Logged: Lean A/F: Small Dry shot
Thread Starter
TECH Veteran
iTrader: (6)
Joined: Nov 2003
Posts: 4,397
Likes: 0
From: Tallahassee, FL
Logged: Lean A/F: Small Dry shot Here is my simplified question. I know some get tired of reading all of the inbetween stuff and would rather just see the question:
Why would my 5.3L w/ bolt ons be running 13.3-13.9 A/F ratio on a .44jetted(75 shot roughly), single dry shot?
-----------------
I just installed a small dry shot on my internally stock 5.3L. The only mods done to the motor are a CAI, Ported TB, and exhaust work.
Just a bit earlier I went and ran a log to see where my timing and A/F ratio were reading at.
1. My STFTs range from -2 to +2 for the most part.
2. Advance NA is 30*
3. I went WOT and NA the A/F was 12.5-12.9
4. NA, advance g/cyl is between .60 and .72
5. Nozzle is 7'' away from MAF
After seeing my NA tune was doing well, I flipped open the n2o act. switch and purged the air out of the line. Increased speed to 40mph, (aka suck-*** gear for a stock 60e) and went WOT.
1. Timing remained in the NA g/cyl cells.
2. Still 30* of max timing
3. A/F ratio ranged from 13.3-13.8 (slightly increasing as rpm increased)
----------------------
It seems to me that the MAF is not recognizing the Nitrous charge.
Why wouldn't I enter under more load?
Please help,
Thank you.
Why would my 5.3L w/ bolt ons be running 13.3-13.9 A/F ratio on a .44jetted(75 shot roughly), single dry shot?
-----------------
I just installed a small dry shot on my internally stock 5.3L. The only mods done to the motor are a CAI, Ported TB, and exhaust work.
Just a bit earlier I went and ran a log to see where my timing and A/F ratio were reading at.
1. My STFTs range from -2 to +2 for the most part.
2. Advance NA is 30*
3. I went WOT and NA the A/F was 12.5-12.9
4. NA, advance g/cyl is between .60 and .72
5. Nozzle is 7'' away from MAF
After seeing my NA tune was doing well, I flipped open the n2o act. switch and purged the air out of the line. Increased speed to 40mph, (aka suck-*** gear for a stock 60e) and went WOT.
1. Timing remained in the NA g/cyl cells.
2. Still 30* of max timing
3. A/F ratio ranged from 13.3-13.8 (slightly increasing as rpm increased)
----------------------
It seems to me that the MAF is not recognizing the Nitrous charge.
Why wouldn't I enter under more load?
Please help,
Thank you.
One thing i forgot to mention on the other forum was your nozzle placement. can you give a quick run down, maybe the shot is basicaly getting past the MAF wire and causing a lean condition?
Robert
Robert
Thread Starter
TECH Veteran
iTrader: (6)
Joined: Nov 2003
Posts: 4,397
Likes: 0
From: Tallahassee, FL
Originally Posted by Robert56
One thing i forgot to mention on the other forum was your nozzle placement. can you give a quick run down, maybe the shot is basicaly getting past the MAF wire and causing a lean condition?
Robert
Robert
I'm not sure how well nitrous is distributed when injected....
I wrote a lengthy response.
Thanks again.
Maybe the MAF sensor is bad....it SHOULD be seeing the change in temp in the air, thus increasing the air flow signal to the PCM. Id try another MAF if you have one available. How you removed the screen? If not that could POSSIBLY help some.
Or you could just go to a wet shot.
Or you could just go to a wet shot.
12 Second Club
iTrader: (10)
Joined: Sep 2005
Posts: 948
Likes: 0
From: From Ohio now in that state up north
I thought dry shots tend to be a little lean with out tunning any way my buddy almost found out the hard way with his mustang he sprayed a dry shot and was 16 to 1 before he got it tuned.
Make sure the wire isn't oil coated from your recent oiling/filter change. Also, maybe try aiming your nozzle into the air stream, as it could be getting past the maf and does happen sometimes. but if you have a spare maf to try, that would be great, but try to eliminate other problems before buying one. good luck.
Robert
Robert
Trending Topics
If you're running CATs in your exhaust and the WBO2 was put in the tailpipe or behind the CATs then that would explain it.
Otherwise, it's probably a placement issue.
Doublecheck your commanded AFR when this is happening.
Otherwise, it's probably a placement issue.
Doublecheck your commanded AFR when this is happening.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
TECH Veteran
iTrader: (6)
Joined: Nov 2003
Posts: 4,397
Likes: 0
From: Tallahassee, FL
Originally Posted by white2001s10
If you're running CATs in your exhaust and the WBO2 was put in the tailpipe or behind the CATs then that would explain it.
Otherwise, it's probably a placement issue.
Doublecheck your commanded AFR when this is happening.
Otherwise, it's probably a placement issue.
Doublecheck your commanded AFR when this is happening.
I'll have to check out the commanded A/F.
What exactly do you mean by a placement issue?
Here's a picture.
Thanks.
Is that your MAF sandwiched between those large diameter metal tubes?
How big are they anyway?
It may just be a case of too much air space inside the tube. In that case you just move the nozzle closer to the MAF and aim for the wires.
How big are they anyway?
It may just be a case of too much air space inside the tube. In that case you just move the nozzle closer to the MAF and aim for the wires.
Thread Starter
TECH Veteran
iTrader: (6)
Joined: Nov 2003
Posts: 4,397
Likes: 0
From: Tallahassee, FL
Yes, that is the MAF. I believe it is 4'' tubing.
I appreciate the ideas... I'm going to give them all a
shot as I try and get things working correctly.
Thanks.
I appreciate the ideas... I'm going to give them all a
shot as I try and get things working correctly.
Thanks.