LS3 difficulties

[wolfhound]

Information is rather scarce. Wish I could find more LS3 owners easier. I am aware FFR has some info available. I'm wanting to install one with a T56 & wondering what the challenges would be. My factory finish date is Feb 8th.
Hoping to brake out of my shell & be fully involved soon !

[esff32]

You might want to do a search on the "other" forum, I believe I just came across someone there that did just that. Unfortunately I dont recall his user name. If you need any additional help when you get your kit, feel free to PM me.

Evan

[Tim Whittaker]

We're there to help with your buils as well. Just give us a call or check the web site.

Tim
Whittaker

[Data]

Welcome to the community!

The "biggest" challenge will likely be exhaust. Most of us have had to severely modify or make our own, as Factory Five's LS exhaust plan fell apart about 1 minute after they designed it. (I was told the headers they designed it around were never put into production.) Thought definitely not too tough to handle, the second biggest problem will be the cooling system. The kit's radiator isn't already set up for the LS3 steam vent, though I just ran min into a T in the upper hose. Some guys are tapping it into the water pump but I wasn't feeling that brave. Additionally, the water-neck/thermostat housing will have to be rotated/changed to keep from hitting the frame, but that's an easy fix.

The LS3 is pretty well self-contained, so you won't use some stuff, like the thermostatic/fan switch in the Factory Five wiring and radiator, or the fuel pump wiring in the Factory Five harness (though I spliced the impact-cutoff switch from the factory five harness into the engine's wiring).

I'm not aware of any trans install problems you'll run into. Are you talking an original T-56? or the "magnum"/tr-6060?

I used an E-Rod LS3 setup, including the exhaust system. I used Corvette manifolds and made my own connections to the E-Rod Cats, and then my own link from the cats to the F5 rear exit exhaust. My intake is all Spectre pieces (MAFS adapter, two 4" 90 degree boots, 4" long 4" tube, and air filter) from various locations (amazon, jegs, etc). My alternator is a CTS-V alternator (GM part 25925447) that required cutting/shaving of a mount tab at about the 2 o'clock position looking at the front of the alternator, to clear the front suspension pieces. I mounted it on a CTS-V mount (GM part 12578550) with the tensioner on the upper passenger side of the engine. I have not yet installed all of the AC. I haven't gotten the compressor yet, or worked out how it will fit (it looks to be very tight if it fits at all) on the passenger side. I expect I'll have to use something other than GM mounts for it to make it fit, but I'm not sure yet.

I mounted the ECU on the face of my A/C unit under the dash without any problems, and mounted the pedal module to the side of the pedal-box instead of the firewall. I removed the pedal module from the bracket GM put it on and made my own to gave me variability to move it up/down and in/out from the firewall. Where I have it (left/right) makes the foot room a little tight for the clutch and brake, but I didn't have to monkey with cutting any out of the tunnel (May not be a factor with the newer tunnel design you should get) and both of my fuse boxes (kit and engine) fit between the pedalbox and AC unit. I think you could change that mount depending on how much room you want by spacing it more off of the pedal box (depending on your fusebox mounting choices) and by bending the pedal and to make the foot-pad more vertical, but I haven't had any issues with it where I put it.

I'll post some pictures of my setup this evening when I can get to them. Let me know if you have any other questions on my setup.

Data

[wolfhound]

Thank You all. Data, I am looking at the Chevrolet Performance T56 Super Magnum 6 Speed that comes with one of the Chevy ls3 crate deals. Hoping to know by the end of this week which way I will go & lock in on ls3 or sbc. The extra expense would slow down my build but worth it I believe. Coming back into rods from motorcycles so a bit "out of place" & behind in this world.

[wolfhound]

Looks like the LS3 T-56 will be my choice. Still wanting IRS but may only be able to swing 4 link after the '33 kit & motor/tranny package reality sinks in ! Checks in the mail as they say , this week. Will be paid in full to this point but mostly tapped out to start the build. I do have a $10K body fund set aside if I can keep out of it.

[Silent T]

I too am building an LS3 and can tell you that its tight up front but possible.
I custom mounted the alternator low on the drivers side and the AC compressor low on the passenger side. Both have about 1/2" clearance from the frame. I too used the stock tensioner for the alternator but have to custom mount 2 idler pulleys to get the proper belt routing and contact on the water pump and alternator pulleys. The AC was mounted separately using the 4 rib internal pulley and one ear had to be removed. It won't fit on the outside pulley as it gets too close to the frame. I made a custom tensioner off the side of the block to tightening the belt. Very tight - thankfully the LS3 has many mounting bolt holes all around to mount things. They are all M10 x 1.5 metric.
The straight water neck can be found on Ebay.
I also think the heater hose barbs need to be switched out unless you run the hose on the outside of the frame which I’d rather not do. I believe I read that you can remove the barbs and tap the pump housing and put 90° or 45° fittings on it but have not tackled that yet.
Good luck!

[wolfhound]

Thank You Silent T for the info !
I have not been looking forward to the pulley setup. Hopefully this will all come together in a timely matter. I have been trying not to stress over the unknown & just figure it out as I go along once the parts begin to arrive. I have tried to read all the info I can from both forums but hesitant to post much as I really hate sounding foolish until I have the kit in hand.

[TigerBill]

I've got an ls3 as well. The E-Rod package like Data. I've done a couple of carbureted SBC's before and always had trouble with tuning, and especially the stinky exhaust. This LS3 with the cats is awesome - smooth, powerful and clean. You'll love it. I'll be glad to help with suggestions as you go, but am no expert. For starters, on the pulleys, I had problems locating the right setup for non ac, non power steering until I stumbled onto a site called water thunder. they sell LS accessories for boats - no ac or power steering, right! I had to saw off one unused ear off of the alternator to fit (interfered with motor mount), but otherwise worked great and pretty clean look.

[Vegas33]

TigerBill,
Thanks for the tip on water thunder. I'm planning on running a similar setup: LS3/TKO600 no pwr steering or AC. I had been searching for an accessory drive and theirs looks good.

[Pogie]

March Performance has a nice set-up for accessory drives. I'm running the Fast 2.0 set-up on a LS1.