I have 2 great hobbys, Porsche 914 and Car Stereo Sound.

I might not be faster than you guys, but I will have a very unique 914. I pulled all the stereo stuff out of my car, and I am starting all over. I just recieved my Kinetik batteries today.

I got a HC1800 to replace my optima, the 1800 is rated at 1900 Amps. I also purchased a HC800 rated at 950 amps. I just found a upgrade 75amp alternator and a guy who will wind it to 120amp output to drop in place of the 55amp unit. I am going to be High Voltage!

The totall draw on my stereo install will be about 120 amps at peak. I am keeping my amplifiers but building a different cabinet for the rear trunk. It will house both amps and the 800 power cell. I am ditching both capacitors that were in the trunk. The wiring will be upgraded from the alternator (Jeff Bowlsby) and I will run "0" guage from the batterys to hook togeather + to + and - to -. I will also add a few more heavy grounds from each battery to chasis and from chasis to engine. Yes there will be multiple inline fuses on the positive leads. (saftey first)

I will update this thread with pics and progress as i go.




(any comments)

Not that big car stereos are my cup o' tea... But good grief man, that 1.8L motor will barely be able to stay idling with that kind of load...

I hope you're planning on replacing -all- of the high current wires in the car. The old (corrosion laced) wires in a 914 will most likely just let the magic smoke out once you crank that bad boy up. That includes the grounds. Especially the grounds...

-Josh2

I have a question. Being an old guy, I have to ask, isn't that really overkill? I've had 20 watt stereos in cars that would be so crisp & loud you couldn't be in the car with it cranked up. We didn't have subs back then, but never had a lack of bass. Won't you do some really bad things to your ears with that much power?

Rock On Sparky ..................

Yup. I have been a drummer for 35 years. The last 10-12 years I was lucky enough to spend a significant amount of time touring. My monitor system was a 750 watt 18" front loaded sub with a 500 watt 15/horn on top. I also used a tactile throne (it is basically a large magnet attached to a drummers throne that allows you to really feel low frequecies). Now at 41, I try really hard not to say "huh?" as much as I am thinking it.
I went to an in ear monitor in 2007. The guys at the board consistantly comment at how the levels I ask for are close to double what the other band members have their settings at.
I should have listened when others raised concerns when I was younger. I had a doctor tell me he could actually see some damage back in my 9th grade physical to play football - and that was before my 80's hair band years (some very loud years). Now the concerns are all mine. Please be careful.

Same here, permanent damage to the ear drums and a invisible friend called "Tinnitus Maximus" ...

http://en.wikipedia.org/wiki/Tinnitus

http://en.wikipedia.org/wiki/Noise-induced_hearing_loss

What?

I know what you mean. I was a DJ (live & radio) for a bunch of years, and owned a karaoke business (screeching voices can be VERY hard on the ears ) for a bunch more, and really am in need of hearing aids, but haven't broken down & got them yet. My live system now has a nice sub that helps you feel the bass without hurting the ears, & my volumes are a lot lower than what I used to run. But then again, I'm old.

Thanks for the concern guys. I really do feel the love from this site.

I am not trying to cause death of hearing tissue. I just want to rock. I googled Decible loudness and found a chart, after i google translated andys comment



osha daily permissible noise level exposure

90db> (train whistle at 500ft or truck traffic) 8hrs per day

95db> (subway train at 200ft) 4hrs per day

100db> (Motorcycle) 2hrs per day

105db> (Power Mower at 3ft) 1 hr per day

110db> (Power Saw at 3ft) 1/2 hr per day

115db> (Rock Concert) 15 min per day

Hi Andy -
Yeah, me too. I have been lucky that it comes and goes - not a consitant squeal/whistle.

oh, and yes she does.......

Having been an IASCA judge for many years... That's way more power than a 914 needs in a sound system. With that said, AWESOME! It may be possible for your sound system to load up the motor on idle, enough to kill the engine. You may need to run slightly higher idle speed.

You really should consider a single 10" woofer built into a fiberglass box to replace the passenger kick board (foam). A set of 6.5 inch seporates in the doors and lots of dynamat. This setup would be plenty for a cockpit this size.

I won't stop you or knock you from doing your own thing... Good luck with the install.

So, two hours a night, a 100 or so nights per year (not including rehearsals) pretty much says I am fuched.... but I had a great time!!!

I have 400 watts in my bus and I still can't hear the damn thing at highway speed.

Hey, you only die once!

Rock music, loud industrial equipment, hunting and race cars .........

What did you say?

That constant white noise is my head will hopefully not turn to voices.

You need DYNAMAT. Cover the whole interior (not cheap) and most road noise will go away. If you weld over all the windows and install a parascope, most of the wind noise will go away.

I think high power systems sound much crisper and produce better bass at low volumes.
I am running 2 - 8" subs, a pair of 6.5's and 5.25's with three Alpine power amps
in my car, it sounds great without having to crank it. With the top off on the high way i do have to crank it up a bit, lose the high fidelity but have plenty of sound.

My engine cranks up the noise when not listening to the tunes.
Tunes are great when i have the car parked at the shows i've been to. I have a 60's - 70's music disc i made and play it for all to enjoy when they are checking out the car.

Install away it's your car and your ears......

I lost some of my hearing at a Plasmatics concert, i can think of much better ways to go deaf......

Double layered in the stuff NEXT!

Wendy O. !!!

Too bad she killed herself ...
Andy

ROCK ON, DUDE!

You'll have a kick ass stereo and the electrical system to power it.

Good luck with your build. Take lots of pics.

0 gauge wire is the way to go.

I recall a bunch of years back (more than 10) before these 1 Farad capacitors were commercially available, a high end stereo shop had a system with gold plated wires and 2 extra car batteries in the trunk for the umph needed to power the system.

your system will draw 120 amps.
Your alternator will produce 120 amps.

This is a problem. No other accessories will function without draining the batteries.
You need to redesign so your total draw on the electrical system...lights, wipers and stereo, is less than the total output of your alternator or you will never keep the batteries charged enough to start the car.

Batteries are stored energy. You are drawing more out of the batteries ( no matter how many batteries you use) than you are putting back in.

Consider mounting an additional alternator in the position of the AC compressor to compensate...this is typical of RV's and custom cars with large draws of current.

Rich

i used to have a bumper sticker on my olds 442 that read 'if it's too loud- your too old"... thats before i got old

seriously more power to you just don't overdo it. hearing loss IS acumulative and once it's lost it's lost.

mike

Thats what I thought too, but my son put a whoppin 1000w system in his E 30 BMW (65 amp output) that I thought would be unusable, but the thing NEVER draws anywhere close to full load, and he runs it pretty LOUD.

IDK, I'm sure it is possible to truly overpower the alternator, but I would be more concerned about heat....

Anyway, it might work, or it might smoke the belt. Hehe. Just kidding. I wanna see pics of Chappy's install.

I believe to correctly specify the electrical system needed to drive the sound system and car, one would need to consider more about the characteristics of the music.

The peak current draw is one of the specs needed. The other is the RMS current which is the average current. Peak and RMS values are generally associated by the square root of 2 such that:

RMS = Peak / sqrt(2)

Also with music, it is a good design practice to allow at least a factor of 2 or more between the absolute peak and average peak. This is obvious if you have a power meter on your stereo and watch the peaks which usually occur on drum beats or the bass chords. So the average current would be:

RMS = Peak /(2 x sqrt(2)) = 120/(2 x sqrt(2)) ~ 42Amps

Consider also that even though all this power is available, there may be few times where the volume is cranked all the way to its maximum and the music amplitude is at the constant peak of the amplifier.

I dont believe i will ever be running at constant peak current draw.

Amplifier 1

Continuous current draw @ full power 55amps
peak current draw @ full power 85amps

Amplifier 2

Continuous current draw @ full power 30 amps
peak current draw @ full power 40 amps

The rest of the processors and head unit do not pull a noticeable amount. The extra kinetik battery is more powerful than 200 of the 1 farad caps i just took out of the trunk

I dont think I will have any problems with 120 amp alternator charging the batteries. Time will tell

Worst case, shut off the sound system for the last 10 minutes of driving before you park the car... make sure the battery is ready to go next time you go to crank it. (The car, not the volume)

I have one of the amps mounted under the dash stereo, and the other inside the gauge console, the 5.25's are driven by the head unit.

Sub enclosures are a pair of Stainless steel mixing bowls recessed into the firewall.

WOT: Speaking of Math, i was recently asked to help out a very well known wall street investment group with one of their main investment matrices.

First of all, it's just one GIGANTIC excel spreadsheet.

But more importantly, it had a very peculiar hard-coded multiplication factor that was added to a lot of the cell formulas:
sqrt(100)

Anyone see anything wrong with that?
Andy

it = 10

After all this, will the 1.8 be a 50hp output monster?

Think positive!

He can now use the stereo as a emergency brake!
Andy

Kind of like E = mc^2

where c is a constant, therefore c^2 is a constant?

Either that, or it will feel like he's got a bad TPS whenever the music hits a big bass note.

It's kinda like railroad locomotives use their drive motors as dynamic brakes. Want to slow down? Crank the stereo.

Huh? Did you say something.

Looking at the numbers, it would appear that at steady state, you're pulling 85 A. Now, a 120 A alternator can push that much current. But at what RPM? Can a 120 A alternator push 85+ A at idle speeds?

-Josh2

i will let you guys know, once i get her installed. I recieved my new alternator today.


I am now waiting on Jeff to send me my custom, mega harness to hook it up.

what?

Did you have a question??

I think you have to talk a little bit LOUDER.


Good luck on the installation. The proof is in the pudding. I'm sure your sound system will kick ass. Let us know how it works out.

figured i would post the pics of my swap. Basically I orderd a VW bus 75 amp alternator brand new. Got it wound to 120 amps, got Jeff Bowlsby to make me a custom harness with 2 runs of 8guage to handle my maddness. Got a few much needed parts from Detoxcowboy and my plastic seal from the samba.


have a look.




Picture of the original 55 amp alternator in its snug home
Click to view attachment

Picture of the original 55 amp alternator stolen from its home
Click to view attachment

Pics of the alternator, inside and out and the krusty boot
Click to view attachment
Click to view attachment

Picture of the old harness and the new harness
Click to view attachment
vs (thanks Jeff)
Click to view attachment

side by side comparison 55 amp vs 120 amp

Then to get the pullys off it is a little tricky, but with the (world) i got some tips

Now that they match, I painted the pulley so it would be pretty

The Bolt was a little tight so had to be adjusted (with the hacksaw)

The Final result, looks almost stock and fits exactly like the old one, with the new rubber boot it fit perfectly.

Now I should have just enough power to listen to my music

Any way you could have kept the cooling fins? Would seem like a good idea ....

Andy

There is alt. tin for the 70 amp alt. style which also hads the pulley fan, basically the 120 amp. alt is a 70 amp alt. wound to 120 amp. (vw bus bosch alt.s) The 55 amp alt. style (stock 914 and some 75 amp alt.s same body desighn) does not have the fan and the tin is diffent and will not work with the fan impeller.. Both tin styles can be found at Samba or elsewhere.. The 55 alt. tin has a smaller opening which will rub on the fan blades, where the 70 amp alt. tin has a larger opening to accomadate the fan blades.. both will mount directly to the 914 stock allighnments..

Why are you running two different batteries? One is 1800, the other 800.