Lightning 90mm MAF on Turbo SHO. HELP!

SHOWYA · #1 07-29-2009, 09:15 AM

Plugged the Calibration on the Tweecer and it just wont stay running.

Can anybody send me a working calibration just so i can at least get it running and work from there.

Thanks!

yamahaSHO · #2 07-29-2009, 11:02 AM

What else have you done with the tune? Are you SURE you have the right MAF curve?

Sho Amo · #3 07-29-2009, 11:59 AM

what injectors are you running? also, try putting the tune on selection 4. i had mine on 1 and it would never work. i dunno why i tried 4 but it worked.

Toolman · #4 07-29-2009, 04:03 PM

What type of connector are you using? Did you wire one in, are buy an adapter?

yamahaSHO · #5 07-29-2009, 04:35 PM

For the MAF? Cut and OBD-II MAF connector off of a junk yard car, cot off stocker, solder and heatshrink into place. It is a straight through design. I did this back when I first SC'd my car in 2005. I originally had the line long enough to go to across the engine bay and into the fender (draw-thru MAF).

ycode90 · #6 07-29-2009, 10:23 PM

Thread jack . How was the draw thru ?

92sho16 · #7 07-30-2009, 05:03 PM

Quote:

Originally Posted by SHOWYA

Plugged the Calibration on the Tweecer and it just wont stay running.

Can anybody send me a working calibration just so i can at least get it running and work from there.

Thanks!

Im using the 90mm lightning. I havent had that problem, have you tried raising the idle? Another thing to try is turn the tweecer switch to another position and then back to the one being used then write the tweecer.

SHOWYA · #8 07-31-2009, 06:17 PM

I have 50lb injectors 50/60 for low and high slopes.. And have the adapter from shonut performance. My idle is at 1050rpm ... What it does is that it hunts for the idle then it eventually dies.

Can any body with a turbo sho post the original maf calibration and maybe one that has been calibrated so i can see the difference.

yamahaSHO · #9 07-31-2009, 06:24 PM

Have you had a look at this thread? http://www.shoforum.com/showthread.php?t=100584

SHOWYA · #10 07-31-2009, 11:15 PM

i just did ... went and raised the idle to 1200 and changed the maf calibration to what i calll the jagged maf curve. which keeps it running. seems the sweet spot is between 1v and 1.5v for the idle. i was able to drive it but when i comes to a stop it starts searching for the idle till a come to a complete stop.

plus it runs pig rich. i cant boost it.

92sho16 · #11 08-01-2009, 11:22 AM

Quote:

Originally Posted by SHOWYA

i just did ... went and raised the idle to 1200 and changed the maf calibration to what i calll the jagged maf curve. which keeps it running. seems the sweet spot is between 1v and 1.5v for the idle. i was able to drive it but when i comes to a stop it starts searching for the idle till a come to a complete stop.

plus it runs pig rich. i cant boost it.

Did you start having these problems once you changed the maf? Also how did you wire the maf, with a plug n play adapter or did you cut the harness?

SHOWYA · #12 08-01-2009, 01:22 PM

Quote:

Originally Posted by 92sho16

Did you start having these problems once you changed the maf? Also how did you wire the maf, with a plug n play adapter or did you cut the harness?

plug and play adapter ... yes once i switched MAF.

Another thing that i knowticed is then when the car starts going rich my water temp starts climbing like crazy!

ycode90 · #13 08-04-2009, 05:38 PM

Sounds like a ground or sensor issue.

SHOWYA · #14 08-05-2009, 09:28 AM

Im going to try Tim's recommendation of going to a draw through instead of blow through. I will have to check on my ground that goes from the engine to firewall.

Question ... when an engine is in boost and you lift off, no matter what the MAF is reading ( being a blow thru or a draw thru setup) it will cut off fuel correct?

ycode90 · #15 08-05-2009, 11:27 PM

Yes .

somedude_001 · #16 08-05-2009, 11:52 PM

if you have a blow off valve instead of a bypass valve won't your part throttle maf signals be screwy with a draw through setup because you will be venting a lot of unused air that was metered?

SHOWYA · #17 08-06-2009, 12:09 AM

i think its the same since you will be letting off the throttle in order for the system to vent or recirculate... the system (ecu) is still going to cut off fuel ... right? Part throttle should be ok.

Toolman · #18 08-06-2009, 10:26 AM

Quote:

Originally Posted by somedude_001

if you have a blow off valve instead of a bypass valve won't your part throttle maf signals be screwy with a draw through setup because you will be venting a lot of unused air that was metered?

The worst problem I have ever had with my vent to atmosphere/draw-through setup is that every great once in a while, when you go from full throttle to part throttle very quickly, there would be a hickup. And that only happened when I first got the car. After I leaned out the ridiculously rich SHOSHOP tune, the car had nary an issue. After the Tweecer, and a much better tune, the car drove near perfect. The absolute best case scenario would be to have a draw-through setup with a recirc valve, or a drop in MAF that is meant to be in heated/pressurized air (the 80 and 90 mm FORD MAF's that we all use are not intended for this).

My belief is that nearly ALL the idle issues that S/C SHO's have can be linked to using a draw-through MAF in a blow-through setup. It is certainly a less ideal setup than a draw through and vent to atmosphere valve.

Sho Amo · #19 08-06-2009, 02:52 PM

whats a good blow through maf?

Toolman · #20 08-06-2009, 03:29 PM

Pmas hpx

Lupo · #21 08-06-2009, 03:40 PM

Quote:

Originally Posted by Toolman

Pmas hpx

Which MAF are you currently using for your draw-through?

Toolman · #22 08-06-2009, 08:02 PM

I have only ever used linc 80mm. I have not decided which route to go on my track car yet, either a 90L or the PMAS HPX.

Lupo · #23 08-07-2009, 10:28 AM

Quote:

Originally Posted by Toolman

I have only ever used linc 80mm. I have not decided which route to go on my track car yet, either a 90L or the PMAS HPX.

The Linc 80 is a good MAF, but what do you do when you peg it (which I'm sure you do quite easily!)?

Toolman · #24 08-07-2009, 11:25 PM

Actually, I don't think I ever pegged it. It flowed 400whp with some room to spare. Keep in mind, it takes less airflow for a turbocharged SHO to make the same power as an S/C SHO, and when you use a draw-through MAF in a blow-through design, I have heard you lose as much as 30% of it's metering ability. The only reason I have ever considered a 90L is because I plan making an insane amount of power with this new setup (well north of 550whp), and the only reason I considered blow-through designs is because of the pain of trying to package the huge 90L and it's associated filter within the limited space I have (based on my current turbo placement).

Lupo · #25 08-13-2009, 12:51 PM

I can't imagine that you would lose any metering ability with a blow-though setup, you would simply be reading the wrong amount of air.
These MAFs read from 0-5v for their signal.
If the same amount of airflow is getting 2 different voltage signals from the same MAF on draw-through versus blow-through, then the ECU is getting the wrong information on one of them.
What you would need to do is use a different MAF curve on blow-through systems which are using MAFs designed for draw-through.
Now figuring out the new proper MAF curve on a blow-though setup would be the hard part.

SHOWYA · #26 08-15-2009, 11:30 AM

I was in town last week and started checking out the SHO to try to figure out how to do the draw through setup, and simply enough, my current setup doesnt allow that big of a MAF to go right before the turbo.

So while looking at the spare parts i have in the garage i saw the old 55mm MAF and decided to throw it on to see if it would make a difference knowing that the MAF curve is already stored on the ECU.

Turned the car on and it idles really good. As i rev'ed it up while parked, it seems like if it was still naturally aspirated... good! Only thing is that when i did that the MAF numbers on calcon shot up to 500 and this maf is only meant for 800 max!

I have 50lb injectors and by what all you guys have been posting for 47lb injectors, i just winged it and put 50/85 for the injector slopes.

Im back in Texas so i couldn't do anything else and i really dont know how the car runs on the street.

Lupo · #27 08-17-2009, 03:43 PM

Well I bit the bullet and went with a draw-through setup using the lightning 80mm. Car runs pretty good, and idles steady.
Now I have 2 MAFs on my car, the lightning 80mm, and the lightning 90mm. It's just that one of them isn't hooked up right now

I'll need to make some piping to delete the current unplugged 90 in the intake tract , but I'm too lazy right now.

Toolman · #28 08-17-2009, 04:06 PM

Very interesting. Look forward to pics, as everything you do on that SHO is top-notch. Also looking forward to your driving results.

Did you change anything else in the tune, or just swap out the MAF xfer?

Lupo · #29 08-17-2009, 06:31 PM

Quote:

Originally Posted by Toolman

Very interesting. Look forward to pics, as everything you do on that SHO is top-notch. Also looking forward to your driving results.

Did you change anything else in the tune, or just swap out the MAF xfer?

I swapped out the MAF transfer to the 80mm Lightning. Take in account that the 80-90mm lightning MAF transfers from Caledit are assumed to be draw-through. So they really wouldn't work 100% correct for a blow-through setup.
SHOShop simply manipulated the WOT fuel multiplier to make up for the inaccuracies of the blow-through, not to mention pegging the MAF signal well before the car stops making power.
While that worked good enough for a dyno run at WOT, it made the drivability in closed loop and partial throttle suffer, and never work 100%.

So far, the car runs great. Rock steady idle, and PT seems a little crisper.