LTX and LSXPutting LT1's, LS1's, and their variants into Third Gens is becoming more popular. This board is for those who are doing and have done the swaps so they can discuss all of their technical aspects, including repairs, swap info, and performance upgrades.
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Here is my DIY on my LS1/T56 swap, there are a few different ways to do things involved in this swap so what I did is not gospel, it is merely my originality so anyone tackling this swap please keep an open mind, have fun and be creative. Any and all information can be found on the web, the Internet is an unlimited resource; use it to your advantage. A lot of the pix are mine from my swap, others I have snipped from other posters including some wiring diagrams.
First things first, the things you will need:
· 98-02 LS1/LS6 motor out of a Camaro/Firebird or Corvette, preferably a IMG]http://img.photobucket.com/albums/v229/orangeiroc/LS1%20swap%20pix/cruisin053-1.jpg[/IMG]
[IMG]http://img.phCamaro/Firebird as there are a few differences in accessories.
· 98-02 T56
· 98-02 computer & engine wiring harness (scroll down for more info)
· LS1 swap headers or stock exhaust manifolds, I used Stainless Works 1 ¾ primary long tube headers, tig welded stainless steel, very awesome quality! Click for pics and info on Headers
· LS1 swap motor mounts, Hawks sells all the necessary swap parts, they have an entire section dedicated to LSx swap parts. Click for pics and info on motor mounts LS1 motor mounts on the block are actually located 2.5 inches further forward than on a Gen I or Gen II small block. You can see in the pics below I have an aftermarket k-member and the LS1 motor mounts are located further back than the norm. I took some plate steel, extended the k-member mount back and then welded a gusset behind it. On a stock k-member all that is needed is to re-drill new holes to relocate it or you can buy the aftermarket LSx k-member for this swap.
· T56 cross member, Spohn Performance, BMR and a few other companies sell these. You can either get just the cross member or a complete torque arm/ cross member package which relocates the torque arm from the transmission to the cross member. I like homemade pieces anytime I can make them or buy them, I used a homemade cross member which allowed me to pass my exhaust thru the cross member keeping it tucked up high, very nice since my car is lowered 2 inches.
The mechanical swap is actually very simple and virtually bolt-in. The tricky part is wiring, it can be as difficult as you want to make it. Here are a few pix of the engine when delivered and then mocked up in the car then I will move into the electrical side of the swap.
98’ LS1/T56 & 99’ LS1/T56
The 98’ motor had a broken rod and was not used obviously, unfortunately I found out the hard way when I started it up. I got the 99’ motor, cleaned it up, gave it a quick tear down, clean up and heads/cam swap which I will go over in a different DIY thread for anyone that is interested.
98 & 99 LS1 / T56 motors
98 motor mocked up for fitment
LS1 engine harness wiring
As I said above, the wiring for this swap is as hard as you want to make it. In reality you only need five +12v (2 constant, 3 ignition) wires hooked up to actually start the motor. In addition to those wires are wiring in your gauges and that for the most part is it.
Parts needed for this step:
· LS1 wiring harness & computer
· 4 relays (fuel, computer, injectors and coil packs)
· extra wire, (10, 12, 14 & 16 gauge)
· an assortment of connectors mostly pole and spade connectors
· A soldering gun and shrink sleeving
First thing I did was lay out the harness, connect every connector you can to the motor and transmission that you can.
Harness laid out on the floor
Harness laid out on the motor
Next the re-wiring. Some people get the whole engine and chassis harness for this swap, others buy an aftermarket harness from Painless Wiring, Howell, Speartech, etc. For these harnesses you have to have an original TPI 3rd gen car, these harness are made to adapt into the stock harnesses, very simple plug and play but definitely not cheap. The cheap route is to do the wiring yourself.
There are 5 connectors on this harness that are not connected, these are the ones that need to be spliced into your exsisting chassis harness, interior harness, or wired to relays.
99 LS1 PCM to Dash Harness
White (220) Plug
A TAN Oil Pressure
B GRY PCM 32 Clutch Anticipate Switch Signal
C PNK C105-B IGN Power for TCC Stop Lamp Switch
D PPL PCM 33 TCC/Cruse Brake Switch
E BLK/WHT Ground
H ORN/BLK PCM 34 PNP Switch Signal
J YEL/BLK Low Coolant Indicator
K DK GRN/WHT PCM 50 VSS Output
Blue (230) Plug
A GRY PCM 46 5V Feed (Fuel tank pressure)
B Brown w/Stripe PCM 25 MIL Lamp Control
C WHT PCM 45 EVAP Canister Vent Valve Control
E Blue PCM 55 Theft Deterrent Fuel Enable
F DK GRN/WHT PCM 17 A/C Request
G GRY PCM 23 Fuel Ground
H DK GRN PCM 64 Fuel Tank Pressure
J PPL PCM 54 Fuel Level Input
K DK GRN PCM 58 Serial Data (Class 2)
99 LS1 PCM to Front Harness
Large Plug C100 Plug
A PNK Hot in Run and Start (IGN/INJ Bank 1 15A)
B DK GRN/WHT PCM 43 A/C Clutch Relay Control
C DK GRN PCM 18 A/C Clutch Status
D GRY TPS +5v to TCS
E DK BLU TPS signal to TCS
G PNK Hot with IGN 1 Relay Engaged (Tranny/EGR 15A)
H DK BLU PCM 33 Cooling Fan 2 and 3 Relay Control
J DK GRN PCM 42 Cooling Fan 1 Relay Control
K BLK TPS sensor low to TCS
C101 Plug
A YEL/BLK Low Coolant Sensor
B PNK Hot in Run and Start (IGN/INJ Bank 2 15A)
C BRN PCM 36 Air Pump Relay Control
D DK GRN/WHT PCM 9 Fuel Pump Relay Control
E PNK/BLK PCM 19 Ignition Positive Voltage for PCM
G ORN PCM 57 Battery Positive Voltage for PCM
H BLK/WHT Ground
K GRY/BLK PCM 53 TCS Spark Retard Signal to Brake Control Module
C105 Plug
B PNK Hot with IGN 1 Relay Engaged (TCC Stop Lamp Switch/MAF/O2 20A)
D DK GRN PCM 37 Cruise Control Inhibit
F WHT PCM 13 Cruise Engaged Signal
G WHT PCM 10 Tach out to Brake Control Module
H PPL PCM 4 AIR Solenoid Relay Control
These are all of the pins/wires I did not use:
220- E,H,J,K
230- A,C,F,G,H,J
C100- B,C,D,E,K
C101- A,C,K
C105- D,F,H
If you take your time its very straight forward, one wire at a time, keep them organized and solder everything. Using distribution blocks and terminal blocks really make for a clean organized install. Here’s a picture of my distribution block under my dash, I ran +12v constant, +12v ignition, and a few other misc wires.
Distribution Block
Terminal Block – Good for connecting +12v from starter so you don’t end up with a buildup of wires.
LS1 Fuel System
Some use their stock 3rd gen gas tank and stock lines, others choose to use the 4th gen gas tank whether it’s the 98 metal tank or the 99+ platic tank. I opted for the plastic 4th gen tank. The charcoal canister on the tank can be removed if not using emissions, the stock pump is fine for stock and lightly modded builds. I chose to upgrade to a Racetronix 255lph pump and hot wire kit because as most people know I can not leave anything stock.
For the fuel line I used –8AN feel line from the tank, and –6AN return line from my Aeromotive regulator. The LS1 fuel system is a returnless system, if you plan on making any amount of real power I’d recommend making it a return style system. Heres a pic of a modified gas tank, I did it the same way except I used –AN lines and fittings.
There are a few other misc pieces needed but its moreso going to autoparts stores and hunting down coolant lines and small goodies. Here are some pics of the finished product.
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__________________ 1988 Camaro IROC-Z
99' LS1/T56 swap.. now rumbling..
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wow big letters.. I got it from a local autostore, most carry them, Autozone, Carquest, Advance.. Or you can order them from McMaster Carr, do a google search they have killer deals on bulk electrical stuff plus a ton more.
your wiring fascinates me! I was wondering if you could elaborate on a couple points you made.
You say theres "4 relays (fuel, computer, injectors and coil packs)". I also see no engine fuse block (i see your inline fuses on the 12v ignition), which is where i thought the relays were, could you tell me how/where you wired them to the harness?
If it isn't too much trouble could you post some more pictures of your wiring setup?
Awesome job on the build though, it looks amazing!
I removed the stock engine fuses from the firewall and bought all new fuses, incorporated them into the ls1 harness. the fuses are in the top left corner of the pic below, not the greatest pic. Some people use the 4th gen chassis harness, i chose not to. I thought it was easier to rewire myself, then i adapted the ls1 harness with the interior harness. I'll have to dig up some more info, i seem to have misplaced the wiring diagrams i made. Its all pretty straight forward tho.
Maybe this should be made a sticky. Good information. I can't wait to get started on mine.
__________________ KONIs I Eibach Pro-Kit I 36mm/24mm sway bars I Spohn: Adjustable PHB I Wonder Bar I SFCs Custom LCAs I LCARBs I J&M Products Camber/Caster plates I Hawk's Ceramic Pads I 4th Gen 3.23 Posi I LS1/LT1 Brakes
Do It guys you wont regret it, dont be intimidated by the work involved, dive in head first and before you know it you'll be out cruising, take your time make it clean. Best swap i ever did, it is so fun and the power is amazing from these motors.
This winter i have a 6L 370ci going in, new custom cam, and more spray. Stay tuned for updates i'm gunning for 9's.
Mike
__________________ 1988 Camaro IROC-Z
99' LS1/T56 swap.. now rumbling..
Hey, what set up is the LS1 you have now? Would you be interested in saling it?
Its not complete, i stole a bunch of parts off of it to complete the new motor, oil pump, pickup, etc. All i basically have is a bare aluminum block left over.
Where did you hook up your steam tube hose? Also, I just pulled my engine out of my 91 Z28, there was a coolant hose running on the left frame rail. Does your have that? I am just trying to figure out if I have to tee off my hoses going to my heater core. Lastly, did you hook up your cruise control? I read our cruise is vacumn controled and didnt know if it could be hooked up. I hope my LS1 swap turns out as nice as yours. Thanks..
man you have some great info on here... i have a 99 ls1 motor with auto out of a T/A and i am at the fuel and wiring aspect of it. i notice that the pictures are no longer available. is there any way i could view what you did? i am planning on just getting an aftermarket fuse block as i cant find any from a 4th gen.
__________________ 358 block, rpm perofrmer heads, rpm air gap intake, comp cam 275 (maybe), 1.6 comp silver lifters, edelbrock 600 carb, mallory dizzy, 150 shot NOS, rebuilt 350 turbo, B&M megashifter, 3.23 gears and more looking to be in by january. shooting for 400-450 hp without NOS. tired of seeing that antifreeze green mustang trying to be a badass around town.
Looks Nice! I may hit you up on some wiring questions soon. I am sorting through the Medusa of wiring as we speak! 
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