Cartridge Exhaust System

[Robert Linton]

After considerable preparation work, next week we begin to build the Cartridge Exhaust System for the Z8. The system should be completed by February and I will keep you apprised. Virtually all of it will be built from 321 stainless and, as appropriate, aluminum alloys might be used for certain hangers as titanium will be used as appropriate for fasteners. The principal goals of the system will be to reduce weight, improve sound quality and, possibly, produce a bit more HP. If we do our job right, it should be the highest quality exhaust for a Z8. It will not be available for general purchase but only on a very limited basis.

[thegunguy]

Bob,

I'm anxious for the pics. Are you still expecting to save ~100lbs?

[Robert Linton]

The exhaust system alone was never intended to save 100 lbs. I do, however, believe it will reduce the vehicle's weight by approximately 60 lbs.

[Robert Linton]

A minor six months late, the exhaust system is well under way due to delays caused by extensive suspension improvements. Although the intent was to make it from 321 stainless, we are looking at the possibility of titanium mufflers.

[macfly]

Don't forget a pair for me please, Santa!

[Robert Linton]

Still thinking about the mufflers and pipe coming out of the mufflers -- titanium vs. steel. Titanium will, assuming 321 stainless steel mufflers will weigh approximately 3 lbs. each, save approximately 1.05 lbs per muffler. On the other hand, as one cannot weld titanium to steel, one will need a Marman clamp on each side which clamps will weigh approximately .60 lbs per clamp.

FYI -- attached are pictures of stainless steel nose cones that have been made for potential stainless steel mufflers.

[thegunguy]

While I admire your ceaseless quest to shed weight from your car, saving a few pounds per side, based on materials, may be a bit much. I imagine your customer mufflers will already be amazing, even if they're "merely" 321 stainless.

[Robert Linton]

The stainless ones will I suspect, with due respect to Eisenmann et al, be the best quality ones available (as to sound, we have tuned them to permit what we think is an attractive sound but, in this respect, beauty is in the eye of the beholder). As to ti versions, the tradeoff is weight vs. durability - the 321 will be more durable and, hence, probably more appropriate for the Z8 which is a car to be kept long term. Finally, we are not just making the mufflers but, in fact, the entire exhaust system from the header flanges back (and if this were not an Alpina, we would also remake the headers [the Alpina gives little room for any significant improvement]) including even the exhaust system hangers.

[Robert Linton]

Have decided to go with steel to see how elegant/lightweight we can get without exotic materials.

[Robert Linton]

Good news! The latest figures show that the new exhaust system should save more than 65 lbs. of weight. Hope to post pictures of progress by Monday.

[Norcal]

Wow...65 lb savings, that's massive. Can't wait to see it.

[Robert Linton]

Scared to admit it yet, but looks like the real number will be slightly in excess of 70 -- and everything will be of higher quality.

[Robert Linton]

Just the beginning of test pieces and test fittings (e.g., welds not permanent and certain sections will be one piece 321 tube). Also, all new exhaust hangers have yet to be made.

[Robert Linton]

As the exhaust sytem will be 70+ lbs lighter, the washers/hangers at the end of the rear subrame can be replaced be lightweight aluminum pieces.

[macfly]

Wow, gorgeous, rour car is the only E52 that looks as pretty underneath as it does up top!

[thegunguy]

Bob, if I had your car, I'd put it on display in my living room...on a lift!

I love the small extrusion on the sway-bar mount. Every unneeded ounce must go!

[Robert Linton]

73+ pounds and reducing -- and, if we were in the exhaust business, the cost of the entire system would be less than the stock exhaust.

[macfly]

Great news! Can't wait to get mine!!

[thegunguy]

Is the 73 pound savings the entire system (headers, pipes, and cans) or just the cans at the back?

[Norcal]

Is the pick-up point at the header flange, and everything behind that, the same for the Z8 and Alpina?

[Robert Linton]

I believe so.

[Z8doc]

any estimated performance boost from the new exhaust?

[Robert Linton]

Do not know yet other than the improvement in performance that comes from reducing weight by 73 lbs. Over the next few months we will dyno. Having said that, given certain constraints in the system (e.g., lack of space for proper headers, need for catalytic converter, etc.) I doubt that much additional HP and/or torque will be seen -- and, of course, that was not the goal of the new exhaust.

P.S. With the weight reduction success of the new system, the car's over weight savings should be 225+lbs.

[Robert Linton]

Though not finished, the lightweight support forward of the cats.

[///M Blitz]

Do not know yet other than the improvement in performance that comes from reducing weight by 73 lbs. Over the next few months we will dyno. Having said that, given certain constraints in the system (e.g., lack of space for proper headers, need for catalytic converter, etc.) I doubt that much additional HP and/or torque will be seen -- and, of course, that was not the goal of the new exhaust.

P.S. With the weight reduction success of the new system, the car's over weight savings should be 225+lbs.

Since my car will never see a track, and weight reduction is not that important, the sound is the most important thing to me. If you can get this thing to match the sound of the Tubi (heard one on an e39 M5), I'm buying!!!

[Robert Linton]

The good news is that we could easily get it to match the Tubi in sound. In fact, we could let you come to the fabrication facility and let you work with the fabricator to alter the sound as you like, i.e., when given a choice, you might even like something slightly different from the sound you heard. The bad new, however, is that we are not in the retail business.

[365gtb4]

Robert,
I am ready to buy a more performance sounding exhaust for my '02 Z8 and would like to ask if you would be willing to build me a cartridge system for my car which is in Houston Tx. Please respond to my regular address: Thanks,
365G[email protected]

[macfly]

I'm not sure that Robert is on our board anymore. He last visited the site back in mid-Feb, he has since left the Z8 Club, and also not responded to my phone calls or emails, so I fear we may have lost him for good.

If he does not respond I would suggest Dinan or Supersprint as being the two best full system upgrades.

[dwz8]

I'm not sure that Robert is on our board anymore. He last visited the site back in mid-Feb, he has since left the Z8 Club, and also not responded to my phone calls or emails, so I fear we may have lost him for good.

If he does not respond I would suggest Dinan or Supersprint as being the two best full system upgrades.

Robert made his last post on the German forum on March 26, his last visit was on April 20, 2008.
So it may not be the worst case yet.

[Robert Linton]

I believe that the words of Sam Clemens might be appropriate, "the reports of my death are greatly exaggerated".

[macfly]

Phew - thank heavens, I was a little worried!

[thegunguy]

I believe that the words of Sam Clemens might be appropriate, "the reports of my death are greatly exaggerated".

Cheers! Glad to hear from you Bob!