DPI SPEC I Exhaust Install - 5875

[5875]

After purchasing the DPI SPEC I set-up this past December, I'm finally getting around to installing it. I'll post the progress and pictures here in this thread as I know a few others were curious about this too. It may help as a how-to for some. By no means am I anywhere close to being a mechanic so I'm learning as I go. I'm more than comfortable working on large home renos and consider myself a capable handy-man in that area, but working on cars is relatively new to me. My brother who was a Honda tech apprentice a few years back is helping me along the way as well which is great. Plus he has cool tools!

Anyway, first a bit about the car's existing system - it’s not completely stock. The PO removed everything from the Y-pipe (cross-over pipe) back and simply straight piped it and dressed it with some after market tips. Easy to remove the system from that point since it’s only a few years old and I don't have to deal with the muffler asbestos heat shield. For me, the car was always too loud for my liking and since it was missing the muffler and cat, the exhaust fumes were pretty noxious.

[5875]

The front end of my car has been lowered quite a bit, so we opted to jack up the front and slide in some ramps to try and keep the car level when jacking up the back. We then pumped up the back and placed two jack stands on the engine cradle frame and left the jack in place as a safety.

First up, we removed the PO's mod from the cross-over pipe back. It came off really easy since it was a couple years old and the hardware was new.

[5875]

Now the dreaded cross-over pipe and into the original stock (rusted) nuts and bolts. We tried removing the bolts from the cross-over pipe (Y end first). No luck there as everything was completely seized. Also, on top of the Y section, there's a bung and it's next to impossible to remove the top bolt because the bung is in the way. In the back of my mind was also the fact that most owners remove one of the axles in order to slide the cross-over pipe out properly. The thought of doing this really didn't appeal to me, so instead I opted to take my Dewalt saws-all and cut the cross-over pipe just before the Y end. This would kill two birds with one stone. So, being very careful not to hit anything else nearby (brake lines, coolant lines etc), I dove in and cut the pipe. It took about 20-30 minutes to cut through the whole thing - not easy at all, but worth it in my mind.

[5875]

After that, we made sure to disconnect the Lambda sensor wire in the driver's side wheel well and pull it through the frame. That way when the Y end was cut and the exhust manifold unbolted, it wouldn't damage the sensor or wire. There was no way the Lamda sensor was coming out of the pipe when mounted - there just wasn't enough room to grip it. We figured the best thing would be to work on it with a bench vice.

So after that, we tackled the driver's side exhaust header. I had hit all the bolts and nuts with PB Blaster for about two weeks steady before trying to remove. All the nuts came off without an issue and we had one entire bolt come out completely - bonus! After a few careful wacks on the header, it came off without issue. Glad I unhooked the Lamda sensor since it was so heavy and dropped like a stone.

[5875]

Next up I tackled the O2 sensor on my bench vice. I let it soak with some PB Blaster for a night, and tried it the next day. It came out of the bung smoothly. I'll be able to reuse this on the new DPI header.

[5875]

We focused on removing the cross-over pipe next. The bolts connecting to the pass side header are much more accessible than the driver's side. The first of two bolts came off relatively easy, but the top bolt gave us some trouble. We had to use a torch to heat up the nut and it slowly came out after using a couple of breaker bars multiple times. Unfortunately the impact gun wouldn't fit in that spot so we had to use elbow grease. Once that bolt was off, my brother easily slid the cross-over pipe out and over the tranny. Since we previously cut the Y-end off, there was tons of room and no need to remove an axle.

[5875]

A few nights later we turned our attention to the pass side header which is a lot more cramped because of the starter, alternator, wiring and oil filter. First there's a metal heat shield that needs to come off to get to the header and then asbestos heat shield protecting the starter and wiring.

We masked up and tackled the metal heat shield first. The shield is just clipped onto the header with spring clips. It came off after banging on the spring clips a few times. After that, we tackled the asbestos shield. That shield uses two of the header bolts for mounting, so we had to be careful here. The first one came out like butter – the complete bolt, but the second one snapped off at the header – Damn! After the asbestos one was removed we disposed of it right away. We then vacuumed all the area around it to be safe since we could see some particles floating around in the flashlight beam.

[5875]

Moving onto the pass side header, we started to remove the header nuts. 4 of them came out in one piece with the stud leaving the snapped one from the asbestos heat shield and one stubborn stud. A couple of taps on the header and off it came. I used the impact driver on the stubborn stud by putting the nut back on and giving it a few cracks when it was fully on. It snapped the seal and reversed out without an issue. We tried everything on snapped stud, from heat to impact wrench and vice grips - no luck.

On the driver’s side, I was down to 4 out of 6 studs that didn’t come out. I tried the impact driver and that managed to pull out one more. We tried everything on the last 3, but no hope. I’m not going to bother with an extraction tool because of mixed results. The nice thing about the DPI system is that you can use the opposite bolt holes for mounting the new header, so I’ll just go that route. The OCD in me wants the last 4 studs out, but really it does not matter in the end (IMO anyway). If I ever have the car up in a capable shop, we can see about extracting them at that point.

[Delorean Industries]

My staff sent off a pair of bushings and extra hardware just in case. Stay in touch and let us know if we can assist further. Most of all.... Enjoy your awesome exhaust!

[5875]

Seeing everything is off and accessible, I tackled two other small jobs. My oil sender wire had been nipped by one of the belts. The wire was okay, but the black sheathing had fallen off. I cleaned the wire with brake clean and tapped up the wire and moved it out of harms way so it won't rub again. The other small job that's an option with the DPI kit if you request it is that you can replace the bumper heat shield with a new SS one. My old bumper/facia heat shield had seen better days and was heavily rusted and bent in some places. The bottom of the bumper facia looked wavy because of it. I swapped that out fairly quickly and now the bumper lies much flatter. You do have to take some care taking off those nuts attached to the bumper since the bolt studs are integrated into the facia.