LS1/LQ7 fi looms & ECU mounting position.

[zgeezer]

I've used the search button for the last hour and still need information:

 

I'm mounting a 2001 LQ7 (Middle sized chevy GENIII truck engine) and 4L60E in my '70 Z. Lots of information about engine mounting and exhaust clearance on the LS1. Can't find information relating to where you LS1 folks have mounted the ECU and if anyone has used or modified the stock LS1 FI loom. Has anyone used the standalone GM performance loom and ecu (part#12480054 & 12480055)? My preference would be to keep the original ECU. If this has been covered before, please give me some direction.

 

For anyone contemplating this smaller or larger cast iron version of the LS1 consider the following: 1. it is a Truck engine and cannot be made smog legal in California; 2. The truck pan sits well to the back and it is DEEP (it hangs about 3 inches below the transmission pan) and will hang up on most anything larger than a beer can in the road (you don't really want to drag road kill home to the garage); 3. the intake manifold volumn is very close to the LS1, but it stands about 2 inches or so higher that the LS1; 4. with the exception of the A/C compressor, which is specifically designed from the factory to interfere with Z motor mount stands, all other accessories are mounted in a different order and higher that an LS1; 5. although the intake valves are smaller and the CR lower than the LS1, the combustion chambers are smaller than an LS1 and I think the intake/exhaust ports are the same; 6. you cannot retrofit an LS1 intake manifold to this engine w/o using all LS1 accessory mounting brackets and a new h20 pump; and, finally, unlike an LS1, which uses a rail cover that shows off the intake manifold to great advantage, the stock "Vortech" plastic bolts onto the manifold and is truly "butt ugly". The only stock dressup plastic I've located is on Cadillac Escalade and it's not too much of an improvement...expensive too.

 

There are benefits (?): 1. In this neck of the woods they are dirt cheap (See above); 2. Stock LS1 cams are reputed to add another 25-30 hp (LS1 stock used cams sell on EBay for about $20 + shipping; 3. The LS1 oil pan & pickup are bolt on; and it appears to clear a 240 hood when mounted using a separate crossmember and corvette isolators (this is by measurement not actually installed).

 

In reading the truck page of http://LS1.com I've concluded that about 50% of every late Silverado in Oklahoma and everyone of them in Texas is running a positive displacement supercharger. Consequently, there always seems to be a used supercharger for sale at that site.

 

g

[jeromio]

I have pics on my site of my ECU mounting. Lonestar put his in the engine bay (which is where it is on the Camaro). There is a bracket you could prolly get from a salvage yard. I made my own.

 

I modded my harness - mine was an A4, but I switched to T56, so I just cut off the A4 parts. I know Cyrus took his completely apart and removed all excess. That takes ambition. He claimed the extra wiring weighed quite a bit (I forget the number, but it was high). I believe Lonestar used the GM harness.

 

You'll need a shop manual. I got a second hand set on CD. Mine is for all GM 97-2000 or something. Very, very useful and only cost like $50 on ebay.

[Phantom]

I used the original '98 Camaro Z-28 LS1 engine wiring harness and ECM - although it was edited for my application in the 280Z. The ECM is mounted inside the passenger side footwell, just below the heater blower. Gets it out of the hot engine compartment and leaves more room in the compartment for other things.

[zgeezer]

Jeromio and Phantom:

 

Thanks for the responses.

 

g

[Guest Wicked C5]

1. In this neck of the woods they are dirt cheap [/b'](See above); 2. Stock LS1 cams are reputed to add another 25-30 hp (LS1 stock used cams sell on EBay for about $20 + shipping; 3

 

A little off the subject but I have a stock Ls1 cam out of a 97 Corvette if anyone want's it for $20.00 + shipping.