Small pop / backfire with header and exhaust

[jeffgilbert]

I have installed Ulmers header and a osp exhaust i have some new mapping and i noticed a small pop / backfire when I come off the throttle. I basically have ulmers performance pack #6 with a different muffler. Has anyone noticed this before? Could it be from having such a short header and open exhaust?

Thnaks
Jeff

 

[NOS-PRO]

Its because of the more free exhaust and the 2015 ECU.....you have the lean pop issue.
I take it you have a fuel controller, PCV? If you do, the area outlined in black is the area you want to change. **Now, this is just a sample map** If you are a -10 for example, change that to a 0 or +5....this will help your idle and part throttle.

 

[jeffgilbert]

That's exactly what my map has going on i have some -10 and -5 in this area . What kinda mods are you running for this map I am also using and PC ignition module.

Thanks for the help
Jeff

 

[jeffgilbert]

Do you think this lean pop will cause any issues?

Jeff

 

[putz21]

I had the same thing going on with mine, and NOS-PRO helped me out last weekend. I had all zero's in that same area and I switched them to +5 and my idle and startup is much better now.

 

[jeffgilbert]

I have a lot of -10 in this area I may try putting in zeros up to 3250rpm should I change anything in the second column?

 

[NOS-PRO]

That's exactly what my map has going on i have some -10 and -5 in this area . What kinda mods are you running for this map I am also using and PC ignition module.

Thanks for the help
Jeff

I have the EVO header, muffler, airbox mod with EVO stage 4 flash.

Your welcome bud!

 

[NOS-PRO]

I have a lot of -10 in this area I may try putting in zeros up to 3250rpm should I change anything in the second column?

If it were my sled, I would have the 0 and 2% throttle columns at +5....down to 3,750 rpms and all 0's in the 5% down to the same 3,750 rpm. This should clean a lot of the burble and poor idling.

 

[MrSled]

I have Excell Air box Mod, Straightline Header, Excell exhaust and the EVO Flash #4, I get a little on and off throttle burble, almost like a back fire here and there as well. I am sure its in the tune or maybe the short header does it...either way I cant really do anything about since the Evo Flash is non adjustable.

 

[TD Max]

If it were my sled, I would have the 0 and 2% throttle columns at +5....down to 3,750 rpms and all 0's in the 5% down to the same 3,750 rpm. This should clean a lot of the burble and poor idling.

When you say "down to" you are referring to table columns top to bottom and not RPMs correct?

 

[NOS-PRO]

Yes, top to bottom starting from the left top corner.

I would call this 2 columns

I think jeffgilbert should change column 0,2,5 of the % throttle and from 500 to 3,750 rpm to the numbers I gave him.

 

[jeffgilbert]

View attachment 114748

Yes, top to bottom starting from the left top corner.

I would call this 2 columns

I think jeffgilbert should change column 0,2,5 of the % throttle and from 500 to 3,750 rpm to the numbers I gave him.

Thanks alot NOS-PRO I will make these adjustments the weekend and let everyone know what turns out like

 

[NOS-PRO]

You betcha bud

 

[jeffgilbert]

Do you think this may help with some of my hot start issues I always found that I had to give it a little throttle to get it started when it was hot or sometimes when it would start it was hang really low like 950 and would be rough until I gave it a little tap on the gas?

 

[NOS-PRO]

Do you think this may help with some of my hot start issues I always found that I had to give it a little throttle to get it started when it was hot or sometimes when it would start it was hang really low like 950 and would be rough until I gave it a little tap on the gas?

Yes, this should help with that. The problem is not enough fuel and giving it throttle helped start it.