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AJ4
Guest
blame Bruce on the 'adults' board for giving me duff info 
Mallory Performance ignition systems
- Thread starter campbellju
- Start date
Spoke to him first thing this AM :-D He said what I planned to do would be fine. :-DRishiGTiR said:
Just got to find the time to do it now :shock:
Who the f**k is Trisha and Judge Judy :noidea: :roll:
Anyway all fitted and running.
Not had chance for a real long run as yet but went for a short blast earlier. Throttle responce is up, general driving is much smother and power up in the higher rpm band is far, far better :-D , no misfires either, just pulled very hard all the way :-D
Will get some pictures up later.
One question though, the MSD ignition unit takes it's main power straight from the battery, wires from the unit are supposed to be connected directly to the positive and negative poles of the battery. My battery is in the boot, I have a positive junction box under the bonnet thats connected directly to the battery but the battery is earthed via a strap connected to the boot floor. So I have the positive MSD cable attached to one of the terminals of the juction box and the the negative (earth) bolted to the chassis under the bonnet.
The question is, is that the best place to earth it, or would I be better off running a cable up the length of the car to the battery. If so, what sort of cable, little skinny wire or big fat (like battery terminal wire) wire.
What would be best
Steve
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Partly agree with that. In my view, an earth is an earth, is an earth, as long as it's a good one ! No point going back to the battery, as you're just doing the same thing by connecting it, via a short, adequate gauge lead, to the chassis. The way you have it now is more effecient imho. At a very basic level, you're just trying to create a good circuit and you'll easily achieve that with what you've done !stumo said:
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Odin
Guest
stumo said:
I believe you did old fella :lol: :lol: :lol: :lol: :lol: .....
I would think that it would be better to use the short earth in the engine bay rather that run a long one to the rear ;-) , After all an earth is indeed an earth
:lol: :lol: :lol: :lol: .......Rob
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AJ4
Guest
obviously never heard of the term 'star points' then
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Odin
Guest
AJ4 said:obviously never heard of the term 'star points' then
Is this some sort of guide to where about it is best to mount an earthing point ? :? , Or just your normal drivel :roll: .....
Rob
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AJ4
Guest
In a nutshell, any electrical system ( especially where high currents are involved ) should have all the earths coming to a single point so they are at the same volatge ( or 'potential', before some smart **** corrects me ). Otherwise, electrical currents can flow between earths which can upset some equipments. Its more for shielding and anti-static, but the principle still applies for cars. Manufacturers dont do it because its cheaper to earth everything locally.
Although the car chassis is metal and can be thought of as 'one point', in reality it has different resistance values all over it due to metal thickness / impurities etc Thats why people fit aftermarket 'circle earth kits' in their engine bay, to ensure that all the equipments are grounded at the same potential.
No doubt I'll be corrected on it, but thats the simple version
Oh, and a star earthing system is connected to a.... wait for it...... 'star point' ( which is the generally 99.9% accepted term for it in the electronics industry )
). Otherwise, electrical currents can flow between earths which can upset some equipments. Its more for shielding and anti-static, but the principle still applies for cars. Manufacturers dont do it because its cheaper to earth everything locally.Although the car chassis is metal and can be thought of as 'one point', in reality it has different resistance values all over it due to metal thickness / impurities etc Thats why people fit aftermarket 'circle earth kits' in their engine bay, to ensure that all the equipments are grounded at the same potential.
No doubt I'll be corrected on it, but thats the simple version
Oh, and a star earthing system is connected to a.... wait for it...... 'star point' ( which is the generally 99.9% accepted term for it in the electronics industry )
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Odin
Guest
Now keep it on track people, Its a very good thread that I don't want it ruined by rubbish.....
Rob
Rob
AJ4, does that mean that you're an advocate of 'earth bondiing' kits ?
Although I have an admittedly very limited understanding of electricity, resistance etc.... I fail to see how a good 'earth bonding' kit, fitted correctly, can't give tangible improvements to the way a cars electrical system performs. Or, am I missing something ?
I must say though, I don't agree with paying a fortune for them, when you can make a good one yourself for very little money !
Although I have an admittedly very limited understanding of electricity, resistance etc.... I fail to see how a good 'earth bonding' kit, fitted correctly, can't give tangible improvements to the way a cars electrical system performs. Or, am I missing something ?
I must say though, I don't agree with paying a fortune for them, when you can make a good one yourself for very little money !
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AJ4
Guest
If you have bad earths anywhere, then its possible for signals to interfere with each other. You wouldn't necessarily want the signal from you knock sensor being mixed with your AFM signal for example
I'll try and extreme example. Suppose one of your equipments is grounded onto the inner wing or the bulkhead of the car. It should be a good electrical connection back to the battery but sometimes its not... Suppose the bulkhead is a painted one piece job that is only rivetted to the main chassis. In which case the resistance of the rivets holding it on is the only path back to earth. Depending on the material of the rivets and how much contact area they have with the main chassis, that resistance could be a random value instead of zero. Not very likely admittedly, but it happens...
Bringing all the earths or grounds together is pretty common in the electronics industry. Unfortunately on cars everyone assumes that every point on the chassis is a good earth because its all metal, but add a few bits of rust, crappy cables and random signal paths and its not actually that great.
Put simply, if two equipments have a common good earth, they cant interfere with each other. If they both have crappy earths, they can.
I'll try and extreme example. Suppose one of your equipments is grounded onto the inner wing or the bulkhead of the car. It should be a good electrical connection back to the battery but sometimes its not... Suppose the bulkhead is a painted one piece job that is only rivetted to the main chassis. In which case the resistance of the rivets holding it on is the only path back to earth. Depending on the material of the rivets and how much contact area they have with the main chassis, that resistance could be a random value instead of zero. Not very likely admittedly, but it happens...
Bringing all the earths or grounds together is pretty common in the electronics industry. Unfortunately on cars everyone assumes that every point on the chassis is a good earth because its all metal, but add a few bits of rust, crappy cables and random signal paths and its not actually that great.
Put simply, if two equipments have a common good earth, they cant interfere with each other. If they both have crappy earths, they can.
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You should be a politician with answers like that, yes or no would have been fine !! :lol:
Seriously though, I see what you're saying and gather whether you favour them or not !
It seems to me that anyone who understands even the basic principles of resistance etc, etc will recommend a good earth bonding kit. Those who don't have a clue just think it's a marketing ploy. I can see their point when companies like HKS want to charge £100 + for some copper, plastic and gold coloured.... I mean plated metal though !
What's your opinon of these boxes of tricks that are supposed to stabilise the voltage of the cars electrical system ?
I understand the principle of them (stored energy for peak demands etc...) but, would you truely see a benefit on say the GTiR ?
Sorry to hijack the thread by the way !
Seriously though, I see what you're saying and gather whether you favour them or not !
It seems to me that anyone who understands even the basic principles of resistance etc, etc will recommend a good earth bonding kit. Those who don't have a clue just think it's a marketing ploy. I can see their point when companies like HKS want to charge £100 + for some copper, plastic and gold coloured.... I mean plated metal though !
What's your opinon of these boxes of tricks that are supposed to stabilise the voltage of the cars electrical system ?
I understand the principle of them (stored energy for peak demands etc...) but, would you truely see a benefit on say the GTiR ?
Sorry to hijack the thread by the way !
F
Fusion Ed
Guest
Just to add this is why the ECU provides its own earth to all the vital sensors in a car: maf, water, tps, cas etc.. Which is why these earthing kits for ecu probs will be little more than a placebo effect in most cases. However AJ4 is right about the chassis not being so great etc, causing ground loops (often reason for interfearence in ICE installs)
Earthing kits imo are mostly for show. If you sort your main earth straps you wont have a problem -batt to chassis to gearbox is one of the main ones, and the others around the alternator.
I have had to fix some bizzare and seemingly impossible earth faults in the past...
Earthing kits imo are mostly for show. If you sort your main earth straps you wont have a problem -batt to chassis to gearbox is one of the main ones, and the others around the alternator.
I have had to fix some bizzare and seemingly impossible earth faults in the past...
building on what the last 4 posts are saying and adding my own experience.
Earthing problems can cause very bizzare effects or can just cause subtly different readings.
IMO, earthing kits are more for show and don't solve the real problem
IMO, earthing kits are oversized for the needs, picking on Stu's point. If they weren't then Nissan would be building cars with big fat earths everywhere.
Re-earthing any 15 year old car is worthwhile and will improve things.
I just used 4mm2 cable which including the connectors and crimps cost less than £20. I could probably do about 20 cars with that.
0. (My engine to chassis was already new from when the battery was moved to the boot)
1. Existing connectors I either removed and re-crimped or just cleaned if the condition was okay. I then dremeled the body work the earth was strapped to to make shiney metal removing the need for the screw to conduct from the connector to the chassis.
2. I connected the 2 main engine bay earth points together with 4mm cable at the front of the car as they were slightly different and sent another lead to the ECU earth so all the earth points were bonded.
3. In the same way as people re-earth the MAF, I stripped and soldered new earths onto the CAS, TPS and ignition amp, returning them back to a common point.
I did 1 and 2 at the same time and the car was noticably smoother at idle and operation. I did 3. because I was trying to solve a problem with the PFC and it seemed like a bizzare earth so my solution was earth everything.... twice
I think someone has asked for a kit in another thread but TBH, I think the most benefit it gained by cleaning the connectors and connector points which a "kit" can't solve.
However, I will be happy sell anyone some lengths of cables with some connectors on the ends to liberally place around your engine bay for the bargain price of £30.
Seriously though, the cost was not in the wires but in the time it took me to go through the car, check all the earths with a multimeter, clean them up and when I added new earths, to do it in such a way that the cable was neatly routed and can't be seen.
Earthing problems can cause very bizzare effects or can just cause subtly different readings.
IMO, earthing kits are more for show and don't solve the real problem
IMO, earthing kits are oversized for the needs, picking on Stu's point. If they weren't then Nissan would be building cars with big fat earths everywhere.
Re-earthing any 15 year old car is worthwhile and will improve things.
I just used 4mm2 cable which including the connectors and crimps cost less than £20. I could probably do about 20 cars with that.
0. (My engine to chassis was already new from when the battery was moved to the boot)
1. Existing connectors I either removed and re-crimped or just cleaned if the condition was okay. I then dremeled the body work the earth was strapped to to make shiney metal removing the need for the screw to conduct from the connector to the chassis.
2. I connected the 2 main engine bay earth points together with 4mm cable at the front of the car as they were slightly different and sent another lead to the ECU earth so all the earth points were bonded.
3. In the same way as people re-earth the MAF, I stripped and soldered new earths onto the CAS, TPS and ignition amp, returning them back to a common point.
I did 1 and 2 at the same time and the car was noticably smoother at idle and operation. I did 3. because I was trying to solve a problem with the PFC and it seemed like a bizzare earth so my solution was earth everything.... twice
I think someone has asked for a kit in another thread but TBH, I think the most benefit it gained by cleaning the connectors and connector points which a "kit" can't solve.
However, I will be happy sell anyone some lengths of cables with some connectors on the ends to liberally place around your engine bay for the bargain price of £30
.Seriously though, the cost was not in the wires but in the time it took me to go through the car, check all the earths with a multimeter, clean them up and when I added new earths, to do it in such a way that the cable was neatly routed and can't be seen.