What can rob power?

[ActiveMonkey]

Hey Everyone,

The question in a nut shell is "What can rob power on our cars?"

The Specific Situation
B5 S4 manual
BW K04 Turbos
3" downpipes (no cats)
dual 2-1/4" Auto speed Exhaust
044 In tank fuel pump
EV14 550cc injectors
85mm MAF housing with Hitachi conversion
AWE SMIC
x34 Intake
Forge 007 DVs

The car was running very well so I had a baseline dyno performed. 300hp/323tq to the wheels on a mustang dyno. The Previous owner claimed 370hp to the wheels.

I thought that 300hp was low and after reviewing all the service records I received from the previous owner, my best guess was the car had been returned to the GIAC Stage 3- tune so that it could pass smog. That and the as that was the GIAC Stage 3- tune was the only tune I had a receipt for. With the car still running solid I went down to 034 Motorsport for a new Stage 3 tune hoping to unlock the remaining HP. Nope... The car honestly felt a bit slower. Which brings me to this thread. What can be wrong with the car to rob 50+ HP and not throw a CEL or make the car run like shit.

Baseline Dyno from Griffin Motorwerke - Mustang Dyno.

[landfill]

You should be at 375-400whp on 91-93 octane with your mods. There’s cars on k03’s with pretty much 300 wheel.

[ActiveMonkey]

You should be at 375-400whp on 91-93 octane with your mods. There’s cars on k03’s with pretty much 300 wheel.

Agreed. So wtf?!

[kalyjor]

Long shot but CEL might be burnt and you have a cylinder completely not firing, it'll sometimes feel like it's running normal if you aren't familiar of how it's should run, $20 cable from project B5 and free vagcom sofware will help find out

Sent from my XT1650 using Tapatalk

[LINDW4LL]

Have you logged the car? Would be good to verify it's meeting the desired boost targets, and even if it is, logs can aid in identifying whatever is going on.

Low compression could cause low output, but is pretty uncommon.

[erykv1]

x2 on the log.

There are too many variables to be guessing what the cause is.
Without a previous dyno, I'd take the previous owners claims lightly.

Did you get a retune at 034?

[VR6Bomber]

Pressure tested?
Making desired boost?
Measure fuel pressure?
WG's working?
swap n75?
DV's in good shape?
scan for codes even if no light?
Cyl compression? This is a strong possibility with no cel

[TylerT]

OP ... this is a very loaded question. Good posts in this thread.

Assuming the car is healthy, it may be an off-the-shelf 034 tune and they're known for being conservative.

I would join the FB groups and talk to Blake Beadle .. great tuner and does it all remotely.

[Slickn]

Just to add more things to check to the already large pile... I've lost power before from a stuck open thermostat(no codes), coolant temp sensor(phantom code), and a bad lifter that was causing the knock sensors to pull timing(ultimately the noise let me know that this was an issue). Good luck!

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[mikeb17]

Definitely something wrong, I had more power on k03s and a ton more torque 😯. Logs will tell a lot.

[ActiveMonkey]

I did get the car retuned at 034 with their full stage 3 file. Felt a tad slower.

Pressure tested? Happening today.

Making desired boost? On my boost guage it shows 21psi spike and holds 19-20psi.

Measure fuel pressure? Not yet.

WG's working? Yes.

swap n75? I will do today.

DV's in good shape? Yes.

scan for codes even if no light? Yes, none pending. I will rescan today

Cyl compression? This is a strong possibility with no cel. I have not done this yet.

[BB2001S4:Tim]

Even though these are low #'s for a stage 3...what do other stage 3 KO4'ed S4 put down on this dyno? It maybe a low reading dyno...just a thought.

And also...I suggest a custom tune!

GL

[ActiveMonkey]

This dyno is nearly identical to 034's and this setup should conservatively be 350awhp - 375awhp

[brokenwrench]

That dyno graph doesn't look normal to me, although I'm not overly familiar with them. Is it normal for a stage 3 dyno plot to be so "bumpy"? The torque curve should be much flatter through the mid-range, although I can only speculate on what the cause might be here. But maybe this is a normal shape for these mods, dunno.

[ActiveMonkey]

I agree which is why i thought it was a GIAC stage 3- that then had the 044 pump, ev14 550cc injectors, and 85mm Maf added but never retuned.

[brokenwrench]

I mean, just based on what I'm seeing here, it looks like the ECU is asking for boost, then shutting it off almost immediately. You definitely need to get some logs posted so everyone can see just what's going on here.

Or maybe this is your electrical gremlin branching out into new territory.

[FlyboyS4]

By the looks of the boost curve on the dyno chart the boost is building very slowly for K04's.

If the tune holds 19-20 psi I'd expect around 350 whp. You might want to log a FATS pull to crosscheck the Dyno numbers, around 3.7 sec. would be what I'd expect if that dyno is reading low. 034's reads pretty low.

It's already been mentioned numerous times, you need to log the car if you want to troubleshoot.

[rguil]

Im going to bet on how they tuned your ignition timing table and fuel VE table.
Too safe...

[ActiveMonkey]

Hey Everyone, from what I'm reading, logs would be helpful. I totally agree. Let me figure out how to run some logs and I will get back with that info.

Is there any specific information everyone is wanting to see?

[FlyboyS4]

This is a basic cfg file for use with ME7Logger that should get you started with a decent core set of variables.

[jimmer009]

You certainly need to have me7 logger it's a great program./tool.

My car is pulling timing up top on me. I have tryed everything and researched the crap out this. Me7 logger will point you in this direction probably to.

So my problem is the cam adjuster pads are worn. This is not allowing the car advance the timing on one bank so the motor sees this and pulls timing back to protect it's self. If you pop the vavle covers you can visually inspect them. They sit in between the cam chains. On both heads. I'm betting this is your problem. How many miles on your car???

[ActiveMonkey]

~160k miles

[Zba]

I didn't see an answer; was this dyno done with your alternator acting up?

[ActiveMonkey]

I didn't see an answer; was this dyno done with your alternator acting up?

No, alternator was working fine at that time. Or at least to the best of our knowledge.

[james 408]

on 91 octane, 350-370whp is more the target figure on 91 or 92. 034 advertises 390 some odd whp as typical, but it is not typical nor was the vehicle used to present the 'typical' a standard stage 3 car. In addition to admitting these facts, there is further evidence the car in question only made an additional ~10hp going to meth, and it's the service managers car -- which suggests there's even further tomfoolery going on here.

034 just flashes their off-the-shelf tune, no custom tuning involved. They also have that janky MAF housing where the sensor doesn't fit in all the way (assuming they haven't sold off the faulty inventory yet), so not sure if that's part of the problem with compatability.

That said, yeah run some logs and figure out what's wrong.

[killerkali]

I'm sure you'll figure it out first; but if you happen to be in Sac pm me, I can help set you up with ME7 logger