Bosch Platinum +4 Plugs

bklyn · 01-17-2009, 12:08 PM

Gents can you advise if the Bosch Platinum +4 spark plug I have installed in my 87 Targa 3.2 are a good choice. I have a SW chip, KN air filter, cat bypass and a Bursch performance muffler. The vehicle runs great but I hear so much about NGK and other plugs. Can anyone advise if I should change? And if so to what and what brand and number?

Hendog · Hendog's Garage

NGKBPR6ES There's been some discussion related to platinum plugs if I rememeber correctly and it has mostly, if not all, been advised against using them.

DRACO A5OG · DRACO A5OG's Garage

DO NOT USE PLATINUM. I had the +4's , they do not start the car immediately and at times causes miss-fires.

If you are going to go exotic, try the NGK Iridiums, I just installed them and they are amazing.

But stick to OLD SCHOOL NGK's "ES" if you are anywhere a bit skeptical.

.02

efhughes3 · efhughes3's Garage

I've run Bosch +4's for about 3 years or so with no problems. My car starts immediately and doesn't misfire...

porsche8777 · 01-18-2009, 03:46 AM

I put NGK iridium's in my M# and had two of them fail. The iridium tip came off. Fortunately the tips seem to have blown out the exhaust without damaging the engine. I will give them credit though, NGK was going to repair any engine damage done by their plugs failing.

jhoagg · 01-18-2009, 07:11 AM

Interesting. I installed NGK Iridium in an 85 3.2 and have had the same experience as Draco. They have been great. But now I'm going to worry a bit about the tips coming off!!

Joe Bob · Joe Bob's Garage

Platinum plugs suck......

DRACO A5OG · DRACO A5OG's Garage

Quote:

Originally Posted by efhughes3

I've run Bosch +4's for about 3 years or so with no problems. My car starts immediately and doesn't misfire...

Hey Ed,

I was too a big advocate for the +4 but While I was in there changing out my injectors, I wanted to compare and oh boy what a difference.

PM me and I will tell yeah what I paid for the IR's

wswilburn · 01-18-2009, 09:30 AM

I have been happy with the Denso iridiums (IW20). My theory is I want the plugs to fire at the lowest possible voltage to reduce stress on the HV components of the ignition system. Therefore I want the sharpest possible plug tip.

bklyn · 01-18-2009, 11:57 AM

Thanks Gents, plan to go with the NGK soon.

bklyn · 01-18-2009, 12:03 PM

If I go with the NGKBPR6ES, what should the gap be set at?

burgermeister · burgermeister's Garage

I had +4's installed from PO. I replaced them with the old fashioned copper (no idea how long the platinums were installed - but I am a firm believer in at least checking the plugs at every valve adjustment, if only to prevent seizures and have a look-see). No difference whatsoever in how the car ran.

DRACO A5OG · DRACO A5OG's Garage

Quote:

Originally Posted by bklyn

If I go with the NGKBPR6ES, what should the gap be set at?

Per Bentley 0.028-0.032 inches, Iridiums are "pre-Gapped"