Bass hits, car jerks

[Typicaljawaiian 3]

I'm driving along and hammering down on the system and my car is jerking to the beat (cmon,minds out of the gutter now). It's like I'm doing the so called "gas brake dip". It's pretty fucked up and I'm not enjoying it at all.

Anyway, I drive a 09 yaris sedan and I recently put a 320 amp DC Power alt in. I didn't have this problem w/ the stock alt, but then again, I wasn't nearly as loud. What I'm wondering is what is going on and what could I possibly break by doing this on a regular basis? Should I downgrade my amp?

15" SMD on a Stetsom 7k2e

Thanks

[Randal Johnson 544]

Never really heard of a stereo system starving a engine of voltage or too much current draw. Hope you figure this one out.

[Kanaworm$ 292]

At loss as well!

[Duran 387]

It's from having such a large alternator in there. With your ECU controlling the engine you shouldn't have any problem with breaking anything.

[kirill007 52]

It's just the alot that is doing that, it's normal with such a HO alt on a smaller engine.

[sandt38 448]

Do you notice any belt noise when it really hits? If not a squeal, maybe a rattle or a thump. Maybe have someone ride next to you and listen for it. Also, do you notice lights dimming? Are the gauges or lights on the dash acting funny? Is it a very abrupt feeling, like a jerk, like someone grabbing and stopping the motor instantaneously, or is it more laid back, like the way the engine will respond to jumping on the accelerator... not exactly immediate, but noticeable.

There are a few things going through my head. The Yaris isn't exactly a beast, and it takes HP to turn that alt. Being so heavily wound it will definitely require more effort then a stock alt. Most people don't know that you can have a locked up alternator stop an engine from moving at all when there is a serpentine belt in the system. I have seen more then a few cars that were misdiagnosed with blown motors only to pull the belt off and have it run fine.. So I ask about the chirp, like the belt is slipping and dragging the motor down, or a thump or rattle, as if the belt were locking so tight it may be causing the automatic tensioner to jump, as it is just a spring loaded pulley.

Finally I ask about the dash lights and gauges as you may be snagging too much power for the system, and the voltage is dropping too low for the ECU (car's computer). The ECU expects to be able to deliver ~12 volts to power actuators, like your injectors, and it also expects a minimum voltage as an input so it can step down the voltage to provide a 5 volt reference, which is the common computer output to sensors, which the sensors in turn manipulate either by frequency or voltage fluctuations so that the computer can determine how the engine is functioning. If the ECU is not seeing the initial expected voltages, it can really throw everything else out of whack.

Hopefully we can get somewhere with a little more info, or maybe something I said may ring a bell for you. Either way, I look forward to hearing back from you with some more details, or better yet a fix.

Edited July 12, 2010 by sandt38

[Typicaljawaiian 3]

Man, thanks for the replys! I'm on my phone sitting at the DMV right now (hopefully I'll get outta here sometime this year lol). When I get home and I'm on the desktop I'll input more info and try to get to the bottom of this

Thanks again

[shizzzon 461]

if it only does it when jammin loud then it's the alt pullin lots of horsepower out of the engine.

With an alt like that, at full tilt output above 1800rpm or so, u can easily lose about 30hp.

[Julian 641]

does it have an overdrive pulley on it?

[sandt38 448]

if it only does it when jammin loud then it's the alt pullin lots of horsepower out of the engine.

With an alt like that, at full tilt output above 1800rpm or so, u can easily lose about 30hp.

That's pretty much what I am thinking too.

[Typicaljawaiian 3]

1. No belt noise

2. Lights dim a little (expected w/ only a stock battery)

3. When I'm full tilt on a real punchy song the rpm gauge fluctuates.

4. It's a pretty abrupt jerk like pumping on the brake while driving

5. Not sure about the pulley, pretty sure it does though

Yeah so I'm thinking it's not the best thing to do to your car. If I got more batteries would that help. It's not really a deciding factor, I'm getting batts anyway.

I'm thinking of downgrading power and doing a sound quality setup. I have a three year old and just had another baby a month ago so I need the space. I just want to meter at one more comp before I take everything out. I'm at 144.4 so far but I KNOW I can squeeze a xxx.xx out of it. Haha I'll post that score up when I get it.

But yeah, I don't want to break my car in the mean time

Edited July 13, 2010 by Typicaljawaiian

[Duran 387]

It's from having such a large alternator in there. With your ECU controlling the engine you shouldn't have any problem with breaking anything.

I'll requote since no one obviously read my post.

[slim2fattycake 85]

lol. This was my problem at first too. But mine may be a little different than yours. Like others have said, alt is pulling hp from your engine. 320 amp on a yaris is beast lol. Just step on the gas harder when you are about to feel a beat.

[Randal Johnson 544]

WOW ...

[Typicaljawaiian 3]

Duran, thanks man and thanks to Errrbody else. So........basically the solution is get a bigger ride hahaha!

[Mark LaFountain 1,054]

if it only does it when jammin loud then it's the alt pullin lots of horsepower out of the engine.

With an alt like that, at full tilt output above 1800rpm or so, u can easily lose about 30hp.

x2. Call DC Power.

[Typicaljawaiian 3]

Been in contact w/ them already about another issue, seems like their busy or something. Takes a while to get a response. Nothing wrong w/ the alt at all, just to much for my applications I think. That's why I'm thinking about scratching the SPL and doing SQ w/ headrest monitors (I got a pioneer 2 din in the dash already), fiberglass door panels, the works

I know Rob was dealing w/ some personal things so........

Edited July 13, 2010 by Typicaljawaiian

[Mark LaFountain 1,054]

Been in contact w/ them already about another issue, seems like their busy or something. Takes a while to get a response. Nothing wrong w/ the alt at all, just to much for my applications.

I know they are a bit busy at the moment, the owner has recently been injured in some way and are a little behind on things. Other then that from what I hear, it's quite normal for this to happen with that large of an alternator.

Best bet is just to continue to try and contact them and ask their opinion.

GL

[Typicaljawaiian 3]

Edited my post, I type slow, my bad

[CadillacMatt 31]

I second the idea of the alt putting a strain on the engine... I'm guessing as the alt tries to deliver more power it creates more rolling resistance against the rotation of the pulley. I had the same problem even with my MechMan alt, due to a weak battery... at full tilt every now and then the car would misfire and the belt would slip a little

[BanginGMC 23]

How do you like your SMD? i know its off subject, but i haven't seen shit for reviews. You can message me if you'd like, i'll really appreciate it because i'm going to be ordering two of them tomorrow.

[emh9009 199]

if it only does it when jammin loud then it's the alt pullin lots of horsepower out of the engine.

With an alt like that, at full tilt output above 1800rpm or so, u can easily lose about 30hp.

That's crazy. almost makes me not want to upgrade... ALMOST! haha GL with fixing your problem.

Will more batteries help? or is it just too much of a low HP to alt. ratio?

[Duran 387]

if it only does it when jammin loud then it's the alt pullin lots of horsepower out of the engine.

With an alt like that, at full tilt output above 1800rpm or so, u can easily lose about 30hp.

That's crazy. almost makes me not want to upgrade... ALMOST! haha GL with fixing your problem.

Will more batteries help? or is it just too much of a low HP to alt. ratio?

Nope, the alternator still has to be driven by the engine. Nathan should have warned you about this issue though, when I was speaking with him about the XP 270 he said this would happen, as I have a 2.4 L I4 in my car.

[slim2fattycake 85]

I thought the XP line was from DC Power?

[shizzzon 461]

maybe that's why rob got injured... attack of the companies!