Golf R -v- Golf GTI

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Turbo lag down low on the Golf R was not the only issue I found with the KO4 boosted older EA113 motor. The pressure fluctuations between throttle applications and lack of motor response, or at times, too much motor response, was noted on my Golf R test drive and it detracts from the driver/vehicle feeling of connectedness.


Volkswagen has done a sterling job of reducing the turbo lag in the KO4 Golf R EA113 motor. The difference in fuel pressure build-up between the older EA113 motor and new EA888 motor feels tangible, as mentioned by myself in post # 1-2 and other forum members in subsequent reviews. Other forum member’s reviews described the throttle response of the Golf R as ‘wooden’, ‘unresponsive’ or ‘inert’.

Cheers
WJ

My experience with the R is at odds with their assessment. I didn't find the throttle response either of those. There is a bit of lag but it goes away in Sport mode and/or with a Stg 1 tune.

[Corey_R]

There was a stage a several years ago where guys that boosted their turbo-chargers on the EA113 MKV GTI motor experienced fuel delivery problems esp. when going to stage II turbo boosted tunes – this came down to issues with the OE fuel pump and absence of the four lobe cam actuator in the older MKV Golf EA113 motor.

Cheers
WJ

I'm not convinced by your post. I mean, by going to a 4 lobe cam they've been able to increase the rate of pressure build up etc, but when your revs are 5000rpm, this means they is a single revolution every 12ms, can a driver really determine the difference in the reactions of the 4 lobe cam? Or maybe my understanding of how that all works is wrong.

But more to the point. The fuel pump itself is the same.
Another point is that the fuel delivery problems you mentioned on the EA113MKV GTI issue when going to a Stage II+ or III tunes were solved by a modification to the fuel pump by APR. When going to a Stage II+ or Stage III tune on the EA888 motor, this same fuel pump modification is STILL required.

So whilst I believe Volkswagen have improved the operation of the fuel pump by introduction of the four lobe cam, I'm not convinced that the effects are what you're stating in your post.

[WhiteJames]

Service Training

Self-Study Program 824803

The Volkswagen 2.0 Litre

Chain-Driven TSI Engine



High Pressure Pump


The high-pressure pump produces a maximum
pressure of 2175.5 psi (150 bar). The fuel pressure
requested by the engine control module is adjusted
by Fuel Pressure Regulator Valve N276. The pressure
is regulated between 725.1 psi (50 bar) and 2175.5
psi (150 bar) depending on engine requirements.


The high-pressure pump now has its own pressure
limiting valve. This valve opens at approximately 2900
psi (200 bar) and admits pressure into the pump
chamber. Previously, pressure was discharged into
the low-pressure circuit. Excessively high-pressures
can build up in overrun or when the engine heat
soaks after shut-off.


The pressure pulsations in the low-pressure circuit
are reduced by a damping element integrated in the
pump.


High-Pressure Regulation


Fuel pressure and fuel quantity are regulated by Fuel
Pressure Regulator Valve N276. The signal from Fuel
Pressure Sensor G247 is used by the engine control
module as a parameter. This sensor is located in the
fuel rail.


Power demand has been reduced significantly
through a newly designed fuel pressure regulating
valve and associated control concept.

At the start of delivery, Fuel Pressure Regulating
Valve N276 is activated only very briefly. The intake
valve closes, fuel pressure builds up, and fuel
delivery immediately begins.

There have been several improvements to the fuel pump on the EA888 motor.

I have found that the throttle application on the EA888 to be more precise than the EA113 motor having owned a MKV GTI and now a MKVI GTI, making it that bit easier to balance the chassis on the throttle.

Cheers.
WJ

[Corey_R]

Aah ok, thanks for the additional information.
Also, on review, it seems the HPFP upgrades for the MK6 are not related to the EA888 Stage III kits anyway, so that comment in my post above is incorrect.

It's still interesting that the differences can be felt through throttle application. I must admit that I haven't noticed the difference, but then I haven't had the opportunity to drive both back-to-back either.

[G-rig]

The MK6 EA888 fuel pump is good for stage 3, not bad huh.

[thezoneR32]

Has anyone here had their R modified by APR yet?

[G-rig]

Has anyone here had their R modified by APR yet?

Guy told me APR tuned 13 or so new R's last week

[thezoneR32]

Where are those people we need them here making us jealous. Oh wait a minute, they wouldnt have time to be here while they're out blowing the doors of wrx, evos and hsv's

[REXman]

What would an R do 0-100, 1/4 mile in with just an APR tune (with DSG).

Any ideas?

[G-rig]

I'd say 0 - 100 in 5.0 sec.. not sure about 1/4 mile, maybe 13's?