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2001 6.0 Vortec LSA Supercharger Project (1999 Sierra)

14K views 34 replies 13 participants last post by  suburbanoutdoor 
#1 · (Edited by Moderator)
I introduced myself back on March 21, the day I ordered an LSA supercharger kit from Boost District. After many travails and delays and heated phone calls and e-mails, the kit (well, most of it, anyway) finally arrived in mid-May, while I was out of the country.

This past weekend my son (who owns his own independent general service/repair shop) and I started the build....

Some background...

The truck is a 1999 GMC Sierra 1500SLE 5.3L regular cab, short bed, stepside, formerly a 4x4 Z71 model.

I'm the second owner of the truck and have had it since 2015. I bought it with 69,000 miles on it, and it now has 95,000 miles on it.

It is stock except for replacing the engine, the transmission, the transfer case, the front differential, the rear differential, and the PCM with the complete 6.0 AWD drivetrain from a one-owner, wrecked, 31,000 mile 2001 GMC Sierra C3 (Denali predecessor) in late 2017/early 2018.

I also lowered the truck to a stock 2WD ride height, added a rear anti-sway bar and upgraded shocks. It also has a Black Bear Performance 93-octane performance tune, the C3 17-inch wheels, and a few other minor tweaks, but still appears stock:

1999_C3.jpg


So this thread will hopefully document the final phase of the build. I'm not going for maximum horsepower; and I'm doing some things that some may find incomprehensible. I'm keeping the stock exhaust and - if possible - the stock air-box.

My goal for this project is to have a truck that GM might have built in 1999 if they had had the AWD technology that they put in the C3 Sierra in 2001 (later teh Denali) and the LSA supercharger technology that they introduced in the 2009. I want it to have OEM sound levels and NVH, and not to be identifiable at all as a modified truck to the "general public."

I'll try to put together a coherent timeline, but photos were quick and sketchy as we finally dove into the project. I also have some questions for the more technically savvy members here; while my son is a fantastic mechanic [and did all the swap work installing the LQ4 and AWD drive system in the truck) and I have a lifetime of history of building motorcycles, this is our first foray into forced induction, and the interwebz are filled with contradictory information.

Making room for the supercharger:

intake_manifold_removed.jpg


The supercharger in the box:

supercharger_in_box.jpg


The supercharger installed:

supercharger_sans_lid_installed.jpg


And with the ZL-1 lid installed:

supercharger_in_place_with_lid_1.jpg
 

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#3 · (Edited by Moderator)
We installed a Walbro 450lph fuel pump in the stock fuel pump/float assembly.

fuel_tank_removed.jpg


The new pump:

new_fuel_pump_on_bench.jpg


Disassembling the pump/float assembly:

fuel_pump_disassembly.jpg


Reassembled:

fuel_pump_and_float_assembly.jpg


It was instructive watching my son, who basically grew up in the garage at home, working on my motorcycle projects and racebikes with me. He is an amazingly accomplished mechanic, and I learn an incredible amount every time I am fortunate enough to spend time in the shop with him.

Here's what my son looks like:

head-deep_in_fuel_tank.jpg


Here's his old man:

dirty__smelly_tired_happy.jpg


Now you know what the old man who is messing around with a 20-year-old GMC Sierra looks like. :lol:
 

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#4 ·
very cool build. Why not just put a Holley Blue pump on there for the gas?
 
#5 ·
Nice setup. I have tried calling boostdistrict, was looking for a setup for my 2500, not totally sold on it, but on the fence.
The lack of comms has me worried...
Does the kit come complete? I'm sure there's some odds and ends I might have to pick up here and there.
Can you post some more pics of the completed engine bay? How did you mount the intercooler?
Thanks

they just called me back...woohoo, might pull the trigger.
 
#8 ·
orbitingHQ said:
Nice setup. I have tried calling boostdistrict, was looking for a setup for my 2500, not totally sold on it, but on the fence.
The lack of comms has me worried...
Does the kit come complete? I'm sure there's some odds and ends I might have to pick up here and there.
Can you post some more pics of the completed engine bay? How did you mount the intercooler?
Thanks

they just called me back...woohoo, might pull the trigger.
My best advice is to be patient. In my experience, Rosh is very slow to respond, and promises a lot of things that he either can't or won't deliver. The kit is semi-complete. I had to buy a PCV oil separation system, the drive belt, an aftermarket heavy-duty tensioner system, the EGR blank-off plug, corrugated flex fuel line, cold air intake system, and throttle body-to-intercooler 3-bolt to 4-bolt adapter plate among other things. I am also working on solving an issue with the fact that my truck has a full length fuel return to the tank, and the LSA fuel rail is a non-return system. That was a rude surprise.

Rosh never seemed to do anything for me until I filed a grievance with my credit card company and they stopped payment to him. That got his attention. When he later promised that everything was ready to ship, I released the hold on the funds, and then another long delay ensued until I told him I was going to do the same thing again. Then he finally shipped my packages.

Tim
 
#10 ·
1999SierraC3SC said:
orbitingHQ said:
Nice setup. I have tried calling boostdistrict, was looking for a setup for my 2500, not totally sold on it, but on the fence.
The lack of comms has me worried...
Does the kit come complete? I'm sure there's some odds and ends I might have to pick up here and there.
Can you post some more pics of the completed engine bay? How did you mount the intercooler?
Thanks

they just called me back...woohoo, might pull the trigger.
My best advice is to be patient. In my experience, Rosh is very slow to respond, and promises a lot of things that he either can't or won't deliver. The kit is semi-complete. I had to buy a PCV oil separation system, the drive belt, an aftermarket heavy-duty tensioner system, the EGR blank-off plug, corrugated flex fuel line, cold air intake system, and throttle body-to-intercooler 3-bolt to 4-bolt adapter plate among other things. I am also working on solving an issue with the fact that my truck has a full length fuel return to the tank, and the LSA fuel rail is a non-return system. That was a rude surprise.

Rosh never seemed to do anything for me until I filed a grievance with my credit card company and they stopped payment to him. That got his attention. When he later promised that everything was ready to ship, I released the hold on the funds, and then another long delay ensued until I told him I was going to do the same thing again. Then he finally shipped my packages.

Tim
I don't need that kind of jive....
Thanks for the reply. :)
 
#11 · (Edited by Moderator)
So, we also fabricated brackets for the intercooler. In order to fit the intercooler, we needed to relocate the transmission oil cooler. we tried to keep things as close to stock as possible and fabricate in a "minimalist" fashion, so that we could later maintain the truck without a lot of hassle.

Here's the stock cooler setup:

stock_cooler_configuration.jpg


Here's the relocated trans oil cooler:

bracket_fabrication_detail.jpg


Looking at the modified and fabricated brackets from the driver's side of the truck. We spaced the trans cooler outward, and added a rubber base to the existing bracket that the trans cooler used to be bolted to, and riveted an aluminum bumper strip to the back of the brace. The new cooler rests on the "ledge" of this brace, and the aluminum "bumper strip keeps the intercooler off the mounting bolt heads at each end of the factory bracket.

bracket_fabrication_driver_side_view.jpg


From the passenger side:

bracket_fabrication_passenger_side_view.jpg


The two upper brackets are bolted at top, and have self tapping sheet metal screws in the middle, and then bolt to flanges on the each end of the new intercooler. The intercooler slides between the trans cooler and the air conditioning condenser, and is offset to the left to clear the power steering cooler. Here's the view from the front:

bracket_fabrication_front_view.jpg


Unfortunately I did not get a photo with the intercooler bolted in place! I will try to add that later when Justin and I get back to work on the truck (not this weekend, though!)
 

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#13 · (Edited by Moderator)
I've been working on the design for the fueling system for the truck. The OEM fuel system includes a return line; while the LSA fuel rail is "returnless." I have learned a lot about Pulse Width Modulation, boost reference fuel pressure regulation, vacuum reference fuel regulation, return line pressure regulation, and all sorts of other things I knew nothing about. This is my current thinking of the design for the fuel system:

C3_LSA_Fueling_Diagram.jpg
 

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#14 ·
I'm not sure you can get the flow rate you may need through the schrader valve. I would suggest a splitter just before the input to the fuel rail, with the other port going to your regulator instead.
 
#15 ·
I'm working on a LSA transplant myself. We are using a vapor werks controller to control the fuel pressure. I'm a bigger fan of a return system myself. The test port will not be big enough to return the fuel. The issue your going to fight is the ECM on that truck does not support returnless fuel pump control. This can cause all types of injector flow rate calculation issues when the intake pressure exceeds atmospheric. It can be compensated for without a boost referenced fuel pressure regulator but I would suggest you run a boost refed regulator.
 
#17 ·
Companies make return style rails for the LSA so you can keep the regulator downstream of the blower. If upstream it's literally just a restriction to flow. My setup is a little different on my 04 which was a returnless truck originally. I put dual 450 walbros in the stock bucket in the tank, 1/2" feed line, 1/2" rails and then used the stock 3/8" feed as a return from the regulator to the tank. It's a TVS 2300 on a forged 370 so not quite the same lol. If I can get an LSA for cheap I want to do one for one of my projects...
 
#18 · (Edited by Moderator)
So, with input from numerous sources (including this thread, thanks!) I've rethought my fueling layout, and have V2.0 designed. The original design was, btw, boost referenced. This design is too, but now the return will come directly from the Aeromotive A1000 Gen II regulator's bypass circuit instead of from the Schrader valve on the LSA fuel rail.

C3_LSA_Fueling_Diagram_Design_2.jpg
 

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#19 · (Edited by Moderator)
Fuel system installed and pressurized and checked for leaks.

7D5E1C79-1BF0-455D-8921-694A959B8254.jpeg


A6DCAC1C-F974-4F15-9ED7-FABB6E145162.jpeg


36109720-9106-490D-AACD-79E3E05F5D2D.jpeg


Intercooler installed.

369A1F06-0C42-4F3B-B035-B865F6741E9A.jpeg


Air intake tubing from stock air box to stock throttle body fabricated and test installed.

CA089C2E-1D9C-468C-88E6-DFC31B8C86B1.jpeg


Next up: supercharger cooling system completion, PCV system reconfiguration, throttle cable, vacuum lines, sensors, etc, re-routed and hooked up, basic supercharger ECM tune download, and first start.
 

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#21 ·
Thanks, Silentbravo. It is a little bit of a different build than most people's "max performance" builds. While I know I am giving up "free horsepower" by not using headers, a different cam, low restriction exhaust, and true cold air induction, etc; for me the focus of this build remains oem-like look, NVH levels, and a stealth outward street appearance, plus driving comfort including sound levels and power delivery "feel."

I've had many high performance vehicles, and several of my street projects in my younger years went "one step too far" and became (while measurably faster) basically unstreetable, and ultimately, no longer fun to drive/ride on the street.
 
#22 ·
1999SierraC3SC said:
went "one step too far" and became (while measurably faster) basically unstreetable, and ultimately, no longer fun to drive/ride on the street.
Something im trying to avoid with my current project vehicle. I wish I knew what the best all around power to weight was for any given vehicle then it wouldn't be a guessing game.. guess ill just shoot for 500 to the wheels and hope I like it haha

Sweet project truck you got going on!
 
#23 ·
My son (Justin) and I completed the supercharger install on my truck and started it this past week. Initial observations:

1. initial rough idle on cold start. Idle smooths out after truck warms up. Idles at 600 rpm after warming.
2. intermittent miss on number 3 cylinder. Justin swapped plugs, fuel injectors, and coils. Miss did not follow any of these items to another cylinder, but remained in number 3. Justin also tested all eight fuel injectors (58psi injectors) and all tested good.

Today I took it out for about a 20 minute test drive. I data logged yhecdrive to send to Black Bear Performance. Conditions were as follows:

1. 95 degrees with 43% humidity.
2. 1/2 tank of fuel; about four or five gallons from the first week in June, with nine fresh gallons added today. All 93 octane pump gas with 10% ethanol.
3. Base fuel pressure set to between 55 and 60 psi.
4. EVAP system disabled. (This is the *ONLY* trouble code from the engine on my son's reader)
5. 195-degree thermostat (did not observe coolant exceed 195 degrees on the gauge.
6. We have not installed a boost gauge, but I think we need to.
7. We do not have an in-cabin fuel pressure gauge (we have an oil-damped gauge in the engine compartment at the fuel regulator) but I think we need one.

Test drive observations follow:

1. At no time did I exceed 50% throttle, per your instructions
2. Truck responds well to small throttle openings in first and second gear. Up-shift to second gear is very early on light throttle.
3. Truck falls flat on its face immediately after the shift to third. This happens whether going uphill or down, with 1/16 throttle, 1/8 throttle, 1/4 throttle, and 1/2 throttle. RPMS fall precipitously, truck does not respond to throttle at all. Maintaining small throttle opening, after 3,4,5 seconds, or maybe even a little longer, the truck comes up on throttle and resumes accelerating.
4. At higher road speeds (50~60mph) the truck seems to drive fairly close to normally; you can feel it pick up throttle and accelerate. I think the highest road speed I hit was 80mph.
5. At small throttle openings and cruising at 50~55mph, initial tip-in of throttle results in audible pinging. I backed off when this happened. Slightly larger throttle opening did *not* seem to cause the pinging.

Data log has been sent off for analysis followed by an updated tune.
 
#26 ·
Yeah first I've heard of that too out of what must be many of LSA swaps to cathedral heads. I'm interested to see what you've found out. I'll be doing an lsa swap soon on my 03 Denali, so similar to your current build!
 
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