Got my Yukon tuned today

[JDopirak]

So I've owned my Yukon about 4 months now and I did your basic bolt ons some of which people will say are a waste of money, Not here to debate I did what I wanted to my truck and I had some fun doing it "except the broken manifold bolts". Today i got it tuned by Complete Street Performace here in West Chester PA.

Truck is a 09 Yukon SLT with LMG 5.3 with 111k

"Mod list"
S&B cold air intake
Gibson shorty ceramic headers
Magnaflow 12589
SLP resonator delete<---not really a mod but we will put it on the list.

I never got a stock base line dyno.

But initial results before tune were
248hp 281tq

Results after tune were
268hp 291tq

85 degrees

The hp is what it is I'm mostly surprised about how low the tq was.


I'm curious if anyone has similar mods what there dyno results are??

 

[esoteric_ast]

20hp from a tune is pretty good!

 

[swathdiver]

Dynos can read differently. Now go on over to Maple Grove and make a trio of passes at least to see what is actually making it to the pavement.

My 2009 is stock save for the Magnaflow Y-Pipe and cats and a BlackBear Tune, she puts out 307 Rear Wheel Horsepower through the traps. A little more would probably be let loose if my KO2 tires weren't stuck to the track.

I don't know how dyno horsepower corresponds with track horsepower.

Give it a few days of driving and you'll see her adjust to the mods and tune, how do you like it so far? I LOVE the way my transmission performs now.

 

[JDopirak]

Dynos can read differently. Now go on over to Maple Grove and make a trio of passes at least to see what is actually making it to the pavement.

My 2009 is stock save for the Magnaflow Y-Pipe and cats and a BlackBear Tune, she puts out 307 Rear Wheel Horsepower through the traps. A little more would probably be let loose if my KO2 tires weren't stuck to the track.

I don't know how dyno horsepower corresponds with track horsepower.

Give it a few days of driving and you'll see her adjust to the mods and tune, how do you like it so far? I LOVE the way my transmission performs now.

I'm actually thinking about going to Cecil on Wednesday if the weather is nice. Overall it's much smoother. When it downshift one gear going up hills ot doesny bog and than jump down another gear and take off like a bat put of hell anymore. I still cant do a damn burnout!!!! They said they took all the tq management out but it's still a dog out of the hole for the first 50ft"it does have 20s factory and cooper discovery tires" . But with that being said it's much better than it was, I did a highway pull and it definitely picked some pull up top.

Downshift is alot smoother no more clunking when doing 3-2 -1 shifts. He said he did minor adjustments to trans, He said next summer when I do a cam he will adjust the trans more.

 

[swathdiver]

I'm actually thinking about going to Cecil on Wednesday if the weather is nice. Overall it's much smoother. When it downshift one gear going up hills ot doesny bog and than jump down another gear and take off like a bat put of hell anymore. I still cant do a damn burnout!!!! They said they took all the tq management out but it's still a dog out of the hole for the first 50ft"it does have 20s factory and cooper discovery tires" . But with that being said it's much better than it was, I did a highway pull and it definitely picked some pull up top.

Downshift is alot smoother no more clunking when doing 3-2 -1 shifts. He said he did minor adjustments to trans, He said next summer when I do a cam he will adjust the trans more.

Awesome, looking forward to the results. I can spin my KO2s depending on the road surface even with TCS on. More often than not, they stick to the road like flypaper; especially at the drag strip!

 

[gooffeyguy]

I can't even spin my tires when it's wet. It just grips and goes!

Actually, I've never floored it from a dead stop, wet or dry. I've gone about 75-80% throttle though.... Lol

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

 

[JDopirak]

They supposedly turned off all of the tq management but it still feels the same when you dead stop and punch it. It hesitates for like 20-40ft than takes off. I thought a tune woukd fix this but I guess not.

 

[gooffeyguy]

I thought torque management took effect between shifts, not from a stop?

Like it pulls timing from the motor during a shift. At least that's what it does on the mustangs I own.

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

 

[iamdub]

I thought torque management took effect between shifts, not from a stop?

Like it pulls timing from the motor during a shift. At least that's what it does on the mustangs I own.

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

Maybe? I know that something reduces power when an amount of throttle is commanded that would put a certain amount of stress on the trans and drivetrain. Maybe the DBW throttle system controls that but the TM programming pulls timing between shifts. Or they both work in unison for both? I'd have to watch my ignition retard and throttle angle response when flooring it from a stop to see.

 

[kbuskill]

There is torque management in the ECM and in the TCM if my memory serves me.

 

[swathdiver]

They supposedly turned off all of the tq management but it still feels the same when you dead stop and punch it. It hesitates for like 20-40ft than takes off. I thought a tune woukd fix this but I guess not.

Turbo lag...

 

[JDopirak]

Turbo lag...

Ya know the guys at CSP tried to convince me to do a turbo. I said I'd only consider a supercharger, I just prefer them.

 

[swathdiver]

Ya know the guys at CSP tried to convince me to do a turbo. I said I'd only consider a supercharger, I just prefer them.

Either is a lot of fun. I spent many years racing turbocharged Buicks but am enjoying these naturally aspirated LS engines. They do respond very well to forced induction though! But that doesn't solve your problem, neither did my joke.

So could it be the converter flashes to its stall speed and then the motor has to overcome the mass until the motor spins up to maximum torque and horsepower bands? I would say mine does the same thing in that instance.

 

[JDopirak]

Either is a lot of fun. I spent many years racing turbocharged Buicks but am enjoying these naturally aspirated LS engines. They do respond very well to forced induction though! But that doesn't solve your problem, neither did my joke.

So could it be the converter flashes to its stall speed and then the motor has to overcome the mass until the motor spins up to maximum torque and horsepower bands? I would say mine does the same thing in that instance.

Well I dont have alot of technical knowledge past fixing and replacing stuff but I can tell you it has no tq according to the graph till about 3500-4k. And the stock stall doesnt allow me to get anywhere near that range. I was able to start on some gravel and get it to do a burn out and in the rain but clean dry road it wont spin.

 

[swathdiver]

Well I dont have alot of technical knowledge past fixing and replacing stuff but I can tell you it has no tq according to the graph till about 3500-4k. And the stock stall doesnt allow me to get anywhere near that range. I was able to start on some gravel and get it to do a burn out and in the rain but clean dry road it wont spin.

View attachment 227271

So you have shorty headers feeding into what? Still have factory y-pipe and cats? Does it go into a whole new exhaust or just the Magnaflow muffler?

 

[esoteric_ast]

Well I dont have alot of technical knowledge past fixing and replacing stuff but I can tell you it has no tq according to the graph till about 3500-4k. And the stock stall doesnt allow me to get anywhere near that range. I was able to start on some gravel and get it to do a burn out and in the rain but clean dry road it wont spin.

View attachment 227271

2600-3000 stall will help.

 

[JDopirak]

So you have shorty headers feeding into what? Still have factory y-pipe and cats? Does it go into a whole new exhaust or just the Magnaflow muffler?

Shortys, Factory y pipe, magnaflow muffler and slp resonator delete to finish it off. I was going to do a whole custom catback system but factory piping is in perfect condition and it's already 2.75" so I didnt see any point in getting rid of it, Thats plenty big enough piping for the kinda power I want to eventually put down."350-375"

 

[swathdiver]

Shortys, Factory y pipe, magnaflow muffler and slp resonator delete to finish it off. I was going to do a whole custom catback system but factory piping is in perfect condition and it's already 2.75" so I didnt see any point in getting rid of it, Thats plenty big enough piping for the kinda power I want to eventually put down."350-375"

You're spot on, too big, 3" piping, on a 5.3 is too big in my experience. I was thinking that if the pipes were larger, you may have lost the scavenging effect which may contribute to the sluggishness off the line. So that's out. 3.08 or 3.42 gears? I'm thinking the tune needs further work, do you have an AutoCal to do data logs to give to your tuner or can you easily work with him in person?

 

[JDopirak]

You're spot on, too big, 3" piping, on a 5.3 is too big in my experience. I was thinking that if the pipes were larger, you may have lost the scavenging effect which may contribute to the sluggishness off the line. So that's out. 3.08 or 3.42 gears? I'm thinking the tune needs further work, do you have an AutoCal to do data logs to give to your tuner or can you easily work with him in person?

3.42 gears
91 octane

And no autocal, I just called and said I wanted to get it tuned. They asked what I was doing to the truck and than I showed up and they tossed it on the dyno and tuned it. They said it was all messed up from the new parts. They said it was pulling alot of timing prior.

 

[swathdiver]

3.42 gears
91 octane

And no autocal, I just called and said I wanted to get it tuned. They asked what I was doing to the truck and than I showed up and they tossed it on the dyno and tuned it. They said it was all messed up from the new parts. They said it was pulling alot of timing prior.

This not my area of expertise, but did they tune it only at WOT or for idle and cruise and such as well? The computers also learn and performance should increase over time, a tank or gas at most I would think. See if it smooths out after a few hundred miles.