matt-max
09-17-2003, 06:39
Just in case anyboby has been wondering, the power enhancing mod's to the 6.5td Tahoe i picked up out in Oregon earlier this summer have had some good results, thanks to the knowledgeable and helpful folks here at 'the page.'
the L56 is rated at 180/360 with the later year L65's at 195/420. Some sources (like this site)claim the 2000 and 2001 L65 had 215/440. anyway, stock the 'hoe ran ok, feeling pretty peppy ay highway speeds, but definitely lacking from a stop, even unloaded.
g-tech accelerometer testing indicated a staggering 127 shetland ponies with 52k on the odometer. power-braking would occassionally result in a chirp from the passenger-side rear michelin. 0-60 times were in the 12-14 second range, barely enough to stay in front of a loaded semi or athleticly-ridden bicycle. pathetic! after Jim Bigley told me his 94 Yukon 6.5td would run 0-60 in 8.6 seconds or so stock, i knew i had plenty of room for improvement.
for those unfamiliar with the g-tech, it is supposedly very accurate. entering weight (in this case 5800#) and zeroing the accelerometer is all that it takes. testing on my 03 dmax revealed 377hp and 0-60 in 5.98 seconds with a 10# boost 4wd launch. previous dyno testing showed 374hp....just coincidence?
first mod was Kennedy's 3.5" exhaust. big difference in response off the line, great growl and mechanical-whirring noise from the tailpipe that rises and falls in pitch with revs. amazing how much it opened up the exhaust. sound is very v-8 big block, muted 95% of the time with a short span of unannoying resonance. sounds GREAT and i highly recommend this piece to anybody with a 6.5. sounds way better than the BD 4" on my 96 k2500hd.
next up was latest/greatest stock programming. if Kennedy's 6.5td runs on stock ecm, why not? gotta be cheaper than dropping $700+ for an aftermarket program. options...buy an ecm from a junkyard L65 or have stocker reprogrammed? gave the local gmc service manager all the info i'd pulled from posts here regarding program changing and snagged a 2001 3500hd vin from a used truck for sale on autotrader.com. i figured the stock 15000gvw programming for the gm 6.5's last year would be the stoutest whether 215 or 195hp.
$100 later, truck smoked like a tugboat but showed signs of having more pep on occassion. thanks to those who have gone before me and shared their knowledge, some disconnecting of connectors, blocking off of valves and removal of both unnecessary metal and icky black goo resulted in not even a hint of black smoke at any throttle opening and greatly improved pep.
last mod to date, the turbo-master adjustable boost controller thingy set for a peak of 14#.
testing reveals a sucked in airflow check valve that never moved before and a new zest for life. my favorite 'hoe is no longer too shy and impotent to be called a turbodiesel.
g-tech reveals 171 fine arab chargers and a couple complete turns of that passenger-side michelin before traction is gained. (note to self: why isn't G80 working?)
a quick review of the 2000 BD dyno-day puts the little runt comfortably over a couple 93-94 cummins rams and three L65 6.5td's, right there (horsepower-wise anyway)with another cummins and 6.5 and about 30hp off 3 powerstrokes. acceptable.
what's next? a better flowing intake, starting with a freshly cleaned k&n robbed from my 97 or 98, followed by some home-engineered intake/airbox setup later probably.
still need to get the TDC timing set back at the dealer. not sure where it is now. Kennedy says -1.94 or -1.8? is best. any other feedback?
like to get a replacement crossover pipe if they ever become available again or maybe somebody has one used?
is the 6.2 J intake worth adding?
has anybody out there put an intercooler in a tahoe?
i notice a couple guys have port-matched and polished some but i don't really want to get into the motor unless it needs it later.
a great big thanks to all who helped me choose, find, purchase and improve this thing, you know who you are. may we meet sometime and enjoy chilled malt-beverages.
matt :D
[ 09-17-2003, 11:53 AM: Message edited by: matt-max ]
the L56 is rated at 180/360 with the later year L65's at 195/420. Some sources (like this site)claim the 2000 and 2001 L65 had 215/440. anyway, stock the 'hoe ran ok, feeling pretty peppy ay highway speeds, but definitely lacking from a stop, even unloaded.
g-tech accelerometer testing indicated a staggering 127 shetland ponies with 52k on the odometer. power-braking would occassionally result in a chirp from the passenger-side rear michelin. 0-60 times were in the 12-14 second range, barely enough to stay in front of a loaded semi or athleticly-ridden bicycle. pathetic! after Jim Bigley told me his 94 Yukon 6.5td would run 0-60 in 8.6 seconds or so stock, i knew i had plenty of room for improvement.
for those unfamiliar with the g-tech, it is supposedly very accurate. entering weight (in this case 5800#) and zeroing the accelerometer is all that it takes. testing on my 03 dmax revealed 377hp and 0-60 in 5.98 seconds with a 10# boost 4wd launch. previous dyno testing showed 374hp....just coincidence?
first mod was Kennedy's 3.5" exhaust. big difference in response off the line, great growl and mechanical-whirring noise from the tailpipe that rises and falls in pitch with revs. amazing how much it opened up the exhaust. sound is very v-8 big block, muted 95% of the time with a short span of unannoying resonance. sounds GREAT and i highly recommend this piece to anybody with a 6.5. sounds way better than the BD 4" on my 96 k2500hd.
next up was latest/greatest stock programming. if Kennedy's 6.5td runs on stock ecm, why not? gotta be cheaper than dropping $700+ for an aftermarket program. options...buy an ecm from a junkyard L65 or have stocker reprogrammed? gave the local gmc service manager all the info i'd pulled from posts here regarding program changing and snagged a 2001 3500hd vin from a used truck for sale on autotrader.com. i figured the stock 15000gvw programming for the gm 6.5's last year would be the stoutest whether 215 or 195hp.
$100 later, truck smoked like a tugboat but showed signs of having more pep on occassion. thanks to those who have gone before me and shared their knowledge, some disconnecting of connectors, blocking off of valves and removal of both unnecessary metal and icky black goo resulted in not even a hint of black smoke at any throttle opening and greatly improved pep.
last mod to date, the turbo-master adjustable boost controller thingy set for a peak of 14#.
testing reveals a sucked in airflow check valve that never moved before and a new zest for life. my favorite 'hoe is no longer too shy and impotent to be called a turbodiesel.
g-tech reveals 171 fine arab chargers and a couple complete turns of that passenger-side michelin before traction is gained. (note to self: why isn't G80 working?)
a quick review of the 2000 BD dyno-day puts the little runt comfortably over a couple 93-94 cummins rams and three L65 6.5td's, right there (horsepower-wise anyway)with another cummins and 6.5 and about 30hp off 3 powerstrokes. acceptable.
what's next? a better flowing intake, starting with a freshly cleaned k&n robbed from my 97 or 98, followed by some home-engineered intake/airbox setup later probably.
still need to get the TDC timing set back at the dealer. not sure where it is now. Kennedy says -1.94 or -1.8? is best. any other feedback?
like to get a replacement crossover pipe if they ever become available again or maybe somebody has one used?
is the 6.2 J intake worth adding?
has anybody out there put an intercooler in a tahoe?
i notice a couple guys have port-matched and polished some but i don't really want to get into the motor unless it needs it later.
a great big thanks to all who helped me choose, find, purchase and improve this thing, you know who you are. may we meet sometime and enjoy chilled malt-beverages.
matt :D
[ 09-17-2003, 11:53 AM: Message edited by: matt-max ]