ChristianR

iTrader: (1)

worth doing? I see hks sell an earthing mod kit.

David_Wallis

dont believe it myself... just make sure you have a good ground between the block and a good one between the battery and chassis... you could also then link between alternator and block, and inlet manifold and the block.. but still not convinced..

David

Bob Rawle

Yes it is ... you wouldn't believe the interferance that floats around these cars especially the MY01 onwards, ground levels float up and down at will, you can either buy something ready made or diy but it is worth the trouble. the ecu actually has separate ground's for its different input types and still has trouble. Ignition interference particularly bad on some, gets at the TPS voltage.

ustolemyname??stevieturbo

iTrader: (1)

What difference does it actually make then? I would have thought that with the entire engine mass being alu, which is already a good conductor, would conduct any electrical energy a lot better than adding a few seperate earth wires.
Are you supposed to earth seperate items around the engine directly to the battery, or the the chassis ground? ( altho they are both the same thing really.
Im actually an electrician, and the consultants who design things go crazy overboard with earthing things nowadays, even to the extent that it is actually impossible to use the cable sizes they want you to, because there is physically nowhere to connect it to.
Is there a performance gain to be had by doing it?

RichiW

You can buy a Ralliart upgrade kit for the Evo`s, i`ve recently spoken to a guy who has had one fitted, and he claims you can feel the extra torque.Ralliart claim this though in their sales blurb, so he could be just imagining it.....

Rich.

bb

DIY's it to my Legacy Turbo. I can't say I have noticed any power gains or better mpg, but the stereo DEFINITELY sounds much better. Good enough for me for 15quid and an hours work.

submannz

Yes, almost all Subaru's have bad earthing. The earthing mod helps with the known knock sensor retarding the ingintion problem, which in quite a few cases does give better performance

David_Wallis

sorry still not convinced... other than maybe the sensor grounds... if it is just for interference then the cable size shouldnt really matter... 2awg would be taking the p1ss as would 8awg in my opinion.... think it is more a physcological(sp) gain...

lets see some rr proof..

David

dowser

When upgrading home audio equipment, biggest gains are from star pointing everything....still not done it the Scoob, but do have thick gauge cable now

The principle is to provide a common earth reference point for every device - if there's an extended earth path then signal fluctuations or interference can occur, meaning what a sensor gives out isn't necessarily what the ECU see's (for example: that's why lambdalink instructions dicatate not using general body earth for the lambda signal ground..... .2v fluctuation could mean the difference between seeing lean and being lean.

Whether it actually makes a difference to the Scoob, I don't know - but the logic is sound.

Richard

Chris.Palmer

Bob,

Is the reason for the Link recommendation to replace ECU ground wires on the older 95WRX ECUs (ie Pre My97)?

Would be interested to know the specific reason this mod - how the problem may manifest itself.

Cheers in advance,

Chris

David_Wallis

Where did you find that?? any links?

David MY94

Bob Rawle

No that was specifically related to a problem where if the grounding became weak then injectors could stay open too long, known problem on early cars whatever ecu is in.

David, no "links", just a supplier doing the right thing for once and advising customers when a problem became recognised, those in the Link communuty were made aware as and if problems occured. It was not a Link problem but a vehicle Model year problem. Fortunately it has only affected two cars that I was involved in and the ground mods sorted both.

Grounding, David if you want proof then suggest you do the mod and collect some data ... thats what I did which is why I know it is beneficial. If you don't think it worth then obviously no bother.

Some will recall that I "refused" to launch the 44s Link ecu for the MY01/02 WRX last year, reason being this very problem of interference getting at the TPS, after some hard work it was resolved by a software re-write and some hardware mods ... I collected masses of data during the process of resolving this. Works very well now.

STi wanna Subaru

iTrader: (1)

Sorry to be a complete dunce but what would this involve doing on a MY99 scoob?

Turbo_Steve

Cool Thread.

I just broke out the multimeter and clipped one end to the earth on the battery, and tried wandering around the engine bay (and the car) doing a continuity test.

Unbelieveably, the resistance of the chassis of my car is HUGE in places! And before your ask, I always connect to nice shiny fresh metal, none of that Oxidised stuff (or painted! lol)

I know nothing, here...but this would tell me that replacing all the grounding is a good thing.

Subarus wiring is wholly inadequate anyway: I uprated the earthing on the stereo a few days back and could not believe the improvement. I have to do the permanent and switched lives with clean feeds next

Wonder what would happen if we all did the same to our ECUs?

Bob Rawle

I rest my case

Bob

harvey

iTrader: (48)

Did this mod 6mths ago. I was sceptical and did not notice any performance gain other than probably reduced occurrence of radio interference. However some cable cut into 6no. lengths, 12no. lugs, some soldering and Bobs your uncle as it were. Cost under £10 and a leisurely 1.5hrs including getting the cable and lugs.
Christian:If you want more info contact me.

AJbaseBloke

The current B4 (D rev w/same Denso sourced EM as current shape Rexes) had a much bigger earth on it than earlier cars, but was still hopeless.

There has been tons of research done here on it, and the earthing, when done properly defo helps in cars that have issues: smoothness (engine response going up AND down the rev range) and as noted, audio quality. In some cars the mod has cured annoying stutters and hesitation, plus helped a touch on fuel economy, too.

It is not a cure all, nor a 50p = 50hp mod...

STi wanna Subaru

iTrader: (1)

BUT what is actually involved? Is it just a case of running earthing leads from various points on the engine to the body or what?? Are there specific points to earth?

I'm suffering from the hesitation problem and for the cost and time this mod would be worth trying

Thanks for any help

Guy

mutant_matt

Bob,

Can you give us any of the data you collected as this would be interesting to see....???

Cheers,

Matt

David_Wallis

Bob, Im not doubting it and tobe honest if people such as yourself recommend it then I could be tempted to try it... I just hate batterys with loads of cables coming off them... reminds me of fiesta xr2's with loads of spotlights...

Might give it a check with the meter..

David

Turbo_Steve

Dave.....

Why not take a leaf out of Triumph's book:

Run a MASSIVE piece of copper from the negative battery terminal to the chassis with a nice big bolt. Then attach all the wires to this point on the chassis...somewhere you cannot see it too much. If you are really keen on an improvement, use a small copper plate to bolt everything to.

I am amazed at the quality of subaru's wiring: In every instance it is BARELY adequate. Try putting some higher wattage bulbs in your headlights and watch the wiring temperature climb until it burns. Am not sure about MY97 on, but all the earlier cars are terrible. I want to improve my forward illumination, and it looks like I am going to have to re-wire the headlights to support the higher wattage!

AJbaseBloke

Take a look here: http://www.lumine.net/subaru/legacyb4/tuning/

The pics are of a B4 but the layout and points are basically the same - just add a big cable from the body earth to the batt and you've got the lot...although there are some pretty amazing set-ups done here that have even more points.

Cheers

B4 Boy

Also being discussed here....

www.scoobynet.co.uk/bbs/thread.asp?threadid=112723

If Any help...

Matt

[Edited by B4 Boy - 7/21/2002 3:30:38 AM]

ChristianR

iTrader: (1)

Well I purchased the HKS Circle Earth System and it has arrived - will let you know the results.





[Edited by ChristianR - 7/30/2002 7:26:47 PM]

harvey

iTrader: (48)

If you do not mind me asking, How much Christian?

dnb

Wonder if this could relate to my recuring "lack of boost" problem?

Will have to get my meter out...

What size cable would anyone reccomend, and is anyone at all concerned with adding potential ground loops to an already complex system?

BTW have just fitted a CD changer to my head unit - sounds infinitey better than the radio stations. More interference and bad ground evidence???

JohnD

iTrader: (5)

I did a 7 point earthing mod following the original thread on the subject some time ago. Small but noticable improvements in stereo reception and slightly smoother at cold starts. I did all the work myself for around £10-12 which included all hardware and heatshrink tubing.
Interesting to note that my sons new STi7 has additional earthing similar to mine (99my) but not as much!
JohnD

ChristianR

iTrader: (1)

hks kit is 155 - looks lovely though

Turbo_Steve

Holy Gold-Plated-Terminals, Batman!

155 smackeroonies on an earthing kit?

I would want it to be hand made by pretty swedish virgin girls for that much!

I was looking at getting 10 metres of 4awg and 10 metres of 8awg and a metre of 0awg from halfords and it weighed in at about £30, and I thought that was pricey!

I suppose the terminals could come to about £50 if they were gold plated.

£155!!!! Jinkies! Can we see a pic please? It must look the nads.

ChristianR

iTrader: (1)