Bang for the buck engine upgrades - '03 Suburban 2500 Quadrasteer (LQ4 / 4L80e)
11-01-2017, 08:05 AM
#33
It is a two piece now. I had a local shop here make another aluminum one. For those wondering the measurement from the end of the output shaft to the bottom of the U-joint is 68 and 5/8 inches! The new one is a 5 inch aluminum rated for 900 HP. Runs $790 after tax. Should be trying again today.
11-16-2017, 07:28 PM
#34
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So quick update -
I got the truck into the wrench Tuesday, and the list of stuff in his hands includes:
- BTR truck/torque cam Stage II - 212/218 113 LSA, .552/.552 valve lift
- LS6 valve springs
- BTR hardened pushrods, 7.400" (stock length)
- Rockers with trunnion upgrade
- Valve seals
- Valve cover gaskets
- Timing cover gaskets
- Oil pump
- Timing chain
My buddy with the 2010 LSA'd 5.3 appreciated my contribution of my HPT Pro box to his cause, so aside from returning my HPT box he also sent with it:
- NNBS truck intake, fuel rail, and 42lb flex-fuel injectors
In order to make that work, I also ordered:
- Fuel regulator/filter to adapt the NNBS' returnless intake back to the '03's return system
- AN fittings to adapt the fuel line + return line to the regulator
- 4 bolt to 3 bolt throttle body adapter
Finally, I figured I would get fancy, and bought:
- Speed Engineering 1 3/4" headers + Y-pipe (this gets interesting in a minute)
- Steel header gaskets
- Bolts, etc.
So Tuesday I got everything in the mechanic's hands, and he called that he didn't think the exhaust setup would work.
He's right, as what came to me were LT headers + a y-pipe. I need some form of an X-pipe, and I need to figure out how to stagger it with the OEM exhaust that's at a 45 degree angle relative to each other to make room for big fat catalytic converters. He was also trying to figure out how to make the fuel regulator/filter work with the returnless fuel rail but I think there's a way to make it happen...
Yesterday I got him e-fans and the AEM OBD2 wideband, but exhaust will definitely be a limiting factor on getting this done so I decided to 'why not' order both the X-pipe as well as the rest of the system from Speed Engineering.
One caveat: they don't make a system specifically for a Suburban/Yukon XL. If the Suburban has a 130" wheelbase, and a RCSB has a 133" wheelbase, I'm hoping we can either adapt the X-pipe and then I can decide if I want to use the Speed-Engineering mufflers etc. later, or jimmy hangers around or cut down the mid section pipes enough to get the new system in place. Maybe can be the guinea pig and figure out if their system is an easy fit or not.
PCM of NC is lined up to do the tune. Hoping to get this thing back on the road by next week!
Joejamesatou: any updates on your project? Did you also do headers/exhaust?
I got the truck into the wrench Tuesday, and the list of stuff in his hands includes:
- BTR truck/torque cam Stage II - 212/218 113 LSA, .552/.552 valve lift
- LS6 valve springs
- BTR hardened pushrods, 7.400" (stock length)
- Rockers with trunnion upgrade
- Valve seals
- Valve cover gaskets
- Timing cover gaskets
- Oil pump
- Timing chain
My buddy with the 2010 LSA'd 5.3 appreciated my contribution of my HPT Pro box to his cause, so aside from returning my HPT box he also sent with it:
- NNBS truck intake, fuel rail, and 42lb flex-fuel injectors
In order to make that work, I also ordered:
- Fuel regulator/filter to adapt the NNBS' returnless intake back to the '03's return system
- AN fittings to adapt the fuel line + return line to the regulator
- 4 bolt to 3 bolt throttle body adapter
Finally, I figured I would get fancy, and bought:
- Speed Engineering 1 3/4" headers + Y-pipe (this gets interesting in a minute)
- Steel header gaskets
- Bolts, etc.
So Tuesday I got everything in the mechanic's hands, and he called that he didn't think the exhaust setup would work.
He's right, as what came to me were LT headers + a y-pipe. I need some form of an X-pipe, and I need to figure out how to stagger it with the OEM exhaust that's at a 45 degree angle relative to each other to make room for big fat catalytic converters. He was also trying to figure out how to make the fuel regulator/filter work with the returnless fuel rail but I think there's a way to make it happen...
Yesterday I got him e-fans and the AEM OBD2 wideband, but exhaust will definitely be a limiting factor on getting this done so I decided to 'why not' order both the X-pipe as well as the rest of the system from Speed Engineering.
One caveat: they don't make a system specifically for a Suburban/Yukon XL. If the Suburban has a 130" wheelbase, and a RCSB has a 133" wheelbase, I'm hoping we can either adapt the X-pipe and then I can decide if I want to use the Speed-Engineering mufflers etc. later, or jimmy hangers around or cut down the mid section pipes enough to get the new system in place. Maybe can be the guinea pig and figure out if their system is an easy fit or not.
PCM of NC is lined up to do the tune. Hoping to get this thing back on the road by next week!
Joejamesatou: any updates on your project? Did you also do headers/exhaust?
11-16-2017, 10:18 PM
#35
My Sub 2500 already has 4:10s and a LSD due to its tow package, and spins at 2800? rpm at like 75 mph on nearly 33" tires; 4.56s are way too short for the truck to be usable on the highway.
I'm sure a tune helps, but I'm also at 6,000 feet above sea level and already down ~20% NA sea level HP and am trying to weigh how much compression I can aim for in the combustion chamber without having to rev the truck to 6k each time I want to get out of the hole, and while staying away from forced induction for the time being since everyone seems very skeptical about towing longevity if I want to put something heavy behind the truck for long distances. Tough decisions!
At this point I'm leaning towards headers, new heads that can bump the compression ratio + better valve springs while we're in there and better pushrods, e fans, a mild-to-mid cam, and a tune, and otherwise just leave the throttle body and intake alone. I really don't want to make a huge sacrifice in torque to get a bunch of HP when the truck lives 95% of its lift below 3500 rpm.
I'm sure a tune helps, but I'm also at 6,000 feet above sea level and already down ~20% NA sea level HP and am trying to weigh how much compression I can aim for in the combustion chamber without having to rev the truck to 6k each time I want to get out of the hole, and while staying away from forced induction for the time being since everyone seems very skeptical about towing longevity if I want to put something heavy behind the truck for long distances. Tough decisions!
At this point I'm leaning towards headers, new heads that can bump the compression ratio + better valve springs while we're in there and better pushrods, e fans, a mild-to-mid cam, and a tune, and otherwise just leave the throttle body and intake alone. I really don't want to make a huge sacrifice in torque to get a bunch of HP when the truck lives 95% of its lift below 3500 rpm.
11-17-2017, 12:36 AM
#36
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Not drag racing it, just need/want responsiveness. Hopefully with all the randomness I'm throwing at it I'll get something like 400/400 at the crank, increased throttle responsiveness, shift points, and maybe even MPGs from leaning out the pig-rich OEM tune; I bet I end up happy at least in the short term! After that it should still be more-ready for forced induction than it is as it sits.
11-17-2017, 12:54 AM
#37
Everywhere outside of power enrichment is as lean as it would be regardless of tuning. It would still always command stoich (14.68).
A better breathing combo like you are doing though could gain you mpg though. Increasing the efficiency of the engine is always a good thing, part throttle to full throttle should see improvements with a dialed calibration.
A better breathing combo like you are doing though could gain you mpg though. Increasing the efficiency of the engine is always a good thing, part throttle to full throttle should see improvements with a dialed calibration.
11-17-2017, 01:05 AM
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Everywhere outside of power enrichment is as lean as it would be regardless of tuning. It would still always command stoich (14.68).
A better breathing combo like you are doing though could gain you mpg though. Increasing the efficiency of the engine is always a good thing, part throttle to full throttle should see improvements with a dialed calibration.
A better breathing combo like you are doing though could gain you mpg though. Increasing the efficiency of the engine is always a good thing, part throttle to full throttle should see improvements with a dialed calibration.
11-17-2017, 10:28 AM
#39
Sorry for the delay. I got the truck back after getting the wrong measurements for the first driveshaft. Long story short after two new driveshafts, rear transmission seal, two new tires (flat spotted the rears), and one broken dyno we are done for now! It runs and I'm going to chalk up that run as 330 hp since it was still going. Probably another 5-10 with the cutouts open. Runs just fine all day long now!
11-17-2017, 10:31 AM
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Glad to hear it's back on the road! 330whp is probably approaching 400 crank when driven through a 4L80e, yeah?
Wow re: broken dyno. That due to weight?
Just to correct the record, you had provided measurements for your driveshaft a few posts earlier - do you know what the final measurements that were right were?
Wow re: broken dyno. That due to weight?
Just to correct the record, you had provided measurements for your driveshaft a few posts earlier - do you know what the final measurements that were right were?