GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV

4th Gear Lag - APR Stage II MK7R

golfare

Passed Driver's Ed
Location
CT
Going to try to explain the issue I'm having after flashing APR Stage 2 tune on my MK7R 6MT after my tuner said they could no longer support me:

-1st-3rd gear shifts and launches work great, car pulls hard, I'm happy.
-Upon entering 4th gear after a redline shift out of third gear, the turbo seems to lag for about 0.5 seconds after my foot is done releasing the clutch pedal and the 'hard pull' up to that point in time becomes a 'whoa, what huh? when are we going to start accelerating again?'. After that lag, it sounds (I don't have a boost gauge yet) like it builds boost again and begins accelerating and RPMs rise once again.

Here's what you'd see on the tachometer if I had footage of this phenomenon:
-For example, Entering 4th gear goes like:
*Pulls hard 1st-3rd, entering 4th*
RPMs are at 4,000ish, my foot is now fully off the clutch pedal, right foot mashed. RPMs stay at 4,000 / might only get up to 4,200 RPM for what seems like an eternity after a hard pull 1st-3rd, but what is more like 0.5 seconds. Then after what I think sounds like the turbo building boost back up (again, no boost gauge to verify), the car begins to accelerate and the RPM needle begins to rise somewhat quickly again, but obviously way less quickly than it does in the earlier gears.

Here are my specs:
2016 Golf R, 6MT (46k miles)
-APR Stage 2 tune - pops and bangs, aggressive, non APR DP version
-Stage 2 Endurance South Bend Clutch (Properly broken in, about 9,000 miles past break in now)
-APR Carbon Fiber intake
-Billet aluminum rear main seal upgrade
-CTS Turbo 3.5" high flow cat downpipe (the reason my tuner said that APR will not support me with this problem, oof should've just gone APR....)
-OEM intercooler
-OEM clutch delay valve still there, unmodded
-OEM catback

Can someone give me some ideas as to why I'd experience this 4th gear lag? It made me lose the jump off a 4th gear pull race against an LSX camaro recently and I know I would've won in a 3rd gear race (;
 
Last edited:

dcgtimk7

Go Kart Newbie
Location
DC
It sounds like your Diverter Valve is getting stuck. I had the same problem and fixed it by swapping to the latest revision J dv.
 

Razgriz337

Passed Driver's Ed
Location
USA
Car(s)
MK7R
-CTS Turbo 3.5" high flow cat downpipe (the reason my tuner said that APR will not support me with this problem, oof should've just gone APR....)

They would only not support you if they had reason to believe the hardware on the car was causing the issue. That won't stop them from attempting to help, send them an email. support@goapr.com
 

OBP

Go Kart Newbie
Location
ChiRaq
Your issue sounds like the issue with Cobb’s no lift shift option. If you shift it “normally” with clutch in, shift, then clutch out, the ECU would be confused and not send full power until about 500 rpms later.

Does your APR also have no lift shift?
 

Brad.R

New member
Location
Austin, TX
Car(s)
2018 Golf R
Your issue sounds like the issue with Cobb’s no lift shift option. If you shift it “normally” with clutch in, shift, then clutch out, the ECU would be confused and not send full power until about 500 rpms later.

This is not normal for NLS an is an issue that Cobb is working to resolve, afaik. It seems like every protuner using their consolidated (CCF) files is experiencing this issue in one form or another with manual cars. I was having this problem with the latest EQT files, and it went away completely by switching back to an older, non-consolidated tune file. I've confirmed with Cobb that it's a current issue with their software and not the person/company tuning.
 

golfare

Passed Driver's Ed
Location
CT
Your issue sounds like the issue with Cobb’s no lift shift option. If you shift it “normally” with clutch in, shift, then clutch out, the ECU would be confused and not send full power until about 500 rpms later.

Does your APR also have no lift shift?
No, I do not have this.
 

bentin

Autocross Champion
Location
Austin, TX
Car(s)
23 Golf R - 3 Pedals
Is it any time you go from 3 -> 4, or only if you're doing a full run up? Does it matter what the ambient temperature is? Sounds like it could be the stock intercooler not keeping up with the heat buildup and that just coinciding with your drop in boost.
 

golfare

Passed Driver's Ed
Location
CT
Is it any time you go from 3 -> 4, or only if you're doing a full run up? Does it matter what the ambient temperature is? Sounds like it could be the stock intercooler not keeping up with the heat buildup and that just coinciding with your drop in boost.
90% sure it is any time I go from 3 -> 4. I haven't noticed the ambient temperature playing a factor. I got my car tuned back in June. So I've seen this problem in temperature ranges from 50F-90F. I'll keep a closer eye on that.
 
Top