Bad end results with the wrong mods used

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#1925 - 08/11/07 02:41 PM

Bad end results with the wrong mods used

Joined: Dec 2000
Posts: 5,848 teamzr1 Online happy

Owner - Pays the bills

teamzr1

Owner - Pays the bills
Lives in Engine Bay

Joined: Dec 2000
Posts: 5,848
America

What happens when lousy header design and bad choice of CAM is used:

Code

RPM	TPS	CELL	Timing	LTFTB1	HO2B1S1	PWB1	LTFTB2	MAF	PWB2	HO2B2S1	MAFRQ	MAFgrms	INJDC	grmcyc	CFM	VacKpa
916	18	6	20	24	0.840	4.9	9	1	4.4	0.750	4135	8.45	3.4	0.138	77	37
916	9	20	20	24	0.310	4.9	9	1	4.4	0.420	4135	8.45	3.4	0.138	77	37
916	9	20	20	24	0.310	4.9	9	1	4.4	0.420	2719	8.45	3.4	0.138	77	37
916	9	20	20	24	0.310	4.7	9	1	4.2	0.420	2719	8.45	3.2	0.138	77	37
916	9	20	20	24	0.310	4.7	9	1	4.2	0.420	2719	8.45	3.2	0.138	77	38
848	9	20	21	24	0.310	4.7	9	1	4.2	0.420	2719	8.78	3.0	0.155	71	38
848	9	20	21	24	0.350	4.7	9	1	4.2	0.400	2719	8.78	3.0	0.155	71	38
848	9	20	21	24	0.350	4.7	9	1	4.2	0.400	2746	8.78	3.0	0.155	71	38
848	9	20	21	24	0.350	4.7	9	1	4.2	0.400	2746	8.78	3.0	0.155	71	38
848	9	20	21	24	0.350	4.7	9	1	4.2	0.400	2746	8.78	3.0	0.155	71	37
835	9	20	21	24	0.350	4.7	9	1	4.2	0.400	2746	8.82	2.9	0.158	70	37
835	9	20	21	24	0.340	4.7	9	1	4.2	0.400	2746	8.82	2.9	0.158	70	37
835	9	20	21	24	0.340	4.7	9	1	4.2	0.400	2753	8.82	2.9	0.158	70	37
835	9	20	21	24	0.340	5.0	9	1	4.4	0.400	2753	8.82	3.1	0.158	70	37
835	9	20	21	24	0.340	5.0	9	1	4.4	0.400	2753	8.82	3.1	0.158	70	31
763	9	20	21	24	0.340	5.0	9	1	4.4	0.400	2753	8.92	2.8	0.175	64	31
763	9	20	21	24	0.310	5.0	9	1	4.4	0.370	2753	8.92	2.8	0.175	64	31
763	9	20	21	24	0.310	5.0	9	1	4.4	0.370	2769	8.92	2.8	0.175	64	31

NOTE: the sliders are active so you can move through the data

Notice how lean the left head (LTFTB1) fuel trim is to what the right LTFTB2 is.

Stock LS1 with no CATs, mufflers, crappy LG headers with a CAM grind of :

237-242 605-610 112 LSA
STAGE 2.5 5.3 HEADS
UNDER DRIVE PULLEY
STOCK INJECTORS
LS1 INTAKE

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#1966 - 09/01/07 07:58 PM Re: Bad end results with the wrong mods used [Re: teamzr1]
Joined: Dec 2000 Posts: 5,848 teamzr1 Owner - Pays the bills
teamzr1 Owner - Pays the bills Lives in Engine Bay Joined: Dec 2000 Posts: 5,848 America	Here is more PCM data to analyze and follow how using a OBD scanner pinpoints problems without ever seeing the car. Owner had the above mods done and then some so called pro tuner tune the PCM Car ran quite badly. Review the mods installed and then the performance as looking at the torque values recorded. Notice in top graph if you do not analyze all the data as in this case you would not see any real issue Now look at the 2nd graph and you notice PCM never goes into close loop, the fuel trims show no values all due to one O2 not functional Now compare both front O2 sensors and you see the right (B2) O2 never reports over or under 450 mvolts. By seeing they I then called the owner and the shop he went to to find out the problems and told then what the scanner data had told me and shop looked to find both front O2s were plugged into the other sides wiring to PCM. Attached Files Team ZR-1 True Custom Performance Tuning Teamzr1.com

#1967 - 09/01/07 08:07 PM Re: Bad end results with the wrong mods used [Re: teamzr1]
Joined: Dec 2000 Posts: 5,848 teamzr1 Owner - Pays the bills
teamzr1 Owner - Pays the bills Lives in Engine Bay Joined: Dec 2000 Posts: 5,848 America	Now with the O2s plugged into their correct wiring harness we see from new scanner data those functions now working but now that the fuel trims are functional notice that at idle the left head is much leaner then right but both are way too lean as what should be normal Attached Files Team ZR-1 True Custom Performance Tuning Teamzr1.com

#1968 - 09/01/07 08:10 PM Re: Bad end results with the wrong mods used [Re: teamzr1]
Joined: Dec 2000 Posts: 5,848 teamzr1 Owner - Pays the bills
teamzr1 Owner - Pays the bills Lives in Engine Bay Joined: Dec 2000 Posts: 5,848 America	Looking then deeper into the recorded scanner data we see that when idle ( cells 20 and 19) that MAF which normally would be around 35 KPA is around 70 KPA ! Part of this would be due to the LSA of CAM but not this badly. Also notice the fuel trims left head / right head are no where near equal Attached Files Team ZR-1 True Custom Performance Tuning Teamzr1.com

#1969 - 09/01/07 08:16 PM Re: Bad end results with the wrong mods used [Re: teamzr1]
Joined: Dec 2000 Posts: 5,848 teamzr1 Owner - Pays the bills
teamzr1 Owner - Pays the bills Lives in Engine Bay Joined: Dec 2000 Posts: 5,848 America	So with all this PCM scanenr data in front of you what is the remaining problem ? And this again shows why you need a good OBD scanner and have learned how to analyze the data and understand what each engine sensor does for it points to the problem for you in many cases Team ZR-1 True Custom Performance Tuning Teamzr1.com

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