Steel braided wire vs. aftermarket

[911fan77]

I have a 2.7 I am doig a tune-up on and thought about replacing the wires as I do not know what the PO had done. I had bought some Beru, thought about Magnacores, but I got to thinking about the stock ones already on there. What is the differences and what impact would it have on the 2.7 (with CIS)? Definitely going to change the plugs, cap, and rotor.

Thanks,
Dean

[Henry Schmidt]

The braided stainless shielding is to prevent cross firing from one plug to another. With CIS, cross firing can cause back firing and that can blow up the airbox.
If you separate the wires and use a high quality product (we use Taylor wire) you should be fine.

[Jim Sims]

Changed to a set of conventional Beru wires (much less expensive) on my 2.7 76S and there has been no difference in terms of backfiring within the CIS system - very occasional backfire before and the same after. If you're having a lot of backfiring, check the point dwell or adjust the valves. Shielded wires didn't solve the airbox rupturing problem, rebaffling within the improved air boxes helped but a pressure relief valve (pop off valve) appears to be the most practical long term solution. Cheers, Jim

[911fan77]

I have a little backfiring (if I haven't started it in awhile) but the main reason for doing this is to know where I stand on the engine baseline i.e. plugs, wires, etc. I do need to adjust the values too. Mainly concerned on problem from going from braided to non-braided. Thaks guys! Like the wires Henry!

Thanks,
Dean

[Henry Schmidt]

Originally posted by Jim Sims
Changed to a set of conventional Beru wires (much less expensive) on my 2.7 76S and there has been no difference in terms of backfiring within the CIS system - very occasional backfire before and the same after. If you're having a lot of backfiring, check the point dwell or adjust the valves. Shielded wires didn't solve the airbox rupturing problem, rebaffling within the improved air boxes helped but a pressure relief valve (pop off valve) appears to be the most practical long term solution. Cheers, Jim

The problem with air boxes exploding is the tendency for the cold start injector to puddle fuel in the lowest point in the air box main body. If the engine backfires the fuel is ignited and then it explodes.
The spider tubing helped to prevent the standing fuel and the pop valve acts as a pressure relief ( when an explosion happens) but if the engine didn't back fire the box would rarely if ever explode.
Cross firing with plug wires generally only happens when the wires get old and crack or when they get wet.

[911fan77]

Henry,

How'd you tie down those wires in the pic? When I removed the old set the news ones need a loom/separator/etc.

Thanks,
Dean