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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I'm working on my L92 swap today. Part of that is installing my trunk-mount setup, & I'm curious how everyone is handling mounting the kill switch. From looking at it, it appears that the only halfway-decent location is right by the hatch lock - but the electrical hatch motor is in the way. Does everyone just remove that, mount the switch, run the wiring & then mount the hatch motor over the top of all of it??
Also - I don't recall ever seeing anything resembling a list of circuits that need to be hooked up with an LS swap, & I'm thinking that if we can put one together it could be pretty helpful for anyone doing it in the future. So, here's what I've thought of so far:
Coolant temp gauge is ran by a single wire in the original harness
Pin F5 on the C100 with a dark green wire
You got that wrong buddy.
I am not exactly sure what years but in 4th gens, the PCM talks to the SDM, PCM, EBCM, DLC(ALDL) and the IP gauge cluster using Class 2 serial data (an updated version of UART).
This wire is the same DK GREEN wire that goes to all the componenets.
On the IP gauge cluster, the Class 2 serial data is used to send signals for the MIL, Tach, Fuel level, CTS (+99 - idiot gauge with low or High only) change oil, seat belts, security(VATS), TCS, ABS etc. (I might be missing more).
On the IP gauges the only ones getting signal directly from the sending units are Speedo (VSS from PCM), CTS (98 only), Low Oil preasure and Oil presure gauge and Voltmeter (Voltage difference b/w IP gauge Cluster Ign 1 Voltage - PNK and Gnd).
I think I posted a work around for people the 4L60E in another thread- based on Aron91RS writeup.
That may be well and good for the years you posted, but this is a swap forum for 3rd gens and 3rd gens have no such provision
exactly...... and thats why we need a workaround to get those signals (class 2 serial data) from the lsx engine to our gauges thru the orginal harness.
we would not have this issue if we also swaped in the ls1 gauge cluster (along with the whole dash othervice it would not look right) as it can read the class 2 serial data. then only thing is getting a 98 CTS and running that to the CTS gauge and warning light.
if one wanted to use stock or aftermarket electrical/mechanical gauge its not that straightforward.
speedometer
The VSS signal can be tapped at the C220 connector pin # K ckt # 817 - DK GRM/WHT. (this comes from the PCM)
This can be connected to the VSS signal wire comming from the 3rd gen ecm. Since I didnt can a electronic speedo, I dont know what and where.
option 1:
If u have a mech cable driven speedo - need to get one of those boxes that accepts the vss signal and spins the cable.
questions here are:
1. does the vss signal need to come direcly from the transmission or can the signal be adjusted in the ls1 pcm to the correct value?
2. does the speedo cable have to be shortened or is a custom/other oem ones made to adapt?
option 2:
get a electronic speedo
questions:
1. the speedo value can be adjusted on some aftermarket electronuc speedo. what the value on the stock 3rd gen gauge?
Oil preasure
What I have found that a oil preasure gauge is a simple Ohm meter and so the gauge and its sending unit is paired. So we cannot use the stock LS1 sening unit in the back of the block.
Connection point is at C220 pin # A - TAN.
This can be connected to TAN wire on the 3rd gen C100 bulkhead connector.
Option 1: drill and tap
a.Drill and tap the LS1 sending unit with 1/8 NPT thread and use a 3rd gen sending unit.
b. Drill and tap the plate on top of the filter.
Option 2: adapters
a. Get a metric to NPT adapter. equuis part # 6848. may have firewall clearence issues. Its a hot and miss.
b. Get the adapter plate already tapped for 1/8 NPT with a 90* elbow. But $$$$ and may have header clearence issues.
TACH
ESS can be tapped at C105 connector PIN # G - WHT. Already available for M6 car harness. For A4 cars repin unused pin # F.
This can be connected to the tach wire on the 3rd gen C100 bulkhead - WHT.
Question:
What is the correct value for a stock gauge so the pcm can be programmed to the correct signal.
CTS
Again here what I understand is the CTS gauge is a simple ohmeter paired with its sending unit. looks like the 98 sending unit and 3rd gen sending unit are calibrated the same and will work with stock 3rd gen gauges.
On the 3rd gen this signal is send to the gauge using a DK GRN wire available at the C100 bulkhead connector.
Option:
1. Use a 98 3 wire sending unit, in place of the 99+ sending unit. 2 wire go the 2 wires on the sending unit being replaced on the LS1 block.
2. Get adapter equuis part # 6848 and replace the CTS plug on the driver side head.
3. drill and tap the drive side CTS plug for NPT.
last 2 options, may have issues with clearence if using a HVAC box.
Thats it for now. I still need to read more about voltmeter, fuel gauge and MIL. It would be cool to wire in the idiot lights also.
Onece we all correct it. One of the admins may clean it up and if its worthy for sticky we should put it up.
You are correct, Speedo output is at C207 pin K, but bear in mind 3rd gen speedos use a 4k PPM signal. LS1 VSS' use a 40 pulse per driveshaft revolution
They are different
Theres not much you can do for the mechanical speedo except get a VSS that runs of the cable and has an electric output as well. Early swaps used a B4C camaro VSS as it had both cable and electric outputs, but it sends a 4k PPM signal which would require a buffer box
Oil pressure:
Not really sure what the big issue is here
The 3rd gen connector even fits the LS1 oil press sender
You cant drill/tap the LS1 to fit the stock sender because the hole is larger than the stock sender. Hardware stores sell adapters for <$3
You should not have clearance issues since it is located in the rear of the block behind the intake pointing directly up. You will only encounter header clearance if you drill/tap the port above the oil filter and theres no reason to do that
Tach:
Not sure on the specific value for the gauge as it changes between cars
Some swappers directly hook the PCM output (R10) to the tach wire in the C100 (D6) http://www.ls1tech.com/forums/conver...onversion.html
98 3 wire sensor is ideal as it uses factory parts with no adapters, only one wire to splice
It uses a newer style TPS connector so you dont have to search for 98 only wiring
Volt meter comes off the alt, nothing special there
MIL is directly controlled from the PCM (R46)
Fuel gauge is dependent on LS1 tank or stock tank
LS1 tank http://www.thirdgen.org/techboard/lt...swap-into.html (LS1/700r4 Swap into 1987 GTA)
Stock tank uses the correct sender and the wiring is all included in the dash/interior harness. No changes are needed
I plan on using the old keyhole for a 'chute mount and have the sw between the taillight and rear bumper because I didnt have the heart to drill a hole in either
The remote kit gives the majority of the wiring you'll need. I ran two 10ga wires from the batt to the kill switch to the junction block with factory sized wires from there. I took a stock Alt output lead and cut the battery side off and crimped a starter lug on the end
Is the LS1 temp sending unit compatable with the third gen gage? As for the oil pressure sending unit , I used a 16mm drain plug and drilled and tapped the center 1/8" NPT. Later Dean. Oh pocket I see you'r from Mooresville,N.C. ever get over to the dragstrip. sorry for the mini hijack.
Is the LS1 temp sending unit compatable with the third gen gage? As for the oil pressure sending unit , I used a 16mm drain plug and drilled and tapped the center 1/8" NPT. Later Dean. Oh pocket I see you'r from Mooresville,N.C. ever get over to the dragstrip. sorry for the mini hijack.
Dean,
Would it be to much trouble if u can make one fore me? I cant seem to find any metric to NPT adapter at the local store. and looks like the equuis part number is no where in stock .
As far as the CTS, I have read that the 98 LS1 CTS is compatable with the 3rd gen gauge.
Dean,
Would it be to much trouble if u can make one fore me? I cant seem to find any metric to NPT adapter at the local store. and looks like the equuis part number is no where in stock .
As far as the CTS, I have read that the 98 LS1 CTS is compatable with the 3rd gen gauge.
OK, so there's
. and thats why we need a workaround to get those signals (class 2 serial data) from the lsx engine to our gauges thru the orginal harness.
