So I have the RR p38 alternator on my d2 now. It is 150amp.

Im going to need at least a 250amp alternator because of accessories added and car audio.

does anyone know the fitment needed…meaning, on the alternator websites, there are models for every gm, Ford, etc but not specifically Rover and I’m trying to prevent going back and forth with retrofitting etc..

 

They have a pretty good following.
https://www.powerbastards.com/prodde...3990-250-HD1-1

or Eagle High makes a 200 amp for half the price. That's all I've been able to find that are direct fit.

 

Hell yes thank you!

 

Will you need to upgrade your wires? That’s a lot more amps than they designed the D2 with.

 

oh ya wires gonna get pretty how and melt

 

I was under the impression that the P38 alternator is only 150 amp. Did they make a 180 as well? Also, don't the high amp alternators put out like half of their rated amperage at idle? Seems like that may be something to consider as well when going with a really high output unit.

 

Looks like the RR alternator is 150 amps. I'm probably in need of a new alternator. Should I be concerned about using a 150amp alternator in my 04 D2? It came with factory brush guard lamps so it may have been built with a larger alternator. Any thoughts would be appreciated.

 

From what I understand, someone correct me if needed, all the D2's came with a 130a alternator. The P38 had a 150a, and are a direct swap in for the D2, no other mods needed.
Most vehicles only use about 60-90amp while running down the road with all your stuff running, including e-fans, stereo and A/C. They only produce their max amp output at higher than idle RPM's, over 1200 or so. At idle, they put out about 30% less than max. Unless you are running a competition style SPL sound system, or maybe a halogen lighting setup (not LED'S) and a big kitchen outfit you plan to run all at the same time with your stereo, fans, and A/C running while hauling *** down the road, a huge amount of amperage is usually unnecessary. It can take big amps to start a vehicle, that's why the CCA of your battery matters. But after it's started, it's running mostly off the alternator, and any big spikes in power needs are then handled by the battery, which the alternator then immediately recharges. So, unless you are calculating your constant power use with the engine running to be over 120a, you are fine with stock. If you want a lil more, you know, just to have it, then the P38 is a good upgrade. If you do calculate your constant usage to be in need of more than 150a charging, then to be safe you'll need fit thicker positive wires between the battery, the starter, and the fuse box. Upgrading the chassis and engine grounds size would also be highly advisable.
Back in the day, the halogen lights and high drain amplifiers we had barely needed more power than the 90-120a alts that most cars came with (unless you were doing some kind of competition stuff, or had to many halogen lights, lol). Today, we have LED'S, and amplifiers that are much more efficient. Heck, you can save a lot of amperage, just by changing out all your bulbs to LED'S, and have plenty left over for a 50+ inch LED light bar, that takes what, like 2-5a max?
Anyway, just some thoughts....

 

Winches draw up to 500amps. It makes sense the support the battery with a higher powered alternator. In addition it reduces the recharge time of the battery. Some run compressors, electric water heaters and have dual-battery setups, which can push a stock alternator over its limits.

 

I did already