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APR plus, why did they only tune it for 87 instead of more?

tigeo

tigeo

Autocross Champion
Location
Richmond, VA area
GroceryGTIer said:
https://forums.vwvortex.com/showthread.php?5278915-Mk-VI-GTI-87-vs-91-octane-dyno#/topics/5278915

On an mk6, but maybe reflects a bit of what the difference would be.
Click to expand...

Seems reasonable to me - again, a few hp at most that is likely not noticeable by the average person. I don't know why it's so hard to believe that you can run a motor on 87 AND have some performance without it blowing up from pre-det..hahahah The compression ratio on the 1.8 and 2.0 is only 9.6:1...(and yes, I realize it has forced induction which adds to this).
 
YamR1rider

YamR1rider

Drag Racing Champion
Location
Tampa, FL
Car(s)
2017 GTI Sport DSG
I've currently got the earlier version of APR+ which was optimised for 91. When I get back home from work next week I'll be going to reflash to the new version and see how it compares.

Looking at the numbers provided by APR, there shouldn't hopefully be too much in it evening running 87 on the new one. I will also be doing some dragy runs to get some figures.
 
G

GroceryGTIer

Drag Racing Champion
Location
Tri-state
YamR1rider said:
I've currently got the earlier version of APR+ which was optimised for 91. When I get back home from work next week I'll be going to reflash to the new version and see how it compares.

Looking at the numbers provided by APR, there shouldn't hopefully be too much in it evening running 87 on the new one. I will also be doing some dragy runs to get some figures.
Click to expand...

Post the times up when you get them!
 
M

mike-y

Go Kart Newbie
Location
Los Angeles
Car(s)
2017 GTI / 2016 R
APR needs to make sure their product is idiot-proof if they are going to warranty it. That means they need to account for idiots who dump 87 octane into their tuned GTI's.
..or maybe someone just gets a tank of bad gas.

They have to make sure they can cover a worst-case-scenario, which means setting up a "safe" tune that has a lot of room for error, which can account for a tank of bad gas, low-octane gas, and/or surviving super hot Mohave desert conditions.
 
G

GroceryGTIer

Drag Racing Champion
Location
Tri-state
mike-y said:
APR needs to make sure their product is idiot-proof if they are going to warranty it. That means they need to account for idiots who dump 87 octane into their tuned GTI's.
..or maybe someone just gets a tank of bad gas.

They have to make sure they can cover a worst-case-scenario, which means setting up a "safe" tune that has a lot of room for error, which can account for a tank of bad gas, low-octane gas, and/or surviving super hot Mohave desert conditions.
Click to expand...

I thought that was the reason for the revised tunes they just did
 
SRTie4k

SRTie4k

Ready to race!
Location
NH
tigeo said:
Seems reasonable to me - again, a few hp at most that is likely not noticeable by the average person. I don't know why it's so hard to believe that you can run a motor on 87 AND have some performance without it blowing up from pre-det..hahahah The compression ratio on the 1.8 and 2.0 is only 9.6:1...(and yes, I realize it has forced induction which adds to this).
Click to expand...

Not noticeable by the average person, yeah you're probably right. My mom ran her mk5 GTI for several years only filling with 87.

But my mk7.5 was delivered with 87 in the tank; it felt like a bit of a dog when I picked it up, and it hesitated often when going WOT. Acceleration felt a little "rubber band" like, in that it would pull hard halfway through the RPM band, but then fall flat on it's face. After filling with 93, it felt like a little race car and stopped hesitating when accelerating, pulling hard straight to redline.

I guess I don't represent the average person, but the power drop was definitely noticeable. Actually it was kind of annoying.
 
avenali312

avenali312

Autocross Champion
Location
Mableton, GA
Car(s)
2015 GTI
SRTie4k said:
Not noticeable by the average person, yeah you're probably right. My mom ran her mk5 GTI for several years only filling with 87.
Click to expand...

Interesting. I had an MKV for almost a decade but only filled it with premium, because that's what it said on the fuel door (minimum 91). For your mom's car, I'm curious if timing was being adjusted to prevent knock all that time.
 
PLF8593

PLF8593

Drag Race Newbie
Location
Philly
Car(s)
19 Alltrack 6MT
tigeo said:
Seems reasonable to me - again, a few hp at most that is likely not noticeable by the average person. I don't know why it's so hard to believe that you can run a motor on 87 AND have some performance without it blowing up from pre-det..hahahah The compression ratio on the 1.8 and 2.0 is only 9.6:1...(and yes, I realize it has forced induction which adds to this).
Click to expand...



By comparison, what would the co pression ratio look like on a High output NA motor? I’m not well learned on compression ratios.


Sent from my iPhone using Tapatalk
 
PLF8593

PLF8593

Drag Race Newbie
Location
Philly
Car(s)
19 Alltrack 6MT
My 2015 GTI (which was the only model year for the MK7 in America that “Required” 91 on the gas cap) runs absolutely no differently on 93 compared to 87. No notable difference whatsoever.

That was when it was stock. I now run 93 on a 91 Uni tune


Sent from my iPhone using Tapatalk
 
tigeo

tigeo

Autocross Champion
Location
Richmond, VA area
GolfWang said:
By comparison, what would the co pression ratio look like on a High output NA motor? I’m not well learned on compression ratios.


Sent from my iPhone using Tapatalk
Click to expand...

My Ford Focus has a DI 2.0 NA motor and is in the 12-13:1 range....on regular 87....
 
YamR1rider

YamR1rider

Drag Racing Champion
Location
Tampa, FL
Car(s)
2017 GTI Sport DSG
GroceryGTIer said:
Post the times up when you get them!
Click to expand...

I will do. My version 1 APR+ times are up in the dragy thread somewhere, I'm interested to know if this new version can do the same but on 87 Octane. To be honest, I have a feeling I might lose a tiny bit off the v1. But there again that could be something I can live with if in general of there are other benefits like it being a little smoother etc.
 
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SRTie4k

SRTie4k

Ready to race!
Location
NH
avenali312 said:
Interesting. I had an MKV for almost a decade but only filled it with premium, because that's what it said on the fuel door (minimum 91). For your mom's car, I'm curious if timing was being adjusted to prevent knock all that time.
Click to expand...

I'm pretty sure it was, but she didn't notice. She still had enough power to pass people when needed.

The few times I drove it, the hesitation was pretty noticeable to me.
 
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