Which Stage I exhaust is "better" for lack of a better word?

[DrWin]

Hi guys, :)

So, I'm gonna do me some enginework this winter, and as part of the preparation I have been doing some close inspection of the engine from below, with the car on a hoist. Among other things I noted that I have several holes in the exhaust system, which I'm assuming is the reason why the car is very noisy.

It seems to be the stock exhaust and I might just get a SS stock-ish exhaust, but I'd rather take the opportunity to do a little tweaking. Problem is: I'd actually much prefer if the car was both fairly quiet AND fairly powerful. Assuming that's a natural tradeoff, an exhaust that helps with performance makes the engine more noisy, I'd still like to hear some opinions on what stage I exhaust upgrade would be better.

I know of DMCH stage I gen 2 and DPI gen 3 as options. Did I miss some other option? What are your opinions?
Part of me wants to go for more power, but part of me wants the car to be less noisy.

Which is the quieter one?
Which one gives the highest increase in power?

Opinions, questions, comments, please. :)

(Optimally the exhaust would increase performance, but be visually and auditory indistinguishable from stock.)

[sdg3205]

None of them are quieter than stock.

They all offer very small performance gains.

I’ve run DPI and like it very much.

I don’t know if the DMCH option still uses the angular muffler, but that was a real turn off for me.

[WHO1DMC]

Delorean Go has a option.
DMCH still has the angular muffler.

I have one of DPIs early models. I'm not running cats so i'm sure it's a little louder than with. But it's not that loud that you're bothering the neighbors. The cabin is a little noisy until 5th gear. I think it gives a little something to the car. Not sure how much power is freed up but it definitely has to be something. When they got hot they do get a little quieter.


My .02
Dave B.

[Michael]

Performance exhaust in our cars nets an extra 3.2hp @ 5,800 RPM....a 63% increase in BHP!

[82DMC12]

I have the DMCH Stage 1 Gen 1 kit but I swapped out the Flowmaster for a Magnaflow. The Flowmaster is oft criticized for having a raspy sound but the Magnaflow has a deeper, throaty sound. I would not say the Magnaflow is "loud" but it sounds a hell of a lot better than the original exhaust. Like others have said, it quiets down in 5th gear so you aren't getting a drone on the interstate.

You said you'd prefer an exhaust kit that doesn't look different from the outside. I think all of the replacement exhaust systems go downwards before coming back up, so you'll see it poking down below the rear fascia. I haven't seen the UK exhaust up close though.. would like to see a straight ahead view of that one if anyone has it.

[DeloreanJapan]

I have a Friend in Italy ,Named Fabio .
He make Stage 1 exhaust for Italy Delorean club 67277

[painterdave72]

i have the uk exhaust in my car without cats.. i like it.. its a bit loud but not obnoxious by any means..

[MrChocky]

I'm told by the NorCal peeps that DMC is presently out of cats for their exhaust. Also the only non-factory exhaust that will pass inspection in California.

[louielouie2000]

The newest generation DMC Texas Stage 1 system with the catalytic converters installed is the most quiet aftermarket option. Like MrChocky said, this new generation system is CARB compliant which is why I believe they had to make the system a lot less noisy. There are several vids on youtube, but the system doesn't sound much louder than stock:

https://www.youtube.com/watch?v=G-VM0gOYgYg

Quieter = more restrictive = less power. However, I can't imagine there is much difference in power between the various aftermarket systems at the Stage 1/Spec 1 level.

[Helirich]

As far as power, you really can’t expect much. They say long tube headers can make 10% more hp. Of course none of the headers available would be considered “long tube”. So Michael’s joke maybe close to the truth. I like the routing of the UK exhaust, but there is no provision for cats. You may not be in a state that requires emission testing now, but climate change alarmists might get more political power in the future. For these reasons, I went DPI and never looked back. As far as noise, it’s louder when your playing, but very unobtrusive when your not.

[Chris 16409]

The term "UK" exhaust is confusing because it refers to at least two options. The original UK Exhuast can be found here:

http://www.stainless-exhaust.com/

67281

DeLorean Go sells their own version that is based on the one i linked to above. The Go version is advertised without Cats.

[David T]

The stock exhaust will be the quietest choice. All of the others will be noisier and if they do not have "cats" they will be even noisier. Make sure the rear window is fully bonded all around, on some cars the rear window comes loose at the bottom making the cabin very noisy. Don't expect much more performance unless you do a lot of other things like camshafts, head work, and a better induction system. A stock system will be the least expensive option. If you do a lot of driving in your Delorean you should try to go for the quietest exhaust that you can so you can hear the radio and not have a headache when you get out.

[Mark D]

The stock exhaust will be the quietest choice. All of the others will be noisier and if they do not have "cats" they will be even noisier. Make sure the rear window is fully bonded all around, on some cars the rear window comes loose at the bottom making the cabin very noisy. Don't expect much more performance unless you do a lot of other things like camshafts, head work, and a better induction system. A stock system will be the least expensive option. If you do a lot of driving in your Delorean you should try to go for the quietest exhaust that you can so you can hear the radio and not have a headache when you get out.

False.

For maximum quietness, stuff 3-5 bananas in each tailpipe. This setup will also reduce highway drone and total dB output for optimal "radio" listening performance and headache prevention.

http://dmctalk.org/attachment.php?attachmentid=67285&d=1636050680

[Mark D]

For those that don't believe me, just listen how much quieter the exhaust is on the banana-in-the-tailpipe modified K-car than the non-equipped Mercedes in this highly scientific* video comparison:


https://www.youtube.com/watch?v=a_1OVYsLqMU



*Note: extra mayo additive observed in this clip may or may not have contributed to reduction in exhaust volume, NVH, and improvements in overall ride comfort*

[David T]

Potatoes will last longer than bananas but if you want something that will last even longer, pack your exhaust with steel wool.

*Note: extra mayo additive observed in this clip may or may not have contributed to reduction in exhaust volume, NVH, and improvements in overall ride comfort* [/QUOTE]

[mark w]

The term "UK" exhaust is confusing because it refers to at least two options. The original UK Exhuast can be found here:

http://www.stainless-exhaust.com/

67281

DeLorean Go sells their own version that is based on the one i linked to above. The Go version is advertised without Cats.

this is what I have, with CATS. Its the best in my opinion. great euro sound, not too loud. completely polished. good power gains. fitment on the one i have now is not as good as the one I had on my first car circa 2009. i ceramic coated the headers. comes with insulated shields heat since the cats sit close to to the rear lower pontoon sections.

[WNY1983]

I have the DPI exhaust. It was installed back in Feb 2020. My vehicle is an automatic. Yes it is a bit louder. But now by much. Once you get up to speed. You really do not notice it. I feel i get better gas mileage. Overall I'm very happy with it.

[sdg3205]

Here’s something that probably hasn’t been mentioned:

A LOT of the stock factory cats I have seen over the years have had melted substrate, which most often means restriction. This is often the result of the lambda system crapping out, tampering with the fuel mixture or the k-jet just generally not operating properly.

If your car is stock, has a chequered past, “ran when parked” etc there’s a good chance the factory cat is doing more harm than good. Unfortunately having a look usually involves breaking studs and nuts off and needing a new exhaust anyway.

I think this is why so many folks feel a power boost. It’s not a true power gain, but rather a removal of built up restriction, and sure, maybe a 1-2 extra ponies.

[Ethan Rode]

I've been fortunate to install all three of the readily available options in the last couple years. No doubt, all of these systems are louder than stock. With all of these systems, consider exhaust stud replacement a necessity. Make sure to factor that time and expense into your budget My butt dyno says that there's a performance gain with all three systems, but I was unable to distinguish if any system had an edge of another. Here's my two cents:


-DMCH: Fitment is good, finish is ok, but not on par with what I'd expect from an $1900 (at the time) system. Muffler is bulky, and uses the original mounting points. Tips are nicely finished with an etched DMC logo. To my ears, this system sounds best under acceleration, and had an aggressive mid-range note. At highway speeds the noise is unoffensive, but not particularly "sporty" For how large the muffler is, I was somewhat surprised at the lack of bass at idle. Installed on an automatic car with oversize wheels and custom sound system

-DeloreanGO: Of course, no one beats Arran's customer service and shipping time. Finish quality on this system is excellent. It took more time to get this system to fit compared to the other two, but I was able to get a satisfactory result. Uses the stock mounting points, sans the alternator. No cats, so there will be a smell. Muffler case seems smaller than DMC's or DPI's. I love the muffler tips on this one, they look "just right" to me. Sound-wise, wonderful, breathy, deep idle. Expect some extra pops and gurgles due to no cats. Upon acceleration you'll start hearing midrange overtone on top of the fundamental pitch that sounds really great, and surprisingly modern to my ears. This is definitely the "sporty-est" sounding of the bunch I do have concerns about the long-term durability, as the owner of this system has reported a rattle in the muffler recently. Installed in a stock automatic car, and stock manual car.

-DPI: Hands down the best fit of the three. My only gripe on the finish is the tips; mine needed some additional de-burring, and those mf'ers can be sharp! To My ears this is the most refined and maybe the most "mellow" of the three. At idle the system has a growl that I would describe as low and warm. Throughout the RPM range the system maintains this refinement and warmth without sounding harsh. Definitely the easiest system to live with on the highway. Installed on two manual cars, including my own.