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Intmdtr
09-02-2014, 09:29 AM
So had some issues this weekend at the track...car ran fine, didn't break, but was just not pulling the numbers it should be. Car is a stock long block NPI, CC268h cams, PI intake and all the other bolt ons....

The car normally runs a 13.1-13.3 @101mph on nitrous and pulls a 13.8 N/A. Now I know the weather this weekend was not ideal, but the car started off 1 full second slower in both N/A and Nos trim and kept getting slower all day and by the end of the night would only pull a 15.1.........

So this morning I pulled a few plugs (NGK TR55) and low and behold the plugs look fine, but some are showing to be gapped in excess of .060. Is this normal to happen on cars running nitrous? Plugs were gapped at .045 when installed a few years ago......remembering the car sat for the last 2 years. #5 plug was showing oil on the ceramics, not sure how that happened, but no oil anywhere else....

Some good tips have come in so far and I plan to go through the car and just do the easy stuff....clean the MAF, check plug wires (going to take them to be tested.....stupid things are expensive for these motors. And just generally sort this thing out....

So in anyone's experience will nitrous erode the electrode or force the gap to be widened on these plugs?

ZR
09-02-2014, 01:17 PM
Normally they only get wider via electrode wear and yes NOS tends to eat em alive. If it was mine, would start off with gap at .035 for NOS application. If wires are a few years old, would ditch them as well. Decent set of jobber replacements or OEM Ford are all thats needed. Add in a fresh fuel filter + clean the MAF then test results.

Ray721
09-02-2014, 01:57 PM
Hope you get it all sorted out. I could see the frustration in you Saturday. You still ran though. And that's Awesome!!! Can't wait for our proper race

Intmdtr
09-02-2014, 02:41 PM
Thanks ray, can't see it being anything major, just a few minor things adding up.

Intmdtr
09-02-2014, 03:27 PM
New plugs are in, ngk tr6 gapped at .035 as per the good Dr's advice. New fuel filter I will do tomorrow as well as the MAF.

I am thinking now the backfire could be due to a lack of fuel as it was in between shifts when it happened so the fuel filter should help. Also thinking about picking up an adjustable fuel pressure regulator so I can increase the fuel pressure. As of right now it hovers around 30psi at idle and with a blip of the throttle it climbs to 40psi....does this seem normal? The nitrous calls for 40psi at the rail and i draw the fuel from the left bank.