going lean because airflow doesn't increase with boost

[Mellon]

hey guys, I don't have a DSM but a cousin, the Stealth Twin Turbo and you guys are years ahead of where we are with the 3/S platform so I'm asking for your help.

I'm going leaner and leaner the higher I raise the boost. I though originally that I was running low on fuel but after a Supra 310lph fuel pump, hotwired and checking the pressure with a gauge, I know I'm not for sure. base is 43psi and I'm holding 63psi of fuel pressure to redline.

at 16psi I'm plenty rich to redline and the karman airflow shown is 1172 max but when I raise the boost to 20psi I start getting lean by 4000rpm and the airflow still doesn't exceed 1172 which seems strange to me. Also the Airflow will go up and down erradically. It acts like MAS overrun but that doesn't seem possible given that it's a LS6 MAF-T. I have the MAF-T set to Stealth mode and it's zero'd out doing no correction. I do all of the correction with the e-manage. Stock is 360cc and I'm running 720cc injectors so it's doing a -50% correction.

here are a few logs that demonstrate the difference in fuel when boost is high/low:

here's a 3rd gear @ 20psi log

Time	RPM	Knock	Timing	O2	02 (RH)	Airflow	TPS	Inj D/C
00:12.7	2563	0	39	0.92	0.9	347	100	12.05
00:12.8	2594	0	36	0.9	0.88	378	100	12.75
00:12.9	2656	0	35	0.9	0.9	391	100	13.62
00:13.0	2656	0	35	0.9	0.9	416	100	14.75
00:13.1	2688	0	35	0.92	0.92	441	100	15.51
00:13.3	2719	0	34	0.92	0.92	466	100	16.27
00:13.4	2750	0	34	0.92	0.92	492	100	17.63
00:13.5	2781	2	34	0.92	0.92	510	100	18.42
00:13.6	2813	2	32	0.92	0.92	536	100	19.83
00:13.7	2813	2	32	0.92	0.92	561	100	21.04
00:13.8	2875	4	32	0.92	0.94	586	100	22.73
00:13.9	2906	3	33	0.92	0.94	611	100	23.59
00:14.0	2938	3	33	0.94	0.94	636	100	25.11
00:14.1	2969	3	33	0.94	0.96	662	100	26.01
00:14.2	3000	3	32	0.94	0.96	687	100	27.56
00:14.3	3000	3	31	0.94	0.96	718	100	28.21
00:14.5	3063	3	30	0.94	0.96	744	100	29.45
00:14.6	3094	3	30	0.94	0.96	763	100	31.07
00:14.7	3156	2	29	0.94	0.96	788	100	32.37
00:14.8	3188	2	28	0.94	0.96	813	100	33.38
00:14.9	3219	2	28	0.96	0.96	819	100	34.39
00:15.0	3281	2	28	0.96	0.96	832	100	35.75
00:15.1	3281	2	27	0.96	0.96	851	100	35.75
00:15.2	3313	2	27	0.96	0.96	863	100	36.1
00:15.3	3375	2	27	0.94	0.96	889	100	37.5
00:15.4	3406	2	27	0.94	0.96	907	100	37.84
00:15.6	3469	1	27	0.94	0.96	914	100	39.28
00:15.7	3500	1	26	0.94	0.96	933	100	39.63
00:15.8	3563	1	26	0.94	0.96	945	100	40.35
00:15.9	3594	1	26	0.94	0.96	952	100	41.47
00:16.0	3656	1	26	0.94	0.96	958	100	41.4
00:16.1	3688	1	26	0.94	0.96	971	100	41.76
00:16.2	3719	1	27	0.94	0.96	977	100	42.11
00:16.3	3750	5	25	0.94	0.96	983	100	42.47
00:16.4	3781	5	25	0.94	0.96	977	100	42.01
00:16.5	3844	5	25	0.94	0.96	983	100	42.71
00:16.6	3875	5	25	0.94	0.96	1002	100	43.05
00:16.8	3969	5	26	0.94	0.94	989	100	43.25
00:16.9	3969	5	26	0.94	0.94	1008	100	43.25
00:17.0	4000	5	27	0.94	0.94	996	100	41.88
00:17.1	4031	4	28	0.92	0.94	1002	100	42.2
00:17.2	4031	4	28	0.92	0.92	983	100	42.2
00:17.3	4281	4	28	0.92	0.92	983	100	43.91
00:17.4	4188	4	28	0.92	0.92	989	100	42.95
00:17.5	4250	4	28	0.92	0.92	989	100	43.59
00:17.6	4344	4	28	0.92	0.92	1015	100	44.55
00:17.8	4406	4	28	0.9	0.9	1027	100	45.19
00:17.9	4500	3	28	0.9	0.92	1021	100	46.15
00:18.0	4531	3	29	0.92	0.92	1002	100	45.5
00:18.1	4500	3	29	0.92	0.9	1040	100	45.19
00:18.2	4625	3	30	0.92	0.9	1034	100	46.45
00:18.3	4594	3	30	0.9	0.9	1046	100	46.14
00:18.4	4594	3	31	0.92	0.9	1046	100	46.14
00:18.5	4688	3	32	0.9	0.92	1046	100	47.08
00:18.6	4813	3	32	0.92	0.92	1078	100	48.33
00:18.7	4875	2	34	0.92	0.92	1059	100	47.91
00:18.9	4813	7	31	0.92	0.92	1059	100	47.3
00:19.0	4813	7	31	0.92	0.92	1109	100	47.3
00:19.1	5063	7	32	0.92	0.92	1115	100	50.85
00:19.2	4875	7	33	0.92	0.92	1071	100	47.91
00:19.3	5125	7	32	0.92	0.92	1078	100	50.37
00:19.4	5156	7	32	0.92	0.92	1128	100	51.78
00:19.5	5031	6	35	0.92	0.9	1122	100	50.52
00:19.6	5219	6	35	0.92	0.9	1109	100	51.29
00:19.7	5094	6	35	0.92	0.9	1097	100	50.07
00:19.9	5313	6	35	0.92	0.9	1097	100	52.22
00:20.0	5250	6	35	0.92	0.9	1097	100	50.48
00:20.1	5250	6	35	0.9	0.9	1141	100	50.48
00:20.2	5500	6	35	0.9	0.9	1103	100	54.06
00:20.3	5313	5	36	0.9	0.9	1147	100	51.08
00:20.4	5375	5	35	0.9	0.9	1147	100	51.68
00:20.5	5656	5	35	0.9	0.9	1115	100	55.59
00:20.6	5656	10	34	0.9	0.9	1172	100	55.59
00:20.8	5688	10	34	0.9	0.9	1172	100	55.9
00:20.9	5813	19	34	0.9	0.9	1166	100	58.38
00:21.0	5656	19	32	0.92	0.9	1141	100	55.59
00:21.1	5813	18	31	0.9	0.9	1122	100	57.13

Here's a 3rd gear @ 16.5 psi .. both max out the airflow to 1172 but this time it doesn't run out of fuel

Time	RPM	Knock	Timing	O2	02 (RH)	Airflow	TPS	Inj D/C
00:05.3	2969	0	37	0.88	0.88	403	100	14.59
00:05.4	3000	0	36	0.88	0.92	447	100	16.03
00:05.6	3031	0	35	0.9	0.9	479	100	16.84
00:05.7	3063	0	35	0.9	0.92	517	100	18.98
00:05.8	3063	0	34	0.9	0.9	548	100	20.29
00:05.9	3094	0	34	0.9	0.92	580	100	21.82
00:06.0	3125	0	34	0.9	0.94	605	100	23.37
00:06.2	3156	4	34	0.92	0.94	643	100	24.95
00:06.3	3219	6	32	0.92	0.94	668	100	26.83
00:06.4	3250	7	31	0.92	0.94	706	100	27.78
00:06.5	3281	7	31	0.92	0.94	725	100	28.74
00:06.7	3313	7	30	0.94	0.94	756	100	30.44
00:06.8	3375	7	29	0.92	0.94	756	100	31.73
00:06.9	3375	7	29	0.92	0.94	788	100	32.45
00:07.0	3469	7	28	0.94	0.96	807	100	34.09
00:07.1	3500	7	29	0.94	0.96	826	100	34.4
00:07.2	3500	6	29	0.94	0.94	838	100	34.4
00:07.3	3594	6	29	0.94	0.94	844	100	35.32
00:07.4	3625	6	29	0.94	0.94	851	100	35.63
00:07.5	3688	6	29	0.94	0.94	851	100	35.46
00:07.6	3688	6	30	0.94	0.94	851	100	35.46
00:07.8	3750	6	30	0.94	0.94	863	100	36.06
00:07.9	3781	6	30	0.94	0.94	870	100	36.35
00:08.0	3781	5	30	0.94	0.94	882	100	37.16
00:08.1	3844	5	30	0.94	0.94	895	100	37.78
00:08.2	3969	5	30	0.94	0.94	914	100	39.01
00:08.3	3938	5	29	0.94	0.94	920	100	39.55
00:08.4	4000	5	29	0.94	0.94	926	100	39.31
00:08.6	4031	5	30	0.94	0.94	920	100	39.62
00:08.6	4125	5	30	0.94	0.94	920	100	40.54
00:08.8	4125	4	30	0.94	0.94	958	100	41.43
00:08.9	4125	4	30	0.94	0.94	964	100	42.31
00:09.0	4219	4	30	0.94	0.94	983	100	43.27
00:09.1	4313	4	29	0.94	0.94	1015	100	44.23
00:09.2	4281	4	29	0.94	0.94	1021	100	43.91
00:09.3	4438	4	28	0.94	0.94	1021	100	45.52
00:09.4	4438	4	28	0.94	0.94	1021	100	44.57
00:09.6	4531	3	29	0.94	0.94	1034	100	45.5
00:09.6	4500	3	29	0.94	0.94	1002	100	45.19
00:09.8	4563	3	29	0.94	0.94	1034	100	45.82
00:09.9	4500	3	30	0.94	0.94	1040	100	45.19
00:10.0	4625	3	29	0.94	0.92	1040	100	46.45
00:10.1	4656	3	30	0.94	0.92	1040	100	46.76
00:10.2	4688	3	31	0.94	0.94	1046	100	47.08
00:10.3	4688	3	31	0.94	0.94	1065	100	47.08
00:10.4	4781	2	33	0.94	0.94	1052	100	48.01
00:10.5	4844	2	33	0.94	0.94	1065	100	47.61
00:10.6	4875	2	33	0.94	0.94	1084	100	47.91
00:10.8	4906	2	34	0.94	0.94	1084	100	48.22
00:10.9	4969	2	34	0.94	0.94	1065	100	48.84
00:11.0	5063	2	34	0.94	0.94	1115	100	50.85
00:11.1	4906	2	35	0.94	0.94	1122	100	49.27
00:11.2	4969	1	35	0.94	0.94	1103	100	48.84
00:11.3	5156	1	35	0.94	0.94	1097	100	50.67
00:11.4	5219	1	35	0.94	0.94	1078	100	50.18
00:11.5	5094	1	35	0.94	0.94	1103	100	50.07
00:11.6	5281	1	37	0.94	0.94	1122	100	51.9
00:11.8	5125	1	35	0.94	0.94	1109	100	50.37
00:11.9	5219	1	37	0.94	0.94	1103	100	50.18
00:12.0	5250	0	37	0.94	0.92	1097	100	50.48
00:12.1	5250	0	37	0.94	0.92	1109	100	50.48
00:12.2	5281	0	37	0.94	0.94	1147	100	51.9
00:12.3	5500	0	38	0.94	0.94	1109	100	52.88
00:12.4	5594	0	38	0.94	0.94	1109	100	54.98
00:12.6	5625	0	38	0.94	0.94	1122	100	55.28
00:12.7	5656	0	38	0.94	0.94	1172	100	55.59
00:12.8	5531	0	38	0.94	0.92	1128	100	53.18
00:12.9	5719	0	38	0.92	0.92	1172	100	54.99
00:13.0	5844	0	39	0.94	0.92	1153	100	56.19

my mods are as follows:

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91 Dodge Stealth R/T TT AWD Pearl White

Intake: DR-650R's, Dejon Y-Pipe, LS6 MAF and MAF-Translator, 9" K&N PowerStack air filter, HKS SSBOV, Vacuum Reduction Mod
Ignition: MSD 8.5mm spark plug wires, NGK non-resistor R5672A-8 (2 heat ranges cooler than stock) gapped at .024
Electronics: Greddy Turbo Timer, Greddy E-Manage with timing harness, Greddy Profec E-01 watching boost, egt's and rpm's, Palm with Pocketlogger software watching rpm timing, 02's, tps and knock
Fuel: Blitz/Denso 720cc injectors, Denso/Supra 310lph fuel pump, Fuel pump Hotwire kit
Exhaust: EGR Blockoff Plates, ATR downpipe, Borla mufflers
Other: Unorthodox Underdrive Pulley, Stillen Cross Drilled Rotors, Krankvents

 

[Mellon]

oh btw, we tune for .94v on narrowband.

for us :

.90-.92 = lean
.94-.96 = good (best power is at .94v)
.98-1.00 = rich

 

[Mellon]

I swapped out my MAF-T/LS6 MAF with the stock MAF and now I'm seeing airflow as high as 2900hz + by 18psi so now I'm trying to figure out why the MAF-T is clamping the signal.

 

[Tevenor]

Is that timing number a total or advance? That can't be advance can it?

There have been issues with some of hte older MAFT versions reading really low voltage across the baro feed leading to severely modified air signals. Not sure what the situation is with yours though.

 

[diambo4life]

Stock is 360cc and I'm running 720cc injectors so it's doing a -50% correction.

That's your problem. Pretty much the 50% correction is also affecting the timing maps adversely by making the ECU think it's flowing much less air than it really is consequently giving you too aggressive timing from the very low airflow Hz value. Your injectors are flowing 100% more than stock. You cannot only use a piggyback to correct for them. You will have a nightmare tuning the car correctly. I'm surprised you are barely seeing too much knock but I bet the car runs like crap from all that timing.

 

[98spydert]

Since he has the timing harness for his e-manage, couldn't he back off the timing advance? Just a thought, I don't know what the e-manage is capable of.

 

[Mellon]

the e-manage handles the large injectors and timing just fine if you know how to use it.

subtract about 11 from those numbers and you'll be closer to my actual timing

I fixed my problem.. it was the #3 dipswitch on the MAF-T .. it was on which clamps the airflow so that guys with stock injectors (360cc) don't hit fuel cut

now the airflow on the e-manage instead of showing ~2200 max, it's going on up as high as 3584 on a rough rough tune

no more leaning out at high rpm/boost/3rd and being too rich in 1st and 2nd due to the added fuel I was giving in to compensate for 3rd during long pulls.

 

[98spydert]

I fixed my problem.. it was the #3 dipswitch on the MAF-T .. it was on which clamps the airflow so that guys with stock injectors (360cc) don't hit fuel cut

Lol, I was going suggest this but I thought it was too simple.

 

[Mellon]

yeah, I guess I turned on that switch ages ago when I was running the stock twin 9b's and forgot about it.. believe me I'm kicking myself over this one. But it all worked out in the end.. it forced me to do some fuel upgrades while I was troubleshooting and I'm glad I have them now