I recently had my blown 986 reworked to 996 specs, basically bored out to 3.6, billet rods, alloy coated, etc. The second phase of this project is to upgrade the exhaust/cat bypass and ECM. The challenge is that I live and drive at high altitude, between 6000-8500 ft. I feel that most of the commercial ECM codes out there are not set up for high altitude. I also want to know if upgrading the intake plenum will make any difference in performance at this altitude. Anyone out there done a similar upgrade? I could use your advice on any part of this, ECM, exhaust, etc.
Thanks.

 

Sounds like a fun project.

Dave

 

I would call Scott at softronic software ask him if he has something that will work ,You could also call evolution motorsports and ask if theres would work but with a 3.6 this could be tricky and hard to find IMO .

 

May be too late but you're best bet is supercharging (turbo or supercharger). My NA cars at altitude in the Colorado area (when I drive through there) suffer some. A Saab beat my Boxster in an inpromptu "drag" race accelerating on to a freeway in Colorado Springs.

My '96 Mustang GT with a 200+ hp 4.6l engine would get a bit weak going over the highest passes on I-70.

My 01 5.7l Camaro seemed to handle the passes better.

More recently my 06 GTO (6.0l) performed well at 7500 feet (the highest I ever had it around Flagstaff AZ).

Drove m '02 VW Golf with its 1.9l Tdi turbo-charged direct injection diesel) car over I-70 several times and I at first expected I'd have to get out and push the car over the mountain passes with just 90hp and yet the car ran just fine and I didn't even notice a drop off in power. 100+ mph crusing at altitude with plenty of pep to get up the hills.

My 03 Turbo has not yet been over I-70 passes -- I might go that route on a road trip I'm hoping to take in a few weeks -- but I've had it over other high altitude roads with which I have driven on with other cars (listed above) and of course the Turbo is unfazed by altitude.

The only solution for high altitude other than forced induction is more displacement. The larger engine won't make as much power at altitude as it would at sealevel but a bigger engine starts out with more hp and retains more hp. But at 3.6l you're about as big as you can go.

Sincerely,

Macster.

 

Thanks. I looked into a supercharger but at more than $11K, its almost the same cost as the engine rebuild. I'm not sure if there's room for a SC or a turbo in the mid-engine compartment.

 

It's a little late now, but did you look into TPC and their turbocharger? I think they have a setup for the 986, but not sure.

 

There's room. Both for a supercharger if one wants to go that route or for a pair of turbos if one prefers that route.

One owner put intercooler where rear trunk is which is a bit over the top.

But what's done is done.

'course, to max. engine's peformance at altitude ain't cheap. I would think cams would be needed to provide as much lift as possible and perhaps some fancy/sophisticated cam timing would help.

But how to reconcile this with the engine controller and its built in behavior to adjust cam timing on the fly... one's looking at a custom Ecu map I guess.

Generally at altitude engine octane requirements drop but your engine could have higher than "normal" octane requirements and engine power -- mid-range mostly -- affected by insufficent octane number. Even driving across I-40 some stretches have gas stations that sell 90 octane max. Not even 91 or higher. 'course in CA at least where I live 91 octane is about as good as it gets and this even at sealevel.

The other thing you can do is leave things as they are, but of course not before you ensure in good tune after the work. The engine's going to be stronger than stock anyhow and this will make the affects of altitude less. All cars in your areas have to deal with the lack of air and air pressure. After awhile you won't even miss the missing hp even at 8500 feet.

Sincerely,

Macster.

 

I know that when I looked at doing my mods, there was a "power kit" from FVD. Not sure if they still sell them. Some folks I spoke to on this board and other boards swore by these kits which included the cams. Just another idea.

Dave

 

being that you are at altitude, our turbo would be ideal for you. Let m eknow if you do have questions.