Car sluggish with sub on

[AcID ZeR0]

I don't know if it's my imagination but when I have my system on the car seems sluggish in acceleration - even taking into account that it's a 1.4 and on a good day scooters give it a run for it's money.

Is it at all possible, or am I just imagining it?

 

[tim_foster23]

sumthing must be wrong cos my mate use 2 ave a 1.4 rt and it was absolutely rapid for a 1.4 i got a 1.2 16v and i rarse scooters and he used 2 abiltorate me everytime. i got sub in mine i dont fink it makes it any slower

 

[Djw John]

oops misread that post!

anyway, 1.4 and 1.2 16v clios are all pretty much the same after some of my scientific testing!

but back to the problem

is it possible that its killing the electrical system and your not getting as good a spark as you should?

 

[Djw Dave]

Gotta be summat wrong there mate. Get it checked by a garage. My 1.4 was in no way FAST but still was nippy.

 

[AcID ZeR0]

Maybe my alts on it's way out, the lights have been dimming slightly more when it hits deep notes.
Don't think theres anything wrong without the sub on as I've given my mate a drag race, down wisley airfield and I've come near level to him everytime and thats a Rover 200 Inj.

 

[The Fatty]

get a cap..

 

[Djw Dave]

You could try a cap, i would get your alt and battery checked by a mechanic type person first though

 

[The Fatty]

all light will dim with the normal bat/alt without a cap...the amp probaly pulls more than 80amps, and the normal bat/alt is only 45amps...thats 90 at the most when not charging.so when the bass notes come, it pulls all the remaining current and leave no reserve, thus the lights dim. if you use a cap it will improve the sound and create a reserve of power for the amp.

 

[oneeighttwo]

all light will dim with the normal bat/alt without a cap...the amp probaly pulls more than 80amps, and the normal bat/alt is only 45amps...thats 90 at the most when not charging.so when the bass notes come, it pulls all the remaining current and leave no reserve, thus the lights dim. if you use a cap it will improve the sound and create a reserve of power for the amp.

Mine do not dim, with the normal batt and I dont have a cap. I've found in the past with my other cars that if the earth is a bit dodgy then my lights dim. With the clio I found Bolting the earth stratight to the metal work and file the paint down to get a good contact helped. I also made sure the earth cable was as short as poss. Hope this helps. Not sure about the loss in performance. You may experiience slight loss as its a bigger draw on the electrics (like when switching AC on.) But i'm no expert !!

 

[Dansta]

slight loss eh?
i assume we're talking un noticable loss? i thought A/C affected u slightly due to the motor itself and a belt of some sort?

 

[Dink]

all light will dim with the normal bat/alt without a cap...the amp probaly pulls more than 80amps, and the normal bat/alt is only 45amps...thats 90 at the most when not charging.so when the bass notes come, it pulls all the remaining current and leave no reserve, thus the lights dim. if you use a cap it will improve the sound and create a reserve of power for the amp.

caps don't work!!!!

 

[Jones]

It'll be the amount of amps your stereo is drawing from your bat/alternator, i used to have the same prob with my first car (1.2 nova!!!! BEAST) it had a stupid stereo in it with 2 amps one 800W to power my sub and a 400W to power the rest. with it pumping away you could feel the car struggling and the headlights used to dim with the bass!!! I went through a fair few alternators tho so mind how you go!!

 

[Dansta]

why would that make the car struggle when on tho? excuse my stupidness....

im runnin a 400watt amp... and a 1000watt sub i think, but its not turned all the way up.

 

[Dink]

your running a 400w amp, that amp is driving the sub so the sub could be a 4TW sub but will still only get the 400w from the amp which if RMS is only about 45 amps drawn from the electrical system

 

[Dansta]

so thats good?

 

[Dink]

45 amps is a medium amount of extra power to be pulling from the electrical system so nothing to worry about

 

[Dansta]

ok so thats good. its only when i really turn the bass up they lights will dim.

 

[The Fatty]

your running a 400w amp, that amp is driving the sub so the sub could be a 4TW sub but will still only get the 400w from the amp which if RMS is only about 45 amps drawn from the electrical system

id like to know how you worked that out m8, my 280wrms amp takes 80amps...

and caps do work if you dont buy pansy ones with led's on them. get down to maplin and buy the big boys toys!

also, even if it was 45amps, you still have main lights/coil packs/head units/fans ect that pull power, it ends up being more the then normal car can produce...

 

[Dink]

effiency mate you better be running a class A if your pulling 80A

oh that is 400w output with a 75% effiency

and caps don't work (might get a little use out of a 20F one)

 

[The Fatty]

ok caps dont work, thats why the proffesionals use them all the time, there main use is to provide a smooth voltage feed to the amps, but hey they obviusly dont know what there doing lol.

 

[Dink]

power supply rejection of the amp is far in excess capable of taking what the vehicle voltage has to give.

i aint seen no real pro's use them

 

[The Fatty]

cant have seen many pros then...and the fact the practically everyones standard power system with an amp makes the light dip proves its taking more than the car can supply at a constant rate..

 

[Dink]

it's called volt drop and cannot be stopped(even happens in your house switch the kettle on and watch the lights)

 

[The Fatty]

it wouldnt if you had a cap installed, as the cap takes the 'volt drop', thus smoothing out the whole system., and if 1 cap dosnt do it for you, use 2 or 3!

 

[Dink]

lol now we've killed one thread you don't want me to kill this one explaining why caps don't work do you lol

 

[The Fatty]

yeah why not, enlighten me...

 

[Dansta]

u two are smart mutha's lol.

so now tell me... if it were to affect your performance.... why? exactely?

 

[Dink]

well a 1F cap holds 200J roughly @ 14v (watts = J/s)

so that will run a 1000 watt amp for a fifth of a sec But that is if discharged to 0v which it won't it will only go down to about 12.5v which means it will have about 22J which is f**k all and most of that will be lost because of the esr of the cap

 

[The Fatty]

@ Dansta

how do you mean? it could possibly put a strain on the alt, thus using more enigne power to turn it over instead of turning your wheels over. i know if i out the window heater on in my new scienic, the engine drops revs a slight bit...

 

[Dink]

dansta a simple equation 746w = 1hp

not really smart just remember lots about car audio

 

[The Fatty]

well a 1F cap holds 200J roughly @ 14v (watts = J/s)

so that will run a 1000 watt amp for a fifth of a sec But that is if discharged to 0v which it won't it will only go down to about 12.5v which means it will have about 22J which is f**k all and most of that will be lost because of the esr of the cap

yes but your not taking into account how fast they charge up...

 

[Dink]

what from a slow ass battery/alt

 

[The Fatty]

i can see the point your making, but it does work, the one in my car proves that, it dosnt need to supply the amp with power, its only there to take the load when a bass note starts...just to stop the momentary power drain.

 

[Dink]

it is in line with the amp power supply though? it is just extra load on the electrical system.

and after the first note of a couple of bass notes it actually takes power away from the amp

 

[The Fatty]

aha sorry, no not if you wire it up right m8. diodes fix that problem

 

[Dansta]

dansta a simple equation 746w = 1hp

not really smart just remember lots about car audio

ahh, so all in my head then...

thanks.
think i can deal with a loss of 1hp. if that.

 

[Dink]

that is the only way to wire it up (if it is connected to vehicle electrical system it will pull power from everything)

how will diodes help?? (and they have a .7v volt drop don't you know)

 

[The Fatty]

ahh, so all in my head then...

thanks.
think i can deal with a loss of 1hp. if that.

it might not be, if you have a bad/old alt, then it will put more strain on the engine.

 

[The Fatty]

that is the only way to wire it up (if it is connected to vehicle electrical system it will pull power from everything)

how will diodes help?? (and they have a .7v volt drop don't you know)

the cap cant pull power from the amp if a diode it used m8ty, also .7volts is nothing when the amps are 12volt anyway and most car bats push out 13 or more, the problems with the amps on the volts

 

[The Fatty]

the best way to wire it up (from my personal findings) it to put 1 direct wire, and 1 via the cap, this way when the cap has less power than the direct supply, it simply bypasses it.

this is only + wires btw (for you that didnt know), the - is always str8 to car body. (unless you have a really old car where the body was positivly charged, very odd those...)