Bog/Surge Feeling

maxxedout · Aug 15, 2016

Lately, I've noticed a bog/surge feeling right around 1,700 rpm. It's most noticeable on the performance setting, but I can tell it's there regardless.

The best way to describe it is a "flat spot"... The truck fuels off the line, then seems to stumble, then fuels again, and is fine. For example, if I'm coasting, make a turn, then go to accelerate, there's a small dead spot right around 1,700 rpm. It's not a huge issue by any means, but now that I know it's there, I can feel it every time.

Has anyone else experienced this? If so, what did you do to fix it?

Thanks!

bigrpowr · Aug 15, 2016

maxxedout said:
Lately, I've noticed a bog/surge feeling right around 1,700 rpm. It's most noticeable on the performance setting, but I can tell it's there regardless.

The best way to describe it is a "flat spot"... The truck fuels off the line, then seems to stumble, then fuels again, and is fine. For example, if I'm coasting, make a turn, then go to accelerate, there's a small dead spot right around 1,700 rpm. It's not a huge issue by any means, but now that I know it's there, I can feel it every time.

Has anyone else experienced this? If so, what did you do to fix it?

Thanks!

what tune ?

maxxedout · Aug 15, 2016

Midwest MCC files. The truck runs damn strong overall, but something with the low end power feels off. Maybe it's always been there? I don't know... Now that I notice it, it's driving me nuts.

smokeshow101 · Aug 16, 2016

I think its always been there I have noticed mine doing it

maxxedout · Aug 16, 2016

It has probably always been there on my truck as well. Before, it just felt laggy off the line, but now that I've noticed exactly where the flat spot is, I notice it every time. If it's one of those things that is just inherent to these trucks, I suppose I'll have to live with it. I was just wondering if anyone on here has found a way to get past it. I know the rods are a limiting factor to how aggressive the low end responsiveness can be, but it would sure be nice if there's a way to get rid of the dead spot.

dsmracing1 · Aug 16, 2016

Isn't there an electronic torque management control on, for when the torque comes on somewhere around the rpm you describe it at or a little lower? I know when my cold coolant de fuel is on I get that bog at stock power setting, but as soon as I get it up to my tow setting it goes away. It might be that I have the 65.5 streetmax too and maybe it's not enough timing and injection duration to properly run it at stock fuel?? Talk to Morgan man, he's the chit at working to get things figured out. That whole shop is very helpful.

maxxedout · Aug 17, 2016

What's odd is that the bog feeling around 1,700 rpm is most noticeable on the performance setting. Maybe because it fuels harder on the performance setting, so the torque management pulling it back feels more abrupt? I don't know, but it's driving me nuts haha.

I'd love to just send the whole truck to Morgan to upgrade from my 64 mm street max to the new 65.5. With 133k on the clock, a mildly built transmission wouldn't hurt either. I'm trying to buy a house at the moment, so the truck fund is a little weak haha. If there's a way to address what I'm feeling with just tuning changes, that would definitely be ideal. I have more plans for the truck down the road, but like I said, it's going to have to wait for now.

dsmracing1 · Aug 17, 2016

maxxedout said:
What's odd is that the bog feeling around 1,700 rpm is most noticeable on the performance setting. Maybe because it fuels harder on the performance setting, so the torque management pulling it back feels more abrupt? I don't know, but it's driving me nuts haha.

I'd love to just send the whole truck to Morgan to upgrade from my 64 mm street max to the new 65.5. With 133k on the clock, a mildly built transmission wouldn't hurt either. I'm trying to buy a house at the moment, so the truck fund is a little weak haha. If there's a way to address what I'm feeling with just tuning changes, that would definitely be ideal. I have more plans for the truck down the road, but like I said, it's going to have to wait for now.

Ahh I see. Yeah I would most definitely get a hold of him and brainstorm a few things. I know that he worked with me on 3 different trans tunes and the lower rpm shifting ones would make the truck feel boggy. Probably the nature of the beast with a bigger charger and electronic management crap like we talked about. However I ended up using his higher rpm non VGT trans tune as of lately and man it really brings the turbo to life in an instant because it will down shift much quicker to get the turbo in the green zone.. Are you getting pretty smoky from the tailpipe when it bogs?

maxxedout · Aug 26, 2016

Just wanted to give this a little update... I'm still having the issue, but I can't tell if it's more of a turbo/air management problem or a fueling issue. If I tip into it from a low speed roll, there's just a complete dead spot at 1,700 rpm.

Maybe the truck is lugging a little bit? I'm not sure, but I wouldn't think it would be hard to keep a VGT spooled around 1,700 rpm.

To answer your question, yes, the truck is pretty smokey down low. Honestly, I feel bad that it lets a pretty good puff out if I get on it to pass someone. I tried a tune with less low boost fueling, and the truck was an absolute dog under 2,000 rpm.

This thing runs like a bat out of hell on the highway, but the dead spot down low is annoying in stop-and-go traffic. I'm really tempted to give S-partan a try. Everyone seems to like that Warhammer X QR tune on the 15-16 trucks, right? I would assume it would run the same on a 2012 with some 2015 parts. I'm not really thrilled about the idea of buying a new tuner, but I would love to have this truck running a little better.

maxxedout · Aug 30, 2016

Does anyone have anything else to add to this? Are there tunes out there that this is not an issue with?

Jacob @ No Limit · Aug 30, 2016

What kind of boost do you see on the high end? Ideally yes it should run like a 15/16 truck.

maxxedout · Aug 30, 2016

It'll peak around 36-37 for a moment, but usually settles around 32-34 at WOT. At tip-in, it'll be in the mid 20's, but as load and RPM increases, I end up in the low 30's. WOT performance has never been an issue, but something definitely isn't right below 2,000 rpm.

Jacob @ No Limit · Aug 30, 2016

I hate to say it.. But give S p a r t a n a try, I used to have lots of low end lag with p.i.p and I.d.p tunes. S p a r t a n runs amazing. I don't regret it one bit! Also, I peak boost at 37-39, hovers around 34-36 wot.

bigrpowr · Aug 30, 2016

maxxedout said:
It'll peak around 36-37 for a moment, but usually settles around 32-34 at WOT. At tip-in, it'll be in the mid 20's, but as load and RPM increases, I end up in the low 30's. WOT performance has never been an issue, but something definitely isn't right below 2,000 rpm.

did we talk about this yesterday or was it someone else ?

Jomax · Aug 30, 2016

I have zero issues with GH/AS. I love it for city driving actually. My truck lives in the race tune 24/7 even towing. Unless it's super heavy for hours on end.

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maxxedout · Aug 31, 2016

bigrpowr said:
did we talk about this yesterday or was it someone else ?

Nope, that must have been someone else. If you have any suggestions, I'm all ears.

maxxedout · Aug 31, 2016

White15 said:
I hate to say it.. But give S p a r t a n a try, I used to have lots of low end lag with p.i.p and I.d.p tunes. S p a r t a n runs amazing. I don't regret it one bit! Also, I peak boost at 37-39, hovers around 34-36 wot.

It seems like everyone who's made the switch is happy. I probably will sooner or later, but I'm in the process of buying a house, so the truck fund is a bit weak lol.

maxxedout · Aug 31, 2016

Jomax said:
I have zero issues with GH/AS. I love it for city driving actually. My truck lives in the race tune 24/7 even towing. Unless it's super heavy for hours on end.

Sent from my iPhone using Tapatalk

Has GH/AS made some changes in the last year?

I tried their MCC tunes when I first did the turbo swap, and we could never get them dialed in. I finally gave up because I got sick of the back and forth.

Jomax · Aug 31, 2016

maxxedout said:
Has GH/AS made some changes in the last year?

I tried their MCC tunes when I first did the turbo swap, and we could never get them dialed in. I finally gave up because I got sick of the back and forth.

Welcome to tuning. SPRTN is no better for changing tunes IMO. I believe GH has gotten better in the last year for sure.

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