Noise suppression, interference on radio frequencies

[zed4]

Hello,

My neighbour happened to mention to me today that my car causes interference to their wireless phones and also her digital hearing aid. She said it was my car's noise suppression not working correctly.

I also seem to remember the previous owner of my car saying the new HT leads he fitted caused the re volunteer needle to bounce, due to noise suppression.

What's likely to be causing this interference? The HT leads?

Thanks,

Dan

[Chuffmeister]

zed4 said:

Hello,

My neighbour happened to mention to me today that my car causes interference to their wireless phones and also her digital hearing aid. She said it was my car's noise suppression not working correctly.

I also seem to remember the previous owner of my car saying the new HT leads he fitted caused the re volunteer needle to bounce, due to noise suppression.

What's likely to be causing this interference? The HT leads?

Thanks,

Dan

My Magnecores did this with my tacho. I adjusted their routing slightly and the coil forwards. Does it less now. I'm not sure you can do a lot with radiated noise/ interference for electric items not connected to the car. This may help? http://www.dieselduck.ca/machine/03%20electricity/...

As for your neighbour, you could ask her to switch her hearing said to T for TVR.

[QBee]

She could have a point.
My car doesn't have this effect, and I would notice if it did because I have to use the phone to get out of my driveway..

There will be an expert along sometime today who will tell us what the issue is. No point changing everything until you know what to change.

[jamienshelly]

Hi Dan, You must have some interference if its noticed next door.
On a lighter note, Mega kudos to you for owning a TVR whos noise even annoys deaf people!,

[Pupp]

Stick some resistor type plugs in it, you won't find a resistor version of the B7ECS that's the usual but for normal use a BR7ES will be fine, or there are iridium alternatives if you want to throw money away.

There's bugger all shielding on a plastic car

[blitzracing]

In terms of suppression, the Red Magnecores will be the worst as they are designed for race only use, then the blue , followed by the black that are designed for classic street cars. Ive got a set of resistive plugs with about 1k on them laying around if you want to use them FOC.

[zed4]

My plugs are quite new, Southways fitted them, so I'd rather not change them again. I will have to check which plugs they fitted. I suppose plugs are cheap though, so not the end of the world to replace them again.

My HT leads are starting to break down as the last owner had cable tied them together in a bunch, so I am thinking of replacing them anyway. They were magnacores. I see from some research some HT leads are better than others at noise suppression, and the magnacores are particularly good at making the tacho do funny things!

Are there any HT leads that are particularly recommended?

[swallet]

I had terrible radio interference on my chim when I got her. Tacho needle all over the place, no reception on the radio. It had some sporty 8mm blue race leads.
Swapped these out for the standard black variety and made it bettercured the problem. Other than looking nice they will have no beneficial effect on the running of the car in any case.

I have resistive plugs in as well but TBH only because I have toyed with the idea of an aftermarket ECU at some stage, not sure they are really necessary if you already have one point of resistance in the ignition to suppress noise.

[swallet]

Regarding HT leads - save yourself some money and just get the standard (Bosch) units. Under £30 and all you need. I did this on the advice of some guys on here running very highly tuned engines.

I fail to see how a set of £120 HT leads will bring about any improvement in the performance or running of our, lets face it pretty basic, RV8. Indeed I cannot recall seeing any empiric independent data to support their expense aside from the pretty colours.

[QBee]

Not disputing any of the comments above - my TVR guy selected Lumenition silicone clear blue leads for my car and it certainly runs well on them. From what you say your HT leads could well be the culprit and would be the first thing to change. Car might even run better.

On Pupp's comment re Iridium plugs - he's entitled to his view, and so am I. FWIW, I fitted Iridium 6s (so effectively changed two things at once, the type of plug and the temperature it runs at) on Chimpo's advice and have to say i noticed immediately that the car ran better and revved more willingly. It could of course have been the "new plug" effect, but my original 7s were fairly new and were nice and clean when extracted from the cylinder heads.

[SILICONEKID346HP]

Do shrouds do the job ? unless you don`t have resistive one`s .

There is another Gizmo bolted to the live side of the fuel pump ,It`s like a metal block bolted up against the chassis ,I think that may have something to do with it .

Edited by SILICONEKID346HP on Sunday 2nd March 19:24

[blitzracing]

There is a pasts post where a set of Iridium plugs was put up against a set of new standard plugs on a rolling road after much discussion on the subject, and the power output was identical, so whatever the perceived improvement, you cant measure it in BHP output. However, expensive maybe, but I think the increased service life makes up for it anyway. Im with Swallet on the HT leads.

[QBee]

blitzracing said:

There is a past post where a set of Iridium plugs was put up against a set of new standard plugs on a rolling road after much discussion on the subject, and the power output was identical, so whatever the perceived improvement, you cant measure it in BHP output. However, expensive maybe, but I think the increased service life makes up for it anyway. Im with Swallet on the HT leads.

The changes I make to my car are done to improve the driving experience, not the bhp.
So despite many induction mods and so on, my 5 litre only makes 300.1 bhp (most others are between 325 and 360 bhp). But it drives so nicely, idles nicely, no shunting, pulls well, revs freely, it is a real pleasure to drive, and surprisingly quick on the track.
And the iridium plugs are a part of that package. The promised longer shelf life should mean that for the first, say, 12,000 miles they should stay in shape much better than standard plugs, thus hopefully reducing bad running, helping with fuel consumption, and giving me more pleasure. IIRC they were £54 a set, and I shall probably change them at the standard interval to retain the pleasure of driving with them in peak condition. That's my take on it, right or wrong.

ETA - Iridium 6 plugs £50 a set on Ebay, standard 7s £30. Choice is yours

Edited by QBee on Sunday 2nd March 19:26

[blitzracing]

Sorry I was just being pedantic- I like to see something you can measure, and one such claim of them was for improved idle- so it goes to follow that the ignition burn must be better to achieve this, but hey ho, its just a spark that lasts a few milliseconds so what can you do with it in plug terms? You can make the gap wider to expose the mixture to a larger ignition point that may make it ignite a bit better (in that I mean you get a good consistent single flame front) , but you should be able to measure this, as you are effectively making the engine more efficient, as you are not leaving bits of unburn fuel behind. To be fair however, a better test would be for pollutants (As in HC) between stock plugs and Iridium.

[SILICONEKID346HP]

QBee said:

The changes I make to my car are done to improve the driving experience, not the bhp.
So despite many induction mods and so on, my 5 litre only makes 300.1 bhp (most others are between 325 and 360 bhp). But it drives so nicely, idles nicely, no shunting, pulls well, revs freely, it is a real pleasure to drive, and surprisingly quick on the track.
And the iridium plugs are a part of that package. The promised longer shelf life should mean that for the first, say, 12,000 miles they should stay in shape much better than standard plugs, thus hopefully reducing bad running, helping with fuel consumption, and giving me more pleasure. IIRC they were £54 a set, and I shall probably change them at the standard interval to retain the pleasure of driving with them in peak condition. That's my take on it, right or wrong.

What plugs are you talking about ? . The plugs recommended for the Chimaera are a full race plug designed for flat out driving ( shrouded b7ecs)

They would be perfect for trackdays .

I use bog standard RV8 resistive plugs used on Range Rover MGRV8 etc which are a third of the price next to the recommended shrouded b7ecs,My car never misses a beat .(V8D use these plugs)I use NGK BPR6ES 0r BPR7ES ,the "R" resistive is because I have an after market ECU to help stop interference .

B7ECS are used because they cope better with combustion chamber vibration,so the standard Chimaera plug is a full race plug !The only downside is they fowl up quicker ,but for race application they are the plugs to have .

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Edited by SILICONEKID346HP on Sunday 2nd March 20:07

[Chuffmeister]

jamienshelly said:

Hi Dan, You must have some interference if its noticed next door.
On a lighter note, Mega kudos to you for owning a TVR whos noise even annoys deaf people!,

[QBee]

Chuffmeister said:

jamienshelly said:

Hi Dan, You must have some interference if its noticed next door.
On a lighter note, Mega kudos to you for owning a TVR whos noise even annoys deaf people!,

Yup. My wife was born profoundly deaf and my TVR annoys her.....too hot, too cold, too harsh, no aircon, no electric seats, no heated seats, hard ride, cannot recline the seat to go to sleep, no cupholders, too much spent on it.......
Yes, TVRs annoy deaf people

[Chuffmeister]

QBee said:

Yup. My wife was born profoundly deaf and my TVR annoys her.....too hot, too cold, too harsh, no aircon, no electric seats, no heated seats, hard ride, cannot recline the seat to go to sleep, no cupholders, too much spent on it.......
Yes, TVRs annoy deaf people

Point taken QBee, very non-PC, so apologies if I caused offence...

[jamienshelly]

Chuffmeister said:

QBee said:

Yup. My wife was born profoundly deaf and my TVR annoys her.....too hot, too cold, too harsh, no aircon, no electric seats, no heated seats, hard ride, cannot recline the seat to go to sleep, no cupholders, too much spent on it.......
Yes, TVRs annoy deaf people

Point taken QBee, very non-PC, so apologies if I caused offence...

as above Anthony, no offence intended, And if I did then I apologise whole heartedly.

[QBee]

Stop being so sensitive!!!!!
She isn't. She accepts being deaf.
No offence would have been caused, even if she ever went on Pistonheads - which she doesn't.
"OH, cars again"
She just dislikes the car, would far rather be in our A8

My three lines was my attempt at humour - clearly I shouldn't give up the day job.