Moving the engine back is very, very beneficial for two important reasons. One, it helps the front rear weight bias, and further helps the polar moment of inertia of the car by placing the weight more towards the middle of the car. Two, it is basically impossible to get really good front suspension geometry, and good steering geometry at the same time, without moving the engine. The problem is the interference of the oil pan/balancer withthe rack and pinion unit. The systems out there have either compromised the setup by raising the engine, moving stuff around to make it fit and as a result, compromising the geometry, or both. You can't have it all at the same time (as an exercise, compare where the rack and pinion unit is on a C5 Corvette, both in terms of relationship to the engine, as well as the height, to some of the systems that use these components for aftermarket setups).
Before anyone calls BS, I will say that you can improve the performance of the car, relative to the stock seriously flawed original suspension by replacing with an aftermarket subframe. But, you can also tune out a lot of the really bad stuff with the stock configuration by the use of springs, sta-bars, and shocks, etc.
We are in the process of prototyping our go at the front suspension, and through a ton of research, and a lot of conversation with some very, very savy engineers that have been doing this stuff for almost as long as I have been alive, the conclusion has been made that our max effort front setup will require an engine setback. Most folks won't want to do this, because it will require cutting the firewall (which is ironic because there are very few PT cars that don't do a mini-tub job, same amount of effort!!!), but to do it "right," this is the only way. It is looking like a setback on my 70 Camaro will be about 6" from stock location, based on the use of a small block engine. Big blocks are longer up front and will require additional setback. And no, we won't be using C5 parts.
It's my understanding that Wayne Due offers a C5 based setup that requires a setback too, though I haven't seen one in person and can't comment on the geometry.
Mark
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