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APR stage 1 surge

Greasyjonny

Passed Driver's Ed
Location
Mass
Just doing an intercooler would be a band aide (same power from less boost) but I def plan on getting one now that the issue seems to be isolated and resolved.
 
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AsheToo

Ready to race!
Location
North America
Car(s)
Mk 7.5 GTI Autobahn
I'm gonna resurrect this thread to see if anybody has been able to get to the bottom of this.

My setup: I have a '21 GTI Autobahn with DSG and had GMP Performance in Charlotte do a Stage 1 low-torque 91 octane tune and APR catback in January. In May, I drove down to APR so they could pull TCU software from my car to make sure their TCU tune was compatible with the box code on my TCU (it was compatible) and install their TCU tune. In August, they installed APR intercooler and carbon fiber intake. Last week, they reflashed to APR Stage 1 low-torque 93 octane.

Problem: When I accelerate in 1st, 2nd, and 3rd at any kind of a pull, but not WOT, the power delivery from idle to 3,000 RPM feels like OEM - then just past 3,000 RPM, a wall of torque suddenly causes the acceleration to surge unexpectedly and the power delivery will then oscillate as if the torque and power were increasing by step-plateau-step-plateau-step-plateau, etc.

This is not a loss of traction or drivetrain slippage of any kind. You can hear and feel the engine power suddenly appear and then it stair steps its way up. If I do launches or just WOT, it just runs like a bat out of hell (but by 3rd gear and beyond I can tell the IS20 runs out of breath in higher RPM.

So, anyone got any comments, experience, feedback?
 

j255c

Drag Racing Champion
Location
New York
Car(s)
2018 Golf R Manual
I had surge with my Apr stage 1 tune. No more with EQT.
 

tigeo

Autocross Champion
I'm gonna resurrect this thread to see if anybody has been able to get to the bottom of this.

My setup: I have a '21 GTI Autobahn with DSG and had GMP Performance in Charlotte do a Stage 1 low-torque 91 octane tune and APR catback in January. In May, I drove down to APR so they could pull TCU software from my car to make sure their TCU tune was compatible with the box code on my TCU (it was compatible) and install their TCU tune. In August, they installed APR intercooler and carbon fiber intake. Last week, they reflashed to APR Stage 1 low-torque 93 octane.

Problem: When I accelerate in 1st, 2nd, and 3rd at any kind of a pull, but not WOT, the power delivery from idle to 3,000 RPM feels like OEM - then just past 3,000 RPM, a wall of torque suddenly causes the acceleration to surge unexpectedly and the power delivery will then oscillate as if the torque and power were increasing by step-plateau-step-plateau-step-plateau, etc.

This is not a loss of traction or drivetrain slippage of any kind. You can hear and feel the engine power suddenly appear and then it stair steps its way up. If I do launches or just WOT, it just runs like a bat out of hell (but by 3rd gear and beyond I can tell the IS20 runs out of breath in higher RPM.

So, anyone got any comments, experience, feedback?
What does APR say? Do you have logs showing this? Small turbos tuned can do this when you are at partial throttle and it's not just APR - can you "drive around it"? I take it this is in D where it's typically upshifting during boost build which can cause what you are describing? So this is new with the new 93 low t tune vs. the old 01 low t tune?
 
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EpicTech

Autocross Champion
Location
Houston
Car(s)
MK7 GTI 6sp w/PP
Neither of my tunes stage 2 or now the stage 2+ with the IS38 file surge like this. Their is of course a hesitation if traction control kicks on, but once the tires hook, it pulls nice and strong. I am Unitronic though, but still it is a flash tune like APR. 100k miles tuned btw.
 

tigeo

Autocross Champion
Neither of my tunes stage 2 or now the stage 2+ with the IS38 file surge like this. Their is of course a hesitation if traction control kicks on, but once the tires hook, it pulls nice and strong. I am Unitronic though, but still it is a flash tune like APR. 100k miles tuned btw.
I bet you can cause some of these strange "surgy" conditions if you want however - I can on my Uni tuned wagon on each the stage 1, stage 2 IS20, and now stage 2+ IS38. Just partial throttle/partial boost/shifting weirdness...you just drive the car so that you don't put it in those conditions so I never have an issue but I can force it for sure. And of course without a video this is nearly worthless b/c we all describe things differently.
 

EpicTech

Autocross Champion
Location
Houston
Car(s)
MK7 GTI 6sp w/PP
Hmm, I come to Richmond and give you a ride. Mine doesn't surge.
 

tigeo

Autocross Champion
Hmm, I come to Richmond and give you a ride. Mine doesn't surge.
You have a stick - this is a easing into the throttle while in D w/DSG and it doesn't downshift issue....
 

AsheToo

Ready to race!
Location
North America
Car(s)
Mk 7.5 GTI Autobahn
What does APR say? Do you have logs showing this? Small turbos tuned can do this when you are at partial throttle and it's not just APR - can you "drive around it"? I take it this is in D where it's typically upshifting during boost build which can cause what you are describing? So this is new with the new 93 low t tune vs. the old 01 low t tune?
I haven't contacted APR yet; I'm going to take it to my shop (https://www.gmpperformance.com/) before I contact APR. I don't have logs and don't even know how to do that. I can't smoothly drive around it. This occurs when I'm in manual mode or D. This happened with the 91 tune, the 93 tune, with the intercooler/intake, and w/o the intercooler/intake.
 

JPB WORLDWIDE

Go Kart Newbie
Location
Providence, RI
Car(s)
19 Golf R, RIP GTI S
I hate to say it, your car being so new, but check the spark plugs and coil packs to make sure you’re good. And if you haven’t changed the plugs from OEM, that could be the culprit. My GTI is at 100k mi and I’ve been tracking it a lot lately, noticed these ‘blips’ which seemed like spark and that cured the issue. No more blips or lack in powerband
 

Desslok

Autocross Champion
Location
PA
Car(s)
2019 Rabbit
I'm gonna resurrect this thread to see if anybody has been able to get to the bottom of this.

My setup: I have a '21 GTI Autobahn with DSG and had GMP Performance in Charlotte do a Stage 1 low-torque 91 octane tune and APR catback in January. In May, I drove down to APR so they could pull TCU software from my car to make sure their TCU tune was compatible with the box code on my TCU (it was compatible) and install their TCU tune. In August, they installed APR intercooler and carbon fiber intake. Last week, they reflashed to APR Stage 1 low-torque 93 octane.

Problem: When I accelerate in 1st, 2nd, and 3rd at any kind of a pull, but not WOT, the power delivery from idle to 3,000 RPM feels like OEM - then just past 3,000 RPM, a wall of torque suddenly causes the acceleration to surge unexpectedly and the power delivery will then oscillate as if the torque and power were increasing by step-plateau-step-plateau-step-plateau, etc.

This is not a loss of traction or drivetrain slippage of any kind. You can hear and feel the engine power suddenly appear and then it stair steps its way up. If I do launches or just WOT, it just runs like a bat out of hell (but by 3rd gear and beyond I can tell the IS20 runs out of breath in higher RPM.

So, anyone got any comments, experience, feedback?

This is a wastegate issue (that effects cars '19 and newer IIRC). My APR tuned car did the exact same thing.
I read that EQT solved the issue, so I switched to their tune and it solved the problem. Don't know if APR ever fixed it.
 

AsheToo

Ready to race!
Location
North America
Car(s)
Mk 7.5 GTI Autobahn
This is a wastegate issue (that effects cars '19 and newer IIRC). My APR tuned car did the exact same thing.
I read that EQT solved the issue, so I switched to their tune and it solved the problem. Don't know if APR ever fixed it.
Very interesting. I'm def going to uninstall the APR software, and I'm 90% sure I'll switch to come combo of EQT \ Cobb. I've been reading a lot about them, and I like what I'm hearing.
 

AsheToo

Ready to race!
Location
North America
Car(s)
Mk 7.5 GTI Autobahn
What does APR say? Do you have logs showing this? Small turbos tuned can do this when you are at partial throttle and it's not just APR - can you "drive around it"? I take it this is in D where it's typically upshifting during boost build which can cause what you are describing? So this is new with the new 93 low t tune vs. the old 01 low t tune?
To follow up on my earlier reply to you, I took the shop manager from GMP Performance for a spin and let him drive the car. He's a track junky and drives GMP's track cars (with APR Stage 1+ and Stage 2) a fair bit, so he's accustomed to Mk7 \ APR (even though I'm in a Mk7.5). He experienced what I described and could understand why I don't like it, but he said it was normal and best way to cope is keep the revs above 3K. He might be right - that the first 1/4 or 1/3 of the travel of the throttle pedal is just touchy AF at low RPM, especially in the transition from 2 - 3,500 or 4,000 RPM (valve timing switch is about 3,200). So maybe that's just a "feature" of how APR's tune works on this car. If that's normal, I'm not a good target consumer for APR Stage 1. At this point Cobb \ EQT is looking attractive - the convenience of DIY at home is compelling all by itself. Either way, 24 hours from now, the APR ECU & TCU tunes will be off the car. I'm glad I didn't pay for the APR TCU tune.
 

tigeo

Autocross Champion
To follow up on my earlier reply to you, I took the shop manager from GMP Performance for a spin and let him drive the car. He's a track junky and drives GMP's track cars (with APR Stage 1+ and Stage 2) a fair bit, so he's accustomed to Mk7 \ APR (even though I'm in a Mk7.5). He experienced what I described and could understand why I don't like it, but he said it was normal and best way to cope is keep the revs above 3K. He might be right - that the first 1/4 or 1/3 of the travel of the throttle pedal is just touchy AF at low RPM, especially in the transition from 2 - 3,500 or 4,000 RPM (valve timing switch is about 3,200). So maybe that's just a "feature" of how APR's tune works on this car. If that's normal, I'm not a good target consumer for APR Stage 1. At this point Cobb \ EQT is looking attractive - the convenience of DIY at home is compelling all by itself. Either way, 24 hours from now, the APR ECU & TCU tunes will be off the car. I'm glad I didn't pay for the APR TCU tune.
Funny story - when I got my Unitronic stage 1 tune I was convinvced something was wrong. Took it a shop and the owner/tech went for a ride with me. I'm going "SEE SEE" and he turns to me and says "Have you ever driven a tuned turbo car before?"...HAHAHAHHAAH..there was nothing wrong, just a steep toruqe curve on a tiny turbo.
 
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