Turbo bark/surging while towing?

02bigstrokin · Apr 27, 2015

Sideswipe505 said:
You asked for advice. Don't be a bag of diks when it's given to you ***nuts

I asked if anyone has had this problem before. You don't think I know that 37's and 3.55 gears aren't optimum for towing? I don't tow everyday, heck it's really the first time I've towed anything with any weight to it. My point was I grossing 17k at best and it tows like crap. How many super dutys gross well into the 20k's? Like the picture posted in the very tread with three vehicles on one trailer and no issues! And so what his turbo is a stock 15, it's 3mm smaller. Does 3mm make that big of a difference?

02bigstrokin · Apr 27, 2015

truckman1974 said:
Man.....y'all got me wondering if I'm going to have this problem now.......

I was thinking about buying a 34' trailer and trying to haul stuff on uship for people on the weekends. I have an 8" lift with 37" tires (I just installed a sway bar kit trying to get ready for this idea)......and 3.55 gears....

If I bought this trailer I "could" haul a couple vehicles at a time (my truck is NOT a dually)......I'm wondering if I'm going to have trouble trying to pull that much weight. Should I be considering a one car trailer instead???

Sorry for a potential derail......but I think it's not a total derail since my question is in line with the OP question.......thanks.....

Ha, on this forum all you're going to get is you have too much lift and too big of tires.... That's the go to answer. if you have the stock 11-14 turbo it will probably tow just fine. Any aftermarket turbo and will probably suck. The tuning is not there for the 6.7. Ive rode in lly Duramax trucks with a s475 as a single turbo that towed better then the charger I have... All in the tuning though.

truckman1974 · Apr 27, 2015

02bigstrokin said:
Ha, on this forum all you're going to get is you have too much lift and too big of tires.... That's the go to answer. if you have the stock 11-14 turbo it will probably tow just fine.

I do still have the stock turbo.....so hopefully I won't experience any of those problems.

Cheap6.7 · Apr 27, 2015

Did you talk to Morgan or the KEM guys? You need to remember how new this stuff is for the 6.7, your previous dmax had years of tuning befor they got it right.

Jacob @ No Limit · Apr 27, 2015

02bigstrokin said:
I asked if anyone has had this problem before. You don't think I know that 37's and 3.55 gears aren't optimum for towing? I don't tow everyday, heck it's really the first time I've towed anything with any weight to it. My point was I grossing 17k at best and it tows like crap. How many super dutys gross well into the 20k's? Like the picture posted in the very tread with three vehicles on one trailer and no issues! And so what his turbo is a stock 15, it's 3mm smaller. Does 3mm make that big of a difference?

It's not that it's just 3mm smaller. It's 11 blade, better for towing. You have a 6 blade which is more performance based. Maybe you also need more fuel? You say your truck never smokes. I know these run clean, but mine will smoke if I nail it. Maybe you were just starving the charger causing it to bark?

Cheap6.7 · Apr 27, 2015

White15 said:
It's not that it's just 3mm smaller. It's 11 blade, better for towing. You have a 6 blade which is more performance based. Maybe you also need more fuel? You say your truck never smokes. I know these run clean, but mine will smoke if I nail it. Maybe you were just starving the charger causing it to bark?

Very true.

Jacob @ No Limit · Apr 27, 2015

Cheap6.7 said:
Very true.

I mean, just a thought? Mine has never barked on my truck in sig? I've towed heavy with it, even on extreme. Just drive it smart but never any surging. I'd say he's running out of fuel though.

Stangr8cr · Apr 27, 2015

Any chance you have a way to monitor rail pressure? Maybe you can borrow a CTS from a friend to see what's going on there?

Keith

02bigstrokin · Apr 27, 2015

Yeah I have a cts mounted on the pillar. never monitored rail pressure but I know my egts never go over 750-800 degrees. It literally won't smoke any unless im beating on it over 50% throttle. No fuel down low at all. and another thing is I know it's not a wonderful towing setup which is not what I use the truck for but I also have gotten it to bark in 6th gear unloaded. Honestly I think it's tuning related. Going to make a few calls today and get something different. Even if I have to sell the sct and go hs so I can get the mcc tuning then it is what it is. It's so aggravating because I love how the truck rides/ drives and love the interior on the 6.7's etc etc it's just everytime I build a Duramax for a customer or flash one wih my efi live Its just disappointing that we don't have anything like that on the ford side.

Cheap6.7 · Apr 27, 2015

OP what was the EGTs on that trip?

Stangr8cr · Apr 27, 2015

I'd get with Morgan and go from there, I'm sure he can get you straightened out. He has always been more than helpful any time I've needed anything.

Keith

Jacob @ No Limit · Apr 27, 2015

Those are some very low egts unloaded or not. Definitely needing more fuel. I agree with what everyone is saying and call Morgan. Tuning issue or injection pump if rail psi is off spec.

02bigstrokin · Apr 27, 2015

Yeah I'm going to. Truck has 6200 miles so Im doubting injection pump. But who knows

Jacob @ No Limit · Apr 27, 2015

Ok, probably not then lol

Cheap6.7 · Apr 27, 2015

Ya those EGTs are really low, somehow I missed that post. I'd bet the tunes are really clean but you are not getting the full picture out of that truck... Crank up the fuel.

Let us know what was said, I'm interested in the fix.

The Butcher · Apr 27, 2015

Not sure how relevant this is, but I just towed a 20' deck over car hauler 1000 miles round trip with a crew cab Raptor on it behind my deleted '15 with Innovative tunes and it was fantastic. Granted, I have '15 turbo and not an aftermarket performance one like yours, but I had no problems holding 80MPH and I'm running an 8" lift with 38x15.50 Toyos. I have no doubt my 4.30 gears made a big difference as well. Maybe give Innovative tunes a shot? I've got them on my Excursion and my 2015 and I really like them.

KCTurbos · Apr 28, 2015

at what rpms are you having this turbo bark? Like 1500-1900rpms?

Sounds like turbo surge... just like the 7.3 trucks you mentioned.

Turbo surge comes from too high of a pressure ratio at too low of flow... basically too much boost at too low of RPMS.

truckman1974 · Apr 29, 2015

KCTurbos said:
at what rpms are you having this turbo bark? Like 1500-1900rpms?

Sounds like turbo surge... just like the 7.3 trucks you mentioned.

Turbo surge comes from too high of a pressure ratio at too low of flow... basically too much boost at too low of RPMS.

So what is the fix for that? New tune?

KCTurbos · Apr 29, 2015

truckman1974 said:
So what is the fix for that? New tune?

First off. I don't know anything about 6.7 tuning. So take what I say with a grain of salt.

Depending on the rpm at which the problem is happening. Down low you can back off the fueling a little bit and the vgt duty cycle and it should get rid of the surging.

Again if it is super low in the rpm band you can have your truck downshift a little easier to get the flow up.

Another option is to get a turbo with a bigger turbine wheel. If you get too big on the comp wheel and with too small of a turbine wheel... it makes a turbo more prone to surging.

02bigstrokin · Apr 30, 2015

Yeah it's right in that rpm range you mentioned. The truck doesn't fuel hard at all down low, actually it won't smoke any unless wide open so I was thinking maybe let it fuel a little harder but back off on the vgt duty cycle? Maybe let the fuel spool the turbo instead of having the vanes closed so tight at low rpms causing the surging?