Check out this thread CLICK HERE Apparently the Impreza is known to have voltage issues. I know this is true especially with my car since I have a TON of electronics on it. Cruising I'm usually at 13.8 Volts. Clark Turner (a respected tuner on Nasioc) claims that he tested this on a dyno and saw 20 more hp when more voltage was supplied. I don't know the feasibility of this and I would LOVE to have a nice 'friendly' technical discussion with the local tuners about this on this thread......so please chime in Scott Siegel and Doug as well as anyone else that knows what they are talking about. Lets keep this informational and clean guys! I know I am gonna try this since with my electronics I need the voltage to be more stable.
very little information in that thread IMO. lots of speculation and no facts except, "this one time..." and "buy a V7/V8 JDM motor" unless the car already has issues like an ignition problem, IDC too high and fuel starvation, I really don't see how this can help. but I'm not a TOONER, just someone with an engineering background and no products to sell.
http://www.peony888.com/VS/sobogus.htm Interesting read about some of the "spark optimization devices"
Hell yeah, I've got a bitchin ver8 alternator! And half of my original grounding kit hooked up. Honestly the grounding kit worked wonders on my old motor and AVCS wouldnt run on the new motor without it. And in response to the guy adding an additional ground to the ECU, the JDM ECUs wont run AVCS without an additional ECU ground and additional groundign in the engine bay. Not sure how that would relate to the 205 ECUs since they're a little simpler. 20whp, I really doubt that. Most of the ignition kits for other cars add 5-10whp, something thats good after you've done everything else you can do powerwise.
For $2.49 its worth a try. I'm not worried about the power.....my car makes more power than most EJ205's out there. It's the low and fluctuating voltage I get. Like I said I cruise at 13.8ish volts when it used to be 14.5 volts.
I've seen both sides of the "grounding kit" discussion. I've seen cars that ran horribly and were fixed by adding grounds, which I would chalk up to some sort of bad factory grounds, and I've seen cars where it didn't make much difference but smoothed some ripples in the power band. Basically, if the car already runs perfect and has a smooth power band I think grounds / more volts won't do much. If the car might have a grounding / low voltage issue, then adding grounds / volts might make a huge difference. Siegel
i did the "grounding" mod on my old WRX simply because i had a bunch of left over 4 gauge wire. i definitely noticed a difference. not a gigantic/huge/massive improvement. but overall the car was smoother at idle and in acceleration. i could feel it probly because I drove it everyday. someone who drove my car once before and once after definitely wouldn't have noticed anything. if i had some spare 4 gauge sitting around i would probly do it on the L as well. but it wasn't noticeable enough for me to warrant spending money on some cheap "kit"
Well, picked a pack of the power diodes. I will let you know how it goes. If it works well, I will have 3 extras
I would agree that our voltage regulators are extremely random. The evidence I can support this argument with regards the several sets of angel eyes / ccfls I have personally installed on the Subarus. The original inverters were designed to handle load spikes between 0 (if you will) and 20 volts and we (LightWerkz and I) were still blowing inverters left and right. I had to replace a set on one local customer's car three times! We finally had them re-designed to support up to 30 volt spikes and that seemed to solve the problem (about the time I simply gave up and stopped offering the service).
Thing I have seen is a large drop from under hood temps....around .7 volts. In theory though, the sti alt will fit and you can get remaned units at autozone or advanced for like $90. They also jump up the amps 15. Might make for less voltage drop with accessories running.
I think the voltage issues may have been what killed my first lilliput screen. The second one was acting up until pEd and I cleaned the battery terminal and the wire running from the alternator. Since then everything has been working beautifully. Been perfect for about 3 months, but I am starting to see lines on the screen again, that speed up or slow down depending on throttle input, so it may be time to clean again.
420 clean your battery terminals and then grease them to prevent future corroding When I had my carPC I had to ground the screen itself to the chassis to get the lines to go away.
I have noticed my wideband give erratic readings when voltage drops too low...like radio turned up, AC on high and such.
Well... voltage to the injectors determines how much fuel they crank out right? If that is the case I think I would like the voltage to be as stable as possible. Seems like a just decision.
Eh...yes and no...it determines which portion of the latency table the injector uses. It was stable before, just stable at a lower voltage, lol. I think the main benefit will be to the ignition system.
Ya I do....but you can get them cheap at the local radio shack. Or if you are coming to the dyno meet at Orton I will be there too.
Almost all critical sensors on the subaru operate on a 5volt system (ie: crank, cam, tps, iat, tps). So I highly doubt voltage is going to have any effect on them. The only thing voltage may have an effect on is your fuel pump and coils. The coils will only be effected when voltage drops really low, like bellow 11volts low. As for your fuel pump, it will only be affected if your at the limits of what the fuel pump can flow. Any decrease in voltage to the pump will decrease its ability to supply an adequate amount of fuel. Which could cause a lean condition. Only cars I have ever seen a voltage issue are with evo's. I have never in the thousands of subaru's I played with seen any kind of voltage issues that created a problem that wasn't caused by something else. Now that doesn't mean subaru's never have had a problem. I just haven't seen any. I would be more inclined to suggest, its a grounding issue. Since all critical sensors are dependant on having a good ground (see above list) its extremely important they can get one with the least amount of resistance. You see more chassis ground issues with the guys who run their batteries in the trunk. Which is why i do not suggest anyone mounting their battery in the trunk.