tune for a 10.6:1 A/F Ratio, this is with timing at 16* at redline and flowing 39 lb/min according to DSMLink.

Anything leaner than 11.0:1 and I have to reduce timing to keep the knock down.

Did you try less boost? 10.6 is really rich thats why i ask. Maybe you were knocking b/c you were running too much boost, so you had to compecate the boost with more gas to mask the knock?

I tuned mine for 11.7ish on 20psi with the small 16g. Made 303awhp

 

[Mellon]

alright, I leaned the a/f to 11.7 across the board and it's definately feeling better.

my g-tech time went from

12.67 to 12.21
114mph to 116.7mph
4.04 0-60 to a 3.84

I got a touch lean @ 5500-6000 (11.8) which set off 7 knock counts so I'm going to a touch of fuel there to get it closer to 11.6-11.7 and see if it goes away. If the fuel is right and it still doesn't go away I'll pull a degree of timing there and see how that does.

this was at a peak of 16psi on my 91 TT stealth.

 

[Ronin17]

Don't you find it amusing that people who aren't running something like DSMLink on pumpgas with a 2g always get crazy timing (well above stock). That tells me onething..they are really knocking and they just don't realize it because of the false airflow signal. When I dyno'd during the heat of the day (99F), I actually had to retard timing by 2 degrees (14 degrees from 5k up). I was flowing around 41.5 lbs/min @21-22psi. Car made 340 SAE. THis was with an A/F of 10.9 to 11.1:1 on 93 Octane.

Looking at logs with this turbo at 20 psi with the pocketlogger/s-afc combo kind of scares me to see the timing curve I was getting. Nothing beats being able to control timing now. Nice numbers btw.

Did you try less boost? 10.6 is really rich thats why i ask. Maybe you were knocking b/c you were running too much boost, so you had to compecate the boost with more gas to mask the knock?

I ran 23 psi with timing retarded -2 from 4.5k to redline with zero knock, now I run 22 psi with more timing and zero knock. My car likes the A/F around 10.6 to 10.8:1, why run leaner when the car feels faster (and goes faster in the 1/8th) with a A/F in the high 10's? I don't really see running this rich as being a bad thing when the car runs great.

 

[NewB2dsm]

Looking at logs with this turbo at 20 psi with the pocketlogger/s-afc combo kind of scares me to see the timing curve I was getting. Nothing beats being able to control timing now. Nice numbers btw.



I ran 23 psi with timing retarded -2 from 4.5k to redline with zero knock, now I run 22 psi with more timing and zero knock. My car likes the A/F around 10.6 to 10.8:1, why run leaner when the car feels faster (and goes faster in the 1/8th) with a A/F in the high 10's? I don't really see running this rich as being a bad thing when the car runs great.

Good points, by chance what does it do in the 1/8?

 

[Ronin17]

Best I've ran is 8.2 @ 88 mph, flowing ~38 lb/min. Nothing to brag about, but decent I guess. I was running 8.4 @ 84 mph flowing 36 lb/min before so it was a improvement in power.

This is on stock cams/head/IM.

 

[GPTourer]

I am going to the dyno next week with the mods in my profile. I just added the Hahn FMIC and the AFPR which is why I need to retune. I plan on running 20psi on strictly 93 octane gas.

For a good street tune, nothing edgy or extreme, what A/F should I tune for? The dyno I go to uses a tailpipe sniffer. I have no control over timing other then lowering my fuel pressure, but I'll be using my pocketlogger while it is on the dyno. Where should my target be for timing?

Thanks.

 

[jetdriven]

a lot of guys on pump gas shoot for a total advance of around 16-18 degrees by redline. i get 16 degrees with 93 pump at 15 psi with a custom eprom.

 

[diambo4life]

For a good street tune, nothing edgy or extreme, what A/F should I tune for?

Mid-low 11's if you have no control over your timing I would say.

 

[GPTourer]

Thanks.

I think last time I was around ~11.7+ and at 19psi on my sidemount when my HG let go.

Plus since the tailpipe sniffer sees things a bit late I can't remember if it is a bit conservative or optimistic compared to an O2 reading from the manifold or DP. Any ideas?