It's all messed up, JB4 map 2 stock gapped, with intakes only.

[washguy]

Scott ....Why do you add mods to your car without correcting the original problems? It is not rocket science to add a JB4 piggyback.....but then you add other items to your mess without solving the JB4 problems...You are clearly in over your head...... Wash

 

[Scott Curry]

Originally I did the intakes first, then I did the Jb4 but did not put spark plugs in or regap, my mistake there. Before doing anything I did the new spark plugs gapped properly, and all problems seemed resolved. Then I did the full exhaust, didn't have any problems other than the awful sound in drive mode (D). Have been running map 2 with no issues. Just over last week or so I have been noticing the slight misfires, they've gotten worse but then so far this afternoon nothing no misfires everything seems fine. So I'm definitely putting the stock downpipes back on. That will at least alleviate the awful tone and raspiness in drive I am hoping. Now the misfire issue is all separate and we will see how that goes.

 

[Scott Curry]

just to be certain we're all on the same page here about mid pipes are we talkin downpipes or mid pipes those are two separate things. Or with downpipes be replacing the primary Cats. we are talking about removing my OBX racing downpipes and putting the stock catted downpipes back on correct?

 

[Scott Curry]

I'm just finding it very hard to believe that replacing catted downpipes are only an increase of 1 horsepower... Got me thinking maybe we were talking about the wrong thing here within the exhaust.

 

[Toddasaurus]

I'm just finding it very hard to believe that replacing catted downpipes are only an increase of 1 horsepower... Got me thinking maybe we were talking about the wrong thing here within the exhaust.

I think most of us were in the same boat on that. At least one aftermarket company said that their midpipes (ie secondary Downpipes) added a significant gain in power without a tune, but some people tried it out, tested them with 0-60 times and on the Dyno, but didn't see the same gains that one company was advertising.

I agree with you, the logic is there, but real world testing proves otherwise. Evidently the secondary cats aren't as restrictive as we think they are, nor is the pipe shape (ovalled) causing any real restrictions - at least with the stock turbos. If I end up installing primary Downpipes like I want to, I will most likely just put in the stock midpipes/secondary DP's.

For the record, after I installed my ARK midpipes/secondary DP's I didn't really notice any power gains (already had JB4, intake, and cat-back exhaust).

 

[runner1]

Believe what you want, there are no gains to be had by changing the primaries or mid pipes on these cars at the current power levels.... just noise. You probably had some bad fuel on a too aggressive map. My suggestion would be remove the pipes

 

[Oryan]

Downpipes may give you some power on a stock car, but after a tune/piggyback they're not giving you much from what's been seen...which I find hard to believe and will likely try for myself early next year. That being said IMO they're not useless. Sound, sure, if you happen to like it and it varies a lot depending on what catback is behind it. I went with one of the more tame catbacks because I knew I'd be opening up the exhaust more. There's also an argument to be had about engine/turbo efficiency; anything that gets those exhaust gases out faster, lowers EGT's and increases turbine efficiency by increasing D/P across it even if it doesn't always translate into bigger numbers on a dyno or faster runs, should at least lead to more *consistent* runs and times and the motor/turbos being a little less stressed to do the same thing.

 

[Scott Curry]

Yeah I'm sure there's more to it like you said but at what cost. I'm telling you if this thing was a 6-speed manual it would sound amazing all the time because you're always going to rev the gears out more so than an automatic ever would. at any rate here is a few quick snapshots of my logs I'm having major misfire when I get on it usually doesn't matter what speed does it matter which map even map one will do it. This happens to be map 2.

 

[Tonkabob]

I'm just finding it very hard to believe that replacing catted downpipes are only an increase of 1 horsepower... Got me thinking maybe we were talking about the wrong thing here within the exhaust.

Secondaries 1 hp, primaries 3 hp.
Describe these mis fires more.
When i have my jb4 on i get a mis under light throttle. A hesitation / hickup / studder. Maybe 5 times so far in a month or two. Under wot i get throttle closure, Cels and over boost limp mode lol.

 

[Scott Curry]

I wonder if there's any possibility that the pedal tuner is losing voltage or something for a slight second as though I'm coming off the gas. I'm still think it's got to be ignition problems somewhere but this stupid piece of s*** computer won't pick up any codes even with a major misfire that I'm problem hearing/ feeling. This is running 91 octane with 5 gallons of e85 into a full tank. I find it hard to believe that it is fuel-related unless it has to be 93 octane with e85. I'm going to look for race gas tomorrow and see if I can get it to do it

 

[Terry@BMS]

Secondaries 1 hp, primaries 3 hp.
Describe these mis fires more.
When i have my jb4 on i get a mis under light throttle. A hesitation / hickup / studder. Maybe 5 times so far in a month or two. Under wot i get throttle closure, Cels and over boost limp mode lol.

You're also running a custom flash map. So whatever is going on with yours isn't likely to be related to whatever is going on with his, IMHO.

 

[Scott Curry]

Yep they're actually under light throttle/ boost. I'm probably only hitting about eight or nine pounds of boost when it does it and then it goes away and then I have full power full boost everything's fine it just doesn't make any f*cking sense. You think it would come on at higher RPMs with full boost nope it runs perfect at that point. I can almost get it to happen every time I say in 7th gear going about 45 to 50 miles an hour and then floor it.

 

[Terry@BMS]

I wonder if there's any possibility that the pedal tuner is losing voltage or something for a slight second as though I'm coming off the gas. I'm still think it's got to be ignition problems somewhere but this stupid piece of s*** computer won't pick up any codes even with a major misfire that I'm problem hearing/ feeling. This is running 91 octane with 5 gallons of e85 into a full tank. I find it hard to believe that it is fuel-related unless it has to be 93 octane with e85. I'm going to look for race gas tomorrow and see if I can get it to do it

We have a couple cars floating around via email that have a similar unresolved stutter under load on almost any map. In most cases they ran fine for awhile tuned, and then the issue developed, and nothing resolves it other than running stock.This issue only comes up under heavy throttle like 70%+ and usually causes the JB4 itself to reset from the electrical interference cutting off the log.

I think it's probably a faulty coil pack on those specific cars sending feedback in to the electrical system under load. Given how crappy the ignition system is we're going to need to develop some better diagnostic tools for those situations. Just difficult to develop the tools needed when there are only a handful of cars that exhibit that specific issue and none are close by to us.

 

[Scott Curry]

When I say light boost I can go full throttle for a split second while it downshifts begins to spool up and before I'm hitting even much boost it'll start to misfire and then it goes away and then everything's fine through the rest of the RPMs up to red line and pulls like a freight train, I haven't had any cels or limp mode. The shit keeps me up at night.

 

[Terry@BMS]

When I say light boost I can go full throttle for a split second while it downshifts begins to spool up and before I'm hitting even much boost it'll start to misfire and then it goes away and then everything's fine through the rest of the RPMs up to red line and pulls like a freight train, I haven't had any cels or limp mode. The shit keeps me up at night.

That would be different than what I described then. Maybe find a local car and swap coil packs as a test? Shrug.

 

[Scott Curry]

We have a couple cars floating around via email that have a similar unresolved stutter under load on almost any map. In most cases they ran fine for awhile tuned, and then the issue developed, and nothing resolves it other than running stock.

I think it's probably a faulty coil pack on those specific cars sending feedback in to the electrical system under load. Given how crappy the ignition system is we're going to need to develop some better diagnostic tools for those situations. Just difficult to develop the tools needed when there are only a handful of cars that exhibit that specific issue and none are close by to us.

Well I'm in Utah and I'm actually planning to head out to California not too long from now. Simi Valley is about 45 minutes away from where I go in southern California. I have family in Simi, maybe at some point I can stop by your shop and have you guys check it out with advanced noticee?

 

[Scott Curry]

I did actually get it to do it on a partial launch a little while ago coming home in first gear. It's weird I had no issues for probably two weeks and then it started I'm going to pull the plugs and check each of them out to see if there's anything blatantly wrong with any of them.

 

[Scott Curry]

And when I went on a long drive today the only map it wouldn't do it on is map 0. On map one I got it to do it but not as consistent

 

[Terry@BMS]

Well I'm in Utah and I'm actually planning to head out to California not too long from now. Simi Valley is about 45 minutes away from where I go in southern California. I have family in Simi, maybe at some point I can stop by your shop and have you guys check it out with advanced noticee?

Sure if you're in the area just drop me an email and we can check it out.

 

[Scott Curry]

So did you have a chance to look at the log that I sent? Is anything look like it's pointing to anything particular?