GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV

EQT E-Tuning Q&A

crashracer

New member
Location
Portland OR
What are the signs your fueling is weak? I'm seeing rail pressure drop around 5800 rpm with higher corresponding injector time. AFR is maintained. What indicates weak HPFP vs LPFP, or both? I'm on a base stage 2 file, about to get custom tune and I want to address anything before revisions.

Third gear pull:
https://datazap.me/u/crashracer/stg2basecoast-run?log=0&data=15-36-38&solo=38&zoom=3637-4175

Long pull, 3-5th:
https://datazap.me/u/crashracer/stg...-18-19-23-36-38&zoom=1279-1372&mark=1332-1339
 

aaronc7

Autocross Champion
Location
USA
Car(s)
17 S3
HPFP is going to most strained at peak torque. Since the HPFP is driven directly off the cams, its flow capacity increases with RPM....so high RPM is generally not an issue for the HPFP. At peak torque, you can get to a point where the hpfp simply can't supply enough fuel per stroke of the hpfp. At high RPM, you might be flowing overall more fuel volume, but the volume required per stroke is less and the piston is moving much faster.

Like you said, you see rail pressure decrease in order to meet flow demands....similar to a water hose scenario where if you decrease pressure you can increase flow. And of course with less rail pressure, you need to increase injector pw

LPFP on the other hand is most strained at peak flow or generally around peak HP or high rpm. In stock form, there is no low side pressure sensor, so we can of have to guess/infer what's going on. If LPFP pressure starts to really tank, you'll get to a point where it can't sufficiently fill the input side of hpfp, and you'll start to see rail pressure drop off in high rpm or other weird stuff at high rpm. The best way would be to monitor low side pressure...MPI kits add this sensor.

In your case, the HPFP is getting maxed out, HPFP upgrade would be wise.

Another issue you run into especially with is38 / e85 setups is running out of injector at high rpm... you get to a point where there simply isn't enough time/injector pw to get enough fuel into the cylinder for a given rail pressure. You can widen the injector window, but if you start spraying too early or late it can result in fuel just getting dumped out the exhaust valve or overall poor atomization/poor combustion etc. For this reason you'll generally see some HP gains on is38/E85 setups with MPI because you're not getting into this poor combustion region etc. DI only seems to work for some setups but not so well for others.

Is your rear O2 sensor still plugged in and/or do you have a P0420 soft code?
 

Ostateballer

Go Kart Newbie
Location
Oregon
Car(s)
2016 GTI S PP/LP
HPFP is going to most strained at peak torque. Since the HPFP is driven directly off the cams, its flow capacity increases with RPM....so high RPM is generally not an issue for the HPFP. At peak torque, you can get to a point where the hpfp simply can't supply enough fuel per stroke of the hpfp. At high RPM, you might be flowing overall more fuel volume, but the volume required per stroke is less and the piston is moving much faster.

Like you said, you see rail pressure decrease in order to meet flow demands....similar to a water hose scenario where if you decrease pressure you can increase flow. And of course with less rail pressure, you need to increase injector pw

LPFP on the other hand is most strained at peak flow or generally around peak HP or high rpm. In stock form, there is no low side pressure sensor, so we can of have to guess/infer what's going on. If LPFP pressure starts to really tank, you'll get to a point where it can't sufficiently fill the input side of hpfp, and you'll start to see rail pressure drop off in high rpm or other weird stuff at high rpm. The best way would be to monitor low side pressure...MPI kits add this sensor.

In your case, the HPFP is getting maxed out, HPFP upgrade would be wise.

Another issue you run into especially with is38 / e85 setups is running out of injector at high rpm... you get to a point where there simply isn't enough time/injector pw to get enough fuel into the cylinder for a given rail pressure. You can widen the injector window, but if you start spraying too early or late it can result in fuel just getting dumped out the exhaust valve or overall poor atomization/poor combustion etc. For this reason you'll generally see some HP gains on is38/E85 setups with MPI because you're not getting into this poor combustion region etc. DI only seems to work for some setups but not so well for others.

Is your rear O2 sensor still plugged in and/or do you have a P0420 soft code?

Hi Aaron, I’m guessing you were referring to my post? I have the Autotech HPFP and I do still have the rear O2 sensor plugged in. I am not aware of the soft code from memory, but I can double check.
 

aaronc7

Autocross Champion
Location
USA
Car(s)
17 S3
Hi Aaron, I’m guessing you were referring to my post? I have the Autotech HPFP and I do still have the rear O2 sensor plugged in.
Sorry, I was replying to crashracer's post, I guess I should start using that quote function. In his logs you can see actual AFR is richer than target AFR by a little bit...usually an indication of rear O2 plugged in/P0420 soft code.
 

crashracer

New member
Location
Portland OR
Is your rear O2 sensor still plugged in and/or do you have a P0420 soft code?

Aaron, excellent explanation! Yes, the rear O2 sensor is unplugged, I've read about the ECU running rich. I wonder what's going on there too.
I'll upgrade the HPFP and post a follow up. I'm sure this info will useful to many others out there.

Alan
 

HuntR

Go Kart Newbie
Location
Seattle
Greetings all. I don't wish to seem lazy, and I have read a bunch of pages here, but still have question.
To use the big Vortex EQT turbo is it mandatory to upgrade fuel pump/s and to MPI and? For 2017 Golf R. TIA.
 

flipflp

Autocross Newbie
Location
PNW
Car(s)
'16 Golf R DSG
If you're not going to push a Vortex turbo, I recommend some corn in your IS38's diet:



Pretty much the same output (within 20hp) as a Vortex on 91 octane with less top end. No fueling upgrades required, just an OTS stage 2 blend tune and hardware (DP/IC).

This is their non-MPI Vortex (non-XL housing) dynos, for comparison (IS38, Vortex 91 and Vortex E30 w/HPFP):
 

AdamDFKC

Passed Driver's Ed
Location
75154
Car(s)
17 Golf R
2017 R DSG

I bought an ECU staged tune (stage 2) and DSG staged tune back in July. I still haven't flashed the ECU because I'm not installing my downpipe and intercooler until October 3-4. I flashed the DSG mid July and have been running it since then.

I do like how it performs day to day compared to the Cobb files however, I no longer have launch control.

The only mod besides the DSG tune is the MAPerformance Stage 1 OTS tune. With the Cobb DSG tunes I still have launch control but it will not work with the EQT DSG tune.

I'm concerned I selected the wrong options when buying the tunes.
DSG: auto shift disabled
ECU: 93 octane, stage 2, Cobb launch control, Cobb adjustable traction control

Because I selected Cobb launch control with the ECU tune, is the launch control out of commission until I flash the ECU? I'll be flashing the ECU in about two weeks and will find out then but I wanted to do some before and after tests with launch control enabled so I was hoping to get it working before then. Might just have to test with the Cobb files.
 

Mlaplaca08

Passed Driver's Ed
Location
Triangle, NC
I’m not 100% sure I understand what your asking but - both your EQT and MAP tunes will have launch control with them. You are able to turn launch control off through the accessport itself. As long as you are using a tune with the Cobb launch control, you’ll have it active. If that doesn’t answer your question, let me know.
 

AdamDFKC

Passed Driver's Ed
Location
75154
Car(s)
17 Golf R
I’m not 100% sure I understand what your asking but - both your EQT and MAP tunes will have launch control with them. You are able to turn launch control off through the accessport itself. As long as you are using a tune with the Cobb launch control, you’ll have it active. If that doesn’t answer your question, let me know.

I was just hoping to get a response from the EQT guys confirming if it is normal for me not to have launch control with the MAPerformance Stage 1 OTS + the EQT DSG tune. Based on my assumptions and what you wrote, I should have launch control at the moment but I don't.
 

aaronc7

Autocross Champion
Location
USA
Car(s)
17 S3
EQT DSG tunes have oem style launch control settings 'built into them'. But ECU tune can override it and force Cobb style LC. No idea what's going on with the MAP tunes. Might be some weird unintended result of combining ECU and TCU tunes that weren't made for each other.
 
Top