exhaust advice needed

[MPDano]

Mutha Funk Yeah!!! Looks Sweet. Now post the vid so we can HEAR it!

[morriss]

Leaving for a wedding in the morning, then I'll be gone all weekend. I'll try to upload the video early next week. It was pretty loud without the resonator; sounds just right (for me) with it. It's a sleeper; at idle the decibels are not in your face, but at the same time it's obvious that there's something big lurking under the hood. And when I get on it, it roars nicely instead of doing that loud head-throbbing BLAT -BLAT- BLAT-BLAT like some other cars that are running no cats and just a muffler.

[SharkTech]

Got a vid yet?

Lookin forward to hearing the new setup... Looks good.

[morriss]

Alright, I shot a short video, about 1 minute, saved it in windows media format, logged onto YouTube, and am uploading right now. But it says it will take 35 minutes!
Is there something different I can do to make this go faster in the future?

[morriss]

Wow, not impressed with the sound quality at all. I think I should have pulled the 928 all the way out of the garage because I can hear the engine noise (the covers are off so all the sprockets being turned by the tb can be heard).

The set-up; y pipe to single line to resonator to Moroso spiralflow muffler.

FWIW, here's the video.

YouTube - 928 exhaust

[MPDano]

Originally Posted by morriss

Wow, not impressed with the sound quality at all. I think I should have pulled the 928 all the way out of the garage because I can hear the engine noise (the covers are off so all the sprockets being turned by the tb can be heard).

The set-up; y pipe to single line to resonator to Moroso spiralflow muffler.

FWIW, here's the video.

YouTube - 928 exhaust

Sounds hella nice. Yeah, get the car out of the garage and try again. I think the engine noise is amplified by this. Still sounds very nice.

[morriss]

Reviving this thread. I have finally decided to take care of the strong exhaust smell. I can't drive thirty minutes without getting out of the car smelling like fumes. In the process of looking for the best catalytic converter to use while on the other site, I kept seeing threads about taking off the single line federalized exhaust system on the Euro cars and putting the dual factory set up back on. I saw nothing about the single line providing more hp for the 4.7 M28.11 engine when reading those threads. So, I now have two questions.
1. Which is truly better for my 1982 Euro S - the factory dual exhaust set up, or the single line that is currently on it due to federalization when it was brought into the country?
2. Is there any danger to including high flow catalytic converter(s) (no O2 sensor) in the exhaust system? I have seen some threads referring to the cats possibly getting too hot because the M28.11 exhaust system was not designed for cats. I have been looking at the Magnaflow 94008.

[morriss]

Alright, so I've had a few people reach out to me outside of this thread and all have said that the original advice I received was correct - the single line set up is the best, even though duals is what originally came on the car from the factory.

[diverdan]

Love my Borla system. Exhaust pipe size is primarily dictated by the displacement of a single cylinder in the engine since only one fires at a time. An additional pipe adds more weight as it's size is dictated by that single cylinder displacement. "Big hat, no cattle," syndrome.

As for the fumes, check the drains and in the spare wheel well and other spots in under the car and behind the rear bumper cover such as old grommets, but I'd bet on the rear hatch seal. (Or may be the tail pipe length?

Diverdan

[Opelotus]

I'm curious to see what catalytic converter you end up using. I ditched mine awhile ago, but just walking around the car when it's warming up leaves me smelling like dirty exhaust gasses
A new high-flow unit to clean things up a bit would be nice.

[morriss]

There's a pic on the first page of this thread showing the tailpipe; maybe I will angle it towards the ground. I am going to search working with the hatch seal as soon as I am done with this post. I think the PO replaced it about 10 years ago, but it could still be leaking, as suggested. I have noticed drops of water directly behind the passenger rear seat, coming down through the headliner,
a few times when washing the car.

I bought the Magnaflow 94006 cat. I am also planning on replacing the exhaust gaskets. Hopefully all of these steps will stop the stink. I can't even sit a light with the windows down because the cabin fills with fumes.

[AirtekHVAC]

Mine also has the major stinkies....I have no cat installed....I figured I just don't have it tuned right yet... (Which I know I don't). I also have a very cracked exhaust manifold, and a completely rusted out egr (manifold is on the to do list, and EGR is on the to do away with list). I am sure these are contributing factors. I have been considering putting in another CAT, but did not know if it would be beneficial.

[Danglerb]

Get it in tune first. Mark at 928 bought a batch of NOS early cats, $375 if I remember correctly, can cure a world of issues.

EGR is to reduce cylinder temps under very lean conditions, which you will have unless you rework the whole fuel injection system, no effect on full power.

[AirtekHVAC]

Well, I have rebuilt the distributor,, replaced all rubber lines, installed new injectors, new accumulator, new filter, new strainer and replaced both fuel pumps....does this qualify as a rework? If so, I guess I don't need it....I have a replacement, but since the PO bypassed the smog pump, why leave the EGR..right?, or no?

[Danglerb]

Originally Posted by AirtekHVAC

Well, I have rebuilt the distributor,, replaced all rubber lines, installed new injectors, new accumulator, new filter, new strainer and replaced both fuel pumps....does this qualify as a rework? If so, I guess I don't need it....I have a replacement, but since the PO bypassed the smog pump, why leave the EGR..right?, or no?

Nah, I say dig in and have fun those wacky German engineers don't have our keen insight in how a 928 works, so ignore their work and tack whatever wind that pleases you.

OTOH purely stock cars tend to run well.

Smog pump, supplies oxygen to the cats during the rich running period of warm up, otherwise vents to the air filter box.

EGR, under idle and cruise conditions the tune is lean, mixing exhaust gas reduces cylinder oxygen and lowers the burn temperature to make less NOX.

[morriss]

Got the Magnaflow cat put on and it makes a noticeable difference in the fumes.

Mine has no smog pump, but the EGR valve is still on.