Quieting down the Spec 1 exhaust

[Carbuilder]

I like the quality and fit of the DI Spec one exhaust, but find it a little too loud. I didn't want to do any drastic changes to it (cutting/welding) so here is what I did.

Bought some small motorcycle baffle things from Amazon, along with some exhaust packing material. I cut some thin sheet steel into rings and a star-shaped piece and welded it together. My welds are functional; crap, but functional.

71740

71741

Wrapped the packing round it, slid it into a piece of exhaust tubing, and welded it.

71742

71743

I inserted them into the muffler at the exit, where the tailpipe piece clamps on. The star-shaped piece was bent so every other tab would make it fit into the muffler pipe, and the ones not bent were the OD of the pipe. This way it is stable and with the 2 pipes clamped together with the band-type clamp, held it in place.

71744

71745

I measured the sound level and then did a recording of it before and after. The sound reduction was about 3db, which apparently is the limit of what can be heard. But the inserts definitely cut down the raspy/bark sound.

The sound clip is without the baffles, revving to about 2,000-2,500 RPM, then holding it at about 2,000 RPM. Then it goes into the same thing with the baffles in place.

https://www.dropbox.com/scl/fi/re19mdgmm13n2tmnlarg7/Delorean-before-after.m4a?rlkey=gawv3wxl0lfkluwrlv60t9wwa&st=6y11wof0&dl=0

I am really pleased with how this little project/experiment turned out. There is so little added restriction with these that I don't notice any difference in performance (might on a dyno) but the sound is much more pleasant....to me anyways.

Rick

[seventy4burban]

When you say too loud, you mean inside the car or outside ?

Sent from my Pixel 9 Pro XL using Tapatalk

[Carbuilder]

When you say too loud, you mean inside the car or outside ?


Both, but probably more noticeable from outside. I've had a few people mention that the car seemed pretty loud. The system is properly installed with no leaks. I'm not the only Delorean owner that thinks this exhaust is somewhat on the loud side.

[Mark D]

Sounds good! I can definitely tell the tone is a bit more muffled with slightly less rasp. I've been on the fence about buying a DPI exhaust for the past 10 years now and I have to say that I really don't mind the initial sound either prior to your modifications.

It would be cool to hear what it sounds like under load while driving, but I get that may not be practical depending on what you're using to record the sound.

[Carbuilder]

Sounds good! I can definitely tell the tone is a bit more muffled with slightly less rasp. I've been on the fence about buying a DPI exhaust for the past 10 years now and I have to say that I really don't mind the initial sound either prior to your modifications.

It would be cool to hear what it sounds like under load while driving, but I get that may not be practical depending on what you're using to record the sound.

I could record while driving I suppose; it would just be with my phone sitting somewhere in the car. But since I'm not going to remove the inserts it wouldn't give a before-and-after so really wouldn't do much good.

If you have been on the fence for 10 years and don't mind the "before" sound, then why not get it?

[Mark D]

I could record while driving I suppose; it would just be with my phone sitting somewhere in the car. But since I'm not going to remove the inserts it wouldn't give a before-and-after so really wouldn't do much good.

If you have been on the fence for 10 years and don't mind the "before" sound, then why not get it?

No need to go out of your way to record a driving clip, I'm sure it's great. The improvement is noticeable in the idle and revving clips you already posted.

I'm not so much on the fence about buying the exhaust, more so just haven't pulled the trigger yet. I know I want to buy it but I've been managing my expectations of when I'd be able to actually install and enjoy it. Had I bought it 10 years ago it would still be in a box in my garage.

I've got a handful of other car projects to finish first, then I'll be able to circle back to some fun upgrades for the DeLorean. For now I've been holding off and making due with basic maintenance so I can at least enjoy the car for the couple hundred miles a year I've been driving it.

[Timeless]

Sounds good! I can definitely tell the tone is a bit more muffled with slightly less rasp. I've been on the fence about buying a DPI exhaust for the past 10 years now and I have to say that I really don't mind the initial sound either prior to your modifications.
Don't give D.IND a dime! They are the most crooked dishonest company.

[Carbuilder]

Don't give D.IND a dime! They are the most crooked dishonest company.

And how is that relevant here? Seems like it is the most popular after-market exhaust and I haven't read any complaints about it.

[Timeless]

And how is that relevant here? Seems like it is the most popular after-market exhaust and I haven't read any complaints about it.
PSA. Product is ok - just won't support where it comes from.

[seventy4burban]

Both, but probably more noticeable from outside. I've had a few people mention that the car seemed pretty loud. The system is properly installed with no leaks. I'm not the only Delorean owner that thinks this exhaust is somewhat on the loud side.I like loud haha

Sent from my Pixel 9 Pro XL using Tapatalk