General wideband questions/tuning

[Tictakman]

Im going back home this next week and im going to start my turbo install. my setup is:

sacf IIT3 .48 AR Turbine .60 AR Compressor Housing 60 Trim.boost designs dp and manifoldtial 38mm wastegateoil feed and return lines are routed alreadyFMIC 370cc injectorsblow through mafwalbro fuel pumphks ssq bov

for the monitoring aspect, i have: a fuel pressure gauge in the engine bayegt gaugeboost gaugeoil pressure gaugeLM1 wideband

gonna start with 8lbs of boost...

before i start to put all this on im going to knock back the timing to 15 or 16. then ill start the install. my question is what am i really looking for on the wideband. i think im looking for the ratio to be around 11 or 12, i think. depending if it is low what should i do the remedy the problem, also if it is high what should i do? i blew up one engine last yr bc i half assed the install and detonated. i think that was because of timing issues and not haveing a walbro fuel pump to push the fuel. i have an egt gauge too, what temperatures should i stay around and not go above.

just some general questions on reading the Lm1 wideband and tuning the safc II really. anyone can help...

thanks guys,Zak

[Tictakman]

hmmm, maybe just the basics to just get started?

Zak

[IvanAtSPRacing]

Wide band O2 basics

Idle 14.7light throttle cruising 14.7decel 20WOT during spool 12.5WOT under boost 11.5

[Tictakman]

awesome, by looking at the numbers i take it if the number is greater it is more rich, and the lower the more lean.

zak

[CodeWhore]

You got it backwards - the lower the number, the richer.

Besides, you wouldn't want to be lean under boost, would you?

[Tictakman]

well i was thinkin the more fuel going in and air the leanern it is. i dont know what i was thinkin...

Zak

[Structure240sx]

well you were kinda right the first time. if you were thinking still in ratios then yes the greater number would be richer. 11:1 is great than 12:1

[T88lexus]

no greater the number is lean.

[Structure240sx]

posted something but deleted it

now im just confusing myself

[Tictakman]

ill just try to get as close to the numbers as possible i guess.

Im confused too now...

Zak

[T88lexus]

here is easy way to tune your car.. rough estimate

on idle .. the best air fuel ratio is 14.7-14.9on partial throttle would be the same but when you apply the gas, it will go richfull throttle at boost tune it for 11.5 on full boost. if you want to be safe side. tune it richer which is lower number . therefore, like 11.3-11.2

on race gas you can lean it up to 12.3 or so.. but that is depends on your set up and tuner.

if your wideband goes below 10, or 9s which is peg rich.

if your car goes 15, 16, 17, 18,19. fire works.. booom.. ..

[sxseguy]

T3 .48 AR Turbine .60 AR Compressor Housing 60 Trim

Relatively small turbine = quicker spool Relatively large compressor = surge at low boost

Actually, I have yet to use my .63 A/R stage 3 wheel turbine with the same compressor (.60 A/R, 60 trim) as yours. I'm worried that I sized the compressor too big and that it may surge at the low boost levels (6 psi) that I will be running initially. The 50 trim seems to be the house wheel. Let us know how that setup works out for you.

[MarkEmark]

Wide band O2 basics

Idle 14.7light throttle cruising 14.7decel 20WOT during spool 12.5WOT under boost 11.5

This seems safe, but rather rich....no?

A large FMIC and alcohol injection would allow you to have leaner A/F ratios w/o detonation and make quite a bit more power, if I'm not mistaken...?

[T88lexus]

that is not really too safe at all.

taht is very ideal.

try to lean up more on your KA-T and see what happens.

if the AF is 11.5 on dyno. then on street. it will be like 12.0 or more leaner.

alcohol injection .. yes it will make run richer. great tool. not recommanded if you can tune your ecu. detonation can occur with alcohol injection with high boost or timming will be very important as well.

FMIC cold air= make more power til certain extent

[okis14]

Wide band O2 basics

Idle 14.7light throttle cruising 14.7decel 20WOT during spool 12.5WOT under boost 11.5

Good info to know ^

hmmm something isn't right with my engine then.I have a JWT ECUCobra MAF 50lbs MSD SAFC (Knob Style)Car idles like a champ at 900 rpm.

Using a LM1 my afr at idle is 20 - 21 (18.5 - 19.6 with SAFC +30%)When I hold it to 2000 rpm the AFR is 15 - 15.5When I hold it to 3000 rpm the AFR is 14.5 - 14.9This is without any load. Just sitting there revving it.

When driving around with WOT my AFR is 10 - 11 (JWT rich without any SAFC change)I haven't checked AFRs while cruising but I would expect them to be the same as my revving afr's as long as I don't hit boost.

My plugs look like I'm rich as I expected from the JWT ECU. I do have a exhaust leak where the Wastegate dump goes back into the manifold. Weird FMAX design. I have another leak yet to be found. It sounds like it's after my LM1 sensor which is in the outlet pipe. It's too cold to work on my car right now so it just sits but this is making me wonder about my AFR's now. I think I'll recalibrate the LM1 and see if anything changes.


Modified by okis14 at 4:21 PM 12/15/2004

[Tictakman]

curious, u said that you have the jwt ecu. if they tune the ecu to run rich and u have 50 lb injectors why are u running +30 on the safc? that would make it really rich. right now im going to be running 370's from the start but -27 to compensate for the larger injectors. ill soon be runnin the same setup u have but ill be using a 300zx mafs instead of the cobra.

Zak

[okis14]

I only ran +30 to see how my AFR's adjusted during idle trying to get it to 14.7. I know JWT tunes it rich under WOT but not sure during idle or cruising. I don't even know if it's possible to do that. I haven't had a chance to tune it yet so it's set at 0 across the board.

I don't know why my AFR's at idle are so lean. Maybe it's the MAF????

I just ran another little test. This time I recorded the data while the engine was warming up and +30 across the board as it seems I may be lean. Next time I'll run it at 0.

When cold my AFR was 14.7 and gradually increased as it got warmer to 16.5-17 then it dropped. I can't explain why it did this. It wasn't completely warmed up and it did climb back up.http://okifx.dynu.com:8383/dri...p.jpg

After it was warmed up I reved it up to 2000rpm and 3000rpm holding it for about a minute.I was in the 14.7 - 15.5 for 2000rpm and 14.3 - 14.9 in the 3000rpmhttp://okifx.dynu.com:8383/dri...k.jpg

I then just let off the gas and was around 17.5 - 18.5 and still idling just fine.http://okifx.dynu.com:8383/dri...p.jpg

I did a couple of revs just for the hell of it. First spike was at 4000rpm and second at 5000rpm then held it at 4000rpm getting 14.5 - 15.5 AFRhttp://okifx.dynu.com:8383/dri...v.jpg

Now this isn't an accurate way of testing but it's all I can do for now. I can't drive around with it yet but it seems that my AFR's are ok except during idle. Maybe that exhaust leak I have is messing around with the reading?

Also something to note. A few weeks ago I took my HKS filter off and the car would barely run. I had to keep it up to 2500rpm just to keep it going. It was popping like it was rich. I'll run a test on that again later but I can't stay out more then 30 minutes until I start to freeze.

Modified by okis14 at 9:45 PM 12/15/2004
Modified by okis14 at 9:50 PM 12/15/2004

[Tictakman]

what are u running, blow thru or pull?

Zak

[NX95240]

http://www.innovatemotorsports.com were the web site for the lm-1

[okis14]

what are u running, blow thru or pull?

Zak

pull

http://okifx.dynu.com:8383/dri...3.jpg

[Red-KAT]

Go read the tuner section of the LM-1 site... Dont run to rich.