DrJupeman

How much does the stock exhaust system weigh (headers, muffler, cats, etc) and how much weight savings is there to gain from going to aftermarket "stuff"?

I'm wondering if anyone has done the A->B comparison to know how much weight we can save on our turbos from changing exhaust components (cat bypass, etc).

cobalt

Check Out MarkS's flachbau.com site I beleive he said he saved 45 pounds.

DrJupeman

I'm having trouble accessing that site.

forklift

Here is a good thread from the 964 forum: https://rennlist.com/forums/showthre...&highlight=GHL

DrJupeman

Does it apply to turbos, though? I've read the 964 posts but their exhaust systems are different.

Adrian

You can make significant weight savings on the Turbo 3.6 as well. I am sure GHL or AJUSA can supply you with more accurate details. A good 20 lbs saving at least can be made.
Ciao,
Adrian
964C4

cobalt

I left the cats for now and used a J tube to eliminate the muffler. That was nearly twenty pounds saved. No real HP gain. A little throatier sounding and less back pressure. Sounds great when you let off the gas gives, the old 930 burble. You will save additional weight by eliminating the cats and adding an aftermarket muffler but I don't believe it will be street legal and will be much louder.

The B&B paperwork claims that the headers only weigh 13 pounds. The stock heater boxes are well into twenty five + pounds. That is at least 32 pounds. So 45 pounds total savings sounds about right if you figure the weight of both cats removed and adding a light weight muffler.

DrJupeman

Anthony, you have no heat with your B&B headers? I think I will need to maintain heat. Is there any weight savings going to aftermarket headers with heat boxes - that is my question there. Good to know on the J tube and the cat bypass (remove both cats, I assume?).

I suppose losing the cats and the muffler will make too much noise... Perhaps I'm looking at needing a quick connect/disconnect plan on the muffler for track days and non track days...

cobalt

No the thirteen pounds is with the heater boxes. I never had a chance to weigh them so I don't know how accurate that number is. When I received the package with the original stock parts the Fedex label said 45 pounds. I don't think the stock heater boxes weigh that much but it could be over the twenty five+ I estimated.

Regarding the noise my mechanic said he would make me a muffler that would reduce the back pressure, save considerable weight and not be so obnoxiously loud. I am affraid to ask how much. Besides it would no longer be legal and at this stage I feel the car is fast enough. Once I get used to driving her at speed a bit more I may decide to make the change.

DrJupeman

As for fast, my initial question was not looking for straight line speed from these mods as much as simply lowering weight (to improve handling, braking, and associated wear).

I would not want to hurt my performance and for the cost of these upgrades I would also want more power, but I would like extra incentive to make the changes (e.g., saving weight)...

maverick

I am having my flywheel and clutch replaced next week. In addition the stock headers are being changed. I will weigh them for you. I am going back with B&B with heaters so will weigh them for the comparison.
I have a '91 C2T.
Maverick

DrJupeman

Maverick, that'd be great, thanks.

cobalt

I went back and read the paperwork on the headers. I was mistaken. It claimed the B&B headers weighed thirteen pounds less than stock. My only problem with the B&B headers is there fit, at least on the 3.6. They do not seat correctly and leak terribly on initial startup. It goes away after five min but sounds like crap.

DrJupeman

Can anyone point me to definitive A vs. B comparisons with headers and how they actually improve performance?

Someone who has done the mod and dyno'd their car would be more interesting to me than a manufacturer's claims...

Mike Andrews

As you are in NJ you should give the guys at AWE a call (ask for Todd : 215-658-1876). They build exhaust systems and can help you out with your car. They can even dyno the car to give you before and after horsepower figures.

On a related note, they can dyno four wheel drive cars.

To answer the part of your question that deals with weight, it would really depend on what you wanted to do with the exhaust. Our cars can be configured a couple of different ways. There is only one cat on our cars and that leads into a muffler on the passenger side of the engine. Some people leave the cat and replace the muffler. Some people replace the cat (with a by-pass pipe) and leave the muffler. Some people replace the cat and the muffler with a single unit. Which approach you take will have an effect on how much weight you will save.

As to the horsepower part of your last post. I don't think the headers will make a ton more power (maybe 20 - 25 more horsepower). What they will do is allow your car to make boost sooner as they get the heat to the turbo much quicker. It a very worthwhile modification.

regards,
Michael