When you say emissions and non-emissions, are you referring to the Secondary Air Injection or do you mean cat-delete and such specifically for off road use?

 

The GM ECM and wiring harness can be configured in different ways. The non-emissions variant of the harness would include plugs for front O2 sensors only and nothing for EVAP, purge valve, and fuel tank pressure. The software parts of the ECM are rewritten so the check engine light does not come on since these parts are missing. If you live in a state where they do emissions testing, they may be able to detect that the ECM software has been modified and, therefore, it may not pass. The emissions variant of the harness includes all the provisions that came out of the original GM vehicle including front and rear O2 sensors, EVAP, purge valve, and fuel tank pressure. Provided everything is running correctly and the check engine light it off, it should pass in most states with this configuration. It can vary greatly from state to state, so if you live in an emissions area, you should read up on it first.

With this swap, little of the Rover emissions system remains. The Rover secondary air injection would be deleted. Most of the GM engines of the era did not use secondary air injection, so it wouldn't have to be added back in. I wouldn't delete the cats for either configuration.

I'm in the process of putting together a website with all this info listed, which should simplify things.

 

Fantastic work. Very educational as well! Wouldn't it be beneficial to keep the forward O2 sensors in the non-emissions version to help control fuel trim?

 

Yes, even in the non-emissions swap, the front O2 sensors are retained. The rear O2 sensors are in the emissions version to verify the correct operation of the cats. The '02 conversion that we are starting soon is going to be fully emissions compliant.

 

OK, I misunderstood. When you said plugs for the front O2 sensors I thought you meant to eliminate them but you meant connectors. Thanks for the clarification.

 

I plan on doing the conversion on my disco then seeing how much the drivetrain can handle, then ill try a turbo. I have HP Tuners so tuning the pcm is allot easier. I also want to try my luck at running the stock gm accessories because they are cheaper to replace and more readily available. I want this kit asap so i can start tuning it and make videos to share.

 

As soon as I get some more miles on this one and we're sure all is good, then we will move into production. We looked at using the stock GM accessories, but fitment issues with the engine we had were why we didn't end up using them. We figured with most people the Rover accessories were probably in working order, so they wouldn't have a lot of reason to switch over.

I'd be cautious about the turbo, because it'll more than likely exceed the torque specs on the transmission, but with a bigger or second transmission cooler, it might work out. Just the standard truck LS 5.3 is a nice bump in power over the 4.6. It's definitely the fastest Disco I've ever driven.

 

I would be in for an emissions legal kit.

as long as A/C, traction control, and the other power Rover features can still be retained.

 

Update: Just completed a 300 mile trip with the LS-powered Discovery. Mostly highway driving at 70-80 mph. It ran flawlessly and all the dash lights stayed off. The A/C, traction control are all working as expected. I didn't get a fuel economy calculation, but it seems a bit better than a stock Discovery and I was running regular gas.

The driving experience is, for the most part, the same as a normal Discovery. There is noticeably more torque, so even on fairly steep grades the transmission doesn't downshift to maintain cruising speed, which is a nice change. The biggest change is now when the sport mode button is pressed, the LS comes alive and pulls hard. More than enough power to keep up with traffic (and pass) on the interstate.

In the beginning, I was a little concerned in the beginning about using the stock radiator, but it seems to be perfectly up to the task. I sat in traffic with the A/C on with the ambient temperature in the mid 90s and the temp never went over 203. Highway cruising with A/C the temps sat between 194-198. The GM thermostat is a 195. The Land Rover viscous fan and trimmed radiator shroud are working good.

I'm going to continue to daily drive it. After 154,000 miles, the original shocks are long gone, so we're going to order a 2" lift kit this week. We're also starting to work on a 2002 Disco this week.