Effect of a 38mm restrictor on an LS7
Discussion
I can't remember exactly what I did when I fitted the LS7, but I have a Hughes flexplate designed for the TH350 converter. I ended up buying two torque converters as the first had too high stall. It was supposed to fit the LS engine but didn't. We had to weld a bit on one (on the bit that locates the crank) and turn a bit off the other. In 2006 information was a bit thinner on the ground for Gen 1V engines and I don't think the transmission people were that knowledgeable. I'm hoping the 2006 LS7 crank rear is identical to a 2017 LS3.
My TH350 is manual shift with (some) engine braking and a few uprated bits. I've snapped the input shaft but no problems since changing to an uprated one (300m Coan one IIRC)
I did the last rebuild with a fastidious older friend of mine. We took a while and ensured all the measurements were optimal, the improvement was significant.
My TH350 is manual shift with (some) engine braking and a few uprated bits. I've snapped the input shaft but no problems since changing to an uprated one (300m Coan one IIRC)
I did the last rebuild with a fastidious older friend of mine. We took a while and ensured all the measurements were optimal, the improvement was significant.
Edited by C Lee Farquar on Monday 18th September 20:13
It's all in and running
running in
Luckily all of the bolt holes were in the same position as the eleven year older LS7. A big time save was being able to use the older LS7 throttle assembly. This fits neatly in the frame, whereas the GM supplied LS3 stem is a clumsy great big thing. All the ancillaries fitted. Flexplate needed a little flettling
As it turns out all of the sensors are the same, other than the MAF, and I could have used my existing engine loom and ECU. However it was past it's best and I did have an occasional misfire from the old engine.
running in
Luckily all of the bolt holes were in the same position as the eleven year older LS7. A big time save was being able to use the older LS7 throttle assembly. This fits neatly in the frame, whereas the GM supplied LS3 stem is a clumsy great big thing. All the ancillaries fitted. Flexplate needed a little flettling
As it turns out all of the sensors are the same, other than the MAF, and I could have used my existing engine loom and ECU. However it was past it's best and I did have an occasional misfire from the old engine.
13 days from collecting the engine, tuned from the data log, to on a trailer on the way to France 
Longest delay was Partsworld didn't have a loom and controller and their shipment was delayed. After a week I realised I didn't need the specific ecu for my tune as I was changing the cam. So I had a 480hp controller and used EFI Live. Well, I plugged it in and Luis Sola made some pretty graphs.
Longest delay was Partsworld didn't have a loom and controller and their shipment was delayed. After a week I realised I didn't need the specific ecu for my tune as I was changing the cam. So I had a 480hp controller and used EFI Live. Well, I plugged it in and Luis Sola made some pretty graphs.
Anecdotally this engine is more free reving with the restrictor. There may be less initial punch, but most times I'm grip limited anyway.
I did do a 1/4 mile at Long Marston with the LS7 without the restrictor, 12 seconds on my only run so not in your league. I could try that again with the LS3 but I have put a cam in to work best with the restrictor.
I did do a 1/4 mile at Long Marston with the LS7 without the restrictor, 12 seconds on my only run so not in your league. I could try that again with the LS3 but I have put a cam in to work best with the restrictor.
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