DPI Exhaust Stuff

[ccurzio]

So 5311 has had a really irritating exhaust leak for as long as I've owned it, and I'm now starting to explore my options to get it fixed. As part of this effort, I've decided that rather than monkey around with stock parts it might just be worthwhile to put in an upgraded exhaust system.

I emailed Josh to try and get some details on his Spec I option, and while I wait for his response I wanted to get some other suggestions on different options, as well as understanding the benefits of doing this work.

Thanks.

[thirdmanj]

spec .01 !!!!!

[ccurzio]

spec .01 !!!!!

What's that?

EDIT: Ugh, nevermind. No thank you.

[Iznodmad]

Bad timing. I've got 2 SPEC I systems and got free install at my tech session of one system, including cold air intake, wiring upgrade, and K-Jet tuning. My other car already had it on there. There were about 5 more systems in his trailer ready to go. There were Stage systems there as well for a comparison. And turbo systems as well for comparison. And stock of course. In my opinion, there is no choice to be made. From cosmetic appearance, to sound, to performance, DPI is the way to go. Just a satisfied customer speaking. not everyone will make the same decision.

[Delorean Industries]

Bad timing. I've got 2 SPEC I systems and got free install at my tech session of one system, including cold air intake, wiring upgrade, and K-Jet tuning. My other car already had it on there. There were about 5 more systems in his trailer ready to go. There were Stage systems there as well for a comparison. And turbo systems as well for comparison. And stock of course. In my opinion, there is no choice to be made. From cosmetic appearance, to sound, to performance, DPI is the way to go. Just a satisfied customer speaking. not everyone will make the same decision.

Thanks for the review Darren. I sent a email response Chris. I'm supervising unloading 1200 feet of DOM tubing for our new chassis program and will call shortly.

[opethmike]

I'll also vouch for the DPI Spec 1 system. Between Josh's stellar customer support, and the appearance, build quality, and sound quality of the Spec 1, there really is no other choice. Top notch!

[djscoto]

Is there any noticeable performance gain with the Spec 1 Exhaust? Or is it just a nice stainless replacement?

[Iznodmad]

I have an auto trans car and a manual trans car. The auto trans car is a little faster than a stage 2 auto trans car. The manual is extremely impressive over stock configuration, but I have only driven it once since install 2 days ago. Not sure what to compare it to as of right now.

[Delorean Industries]

I have an auto trans car and a manual trans car. The auto trans car is a little faster than a stage 2 auto trans car. The manual is extremely impressive over stock configuration, but I have only driven it once since install 2 days ago. Not sure what to compare it to as of right now.

This is the SECOND time owners have noted that our exhaust installed alone provides a better power band than a stage II platform.

We are throwing a stock five speed with exhaust on the dyno Thursday I believe. I will post the results in another thread just for that.

[Kenny_Z]

When you do the dyno it might be worth capturing sound bytes from inside with the doors closed. It'd give those of us that are worried about droning inside the cabin an idea of what we can expect. You wouldn't have the road and wind noise, just what the exhaust will sound like.

Not that I hate loud exhaust but I get enough of that from my Mustang. I don't want to hear it from my Delorean. She's a different beast, more refined.

[Delorean Industries]

When you do the dyno it might be worth capturing sound bytes from inside with the doors closed. It'd give those of us that are worried about droning inside the cabin an idea of what we can expect. You wouldn't have the road and wind noise, just what the exhaust will sound like.

Not that I hate loud exhaust but I get enough of that from my Mustang. I don't want to hear it from my Delorean. She's a different beast, more refined.

Absolutely. But it is still best to listen to owners with the system or drive one yourself. I have done installs on two of the pickiest owners I could find with that being a major concern with both loving the system.

[Iznodmad]

Josh, I have two cars, but that doesn't mean you can count me twice for being "picky" Lol. Just messing with ya....

Regarding the drone. I don't consider that an issue at all. The auto trans is a little more "high pitched" due to the increased RPM at highway speeds especially. I drove it all the way from NC to FL and back for DCS and I had no problems or complaints with droning issues. My wife was with me for the trip and didn't complain either. I also drive the auto trans car nearly everyday to work. I've racked up about 6000 miles in the past 4 months. Even if I drive the car with a headache it doesn't bother me. If anyone interested in the SPEC I ever finds themselves near me, I will allow rides and/or test drives to evaluate the system.

[sdg3205]

Josh,

When you do the dyne runs would it be possible to dyno both versions of your Spec 1 systems: the "catted" versions and the "cat-delete" version? I've always been curious to know the power differences between them.

Thanks!

[Delorean Industries]

Josh,

When you do the dyne runs would it be possible to dyno both versions of your Spec 1 systems: the "catted" versions and the "cat-delete" version? I've always been curious to know the power differences between them.

Thanks!

We are doing a delete set up this week I think. We could possibly swap out and do the others. I will need to see how much time we have.

[Delorean Industries]

Frankly I'm tired of fielding the questions one on one to why our system is better than the DMCH offering. I am done sitting back on this one and will openly tell people it is just a name. Just because you purchase from our have service by DMC doesn't mean it is any way the "best available". So I have decided to publicly post why our system is far superior in every way. This is not meant to be little another product. Everything posted below are facts concerning why the DPI system is far superior to the DMCH unit. I'm sure there are more but these are just a few major points to why our product is hands down better.

As I posted previously today elsewhere. It is like with strut bars: I could make and market the same product to owners at a cost of about 20 bucks a piece taking owners money for it etc. But if it does not work I will not sell or market it. I have a long track record of making sure DPI does not offer under designed, misleading or faulty products. We are here to show the Delorean community that the bar is much higher than the standards of the past. DPI spends the money with the best sacrificing profit margins not only in R&D but also manufacturing to make sure of this. The end result speaks for itself. We continually gain support throughout the community resulting in us devoting more and more to innovating and perfecting the DMC-12 platform.

DPI exhaust system utilizes reusable copper gaskets at the collector flange to converter/ test pipe joint. DMC uses paper gaskets
DPI uses a ½ thick 3 bolt flange assembly preventing blow out issues. DMC uses a two bolt flange not easily available anywhere leaving inadequate clamping force evenly applied on the flange. Not to mention very thin flanges. (half the thickness of the DPI version)
DPI headers are CNC mandrel bent and TIG welded out of 304 stainless steel. DMC Units are made from a cheaper higher impurity content material with slip joints and rough mig welds distorting flow and performance.
DPI header flanges are professional tested by individuals regarded as the best in the business. DMC units are not equal length or anywhere close and try to utilize a much longer design for power when the engine internals are not set up for it. The extremely long headers are very close to the frame cradle and will damage epoxy over time.
DPI header flanges are port matched and Panasonic machine tig welded to create a perfect transition lip DMC units are not.
DPI header bolt patterns are easily accessible with a ¼ socket on all four flange points. DMC units are not.
DPI converters are expensive high flow catco units. DMC units are not
DPI systems have no mig welds. DMC units are all cheap mig welds.
DPI systems actually fit up under the car and look like they belong. DMC units hang very low and the tips do not fit inside the bumper.
DPI exhausts systems use stainless band clamps that do not crimp the exhaust pipes allowing removal and installation with easy at any time. DMC units use u bolts that distort the material making it difficult to take on and off for service.
DPI systems have an integrated optional metal heat shield to better shield the belts from heat. The unit actually covers the muffler unlike a straight shield on the DMC unit channeling heat away from the motor.
DPI systems also include the rear fasica heat shield in stainless. DMC units do not.
DPI systems include the alternator harness kit to prevent wire to header contact. DMC units do not.
DPI mufflers are the end result of 16 months of testing for optimal performance, no drone high way feature and sound. DMC units are a rectangle of some sort. (still not sure why…..)
DPI headers have oxygen sensor bungs in both collectors to allow dual wide band EFI operation or testing/ tuning/ diag of engine concerns. The bungs are distort proof and 3/8 thick. DMC units are only in the driver side and are prone to distorting and tearing when removing the oxygen sensor.
DPI upper muffler brackets are stainless . DMC units are steel coated black with failure prone inserts.
DPI systems can be ordered with our without converters for the same price. DMC requires extra money and will not sell just the off road set.
DPI offers a life time warranty through stainless works. DMC does not.
DPI system includes slash cut tips giving the rear of the vehicle an aggressive “this should be there” look. DMC units hang way out past the rear bumper exposing a mig weld where the stainless tip is welded on.

[Tillsy]

But, the DMC ones do have a cool DMC logo on them ;)

Great summary Josh - if you could find a way to economically get a bunch into Australia you'd likely sell a few here!

[Delorean Industries]

But, the DMC ones do have a cool DMC logo on them ;)

Great summary Josh - if you could find a way to economically get a bunch into Australia you'd likely sell a few here!

I just finished a Skype call with John. We are working out the details to make a tech day/week happen as soon as January. Basically I will fly into Honolulu to visit my father and leap over to visit after.

And if you really want the DMC logo on the tips. It isn't a problem. We can laser etch it just like only our shift knob patterns etc.

[Kenny_Z]

Even if I drive the car with a headache it doesn't bother me.

That's a very relevant note for me. I suffer from migraines and the day I had to drive the Mustang home from work I found myself on backroads driving slowly just to keep the rpms low. The droning had me nauseated. It's something I'm eventually going to address.

[Delorean Industries]

That's a very relevant note for me. I suffer from migraines and the day I had to drive the Mustang home from work I found myself on backroads driving slowly just to keep the rpms low. The droning had me nauseated. It's something I'm eventually going to address.

Kenny, I'm sure we can find a owner close to you with our system if you are interested in test driving. We will be dropping a car in Arkansas soon and we can detour accordingly as well with an upgraded car.

[TTait]

My wife was with me for the trip and didn't complain either.

Sounds like you have a pretty serious exhaust leak coming into the passenger side of the cabin...

[DeloreanJoshQ]

Frankly I'm tired of fielding the questions one on one to why our system is better than the DMCH offering. I am done sitting back on this one and will openly tell people it is just a name. Just because you purchase from our have service by DMC doesn't mean it is any way the "best available". So I have decided to publicly post why our system is far superior in every way. This is not meant to be little another product. Everything posted below are facts concerning why the DPI system is far superior to the DMCH unit. I'm sure there are more but these are just a few major points to why our product is hands down better.

As I posted previously today elsewhere. It is like with strut bars: I could make and market the same product to owners at a cost of about 20 bucks a piece taking owners money for it etc. But if it does not work I will not sell or market it. I have a long track record of making sure DPI does not offer under designed, misleading or faulty products. We are here to show the Delorean community that the bar is much higher than the standards of the past. DPI spends the money with the best sacrificing profit margins not only in R&D but also manufacturing to make sure of this. The end result speaks for itself. We continually gain support throughout the community resulting in us devoting more and more to innovating and perfecting the DMC-12 platform.

DPI exhaust system utilizes reusable copper gaskets at the collector flange to converter/ test pipe joint. DMC uses paper gaskets
DPI uses a ½ thick 3 bolt flange assembly preventing blow out issues. DMC uses a two bolt flange not easily available anywhere leaving inadequate clamping force evenly applied on the flange. Not to mention very thin flanges. (half the thickness of the DPI version)
DPI headers are CNC mandrel bent and TIG welded out of 304 stainless steel. DMC Units are made from a cheaper higher impurity content material with slip joints and rough mig welds distorting flow and performance.
DPI header flanges are professional tested by individuals regarded as the best in the business. DMC units are not equal length or anywhere close and try to utilize a much longer design for power when the engine internals are not set up for it. The extremely long headers are very close to the frame cradle and will damage epoxy over time.
DPI header flanges are port matched and Panasonic machine tig welded to create a perfect transition lip DMC units are not.
DPI header bolt patterns are easily accessible with a ¼ socket on all four flange points. DMC units are not.
DPI converters are expensive high flow catco units. DMC units are not
DPI systems have no mig welds. DMC units are all cheap mig welds.
DPI systems actually fit up under the car and look like they belong. DMC units hang very low and the tips do not fit inside the bumper.
DPI exhausts systems use stainless band clamps that do not crimp the exhaust pipes allowing removal and installation with easy at any time. DMC units use u bolts that distort the material making it difficult to take on and off for service.
DPI systems have an integrated optional metal heat shield to better shield the belts from heat. The unit actually covers the muffler unlike a straight shield on the DMC unit channeling heat away from the motor.
DPI systems also include the rear fasica heat shield in stainless. DMC units do not.
DPI systems include the alternator harness kit to prevent wire to header contact. DMC units do not.
DPI mufflers are the end result of 16 months of testing for optimal performance, no drone high way feature and sound. DMC units are a rectangle of some sort. (still not sure why…..)
DPI headers have oxygen sensor bungs in both collectors to allow dual wide band EFI operation or testing/ tuning/ diag of engine concerns. The bungs are distort proof and 3/8 thick. DMC units are only in the driver side and are prone to distorting and tearing when removing the oxygen sensor.
DPI upper muffler brackets are stainless . DMC units are steel coated black with failure prone inserts.
DPI systems can be ordered with our without converters for the same price. DMC requires extra money and will not sell just the off road set.
DPI offers a life time warranty through stainless works. DMC does not.
DPI system includes slash cut tips giving the rear of the vehicle an aggressive “this should be there” look. DMC units hang way out past the rear bumper exposing a mig weld where the stainless tip is welded on.

I have very recently helped install a DMC exhaust on a friend's car and last year I installed a DPI exhaust on my own car.
My comment here is not to bash either one. However, below is what sticks out in my mind after installing both:
After installing the DMC exhaust, I found the DPI exhaust to be far easier regarding installation and I believe more thought was put into it during the design. All of the studs and nuts are much easier to reach and tighten on the DPI exhaust. Also, the passenger header on the DMC version is harder to install as it hits the engine cradle/frame easily and required us to remove the alternator and all of the exhaust studs in order to slide it in place. Not that it is a big deal and perhaps we didn't know the shortcut. However, I did not have to do this with the DPI exhaust; it is nicely "tucked" underneath. As stated, the collector flanges are different and I do like the 3-bolt over the 2-bolt version; they lined up better and easier. Finally, the DPI exhaust is no-question better looking/better finish than the DMC exhaust. Although most of the exhaust is hidden, The DMC muffler design (the looks of the welds and "half-muffler"? shape) I am not personally fond of compared to the DPI version. However, the DMC muffler only requires 2 hangers instead of 3 (like the original) that the DPI exhaust requires.
Sound-wise, they both sound great to me...but this is a matter of opinion. I don't have an opinion on the exhaust tips either way, but do prefer the band clamp connections over the u-bolt clamps for the reason stated. Of course price is always a factor.

Josh mentioned "DPI systems also include the rear fasica heat shield in stainless. DMC units do not. DPI systems include the alternator harness kit to prevent wire to header contact. DMC units do not." I do not recall receiving either of these, but perhaps they have since been added to the kit. I was able to wire-tie the alternator wiring away from the exhaust with no issues and my rear fascia heat shield has been re-painted however.

Both exhausts are fine, but for the do-it-yourself-er and Nit-Picker, the DPI version wins from my experience.

My two cents to be taken with a grain of salt....

[Delorean Industries]

I have very recently helped install a DMC exhaust on a friend's car and last year I installed a DPI exhaust on my own car.
My comment here is not to bash either one. However, below is what sticks out in my mind after installing both:
After installing the DMC exhaust, I found the DPI exhaust to be far easier regarding installation and I believe more thought was put into it during the design. All of the studs and nuts are much easier to reach and tighten on the DPI exhaust. Also, the passenger header on the DMC version is harder to install as it hits the engine cradle/frame easily and required us to remove the alternator and all of the exhaust studs in order to slide it in place. Not that it is a big deal and perhaps we didn't know the shortcut. However, I did not have to do this with the DPI exhaust; it is nicely "tucked" underneath. As stated, the collector flanges are different and I do like the 3-bolt over the 2-bolt version; they lined up better and easier. Finally, the DPI exhaust is no-question better looking/better finish than the DMC exhaust. Although most of the exhaust is hidden, The DMC muffler design (the looks of the welds and "half-muffler"? shape) I am not personally fond of compared to the DPI version. However, the DMC muffler only requires 2 hangers instead of 3 (like the original) that the DPI exhaust requires.
Sound-wise, they both sound great to me...but this is a matter of opinion. I don't have an opinion on the exhaust tips either way, but do prefer the band clamp connections over the u-bolt clamps for the reason stated. Of course price is always a factor.

Josh mentioned "DPI systems also include the rear fasica heat shield in stainless. DMC units do not. DPI systems include the alternator harness kit to prevent wire to header contact. DMC units do not." I do not recall receiving either of these, but perhaps they have since been added to the kit. I was able to wire-tie the alternator wiring away from the exhaust with no issues and my rear fascia heat shield has been re-painted however.

Both exhausts are fine, but for the do-it-yourself-er and Nit-Picker, the DPI version wins from my experience.

My two cents to be taken with a grain of salt....

Josh, I try to make sure that the subtle updates along the way are available as tsb's for owners with our products if interested. I can ship you the rewire pieces and the aft heatshield free of charge if you are interested. Both came around as part of the kit after your purchase.

Another note on the hangers: They are for cosmetic purposes only. System really doesn't need any installed and owners have the option of ordering without these brackets now.

[artisticent]

Love the write up Josh. Im in a service oriented field and sometimes you just have to give a no holds barred breakdown on why your product is the best. Its not like you just woke up yesterday, bought a bunch of exhaust parts from china and now claiming you have a better system. This is years of hard work, trial and error speaking. Good job.
On a side note, my D that i just picked up needs a cat to pass smog. (250ish) I would love a new exhaust system before I spend money completing my old stock system. Im in Cali 93021 and ill need a PM on final cost of parts I need shipped to moorpark 93021.

Thanks
Nathan

[Delorean Industries]

Love the write up Josh. Im in a service oriented field and sometimes you just have to give a no holds barred breakdown on why your product is the best. Its not like you just woke up yesterday, bought a bunch of exhaust parts from china and now claiming you have a better system. This is years of hard work, trial and error speaking. Good job.
On a side note, my D that i just picked up needs a cat to pass smog. (250ish) I would love a new exhaust system before I spend money completing my old stock system. Im in Cali 93021 and ill need a PM on final cost of parts I need shipped to moorpark 93021.

Thanks
Nathan

Nathan,
Please shoot me an email at [email protected] and I can send a quote over. I will be in the office until 2am est tonight. Thanks!

[Kenny_Z]

Kenny, I'm sure we can find a owner close to you with our system if you are interested in test driving. We will be dropping a car in Arkansas soon and we can detour accordingly as well with an upgraded car.

Thanks for the offer Josh. Eventually I'll be in the market for a kit but to be honest it is way down on my list of projects. Stripping the paint is my current priority but before I can even think of painting the fascias I need to replace my dying air compressor. I just thought if I could hear it in the cabin I'd know if I want to do any sound deadening as I work through my interior. Engine performance is slated to be my last serious project on Red.

[BABIS]

Josh, what do you think about the Uk exhaust system?
it would be nice to have a direct comparison like the one you did for the DMCH exhaust..
thank you ;)

[Delorean Industries]

Thanks for the offer Josh. Eventually I'll be in the market for a kit but to be honest it is way down on my list of projects. Stripping the paint is my current priority but before I can even think of painting the fascias I need to replace my dying air compressor. I just thought if I could hear it in the cabin I'd know if I want to do any sound deadening as I work through my interior. Engine performance is slated to be my last serious project on Red.

No problem! Just let me know if I can help with anything.

[Delorean Industries]

Josh, what do you think about the Uk exhaust system?
it would be nice to have a direct comparison like the one you did for the DMCH exhaust..
thank you ;)

Other than a few encounters I have limited experience with the system. My biggest issue in the past was removing the headers after running the engine. This could have been corrected in the design since but all of the flanges per cylinder were not interconnected. Making it a pain to take on and off after distorting from running. The headers are extremely short as well. (which has proven on the odd fire platform to aid in a raspy harsh note that some desire)

I haven't taken a set to SW for analysis of the materials used in construction. The polished finish champagnes rather well telling me that it is a better grade stainless compared to the DMCH version.

[ccurzio]

Well I've already decided that I'm going to send 5311 off to get DPi's Spec I setup. At this point it's a matter of financial logistics. Quality work doesn't come cheap, and this job is no exception in either case. In addition, there are a few other things my car needs that it might make sense to have done at the same time, but that's adding more to the cost. So it will likely be a while yet. :(

[thirdmanj]

Well I've already decided that I'm going to send 5311 off to get DPi's Spec I setup. At this point it's a matter of financial logistics. Quality work doesn't come cheap, and this job is no exception in either case. In addition, there are a few other things my car needs that it might make sense to have done at the same time, but that's adding more to the cost. So it will likely be a while yet. :(

It will be well worth it my man! You will certainly get a good return from Josh.

[ccurzio]

It will be well worth it my man! You will certainly get a good return from Josh.

I agree completely. I've heard zero complaints about the work that comes out of DPI which is why Josh already has my money. It's just a matter of piling enough of it up and getting it to him.

The other major thing my car needs is the 2nd gear roll pin. That nearly doubles the price tag of the work I need done, and that's also not counting any other poking and prodding to make sure there's nothing else that really needs to be addressed. (Fuel system, coolant system/hoses, etc.)

[Delorean Industries]

Just let us know when we you are ready Chris. To help with shipping I have a "when we can pick it up" twin turbo upgrade in Charleston so that will help considerably with the transport costs.

[ccurzio]

Thanks Josh. I hope to get my car to you sometime soon.

[Mark D]

This is the SECOND time owners have noted that our exhaust installed alone provides a better power band than a stage II platform.

We are throwing a stock five speed with exhaust on the dyno Thursday I believe. I will post the results in another thread just for that.

Cannot wait to see the results on this!

[djscoto]

Cannot wait to see the results on this!

Agreed. I will be watching for the post on Thursday!

[Iznodmad]

I made a video of my 83 with the SPEC I exhaust last night. Doors open and closed from the drivers seat for comparison. I can't upload it on this site for some reason. I'm not computer savy enough to figure it out. I put it on my FB page though and I know some of you have seen it that way. If anyone is smart enough to take it from FB and put it here, that's fine with me.

[DeloreanJoshQ]

Josh, I try to make sure that the subtle updates along the way are available as tsb's for owners with our products if interested. I can ship you the rewire pieces and the aft heatshield free of charge if you are interested. Both came around as part of the kit after your purchase.

Another note on the hangers: They are for cosmetic purposes only. System really doesn't need any installed and owners have the option of ordering without these brackets now.

I am very interested, would you please send me those pieces?

Thanks Josh!

Josh Q