Ok, what's a good a/f ratio for safe conservative tune??? i know if i run like 10 it'll be fine but i want some balance, some power and good safety.... what's the limit..?

also, say on the dyno you hit 13 A/F, on the street i heard there is MORE LOAD and **** due to wind, friction etc.. hills.... so on the street if i had 13 on the dyno, is it about 13.5 or so on the street???

 

???

 

13:1 would be too lean for a conservative tune IMO and 10:1 would be hella rich. maybe somewhere in the mid 11's would be a better a/f to street tune for

 

A dyno loads the car differently than when on the street. My car is tuned at 8 psi, 12:1 on the street, with alot of timing pulled. Just how I wanted it. If you tuned for 12:1 on the dyno, once you hit the street, with the same 12:1 dyno tune, the engine would be around 12.5:1. PM boosted hybrid. He schooled me on this matter.

 

High 11's (11.8-11.9) is safe for a street motor. You can run it leaner, but for the little hp gain it's not worth it imo, at least not for a daily driver. Now a race car is another story..

 

ok so i'll run 12 then

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by highmilehatch &raquo;</TD></TR><TR><TD CLASS="quote">A dyno loads the car differently than when on the street. My car is tuned at 8 psi, 12:1 on the street, with alot of timing pulled. Just how I wanted it. If you tuned for 12:1 on the dyno, once you hit the street, with the same 12:1 dyno tune, the engine would be around 12.5:1. PM boosted hybrid. He schooled me on this matter.</TD></TR></TABLE>

absolutely!! i have confirmed this many a time. unless you can load your car on the dyno as it would be on the street (need an eddy current or other braking dyno) and do it accurately, the street runs will come out leaner most of the time. That is why I always do street tuning and then never take away too much fuel when i get the car on the dyno.

I find most people are way conservative with their fuel and timing. 12.5:1 is perfectly safe most of the time for high boost. my H22 is needing as much as 28deg advance in boost whereas a b18 will be about 20deg at full boost so much depends on the size of the engine!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GruvyTune &raquo;</TD></TR><TR><TD CLASS="quote">
I find most people are way conservative with their fuel and timing. 12.5:1 is perfectly safe most of the time for high boost. my H22 is needing as much as 28deg advance in boost whereas a b18 will be about 20deg at full boost so much depends on the size of the engine!

</TD></TR></TABLE>

Exactly. A lot of people don't understand the relationship between bore diameter and ignition timing. I've heard people ask why they can't run 40 degrees of timing on their honda like they do on their sbc.

 

if i were on pump gas and it's a daily driven vehicle, i'd tune in the mid 11:1.

if it were race gas, for a race map, i'd tune 12-12.5...

 

I have a 2.0 Liter Type-R and I run 12.5:1 and I am about 26 degree's total advanced on my setup. I get shitty gas mileage, but I am running my hondata on open loop. I am going to switch it back to closed loop for some fuel economy.

 

I was thinking about this today my car is around 12.5/1 running 12psi on bone stock sohc 50/50 93oct and 114oct on the dyno.Being a hot day today I was worried about hitting full boost. But I am almost sure by the time you going past 60mph the inlet temp would be cooler then most dyno's fans can replicate. Would it not?

 

I would also like the experts to confirm this. But when you run race gas, you actually tend to run leaner than you would with regular gas. Race gas just prevents denotation.

On the street, I'm aiming for high 11s:1 or 12.0:1 and this being in 4th gear in full boost. 5th doesn't seem accurate enough for me to measure. Also remember to tune for partial throttle. You want at least 12.5:1 on anything more than 5psi. 13.0:1-13.5:1 is safe for about 1-2psi and 3-5psi you want at least 13:1 if not richer. As for timing, anything more than 20 degrees on a b18 on pump gas is pushing it for me.

Danny

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by R6Elmo &raquo;</TD></TR><TR><TD CLASS="quote">I would also like the experts to confirm this. But when you run race gas, you actually tend to run leaner than you would with regular gas. Race gas just prevents denotation.

On the street, I'm aiming for high 11s:1 or 12.0:1 and this being in 4th gear in full boost. 5th doesn't seem accurate enough for me to measure. Also remember to tune for partial throttle. You want at least 12.5:1 on anything more than 5psi. 13.0:1-13.5:1 is safe for about 1-2psi and 3-5psi you want at least 13:1 if not richer. As for timing, anything more than 20 degrees on a b18 on pump gas is pushing it for me.

Danny</TD></TR></TABLE>

all you say above is true!

 

Anything more then 20degrees at full load in boost, thats what you mean right? So say it starts at 39deg in vac you slow pull timing to about 12psi in boost and then level off at 20deg for pump gas?

What about race gas, what kind of timing advance limit would a bseries motor have on say 116 gas?

 

that is correct...
race gas would allow a bit more timing advance into boost. there is no magic number. you need to advance till you get some pinging then back off a bit. or dyno it and go with most advance till you either ping or power levels off at that point back off just a bit and keep it there.

 

Thanks for the help Gruvytune! Would you say 23 across full load on race gas would be reasonable to start with. Kinda hard for me to hear alot of detonation with boost on the dyno

 

23 degrees on a 1.8l engine may be a bit much timing. at full boost look to around 18-20 deg at most at 12+psi of total advance

on a 2.2L engine like the H22 look for as much as 28deg total advance in full boost with like 48deg advance at lower manifold pressures at high rpm.
if you dont advance enough you will see high EGTs from afterburn and you'll be thinking you are too lean when in essence you have too little advance. that is common with people tuning preludes. seen it in some folks AEM maps posted on AEM's website.

 

If say its like 80-90 degrees out I prefer to tune my car to 11.5:1 a/f.. that way im confident that if the weather goes down to 40degrees 2 weeks later I will not be too lean. Id rather be on the rich side then make max power.

 

doesn't a mustang dyno allows u to add a specific load to the engine
also what about a dyna pack.

 

most eddy current dynos will allow this, the dynopak will as well.
most people who have them dont learn how to use them properly and wont take the time to do load based tuning since it takes time.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DIRep972 &raquo;</TD></TR><TR><TD CLASS="quote">If say its like 80-90 degrees out I prefer to tune my car to 11.5:1 a/f.. that way im confident that if the weather goes down to 40degrees 2 weeks later I will not be too lean. Id rather be on the rich side then make max power. </TD></TR></TABLE>

The temp won't be compensated for? when it gets -10 here I notice i get shitty gas mileage, I assume this is because the computer senses the temp and dumps in more fuel. Am I wrong?

 

you are right. with hondata, the stock compensation tables are still at play so yes, the computer adjusts for intake temp changes.

 

how do you guys set your timing?i have mine a 20 deg at idle,and -.50 degree per pound with a btm,should i change it?im running 10 psi.this is on a b16a3

 

yeh, even w/ the correction the a/f still fluctuates. ive seen it first hand on my wideband.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GruvyTune &raquo;</TD></TR><TR><TD CLASS="quote">23 degrees on a 1.8l engine may be a bit much timing. at full boost look to around 18-20 deg at most at 12+psi of total advance</TD></TR></TABLE>

When you say you're looking for no more than 20degrees of timing total at 12+ psi, you mean complete timing as per the tables correct?

I ask because I've played with an Uberdata map and I've got my running 25.5* of timing as it enters boost and tailing off to 13.75* by 11psi. Sound too conservative? I belive I did this using the .8* per psi method.