Replacing Rear Mufflers 1969 Islero S
By Bill Spohn
This is a description of the replacement of the rear mufflers on a 1969 Lamborghini Islero S with aftermarket parts. The reasons for opting for non-stock were two-fold price and sound. The original Stebro parts are still available, but they are $600 US each side.
My car has less than 50,000 km on it, and still has the original exhaust system fitted. No doubt infrequent use and short drives have contributed to rust in the resonators and corrosion on the chrome tips:
I removed the original piece, which has a flange that bolts to the pipe from the main silencer at around the rear wheel level. It looks like this:
The pipe forward of the resonator was sound, so I hack sawed it off just to the front of the resonator and started planning a replacement. As the stock system was quite quiet, I opted for a tip that would look right and also incorporate a drilled inner tube as an additional silencer, just as the factory tips had done.
I found just such a product made by PaceSetter Products in Arizona ( www.pacesetterexhaust.com ).
The original pipes were 1.75 OD, which isnt all that large, and I wanted to maintain that size without restriction, so I chose a tip that took a 2 OD pipe, a size that would slip nicely over the stub of the original pipe. I had the correct length of pipe welded to the old stub, and fitted it to the new tips by clamping (part no. 95-9904). The assembly (without clamps) looks like this:
The Ferrari/Monza decal shown on the website does not come on the actual tips, so did not need to be removed. The parting line between the black paint and the chrome has a narrow band of yellow tape (shown in my picture) that I removed when fitting. The opening of the tips (looking up the pipes from the rear) is painted yellow, and I simply sprayed it black (it probably would have ended up that way anyway, but might have looked odd until then).
I bolted the flanges together, this time using a steel composite exhaust gasket, though a steel to steel joint would probably not leak, and used the original front hanger tab that was still on the old connector pipe, together with new rubber and metal hangers to stabilize the pipes. I then fitted the tips and clamped them in place ensuring that they were level and that they projected the correct distance from the back of the car. The new pipes look like this:
and are perfectly in keeping with the original appearance. The new tips weigh so much less than the old resonator did, that I elected to omit any additional hangers near the tips (there are two, one on each side of the resonator, staggered a bit on the old one).
The total cost was about $100. The exhaust note is deeper and yes, louder, but because of the resonator tips, it does not rap or pop, and sounds much better to my ear than the rather sedate original did.
~o0o~