L65 & L56 Differences ??

[Scooby]

My 1996 1500 has an 'S' in the 8th digit, so it is an L56. WHat is the difference in the L65 ('F') motor ?? Is it the EGR valve ?? How can I make mine an F ?? Get rid of EGR ?? Is the F a better configuration ???

[Scooby]

Anyone ???
:D

[patrick m.]

the differences vary through several years, for example, the 96 may have been the first L56 to have a "mass air flow" sensor.
Im not 100% certain.
the EGR is a definite. the L65 doesnt have it, it is just an emissions control device, it also will reduce power output by diluting the oxygen content of the charge air

[triggerman]

The only dif between the two is the EGR+MAF on the L56 and the PCM holds the IP to a minimum of fuel delivery and runs the engine with lower boost. Basicaly at steady cruiseing speed the EGR chokes the burn while the PCM makes it thirst for the elixer of compressor engine life, AT the same time. Obviously, the L65 is a much happier Diesel.

[G. Gearloose]

My '96 L56 has no MAF. I don't think the EGR is holding you back that much, nor should be the first thing to dink with.

Start with: Exhaust-cooling-shift improvement - gauges - boost controller

[Turbine Doc]

Scooby,
I've been working on my truck past couple of days and not monitoring the page actively, 1st are you in a emissions watch zone, that will determine how much conversion you can do.

I'll start with the std disclaimer; removal or modification of emissions equipment is a violation of many federal and local laws, that said if you want to enhance your "off-road" capability there are some things you can do, just remember to remove modifications you make when going back on the road ;) In about 20 minutes I can be back to 100% L56, maybe more if I leave the cat at home.

A good place to the how/why to do it is 1st visit http://www.bankspower.com a lot of good info on building Diesel power several links in their FAQs worth reading.

1st mods need to be exhaust and intake freeing up, then gages these are emission legal mods unless you drop or gut the cat which robs power in a L56 in a big way. Until you establish good intake/exhaust flow through the engine mostly wasted money to bolt on anything else Diesels gotta breathe to make power.

I made a special test pipe that goes in place of my cat when I offroad or suspect I might be having plugging problems with my cat, I faithfully remove it when going back onroad to be in compliance with the law :D . Gages are a must before going further; you need to know how much heat to the turbo and boost to the engine before starting to dial up for more boost or fuel.

The way I did mine was (exhaust, air filter, cat pipe), then (FSD cooler/bypass oil filt, opened upper intake plenum), then boost control, then a 99 junkyard L65 PCM(do you have a theft deterrent code-then you will need to teach the code to the replacement PCM).

Once on L65 PCM EGR/MAF/Baro sensors can be bypassed without throwing any codes as it does not look for them. I put a sheet metal blank off shim under my EGR valve as at hi power it can be unseated and leak. Vac then can also be direct plumbed to waste gate from thw WG sol, unpowered baro and EGR solenoids can also cause loss of vacuum.

99-2001 F PCM engines have highest factory fuel curve close to a reflash PCM but $150 j.y. vs. $600 reflash, then removed MAF replaced with 3"PVC to eliminate possibility of MAF honeycomb restriction, , then ceramic coated mandrel crossover, then fan clutch,

Then intercooling http://myweb.cableone.net/tbogemirep/ , added deep trans pan extra 3 qt fluid, and auxillary trans cooler, and now new injectors and extra fuel pump/filtration project currently underway/in progress. Also as a 96 you will want to go to a hi cap cooling system dual therms with 130 gpm waterpump found in 97+ engines. I have pulled a 12K trailer no problems total GVRW 18,700 pre injector swap still haven't finished latest mods to know how much improvement yet.

Also added helper spring www.activesuspension.com, (http://www.activesuspension.com,) HD clutches in trans, 3300lb rims, hi-perf shoes/pads/& drilled rotors. eventually will have full 3/4 T or 1T SRWH suspension and 18:1 block

Why didn't I start with a 3/4T or dually 1st good question, found this 1/2T 1st by accident too good a deal to pass on, then found The Diesel Page, and bought some big toys that needed occasional moving backhoe/tractor/bushhog/disc, & the rest is history.

[ 11-30-2003, 12:20 PM: Message edited by: tbogemirep ]

[Scooby]

Tim- thanks !! I would like to ask you more ??'s possibly by email if that is ok. I called a junkyard, and asked for a pcm for a 1999 2500, since they didnt put the 6.5 in the 1500's that year. (so I am told). He looked it up and told me from 1996 thru 2001 were the same computer, so I am confused. Maybe the 2500's used the same computer ?? Would the fuel curve be right on those?? I am looking for a cat to modify too. No emissions where I live. My email is in signature if you want to reply there.
Thanks, Rick