Bosch W3DP0 Spark Plugs...K & N Filter?

[Tilikum Turbo]

As these really the only plugs one should run in a turbo? I was told to stay away from NGK Iridiums, etc. Looking to improve my MPG(if possible).

K & N filter came with my 86 930 motor...is this just a gimmick filter, and should I go to a stock unit?

Thanks!

[A930Rocket]

We can better answer the questions with a picture of the entire car...

[wwest]

Unless you are on the track running WOT a high percentage of the time then K&N is SNAKE OIL. On the street/highway the throttle plate is always the primary restriction to intake airflow.

Improve the MPG...??

Wire the turbo wastegate(s) wide open and mill the heads to get the CR of a N/A engine.

[mark houghton]

Originally Posted by wwest

Improve the MPG...??

Wire the turbo wastegate(s) wide open and mill the heads to get the CR of a N/A engine.

Hey now, there's a concept I never considered....a simple conversion back to a N/A engine! Who needs a stinkin' turbo gas-guzzler anyway.

I will add this: Properly tuned with some supportive add-on gizzmos, a person can get 20mpg just tooling down the road. If mileage under those mild conditions is crap, look somewhere else (such as state of tune, AFR's and/or driving habits).

As to plugs, NGK are a fine choice but the Iridium version I think isn't so friendly with forced induction (I don't know that for a fact, just thought I had read that somewhere). I use NGK racing plugs R5671A-8 gapped to .040 with MSD ignition. Work fine for me. Plus, I have my ignition timing way advanced over stock and run AFR's at about 14.2 steady state down the road. Both help me obtain decent mpg.

[JFairman]

Originally Posted by mark houghton

Hey now, there's a concept I never considered....a simple conversion back to a N/A engine! Who needs a stinkin' turbo gas-guzzler anyway.

I will add this: Properly tuned with some supportive add-on gizzmos, a person can get 20mpg just tooling down the road. If mileage under those mild conditions is crap, look somewhere else (such as state of tune, AFR's and/or driving habits).

As to plugs, NGK are a fine choice but the Iridium version I think isn't so friendly with forced induction (I don't know that for a fact, just thought I had read that somewhere). I use NGK racing plugs R5671A-8 gapped to .040 with MSD ignition. Work fine for me. Plus, I have my ignition timing way advanced over stock and run AFR's at about 14.2 steady state down the road. Both help me obtain decent mpg.

If you'd like to get a couple more mpg on the highway while keeping the idle around 13.5:1-14:1 for a nice smooth idle and just as much or maybe more fuel up top under boost depending on your fuel head you can take your B.L. adj WUR and turn the steady cruise 4mm allen head in the middle of the bottom and turn it clockwise around 1/2 turn total. I would turn it clockwise 1/4 turn at a time and road test it.

Then to keep the same or have more fuel up top use the special tool that comes with the B.L. adj. WUR to draw the boost control pressure adjustment outwards about 1/8 of a turn at a time.
That lowers boost control pressure so it delivers more fuel and makes it a little easier for the turbo to suck in air at the same time because the air flow meter plate will drop a little farther as the fuel head control plunger raises higher metering more fuel at the same time..

Mark, some of the things you've mentioned in the past about how your car runs
(lack of excessive popping on decel and your AFR's under boost) makes me think your car may already have a modfied fuel head in it.
There are cosmetic ways to tell if CIS flowtech has modified it but other people modify them to some extent too.

[lucittm]

Tilikum,
I think the WR3DP0 plugs are too cold. I think my owners manual recommends WR6DP0 and these work well for me. Expensive, yes, but they last longer than other plugs.

Mark