Looking for a quality amp that won't break the bank.

[n2audio 5,000+ posts]

it's about as good as I would have expected stock.

It could still be the weak link though. You have to figure it's not capable of 90A until 3-4k. How often to you run at 3k+?? For that 2 minutes when you're looking for the smooth water?

Still hard to say until you measure voltages. Check it at the alt and also at the amps - that should tell you how much you're dropping in the power wires.

 

[jmanpc 5,000+ posts]

check out the LA storm X1.800.4 on eGay

 

[questionaire 10+ year member]

Definitely.

To make a rough estimate on your current draw...~500w for the SS, and ~500w for the ppi, plus another 300 for the jbl.

1300 at 60% efficient (give or take) = ~2100w

2100/13 = ~160A

How did you get 13 and way use 60%??

 

[n2audio 5,000+ posts]

How did you get 13 and way use 60%??

13 because I'm assuming some voltage drop in the pwr/gnd wires since the batteries and amps are both several feet from the alternator.

60% because most of the power is a/b. Could be 65, maybe closer to 70...wouldn't make much difference in the end.

 

[Gene3x 10+ year member]

I actually do run at 3300 rpm's when pulling somebody because I weight my boat with an extra 3000lbs and have a low pitch on my prop (yes I burn a ton of gas)! But I do chill at Party Cove and run it every so often. Should I see if there is a noticeable difference at speed versus not?

Nice man.... so you have a Tantrum? Us old guys need to keep pushing the envelope. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif)

So it still might not be enough alt because the amps at idle (40) are still not enough to keep up with your estimate (50rms ) when I have it cranked?

 

[questionaire 10+ year member]

13 because I'm assuming some voltage drop in the pwr/gnd wires since the batteries and amps are both several feet from the alternator.
60% because most of the power is a/b. Could be 65, maybe closer to 70...wouldn't make much difference in the end.

Would you still use 13 if it was 7ft of power wire? If it was mono block what % would be used?

 

[n2audio 5,000+ posts]

Would you still use 13 if it was 7ft of power wire? If it was mono block what % would be used?

no 7' would be on the short side -- no reason to assume more than normal vdrop.

if the mono block is class d I usually figure on 75%

60% on a/b's

with an approximation so rough a few tenths of a volt and a few percent on efficiency really doesn't matter. I was just trying to come up with a reasonable number.

 

[n2audio 5,000+ posts]

Should I see if there is a noticeable difference at speed versus not?

If it's in the water, or you can get water to it I would. Check it with the system blasting vs. off vs. low vol. Since you're going to be doing some measurments you might as well learn as much as you can.

I learned on my car - with the old 75A alt the 15A radiator fan was more of a drain than the 1000w stereo system. Surprised me, but also goes to show you the difference between constant current demand and dynamic (music).

No issues with the new 110A.

So it still might not be enough alt because the amps at idle (40) are still not enough to keep up with your estimate (50rms ) when I have it cranked?

Possible, yeah.

 

[questionaire 10+ year member]

no 7' would be on the short side -- no reason to assume more than normal vdrop.
if the mono block is class d I usually figure on 75%

60% on a/b's

with an approximation so rough a few tenths of a volt and a few percent on efficiency really doesn't matter. I was just trying to come up with a reasonable number.

What number would be good for 7ft?

 

[n2audio 5,000+ posts]

What number would be good for 7ft?

7's pretty short. As in most in-car applications there should be little-to-no voltage drop. Just call it 14 and you should be pretty close.

Or if you have a dmm start your car and measure voltage at the battery, then at the amp's terminals. Unless you're running a giant amp at high volume there shouldn't be much difference at all.

 

[kicker06 10+ year member]

90 amps isn't a lot.

PPI 1500, as in 1500w?

A 90amp alt isn't really going to cut it.

Do the big 3 and add a good battery. Kinetik and Optima are good choices.

 

[n2audio 5,000+ posts]

PPI 1500, as in 1500w?

on a dvc 4 jlw3 -- gain low.

500w or so

 

[questionaire 10+ year member]

7's pretty short. As in most in-car applications there should be little-to-no voltage drop. Just call it 14 and you should be pretty close.
Or if you have a dmm start your car and measure voltage at the battery, then at the amp's terminals. Unless you're running a giant amp at high volume there shouldn't be much difference at all.

Its in a single cab truck. I did the equation you mentioned in beginng an got 152(looking into a 1600w amp). Is this same equation to determine what size alternator needs to be?

 

[questionaire 10+ year member]

Its in a single cab truck. I did the equation you mentioned in beginng an got 152(looking into a 1600w amp). Is this same equation to determine what size alternator needs to be?

^^^^^^^^^^^^^^^