Coil recommendation on 540i...

[MTechnik540i]

Looking to replace the coils on the M-Sport, and was wondering if it'd be worth trying an aftermarket alternative in the search for a few more HP? I've heard some positive and negative opinions on the Plasma coils, so just seeking some knowledgeable $0.02. Also, if one was to upgrade to a different set of coils, would this be best matched with updated ECU tuning?

TIA,

[MTechnik540i]

Looking to replace the coils on the M-Sport, and was wondering if it'd be worth trying an aftermarket alternative in the search for a few more HP? I've heard some positive and negative opinions on the Plasma coils, so just seeking some knowledgeable $0.02. Also, if one was to upgrade to a different set of coils, would this be best matched with updated ECU tuning?

TIA,

Top.

[ThoreauHD]

If you are talking about the bavauto coils without resisters, you will need to get the wiring harness as well. All the rest like bremi/bosch/etc. are OE and you can keep the harness. The ECU is a separate issue. Having more spark/less resistance doesn't depend on the ECU.

If you haven't already though, you should consider getting the conforti or EAT ecu chip. There is nothing to tune. It's either there or it ain't. Once you change your octane to 93, install the ecu chip, and replace the aging coils and harness, it will run much better. I would also recommend denso iridium for the spark plugs. And just in case it's been ignored, make sure you are using synthetic oil in the transmission/differential and engine. I opt for redline and amsoil, respectively. Your mpg will improve as will your responsiveness/initial torque. Good luck.

[MTechnik540i]

If you are talking about the bavauto coils without resisters, you will need to get the wiring harness as well. All the rest like bremi/bosch/etc. are OE and you can keep the harness. The ECU is a separate issue. Having more spark/less resistance doesn't depend on the ECU.

If you haven't already though, you should consider getting the conforti or EAT ecu chip. There is nothing to tune. It's either there or it ain't. Once you change your octane to 93, install the ecu chip, and replace the aging coils and harness, it will run much better. I would also recommend denso iridium for the spark plugs. And just in case it's been ignored, make sure you are using synthetic oil in the transmission/differential and engine. I opt for redline and amsoil, respectively. Your mpg will improve as will your responsiveness/initial torque. Good luck.

I appreciate the comments. I'm leaning towards the Bremi/Bosch replacements as I've had some not so great experiences with BavAuto's products, as of late.

The 540i uses OEM plugs, has an EAT chip, Amsoil synthetics throughout, and has used BP/Amoco 93 since original owner.

[Tiger]

With individual coils per plug... there is not much more you can go to improve it.... With one coil for multiple plugs, there are room for major improvement. Look to see what you have now... if you are going to replace them all, then stick to one brand. They all must be one brand.

If you are going to replace one or two... see what you have before you order new one.

Changing the coil plug boot helps alot expecially with those soaked in oil... prevents electrical discharge loss.

[attack eagle]

I Once you change your octane to 93, install the ecu chip, and replace the aging coils and harness, it will run much better.

I wish there was 93 octane available... 91 is the best you can do west of Dallas