is bigger better

[Jays04TSX-E 1]

I got an 04 GMC Sierra and wanting to put my system from my car into it. I have 1 XS battery and 3 Dekas. I am considering 1-2 more batteries (prob 1 xs). My question is I've been researching HO alts for it and I think the biggest ones in stock for my truck is the sp320 and the xp390. I'll be running close to 7K watts on 2 18s. I know I'll be drawing over 320 amps of current. Is the 320 plenty? or should is the 390 more in the ball park?

[srd150 8]

Remember, that's only your system drawing that much power. You also have all of the other accessories going draw on that too. Anyone correct me if I'm wrong but, my opinion would be shoot over. More spent now could save you from spending way more later.

[Jays04TSX-E 1]

So the xp 390 is my best option? or is there a better option alternator that DC has?

[Ohjay 116]

If you'll look closely, the idle output of the 320sp is lower than the idle ouput of the 270sp. With one of the 2 you mentioned, you're only going to get about 215 or so amps at idle and you will only benefit really at higher rpm. I would suggest a dual alt setup, DC Power offers a dual alt bracket and a single HO alt that mounts up with your stocker for way more amperage at idle and max for less money than purchasing a 390xp.

[Jays04TSX-E 1]

If you'll look closely, the idle output of the 320sp is lower than the idle ouput of the 270sp. With one of the 2 you mentioned, you're only going to get about 215 or so amps at idle and you will only benefit really at higher rpm. I would suggest a dual alt setup, DC Power offers a dual alt bracket and a single HO alt that mounts up with your stocker for way more amperage at idle and max for less money than purchasing a 390xp.

the only problem with that is meca doesnt allow dual alts in street class. so i gotta stick with 1 alt and need to know the best one to get.

[Ohjay 116]

Well you didn't mention that you were going to be competing in one of meca's street classes. In that case, I would opt for the 270xp for sure, unless you don't mind spending an extra $470 for the 15 amps you would gain at idle. Are you running in more than 1 class?

[Jays04TSX-E 1]

Well you didn't mention that you were going to be competing in one of meca's street classes. In that case, I would opt for the 270xp for sure, unless you don't mind spending an extra $470 for the 15 amps you would gain at idle. Are you running in more than 1 class?

no, ill be just competing in 1 street class and occasionally in drive-by (measured 6ft outside the car) for 30 seconds. 470 is alot for 15 amps!

[Ohjay 116]

Indeed it is.

[DC Power Kyle 21]

390XP will walk over any of the alternators for idle output if you're really looking for that. The 390XP will actually do 200 at idle for like 15 minutes straight with no issues at 14v. The 270 will drop down a tad more (170-180) or so. If you're going best bang for your buck though, the 270XP is the best bang for your buck.

[Jays04TSX-E 1]

390XP will walk over any of the alternators for idle output if you're really looking for that. The 390XP will actually do 200 at idle for like 15 minutes straight with no issues at 14v. The 270 will drop down a tad more (170-180) or so. If you're going best bang for your buck though, the 270XP is the best bang for your buck.

i kno yall are busy. ive been tryin to call. Do yall have either of these 2 in stock? i need one.

[DC Power Kyle 21]

I have the 270s in stock and need about 5 days for the 390

[Jays04TSX-E 1]

I have the 270s in stock and need about 5 days for the 390

how can i order 1?

[Ohjay 116]

Just dial (888) 441-0144 and try these 3 extensions, Ext. 2 / Ext. 4 / Ext. 5.

[DC Power Kyle 21]

You can also order it right here on our website: https://www.dcpowerinc.com/category/alternators/xp-series-high-output-alternators.html?make=GMC&model=Sierra&year=2004&engine=5.3L+V8

[ford302redneck 15]

Holy Hell, I didn't realize the 390 cost so much.

Why such a huge increase from the 270? It can't double to make it.

[shizzzon 461]

i'm gonna have to get one for my car.

I believe because the parts inside are custom or at least not a high market for them...

Who else makes a dual rectified ~400A alt with temp sensing..

DC over here tryin to monopolize, lol.

[Jays04TSX-E 1]

Holy Hell, I didn't realize the 390 cost so much.

Why such a huge increase from the 270? It can't double to make it.

see, man, thats what i'm pondering on. thats a big jump. the 270 xp is-what-20 or so more amps at idle. so then 270 will be the max i get out of this one at about 2k rpm and 390 is the max for the 390 xp at 2k? So with a battery bank of 4 in the back and 1 up front, will i benefit greatly with choosing the 390 over the 270xp?

[ford302redneck 15]

i'm gonna have to get one for my car.

I believe because the parts inside are custom or at least not a high market for them...

Who else makes a dual rectified ~400A alt with temp sensing..

DC over here tryin to monopolize, lol.

I mean I'm not doubting the time,effort, and money put into them, and the small market, but I can see why because not many will drop a grand on one alt.

I'm not sure exactly what other company has, but I think one has a 350amp that was a good bit cheaper, with ~200 at idle.

I'm just saying, not trying to compare. I know DC is doing things nobody else is, but I guess the saying goes, Quality doesn't come cheap.

It does seem now, if you want a rather large setup, your going to at least spend the same money on electrical upgrades, as you did on the audio part.

Take a 3000watt amp($600), two 15s($700). Your going to need two batteries($700) and one alternator($600). So pretty much equal give or take. *Example only prices may vary.

[Robert 9]

Your paying for the idle output also. It's doing at idle what the other models do at max then almost coming up on double the max of most other models at its max output. All that in a direct fit case

Edited July 17, 2011 by crunkjuice1

[Sencheezy 689]

Wow... A grand for an alt. Thats pretty step, does it come with a happy meal as well?

[Robert 9]

Funny how SOME people nag on a HO alt price tag. I understand things cost a lot in this hobby why wouldn't you expect the heart of your electrical to cost more than your stock alt that most times can't live at the power levels that higher end audio systems demand?

[ford302redneck 15]

Funny how SOME people nag on a HO alt price tag. I understand things cost a lot in this hobby why wouldn't you expect the heart of your electrical to cost more than your stock alt that most times can't live at the power levels that higher end audio systems demand?

Ok Mr understanding. Being surprised at a price and complaining is two different things.

A lot of just shocked at the price difference. But none the less, if somebody doesn't like the price, they don't have to buy it. I don't think nobody is really comparing to a stock alt either. I think it was more of a surprise than complaining. Even though there isn't much to complare the 390xp to, price wise.

But me personally, I can do without great idle for a fairly cheaper alt. As I have a high idle settin for my truck, and I normal only listen to bass while driving.

[Robert 9]

But you still end up seeing people trying to cut corners trying to make something cheaper do what it wasn't made to do. Patience is a virtue and I have learned to save pennies even for what I want and I know works for car audio. If anything people shouldn't be surprised when things like this cave there wallets in lol. There's always something to sacrifice and if you don't mind not having great idle output that's cool, but that grand will get you at idle what most others will get you while driving. I'm glad to see this, it goes to show what great things are coming as HO alts evolve DC just happens to be ahead of the game and it doesn't come cheap.

I'll look at at how you said more of a surprised reaction, as I myself have had those moments too. Mine was when I started my system ass backwards and didn't have the electrical to back it up. I recently seen what happens with a combination of that and other ill factors come into play at idle.

Edited July 20, 2011 by crunkjuice1

[ford302redneck 15]

That same grand can get you 400 amps at idle if you know how to spend it. And if you can fit multiple alts.

Take tejcurrent bracket(not now but that's beside the point), and 3 other stockers. That's around a grand, with 400 at idle, and 520 peak. Of course there are some downsides to this, but also some pros. Same goes with the DC, it has both.

Just got to think of what fits your install best, and budget.

[Robert 9]

Your paying for the idle output also. It's doing at idle what the other models do at max then almost coming up on double the max of most other models at its max output. All that in a direct fit case

True thats what I was getting at when I said that. Thats bad ass in my book for it to be a direct bolt on. No real need to alter anything, and should fit OE location. I'm limited for my car so a single alt that is a beast is a must. Hell my audio worth more than my car!

I said it along time ago even if I have a mechman alt I will be picking up a DC alt in the near future. For me that will be twice I drop $600+ on an alt but it ain't done overnight.