exhaust?

bradley928 · 07-15-2009, 06:56 PM

Has anyone put an exhaust system on an 82 928? This makes me weary because of tacky noise but im wondering if a stock exhaust system is restricting my full potential. Not a huge mod im just wondering if anyone has had experience with this and if so which exhaust system works best or should i just leave it to german engineering and leave the beauty the way it is?

Danglerb · 07-15-2009, 09:21 PM

Many options exist, most louder, but I think a modern set of mufflers can allow some improvements without increasing sound level.

http://forums.rennlist.com/rennforums/928-forum/432638-best-sounding-928-exhaust.html?highlight=exhaust

bradley928 · 07-15-2009, 10:43 PM

Now dont get me wrong theres nothing wrong with a louder throaty sound of a v-8 but there is a fine line to be drawn between loud and obnoxious. any brand suggestions?

Danglerb · 07-16-2009, 09:07 AM

I'd say its less about brand, and more about the type of muffler. Brands I associate with tone of the exhaust, FlowMaster has the fraaaap, Borla more rumble, Magnaflow someplace in the middle.

There are three types of muffler, straight through or single chamber, two chamber, and three chamber. Now if I could just remember the details of what those look like, but regardless seems like two chambers make a reasonable compromise for many.

Cats reduce the sound.

Resonators (small single chamber mufflers) also reduce the sound and change the tone.

The stock exhaust has a heavy head pipe (thick wall tubing up to the exhaust manifold), big cats, a resonator, then the big bath tub 3 chamber muffler at the back.

For a stock US 82 I would use, and plan to use on my own US 83;

US 85/86 exhaust manifolds.
Custom made Y merge pipe with single OBDII high flow cat.
2.5" single pipe with a Magnaflow 2 chamber muffler in the factory location.
Depending on how loud it is, I may add a resonator after the cat.

123quattro · 07-17-2009, 06:05 AM

An exhaust will probably get you 15whp. Try and find a Borla system. Sounds like what you are after.

m21sniper · 07-17-2009, 09:12 AM

Listen to the exhaust in the video in my signiture.

If you like it do a forum search for the ingredients. Mine is a Borla, and it is LOUD.

bradley928 · 07-18-2009, 11:00 AM

that borla sounds awesome, nothing like a loud throaty v-8...no annoying glasspack crackle. would a full borla system be the way to go? if so who has the best prices? would a custom exhaust and a borla muffler have the same effect?

MPDano · MPDano's Garage

I am kicking myself for not buying Brendans Borla setup but didn't have the cash at the time. I believe a brand new Catback Borla System is around $450

bradley928 · 07-19-2009, 08:55 AM

Does anyone have a used system at the time?

m21sniper · 07-19-2009, 12:15 PM

I had mine custom made at a local muffler shop with a 928 specialists test pipe dumping into a 3"x14.5" Borla XR-1 racing muffler, into a single 3" exhaust pipe. (no cats)

You heard the result.

Craig S. · 07-19-2009, 01:37 PM

Stock manifolds, Ott X Pipe, Random Technology Cats, muffler shop did the 2.5" pipes into DynoFlow Mufflers.

The system is loud when you are on it, but not bad during light load cruising.

paintballer317 · 07-20-2009, 10:12 AM

i have a question, my 83 auto has had upgraded exhaust, i think. it has duel exhaust, i thought that 83's had the Y pipe making it single pipe to the muffler but i have 2 pipes comming back and both going into the same muffler. now, im thinking that the guy that did this did it to add horespower. im thinking i want to delete some items such at the muffler and maybe the cat, im not worried about smog control, i think ill put a pipe through the cat to make it look like it has one but i get the effect of no cat. is there anything i should be worried about doing this? what would it do to gas mileage and what kind of sound would it make?

morriss · 07-20-2009, 03:02 PM

What's all this talk about about catalytic converters?

Danglerb · 07-20-2009, 03:11 PM

Time for me to write letters to all my representatives demanding federal adoption of Calif smog testing.

MPDano · MPDano's Garage

Quote:

Originally Posted by Danglerb

Time for me to write letters to all my representatives demanding federal adoption of Calif smog testing.

...and with this post. You will ONE Wanted man

m21sniper · 07-20-2009, 11:55 PM

Quote:

Originally Posted by paintballer317

i have a question, my 83 auto has had upgraded exhaust, i think. it has duel exhaust, i thought that 83's had the Y pipe making it single pipe to the muffler but i have 2 pipes comming back and both going into the same muffler. now, im thinking that the guy that did this did it to add horespower. im thinking i want to delete some items such at the muffler and maybe the cat, im not worried about smog control, i think ill put a pipe through the cat to make it look like it has one but i get the effect of no cat. is there anything i should be worried about doing this? what would it do to gas mileage and what kind of sound would it make?

Generally speaking, removing the cats saves weight, adds power.

The factory 928 exhaust is extremely heavy, you can save a good 70lbs by going with a single 3 or 3.5" pipe/muffler combo. That alone is like adding another 5-7 horsepower.

Landseer · 01:41 AM

The 85 + 86 exhaust set-up could be what is on paintballer's car if it looks stock and runs parallel dual pipes back to the final big pumpkin.

I have an 85 unbolted in the basement. If you need me to take pictures of it for identification purposes let me know. It has corroded through on the downpipes.

Am running a stock 84 single pipe system in its place on the 85.

Starting at the integral downpipes w/ cats, the early 32 V exhaust systems match-up exactly to the 16 V cars.

(This is true only if you keep the original somewhat constricting cast iron manifolds. If you make the mod to put 32 V SS exhaust manifolds on an early car, the offset changes and you will need a short custom-constructed spacer pipe to be able to match-up to any stock exhaust set up. Odd but true.)

I run a custom dual system on an 84 consisting of aftermarket cats, a pair of Magnaflow mufflers intermediate (that part looks like CraigS car), and a single dual in/out Magnaflow on the end. Pipe is 2.25 SS. All welded. Gives all the power I need from the 84 without that tacky TR 6 sound that I associate with ansa or borla. Sounds great in the cockpit, somewhat stealth to the outside world. I'd build this system again for a car like Bradley's 82. Only difference --- I'd retro the 32V SS headers with the short spacer, else perform the Porken die grind job to open-up the inside of the stock cast iron headers)

Notice on CraigS car how he lowered the right side muffler just a bit. His Battery box is also slightly different than earlier cars, so he was able to just run that right pipe back to the exhaust outlet. Just looks a bit close to the gas tank. Probably gives him a great HP increase. He says he still runs a set of cats, I guess high flow. Cats, even high flow, will take a lot of nasty volume out of the exhaust sound.

Whatever you run, be sure to shield the autotrans hoses and gas tank if you decide to go dual, split side, on the 82. Lots of options, to mix/match components, but not quite plug and play. Plan it out.

paintballer317 · 07-21-2009, 05:23 AM

hey landseer, thanks. yeah, can i see a picture please? ill take one of mine too. and are you saying that the a single exhaust of like 2.5 or 3 inches is better than the dual exhaust because of weight?

Danglerb · 07-21-2009, 07:36 AM

Quote:

Originally Posted by paintballer317

hey landseer, thanks. yeah, can i see a picture please? ill take one of mine too. and are you saying that the a single exhaust of like 2.5 or 3 inches is better than the dual exhaust because of weight?

Correct, its the racers preference, go over show.

Craig S. · 07-22-2009, 08:18 AM

Louis Ott was the prime adviser on the design of the exhaust for my car. The guy I bought the car from did a lot of careful development, and he definitely had horse power in mind for each modification.