KA-T runs rich, would 7:1 fmu over 8:1 help?

[Unstock240]

I have a ka-t with t25, sr20 manifold,fmic,walbro 255, and obx 8:1 fmu running 7psi. Plugs are bkr-6 at.35. The car runs good, but plugs look rich. When running the car will hiccup a tiny bit before boost. Idle is a bit rougher, and exhaust cackles slighty more, usually worse when warmed up from a good drive.

I have no wideband, so would 7:1 fmu run better on mostly stock ka with sr setup? I have about 3k miles on this setup so far. and please don't tell me to toss the fmu, it has been tried and true for many mild boost setups.

[biggie]

I'm not too use to FMUs.

But any way you are not metering all the air going into the engine? IE: wheres the MAF/BOV? And O2 sensor for ECU in good condition?

[Unstock240]

I have the maf on cold side suck through. My bov is on the cold side , and it is recirculated to the short airfilter pipe. 02 is relatevly new and ecu has a code 55. Another thing was iacv vacuum was blocked off when I swapped the motor. Maybe it could need a cleaning?

[biggie]

Assume you mean MAF on Hot Pipe (or intake)? And recirc to intake after the MAF?

IACV shouldn't affect it that much.

[Unstock240]

Yes, and recirculated after maf and before turbo.

[Doya]

A 8:1 is too rich. Get a 6:1 disk. That's what I've been using.

[Unstock240]

I might buy a 7:1 vortech and a 6:1 recalibration. Then just compare new plugs on both discs. I still want to be rich since im without a wideband, but the 8:1 does feel too much.

[Doya]

You'll still run a bit rich with a 6:1...

[neverlift]

7:1 was ok, a hair on the rich side(i cant recall off the top of my head, but iirc it was around11:1 afr under boost. However not on stock maf,and blown through.
I think a 5:1 could do the job, with help of an afpr. DOnt ditch the fmu setup, you know its simple and easy.

pic of plugs?

[s13drifter88]

just curious but you mentioned in your opening post "sr setup". what injectors do you have

[neverlift]

just curious but you mentioned in your opening post "sr setup". what injectors do you have

dood this is step one tuning stuff


he has stock injectors.. he is reffering to sr setup meaning manifold turbo,outlet,downpipe...

[s13drifter88]

ok, i was just asking since i was curious on what he meant. the kid down the street did a ka-t when I had mine and he tried using stock sr 370's without any tuning and had a rich problem. only reason I asked

[neverlift]

and fmu/wa;bro (OR afpr walbro, very dangerous!) is the only way to boost a ka without spending money on a tune/injector or afc/injector setup. And its by far the best solution to low boost applications, period

[nelson8708]

daily drove my ka24e-t for 1.5 years on a fmu setup....t25, smic, 7psi, pulled 2 degrees from the dizzy, walbro, 8:1 fmu

I kind of miss the old simple setup...could beat on it for days and it would keep asking for more.

[lexcrob]

^ what you guys think about running fresh plugs do some pulls then check the plugs? Honestly im cheapin out because its not my daily and a widebands just not in the books to get it runnin when i want to. Is it really that much of a lifesaver/engine saver? I mean if you hear ball bearings get out of it and pull over. I guess over a long time if you were a touch lean it be BAD but you'd see it on the plugs RIGHT?

*Just trying to not do it right but get it to werk i know i know .....NOT THE DD

My theory is if you just cruise around maybe WOT for a sec no biggie like street driving. Now id have to say if you went out and drifted a parkinglot/event/tracked that $hit all out WOT WOT 2nd gear clutch kicks all day ......yea if no wideband check probly bad idea! NOS guys just do plugs all time right???

[neverlift]

nos guy s know how to actually do plug chops, which most people have no clue. If you pull a plug out it has to be wot throttle pass kill engine while still in wot,coast to stop then pull/read plug
even 5 seconds cazn mislead a read

[lexcrob]

^ makes sense

[lexcrob]

So sounds like 6:1 would probly do the trick.

Wouldnt things like air filter restriction,exhaust restriction,turbo size* affect this quite a bit?

Im just tryin to decide which one to get if the guy with t25 used 8:1 just fine and im going to be using a (series 2 rb25det "nylon compressor wheel,ceramic turbine). I guess id have to compare compressor maps or something? If i were to guess id say its more efficient slightly and at 8psi its gonna flow more CFM than t25 so a 8:1 would put me right in stoich???

Just trying to put it all together here got a free wastegate 8psi so...90psi lookin right in the zone! Also power level is looking to be promising but not so much that i go to track and break axles etc. 240hp sounds like the drivetrain #'s

[lexcrob]

^ sorry its a T3 - NO idea if its ball bearing or not infomation isnt out there>.006 endshaft play so that spells journal taking it to a local guru next week. hope he can tell difference ?

[neverlift]

an fmu doesnt give a f*** what turbo you have it cares how much boost it seeing.

[WDRacing]

So sounds like 6:1 would probly do the trick.

Wouldnt things like air filter restriction,exhaust restriction,turbo size* affect this quite a bit?

Im just tryin to decide which one to get if the guy with t25 used 8:1 just fine and im going to be using a (series 2 rb25det "nylon compressor wheel,ceramic turbine). I guess id have to compare compressor maps or something? If i were to guess id say its more efficient slightly and at 8psi its gonna flow more CFM than t25 so a 8:1 would put me right in stoich???

Just trying to put it all together here got a free wastegate 8psi so...90psi lookin right in the zone! Also power level is looking to be promising but not so much that i go to track and break axles etc. 240hp sounds like the drivetrain #'s

Stoich refers to the AFR at idle, 14.7:1 is stoich for a gasoline motor. Once the throttle is lifted stoich goes out the window.

Run a 6:1 fmu, the 8:1 will make the car run to rich. This will give you bad mileage and you'll be losing power.

WD

[lexcrob]

^sounds good i was tryin to throw some BELL in there i skimmed it ....

i know i know but OBX,VORTECH,BEGI,etc.........