voodoochikin04

iTrader: (3)

So i've had my obx headers on for almost a week now.. and mind you I have a W4M tune on this car... jesse said the tune should adjust on its own for the headers.. so ever since they've been installed, at redline when im shifting gears, it pops real loud usually once.. what does this mean?

exhaust leak at collectors and sucking air back up in for a second? because it sounds like the same popping youd get with short open exhaust or open headers.

BudRacing

iTrader: (3)

Mine did this too before a tune. While there will be some adjustment in the fueling tables, I believe a more customized tune is the best solution.

05MallettV

I get the pop as well when I shift, but usually not at red line, or I can't hear it. I don't have headers, but I do have High flow cats/midpipes and a cat back.

The pop is pretty complicated to explain, and is dependent on the modifications and tune to your engine. I just asked one of our engine calibrators about this and the pop can be caused by a number of factors related to fuel tables, cam profile intake and exhaust flow and catalyst position. In most cases the pop is being caused by late burning fuel being sent through the exhaust system.

The popping under decel, or during shifting, is something that modern engine calibrators can turn on and off provided that there is enough flow and reduced sound deadening that the pop is not eliminated once it reaches the end of the exhaust.

As long as there is no pop under load it's not really an issue, unless you don't like it.

Birdmantamu

I had the same issue and what resolved it might seem weird.

Installed 1-3/4" Kook's LT's, no cats, x-pipe, and gutted factory mufflers. Also had a W4Me tune mainly for inspection purposes.

Had the pop in between shifts, most notably when the car was cold and shifting through the neighborhood at low RPM's.

That exhaust setup was just a little too loud (hard to believe yes) and raspy in general so I replaced the gutted factory muffs with Borla Turbo's. Issue resolved.

I really don't know how or why. Or if it's still happening and the mufflers are doing their job really well. But that switch alone stopped the pop and of course made the tone better.

voodoochikin04

iTrader: (3)

I didnt really notice much of a difference with my W4M tune... maybe .5 better mpg.. and maybe 2degrees less on coolant.. nothing that you could feel when you mash the gas.. Makes me still yearn for a dyno tune session..

ls1247

iTrader: (2)

The added back pressure of the Borlas keeps the unburnt fuel mixture in the hottest part of the system just long enough to burn off relatively slowly so it doesn't make an explosive "pop"???

odthetruth

iTrader: (4)

Only time I hear popping is on decel, but thats because I'm running a bit rich. But you know what they say. You can run rich forever... you can only run lean once. LOL


Backfire around 19 seconds in. It does it quite frequently.

voodoochikin04

iTrader: (3)

Odthetruth...what's all done to your car..seems way quicker than mine lol

MN_V

iTrader: (5)

The other car was hitting their brakes when OD would hit the gas... lol

odthetruth

iTrader: (4)

LOL Something like that. Other car was a 200hp VW. It was going to look slow regardless.

I have pacesetters, badlanz cutouts, cat delete, and TuneTimePerformance dyno tune. Put down 372/361 at their Mustang Dyno, which according to a lot of other V members (specifically V2 guys), reads notoriously low. I've seen 2010 Camaro SS autos with headers make 330 on it. Saw a new 5.0 with track key \ red key dyno something like 340. I don't care about the numbers. Its a 370/360 dyno'd car as far as I'm concerned. It pulls stronger than it used to, IMO.

But this is me vs LS1 C5 with cam, full exhaust and intake from a 60 roll. My friend started the camera right as I had finished honking.

I ran a dig with him that I lost, but it wasn't really a clean run (only ran first gear, basically and had to shut down with traffic ahead), although I did post it up in the SRK section anyway. Not able to shift hard or fast, because I'm having clutch drag issues, where the clutch isn't fully disengaging and its showing itself more under high RPM. Seems the pressure plate is still making contact. But thats another story. I'll be hunting for a full clutch\flywheel combo soon.

As far as popping... might be backfire but with cats on, you won't really see the fire. The LSx engines seem to backfire alot with cat deletes and tunes.

voodoochikin04

iTrader: (3)

Your car looks and sounds faster than mine... I have headers cutouts and tune.. Ugh. I'm really starting to doubt this w4m tune.

AAIIIC

iTrader: (19)

My experience with a W4M tune for my stock engine w/Kooks headers was that it made no more power than the stock tune on the dyno (back-to-back testing with a stock ECU and the "tuned" ECU), while running 1/2 point or so leaner than the stock tune. Needless to say, I got rid of the W4M tune and got a proper dyno tune.

odthetruth

iTrader: (4)

This.

It was probably the most expensive mod I had done ($500). Headers were like 300, cutouts around the same, cat delete was free ninety nine with exception of $60? offroad extensions... but I didn't want to cheap out on the tune.

TuneTimePerformance does good work. They mostly work on V2s, but they seem to specialize in LSx cars. Find a good tuner local.

Becker

iTrader: (4)

Which headers are these?? I had no idea pacesetters were this cheap..