I know that the optimal ratio should be around 12 or so,,, but want to know if that is alright running 10 to 11 ratio....

LS-T running 7 psi
what about adding 2 lb of boost to it?

your input is appreciated

 

Very conservative. whats your timing look like?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alghafat424 &raquo;</TD></TR><TR><TD CLASS="quote">I know that the optimal ratio should be around 12 or so,,, but want to know if that is alright running 10 to 11 ratio....

LS-T running 7 psi
what about adding 2 lb of boost to it?

your input is appreciated</TD></TR></TABLE>

Guessing the setup is on a stock motor, using 91-93 oct unleaded fuel on a 9.0:1 compression cast piston setup with a general t3/t4 setup. A good a/f ratio target would be 11.0:1-11.9:1

Good luck.

 

on 7 psi it shouldnt be in the 10s ..itll just kill the power a little and foul out plugs more often..

 

not rich enough to wash the rings and not lean enough to make alot of power. its just, safe

 

fueling isn't as important as timing. the fuel should be left at 12.0. the reason why people go richer is because it burns slower thus in a way "retarding" the timing. Fueling also doesn't have the cooling effect people think it does. 12.0 AFR is suggested because EGT's are kept to a minimum. N/A cars can run 13.0 (the most power) because their intake charges are less dense AND cooler.

 

12.0 is to lean for pump gas -11.5 and the degrees of timing determine all the factors of speed or longevity. It depends on how long you want to last .

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vxhatched &raquo;</TD></TR><TR><TD CLASS="quote">12.0 is to lean for pump gas -11.5 and the degrees of timing determine all the factors of speed or longevity. It depends on how long you want to last .</TD></TR></TABLE>

Yea great reply.

12.0:1 is just fine... especially for 7psi. 10-11:1 is rediculously rich.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by adseguy &raquo;</TD></TR><TR><TD CLASS="quote">fuel richer is because it burns slower thus in a way "retarding" the timing. .</TD></TR></TABLE>

Haha.. I got tuned on 93, octane. I noticed when i put 91 in the car (93 not avail) that the car went a few mph faster.. lol.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vxhatched &raquo;</TD></TR><TR><TD CLASS="quote">12.0 is to lean for pump gas -11.5 and the degrees of timing determine all the factors of speed or longevity. It depends on how long you want to last .</TD></TR></TABLE>

how about if my fuel is 96 octane, Am I still supposed to retard the timing?
If yes, How many degrees per lb? is it still .75/lb??

thanks a lot

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alghafat424 &raquo;</TD></TR><TR><TD CLASS="quote">how about if my fuel is 96 octane, Am I still supposed to retard the timing?
If yes, How many degrees per lb? is it still .75/lb??

thanks a lot</TD></TR></TABLE>
put it on a dyno and find out

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">
put it on a dyno and find out
</TD></TR></TABLE>

There is no dyno close to me now
I want to street tune it

 

in in the low 12s at wot, aroudn 12.1-12.3. im on 7psi gsr motor, is that a problem. runs fine. when tuned, he said he really didnt have to adjust the timing. very reputable tuner

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by playahwitgame &raquo;</TD></TR><TR><TD CLASS="quote">in in the low 12s at wot, aroudn 12.1-12.3. im on 7psi gsr motor, is that a problem. runs fine. when tuned, he said he really didnt have to adjust the timing. very reputable tuner</TD></TR></TABLE>

How did he not have to adjust timing? Stock ECUs don't even have timing values for positive manifold pressure. If you mean he didn't have to adjust the values over the basemap he set, then that's understandable.

You would be ok to lean it out a bit, 12:1 is a good mixture to shoot for at that psi, I'm 12.3ish falling to 11.4 at top RPMs.

The street is not really the place to tune timing, you won't be able to see the effects of your changes.

 

im sorry, he said he didnt have to make physical sdjustments lie messing with the distributor. he did a little sumtin sumtin on hondata. but not positive what was done. he got 238whp out of it on a conservative tune. i just want it to be safe and reliable

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alghafat424 &raquo;</TD></TR><TR><TD CLASS="quote">There is no dyno close to me now
I want to street tune it</TD></TR></TABLE>
in that case then your screwed

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vxhatched &raquo;</TD></TR><TR><TD CLASS="quote">12.0 is to lean for pump gas -11.5 and the degrees of timing determine all the factors of speed or longevity. It depends on how long you want to last .</TD></TR></TABLE>
On 7psi? I'm thinking 12.5 is perfect. Maybe 11:* on 20psi+

 

For all the motors I've tuned, I find gonig from 10:1 - 11:1 A/F is alot bigger gains then going from 11:1 - 12:1. Fine line between way over fueling the motor. I always try to tune for 11-11.5:1 regardless of psi.

 

Every car is different, every wideband is different. A good tuner will use more than just a wideband reading.

 

Ive seen Dynojet widebands reading 12.7:1 and then DFI widebands reading 11.7:1... Thats a whole point difference.. That was on more then 28psi make over 1300rwhp

Just food for thought.

 

where my o2 bung is for my wideband, there is a little leak that isnt fully welded. by how much will that throw off my wideband? because im thinkin at wot, the exhuast is coming at such a rapid rate, it wouldnt matter, or am i just wrong?

 

10's is a little too rich. i think for that boost level 11.8-12.2 is fine. ( ive personally run motors on 13+ a/f at 10 psi by accident and never had a problem, timing was nice and conservative).

just set the a/f to like 12:1 and then spend the time tuning timing. you really need a dyno for it, but since you dont have one, i guess do a plug check rather often. with a gsr you should probably be around 22* up top at around 8-9 psi, for an ls maybe a little less, like 20* for 9 psi

 

can someone please make a comment on TIP IN. My a/f dips to ~11.4 when I floor it and quickly goes to high 11s as I rev out the motor, is that ok? Seems to be making better than average power (119mph @ 2300lbs = ~300whp) @22deg TT @ 8psi. and the plugs look good.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blackeg &raquo;</TD></TR><TR><TD CLASS="quote">
just set the a/f to like 12:1 and then spend the time tuning timing. you really need a dyno for it, but since you dont have one, i guess do a plug check rather often. with a gsr you should probably be around 22* up top at around 8-9 psi, for an ls maybe a little less, like 20* for 9 psi</TD></TR></TABLE>

But, is it OK that if I'm @ 10 psi or lower, I don't need to mess with timimg
I heard this from a tuner that says there is no harm if &lt; 10 psi




Modified by alghafat424 at 1:49 AM 11/20/2006

 

I guess I'll go for 9 psi and shoot for 11.5 a/f
Also, I'll retard timing 10*

Thanks guys