over40driv

I tried the search button for[sc400 ground cable] and came up with zilch, I know this upgade is often mentioned for perf. reasons, but being a starter and alt. rebuilder, I would like somone with the reasoning why this is going to make my car faster.

MJHSC400

It's going to restore any potentially lost conductivity over time--- from all the seams meeting and the metal tarnishing/oxidizing-- as well as the wire's connections oxidizing over time--

I did it to an SR20de and gained alot of driveability back-- just by running two well terminated ground wires -- one to the intake man. and one to the head...

It has made a good bit of difference--

Better grounding = more ignition power makes it to the spark= better combustion

Plus more accurate sensor readings and ecu communication-- Less signal loss for various parameters under continuous monitor.....

All that can equal a few whp and better throttle response-- as well as better efficiency--

Some have claimed to see 5whp on a SR20 powered car.... [G20]

Much more on a turbo engine, especially one on lots of fuel and boost....

Hope that helps

jibbby

Change the main battery ground cable if it feels crusty to the touch... Good to do on the older SC's....

natesiy

The mod itself doesn't do anything but get a better ground connection from the ECU and sensors.

It will net you a more stable electrical path for all your sensors to go thorugh though. (so i hear) Therefore, giving more accurate outputs and thereby "increasing" your performance midly.

Personally, i don't htink it works. U mite get the performance you were supposed to have when the vehicle was new.

over40driv

If your going to check the neg. cable, might as well check the pos. as well.

jibbby

The weak ground cables have the most profound effect on the older Lexus's...Positive cables carry the current much better and seem to last longer in these cars.. You can loose power, reponsiveness, etc...with a bad neg ground cable and should be changed if you car is more then 10 years old in my opinion......It's not that hard to change either but you will need to get under the car...

MJHSC400

Adding extra grounds is a good idea too with an older car--

Several connections besides the battery are at play--

The battery grnd is always a good idea, but take it a few steps further and you'll not only restore the conduct, but improve over stock conduct...

Rollin'ES3

Whatever he said.....

CleanCL

a lot of people go with heavy gauge positive leads for their audio systems and battery connections. this really isn't necessary. i use regular household copper and it works great. a circuit is as good as its ground. ground is very important. if you supply a solid ground the system will be fine. so yes, replacing the main bettery ground is probably one of the more beneficial things to do.

MJHSC400

As far as adding grounds to the head/s , and to the intake manifold, as well as to the block, and tranny, this is considered the most complete method of grounding, and the strut tower is a great/best place to ground to, if you're grounding all those points, you can strap them all to a distribution block on the firewall, and then ground the dist. block to each strut tower, and scrape the paint off thoroughly to bare metal for best contact...

------------------
Audio...


An audio system like mine will melt a 7 ft. 10 gauge wire at full volume in about 30 minutes.... Not only that, but it will distort signal, overheat amps, and fry the expensive stuff due to heat and distortion.

A good ground is imperative, but for an audio system over 375w rms, you need a solid power wire, [solid as in good-- always use high strand flexible copper] --

Most will use 4 gauge to have room for upgrading later-- The stronger power wire, the more power your amp sees withought voltage drop, the more voltage drop, the more distortion, the more distortion, more heat, more heat, more distortion, == dead speakers== expensive ones....

Use a good power wire and ground and you'll be ok....

Here's a good chart to follow... Easy to read and accurate without going into the science of it all...

Lexmex

I have an RX300 that I made this modification first with my own custom ground wires and then I got some ones from Sun Automobile. I have had friends also follow my lead at the track and every time they also report a little bit stronger throttle response, better shifts in some cases (for those with automatics), slightly brighter lights and crisper bass on the sound. What has been mentioned in the previous posts hits on the points exactly.

MJHSC400

If you think about the way an engine is assembled, it's easy to understand why a seperate ground to each seperate part is beneficial.

Every seperate part is seperated by a gasket, and gasket = low or no conductivity..

So you're trying to conduct electricity through paper gaskets, and it's hard to do--

By linking all the different points to a common high conductivity ground, it all gets a much shorter path to ground, and is more efficient with the same power/signal--

Most of your sensors work on signal-- think of it this way--

A 100 w amp channel is sent to a speaker 10 ft. away via a 18ga wire, the amp makes 100w, but the speaker sees only 90w-- still enough to be loud, but still distorted from it's original source-- Change the wire to a 12ga wire, and the speaker sees 97w, and all the sudden it's louder, cleaner, and you can hear it better at the same volume level..

Your ecu can hear the sensors better with several extra grounds.. Some turbo guys have seen 10 whp or more with this mod.. 10 whp is nice when all you have is a 4 banger....

over40driv

This is why Im in C.L..

jibbby

The best places to ground is on an iron block motor, tranny and or subframe...The stock lexus ground location near the starter motor is fine..When changing the ground cable, steel wool areas so you have clean contacts...Even use copper conductors on your battery connection, that should give you the best results...

MJHSC400

Also on a side note-- when grounding to the heads-- avoid the distributor end of it, as it's been proven to cause losses in some engines-- Just ground toward the firewall.....