View Full Version : All plug readers in here

04-27-2012, 11:45 AM
Ok I just want to clear this up for all the newbs to nitrous and reading plugs. I know this post has been made before but I would like to know more about the process. I would like to throw some scenario's out there for the average person. Okay so let's use my car for example. I am going to go out to a pretty open highway tomorrow. I have a bunch of br7efs 3346. So when I arrive at my destination I was going to swap out new plugs. My car is a th350, but would I be able to just spray it in second gear and shut it down up top?? Or do I have to really shift 3rd and ride it out a bit? What about for a 6 speed what's the lowest gear one can spray it and shut it down? Basically the way I see it is as long as you are in the upper rpms when you shut it down. Please correct me if I'm wrong. What happens if I spin will I have to start over? Can I short shift the next gear to stop it from spinning? It's a pain in the arss sometimes to get to the track that's why I'm asking what you plug readers do on the street. Also what do you m6 guys do on the street for all the m6 viewers out there. I don't really think I will be able to plug read on the street if it requires basically making a full pass. I have to drive about 35 miles just to make a pass in a area where it's safe and I can pull over for about an hour to let it cool down and change the plugs. I'm in queens ny so there are really no open roads. I have to roll out to Wrong Island lol I don't know how much the police are gonna like seeing 130+ on their radar, because with my luck I'll get caught.
Let go to the track scenario now. In all the threads I have read it says that there should be very little to no idle time on the plugs. I understand that, but how much is little to no idling time? We all know that when waiting for a test and tune line to move you can easily have the car running 5-10 minutes. I'm assuming this is obviously too long. A track rental can be pricey for some. So now should we change the plugs and push the car to the line, do the burnout and on with the show? Once the pass is over we shut our car off while still applying the throttle? Let's say you come off the track but really end up stoping in a unsafe place blocking traffic, will starting the car to move to a safe location ruin everything even if your car is only on for a minute or so? I hope that all of my questions are clearly stated looking forward to everyone's response.

04-27-2012, 10:30 PM
nice post. im going to stay here till the spray gurus will show up :corn:

04-28-2012, 02:07 AM
Don't all post at once lol

04-28-2012, 03:55 AM
Ok I'll try and be as short as possible with most of your questions.

Highway is fine. Try to start the run in 1st as close as you can to doing it at the track. If it spins short shifting to the next gear is fine. Only problem I see is not trying to run it out in 3rd is not putting enough load on the motor in 1st and 2nd to get a true plug reading. Same thing with a stick got to get load on the motor to replicate what it does at the track.

If you can't push it to the line and are forced to wait in line while waiting for the water box, you'll have to cut the car off and let some of the traffic go before moving and put your plugs in while in the lanes. Shut the car off while waiting and when the car is on rev the motor up while you're waiting with it on to try and keep the plug as clean as possible.

When you cross the stripe push the clutch in or leave it in 3rd gear of your TH350, don't put it in neutral just let off the gas after the stripe and cut it off as soon as you can and coast to the return road by using the brakes as sparingly as possible and hopefully your track or where you are going to test this has a place you can coast like this too and pull off at.

04-28-2012, 08:07 PM
Thanks I also forgot to add in there, when reading plugs and making a pass at the track do you do your burnout too? Or do you just roll too the line and and come out easy then spray it mid track or around the 330'?

04-28-2012, 09:14 PM
You need to run it out as long as you plan to during a race, same scenario as 1/8th mile racing vs 1/4. Your tuneup can't be the same or it can burndown because it puts more heat in the cylinder.

Yes, do a burnout, limit your idle time in the lanes though.

04-28-2012, 09:31 PM
so is this for using nitrous all the time? or just to get it tuned right so the AFR is where it should be for your car and spray application. ill be spraying this year and am wondering if its this much checking and testing all the time. ill just be doing mainly late night open highway pulls. im having a shop install my nitrous and tune it. oh its gonna be a wet nytrex triple threat kit with the safety equipment and supporting mods.

04-28-2012, 09:39 PM
Tow it to the lanes and back to the pits.

Im a firm believer that the fuel ring burned into the porcelin ONLY happens when you are at WOT and the engine has real heat in the cylinder. Making a second pass on the same plugs only helps with the reading from my experience. When cutting the plug apart, my fuel ring on the porcelin was not a thin black ring. It was a 3/16" tall grey ring at the base of the porcelin. I felt this was safe, always ran good, sounded and felt smooth and I would gain 11-13mph on a 200 shot. 127-128mph NA and 140+mph on the bottle. Single .073" jet.

I would shut the engine off after I was on the brakes and car was decelerating safely. Kept it in high gear


04-29-2012, 03:36 PM
So at what point do I cut my plug up? When you guys say you may need to make 2-3 passes to get a reading are you cleaning the plugs then re using them? Or just repeat the process with no cleaning? I'm not sure if I understand how I will know if I have a visible fuel ring if the spark plug threads are covering the area where it is.

04-29-2012, 03:56 PM
So at what point do I cut my plug up? When you guys say you may need to make 2-3 passes to get a reading are you cleaning the plugs then re using them? Or just repeat the process with no cleaning? I'm not sure if I understand how I will know if I have a visible fuel ring if the spark plug threads are covering the area where it is.

use a new plug on each run. I only replace one plug.

1. put new plug in before run. minimize time on plug.

2. after crossing 1/4 marker, kill engine, glide to a stop on return road.
pull the plug and replace with an old one.

3. return to the staging area and analyze.

I like to use an d/c -> a/c power inverter and a pliars/dremel w/cutting wheel to cut away threads. quick and clean.