Mr_ET

Hi guys,

just finished turboing a sohc zc with dsm 450's a t3/t04e 46 trim and I have a chipped pm6 running turboedit.

We did some street tuning on the weekend and at WOT around 6600-7000rpms my a/f ratio is at about 10.6 is that way too rich? It is at around 11.5-11.6 at 4500 rpms and above and cruising I am sitting at about 14.5-15.

It also idles around 14-15 if that matters.

Do you guys think I am running too rich at WOT or this is still acceptable and still really safe.

it's a stock block and head running on 91 octane. 7 psi spring

Dueceification

I would personaly lean it out.

Mr_ET

so to what about 12:1 under boost and 11:5 by redline?

SOHC_MShue

why do you want to vary air fuel by rpm?

SovXietday

12:1 all the way through boost. If the BOOST increase, the AFR should decrease, it should not be an RPM decrease.

redzcstandardhatch

we usually tune our cars (my brother and i) to the high- 10's AFR wise..

you wont hurt anything. you might lose 2-5 HP, and you'll have built-in assurance against bad gas, etc.

i'd leave it if it runs well. i've ran like that for 2 years, no problems. i'll always tune my cars rich. i'd stay out of the 12's for sure, if your pushing it hard

Mr_ET

well since it's a stock block and I can't afford another motor right now I want it to be as safe as possible.

If you guys think that the 10.6 by redline won't foul the plugs or hurt anything, I won't change it.

I'll go for more power when I have it dyno tuned by a professional.

redzcstandardhatch

for probably over 2 years, we've ran mid-low 10's in my engine, from 5k up (was a d16a6).

made 300+whp on a stock head, stock sleeves, stock cam @ 21 psi or so. engine lasted forever, never ever fouled a plug. had decently conservative ignition timing, and was dead nuts reliable. i had people telling me it was way to rich, but it didnt seem to affect power a bit, and it was dead reliable until an injector failed. just rods/pistons were only mod. dropped a delta cam in for the last few thousandmiles. was making about 330 whp there.

i'd say you'r fine, if you've got a normal ignition curve. if it runs well, i'd keep it.

Mr_ET

yeah it runs fine and pulls good without any hiccups in the powerband I just wanted to make sure it would have no negative affect on the car.

Thx!

btw love the project keep it up!

blackeg

10.6 is pretty rich up top. my friends gsr made about 14 more hp going from 10.7 to 11.4 up top.

i think you get the same cooling effect from the fuel at 11.5 and 10.6, but will make a lil more power. you are only runing 7 psi and im probably sure you could run like 12-12.5:1 but you dont have to. take the few minutes and pull a few % fuel out up top.

redzcstandardhatch

dont say i didnt warn you if some crap *** fuel, and unbalanced set of injectors, or a boost spike pops the engine that close to 13:1.

keep it safe. you wont make 14 hp. i HIGHLY doubt that that small of a change (if that was the only change) made that impact on your buddies car too dude. i'd never buy that. ever. sorry. not to bash you.

CoreyR

i usually shoot for mid to low 11's. it wont hurt anything being like that but it can make the car run better if you lean it out a bit and keep the AFR's the same across the whole RPM range in boost. if you wanna be safe just leave it its not costing you that much power.

AWDstylez

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redzcstandardhatch &raquo;</TD></TR><TR><TD CLASS="quote">dont say i didnt warn you if some crap *** fuel, and unbalanced set of injectors, or a boost spike pops the engine that close to 13:1.

keep it safe. you wont make 14 hp. i HIGHLY doubt that that small of a change (if that was the only change) made that impact on your buddies car too dude. i'd never buy that. ever. sorry. not to bash you. </TD></TR></TABLE>

x2

You can lean it out a tad, but on crappy to begin with 91 octane and a stock motor, you aren't really hurting anything by erring on the rich side.

To everyone saying 12.0, are you nuts? On 91 octane? Maybe if he limits it to 1/4 mile pulls only, but his first time WOT in 5th gear is going to be game over.

blackeg

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redzcstandardhatch &raquo;</TD></TR><TR><TD CLASS="quote">dont say i didnt warn you if some crap *** fuel, and unbalanced set of injectors, or a boost spike pops the engine that close to 13:1.

keep it safe. you wont make 14 hp. i HIGHLY doubt that that small of a change (if that was the only change) made that impact on your buddies car too dude. i'd never buy that. ever. sorry. not to bash you. </TD></TR></TABLE>


its fine. im not taking it harshly. i find that most often all we can do here is speak from our personal experience. that was mine.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AWDstylez &raquo;</TD></TR><TR><TD CLASS="quote">

Maybe if he limits it to 1/4 mile pulls only, but his first time WOT in 5th gear is going to be game over.</TD></TR></TABLE>

thats why we shouldnt be doing big long wot 5th gear pulls

redzcstandardhatch

or maybe we just shouldnt have detonation, at all.

Topdawgg

you'll be fine at 10.6....

its conservative if anything...

miro_gt

you should go in the 10s A/F if you're running around 20psi on pump gas

for 7psi - no need to flood the chambers, 12:1 shoud be enough

detonation you control with proper timing, not with flooding the engine with fuel

I've seen up to 12.5 A/F at 14.5psi on my stock block, and yet no detonation .. but I keep it aound 11.5:1 in boost

SovXietday

Have any of you seen EGTs differences between 12:1 and 10.5:1?

10.5 is considerably hotter, detonation should be controlled by timing and a solid fuel mixture. 11.5:1 is considered fairly rich as it is, no reason to be that low at that boost level.

Will it hurt anything, no, but it's not going to help anything either.