I've had this happen so me once before. Happened shortly after my Alta intake and Alta exhaust install. Hasn't happened since and hasn't happened since install of JB+ 250 miles ago. Probably just a slight hiccup in the cold start with the open intake.

 

I get a little weird idle fluctuation going on but in another 10k miles I'm swapping out my spark plugs to the NGK's. We'll see if it still does it at start up.

 

I've had maybe 2-3 people mention a slightly rougher cold high idle with the JB+ installed. Like a fluctuation of 75rpm where it used to fluctuate at 50rpm. For like the first 20 seconds on startup. The high cold idle is obviously very sensitive to MAF signals so its possible some smoothing algorithm, etc, in the JB+ is having a negative effect there. It's not something I've been able to look in to yet but if anyone can recreate the issue on demand wants to trade cars for a few days I'd be happy to look at it again.

 

I was experiencing the idle fluctuations with my Defenders of Speed CAI installed so I've gone back to stock intake in the meantime and still notice the fluctuations. I'm pretty sure i have them on startup at all times. I'll double check tomorrow.
By the way, this is Nate with the 2011 black MCS here in Simi. I can arrange to swap cars anytime next week. Let me know via a PM or email if you'd like me to.

 

hey terry,
i mentioned this occasional stutter in my idle on cold(er) starts a couple of months ago. it still happens occasionally. i originally thought it may have been the hpfp, but that has since been replaced. i haven't really read how much of a dip there is since it usually happens during the needle sweep. next time i start my car after a cool night, i'll pull the CAN tool off and see if i can see the drop in rpm. i wonder if it ever happened when you had my car for those few days, and maybe just didn't even notice it. i'll try to keep an eye out for this.

 

On the cold idle I'm not sure its anything we need to bother with. But, when time permits I'll look in to it.

Also did an install on a local GP today which has the JCW setup. During our impromptu testing it was putting out around 16psi stock and around 19psi with the JB+ at 33%. The owner is planning on using 30% E85 so we'll see how it goes.

 

Installed mine today. Here are some initial comments, several runs this morning while heading to work, sport button engaged, using Torque peak boost 13.2.

Installed JB+ just before my drive home. Got on the highway and was stuck in traffic. Discouraged by the traffic I forgot about it. About 10 minutes later I noticed the pop and burble increased or was louder? Normally can't hear it over the radio, could now. It was obvious. Eventually traffic eased for a few minutes and I got on it to jump past a few people and merge. I looked down and Torque peaked my boost at 16.1. By the time I made it off the highway the car felt really responsive. I decided to get on it and the front end started hopping, I couldn't get traction. Average boost driving aggressively (not wot) was 15.4.

So where did the ecu learning period of 50 to 100 miles come from. I drove a total of 12. Felt immediate difference at like mile 6. I'm about to take it out for an extended drive. Am I about to feel even more?

Initial impressions? This is great.

 

I turned my JB+ to 7. I'm using 93 octane fuel. Does anyone have experience doing this? I have an automatic. I was hoping that this tuner would make me like having an auto more but it just makes me long for a manual so much. I am addicted to the power. I've become a junkie !

 

I have an auto and love it, I almost exclusively use the paddle shifters. Took about a month to get use to using them but now I can't imagine not using them. I only wish the shift demand responded faster.

 

Wow....if my math is right thats about 250hp. That GP2 guys must be happy.

 

What gear and rpm were you at when you hit 16.1? I was playing around today and only got a peak boost of 14.7 with the scan gauge2.

 

Seems like more and more people are getting more and more daring to adjust the JB. I have an auto, run 93 all the time, have a larger intercooler, colder plugs and a bunch of other mods but still left it on the stock setting as advised by Terry.

 

I'll let others blaze new trails, then follow when the dust settles.

 

+1!!

 

I'm impressed Walter, you wanted to turn it up the whole way before you even got it. I haven't touched mine, but since I am going to be up n the mountains running 91 Octane I might want to push it now and get it out of my system.

 

Have an automatic. Have not messed with the JB+. Just installed and have done a total of 56 miles. I felt a difference immediately. Measured with Torque which seems to be dead on with my ProSport gauge. Averaging 16.1-16.4 It's nuts...

 

After turning the JB+ up to 7 all I can say is wow! I think I read that Terry turned his up to 7 when he was doing his 1/4 mile runs with no problems. I am little hesitant to run it as hard as it will go. Just stomping the gas it really accelerates now. I am sure I wont go any higher than 7. it is starting to have torque steer now. I might back it off to 6 just to be safe.

 

What octane are you running?

He was on 94 when he did that.
Keep tabs on your timing to make sure it's not pulling.

 

can someone give a brief explination on how to interpret timing on speedo. I dont know how that works. Yet.

 

Little tough to give a brief explanation, but here it goes.

Ignition is read in degrees. So on the speedo, 10 is 1 degree of timing, 70 is 7 degrees of timing, 160 is 16 degrees of timing.
Degrees is dealing with the angle of the crankshaft. Save that explanation for another day lol.

As your engine speed increases so should the spark advance. You want the spark to ignite BTDC( before top dead center).
*When the piston is at it's highest point in the compression stroke.

You'd want this because as the piston moves down it's power stroke the combustion that happen a split second earlier will push that piston down, making it efficient since it's maximizing the pressure.

If it the ignition happen at TDC or after, then you're losing efficiency because the engine isn't maximizing on the peak pressure that occurs. You want the expanding gases to work for you. If the ignition is off by a bit, you lose power and mpgs.


I need my coffee lol

 

So for example: if I'm accelerating. as the revs go up. the faster the stroke. So more degrees of advance would be better ?

 

Yes, but if the knock sensors start to detect knock then the computer will retard or "pull" timing to prevent damage but it can only do so much.

Also remember that it is possible to be "bad" gas every now and then.

 

Theoretically yes. But there are many more variables that are in play.

Example, If you're cruising as partial throttle you're timing advance can be 36degree, move you're foot a bit then it's 18 degrees. It's all over the place, which is normal.

The reason Terry cautions folks about changing the JB is because some people aren't running sufficient octane. The higher the octane, the more compression it can withstand before it randomly ignites( not due to ignition).

If you up the boost, you're forcing more air into the engine/cylinders, if the octane isn't high enough you get pre-ignition, aka knock. Then timing gets pulled. These cars have pretty good knock sensors.

But if the knock is bad enough.......well we know it's not Terry's fault for what happens to the engine!

 

+1 on the waiting to turn it up .also have auto and was hitting 15.5 lastnight with 50* air temp outside . all i can say is im loving it.bout to order up a cnt exhaus tthe stock is a little to high pitched .maybe later on a downpipe when i get use to the power from the jb+

 

Thanks for the explination! I'm not anxious to dial it up. Just want to learn how to monitor the engine.
Also. I once put the Speedo to monitor IAT. Stayed in 0 every time. Any thoughts?