Spark plug recommendation needed 3.0 euro with Webers
 

I have a 3.0 euro motor that was converted to webers. No changes to the engine except it is running straight headers with no muffler.

What plug should I run?

The plugs that are in it now are Bosch Platinum WR5DP.

Anyone run this combo.

Thanks
Greg

Hi Greg,

Without knowing how you are using the car, its tough to offer specific spark plug heat range recommendations. :) :)

WR5's are fine for all around use, but a bit too warm for racing.

FWIW, you are giving up a substantial amount of low & mid-range torque without a muffler that doesn't provide a payback at higher RPM power due to your mild cams. :) :)

I very well could be giving up the low and midrange as you mention.

Eventually I would like to make this into a DE car. The chassis is a 77 that I purchased without a motor and trans. Found a motor and trans on this site and now have it installed. Just now sorting things out and trying to dial in the webers.

The pipes I have on the car now come out in the center and I just did this as it was a quick way to do the exhaust.

Greg
http://forums.pelicanparts.com/uploa...1243137431.jpg
http://forums.pelicanparts.com/uploa...1243137616.jpg

I use bpr6r's in my 3.0 with webers

My god that thing must be loud, you don't run this on the street do you?

It is loud but not as bad as my 65 GT350R which has a 331ci, 450hp adn straight pipes. I drive both on the street and have never been pulled over.http://forums.pelicanparts.com/uploa...1243176866.jpg

When I lived in Mill Valley, a guy down the street has almost this same car, same color scheme, etc.. He races it all over the place and it is frickn loud when he fires it up.

Yes it is loud. Actually much louder in the car since I have the original R style interior, no headliner, metal door panels etc.... Much fun. I currently do DE with the Nordstern porsche club. Need to get a P car for DE that is why I got the 77 911S with the 3.0 euro.

Greg
http://forums.pelicanparts.com/uploa...1243179218.jpg

Steve,
What heat range would you recommend. I am a bit confused in looking at the spark plug cross referrence guides. The heat ranges vary with brand for the plugs recommended in the cross reference.

Bosch wr5dp heat range 6
Auto lite ap63 heat range 3
NGK 2023 (bpr7es) heat range 7

Greg

Greg,

I'm not a fan of Yankee plugs in these machines so I only use Bosch or NGK's,...:)

Bosch heat range values get hotter as the numbers go higher; NGK's go colder as the numbers get higher.

The WR5DP is a "5" heat range and roughly equivalent to an NGK 7,..its not a one-to-one precise conversion.

I would recommend using hotter plugs to initially get the carbs set up (idle & acceleration), then put in the plugs you will use for the final (main & A/C) jetting. Remember, your muffler setup has a big effect on jetting and I'd kindly suggest you review what you are currently using before undertaking the final jetting corrections.

Steve,
What heat range would you suggest for doing the tuning. Would you go hotter than the WR5DP?

Thanks
Greg