ABV intake dyno evaluation. Farewell. Toyotec's Golf 3 200ps VR6 'Der Ankor'.

Background
It has been almost 1 year I have owned a 97 model year Golf Mk3 VR6.
When the car was purchased, the intention was to leave it as STD as possible. But then the disease in all of us, called tweaking took hold and since then, the car has been going through a series of subtle mods, all in the quest to make it feel better for me. Lets just hope this does not get carried away beyond the WOLF R, but you never know .
With its service booked stamped and perished wishbones,shocks, plugs, thermostat housing replaced, the next step was to start on tweaking the engine.
The car has bought back in Feb 2009.



Airbox mods Feb 09
The car came with a Pipercross pod filter kit and we all know how well induction roar and the name VR6 correlates.

However I found that for normal day to day driving, this noise was a bit too intrusive, even too chav. I did not mind some induction roar but not this boy racer nonsense. Fortunately the previous owner left the original airbox in the car so it was just a matter of time before this was breathed upon. Before fitting back to the vehicle the unit was opened up to see what noise restrictions where fitted from the factory. Like ABF MK3 units there was a long velocity stack fitted to the top half of the air box running to the MAF sensor.



Using a bit of common sense this was removed the larger end was bell mouthed on the stove.

Modifications to the lower section included added an extra hole towards the inner wing.

A standard air filter was placed into the airbox.

and everything returned to that stockish look all tuned for response.


The sound results were, muted and mellow induction roar inside cabin at WOT, and still angry sounding from outside at full chat. No heat soak during heavy traffic and 30+ deg ambient. The std filter was still used. At a later service, the std panel filter was replaced with a reusable K/N element for longevity.

Top fuel economy was 35mpgs, average 30, driving like a tool 22.

First dyno evaluation of hardware Oct/Nov 09
Later last year, when there was access to the Garage Streamline dyno, the car was tested back to back with an unmodified air box and this Toyotec one.
The result was 181bhp@5700rpm and 187lbft@4000rpm for Toyotec airbox.
With OE VW item the power was 177bhp@5600rpm and 184lbft@4100rpm.
The engine had covered approximately 125K miles.
We had the CGTi day and the result was still 181.5bhp@5700ish rpm with 188lbft. Hence the name "correlation car".

Clutch/flywheel and service Dec 09
At 129K miles the clutch starting to slip during 4th and 5th gear changes, so the decision was taken to replace this item and at the same time lighten the flywheel.
Flywheels absorb energy during accels and release this energy during idle to make the transition between combustion events smoother. The "smoother" part is determined by VWs NVH team as to what is acceptable for customers. For me, at bit more NVH is not bad if there free clutch torque to be gained and 6 cylinder engines as usually smoother than in line 4 cylinders anyway.
So before the car was stripped down, a spare VR6 flywheel was obtained and it was skimmed off and balanced to approx just under 6kg. The STD unit taken off the car was weighed at 8kg.

Thanks to the guys at Garage Streamline, we stripped the vehicle down during the cold snap one night.

I am glad to say that this was the first time the gearbox seemed to be coming off the car. All the clips and everything were there. Original clutch and flywheel removed and in with the new. With the car mounted together again it was out of the shop and down to home at 1.30 in the morning. Next the vehicle was serviced again.
My impressions for the first 500miles of driving ( a week)?
Initially I thought the car was the same pre clutch job, but then I was corrupted having just stepped out of 400bhp EVO. However during certain daily manuveours it was noticed that the car seam to be a bit more punchy during accels. It would start to easily torque steer 2nd gear and the EDL seemed to be having an even harder time than ever before. My actual fuel consumption had also gone down. Something had changed. In order to find out why this seemed to be the case, the vehicle was given to a few VR6 owners for appraisal and each one made comments such as "What did you do to it", "it is quite fast for stock VR", "I like this punchy feeling" and so on. So after these comments it was back to the dyno to determine what was really happening.

Second dyno evaluation post clutch service 6kg flywheel Jan 10
With the car strapped on the dyno we did a 3 runs.
My best run was 192bhp@5800rpm and now 199lbft@4300rpm.


I am of the belief that the airbox modification was complimented by the new flywheel modification, clutch change and service. The load at which the engine operates is possibly less for the same clutch torque too and now post 5900rpm there is over fuelling. Very soon due to OE ECU access this will be sorted.

Next steps for 2010

Bosch M3.8.1 calibration refinement.

Ultimately the plan is the turbo this car ( I already have the manifold flange as you do) and it will be done on the original Bosch Motronic 3.8.1 system. On the torque curve there are bumps that seem to align with poor fuel control. With corrective recalibration this would smoothen the torque curve to hit near 204lbft and possibly stop the sudden drop off of torque post 5900rpm to have near to 200bhp.

Exhaust system
The intermediate exhaust box is perishing, so an as quiet system as the standard one has to be found. It may mean that another std unit may just find its place back on the car. Hopefully benchmarking will determine what ultimately is fitted.

Suspension
Suspension works and requirements were submitted to a certain member on here and we are currently working on upgrading this from the current set up that is currently on the vehicle.

 

Eddie - what power gain can you pin the change in ambients? What was the temp @ the RR roughly?

 

That day ambient was 6ish.
Temp probe was in airbox as it was in most previous cases read 16 deg C. I have to upload pictures to in a while. There is a 10lbft delta for the entire torque range to 5800rpm which correlated to my new found responsiveness everywhere.
I forgot to add. With the lighter flywheel the car now struggles to crawl in 3rd on just idle control and engine vibration is slighty more increased in cabin.

 

Thats a nice improvement from the air box mod. Did you replace the clutch with a standard one?

Its been almost year since I first MOT'd mine and a R/R day has shown it only produces 122bhp at the flywheel. The operator though pulse sender (Hall sender from where he pointed) and a code scan said Knock sensor 2.

Cheers

 

Yes, back to std LUK item but 6kg flywheel.

Your car does sound a bit sick indeed. Hall sensor required to know cylinder position. I did respond to your post.

 

Pictures now up.

 

Just looking at the prints you passed me for the VR that day - are the temps listed in the box within the graph space?

 

Yes in the small green box. Look at "IT" this is the temp of the inlet air.

 

Looking at the raw data from the CGTi dyno back in Nov the IT was 16-17 deg C for the 3 runs. The probe was in the airbox as in this test as well as all the other cars. Tire pressure, rpm detection method were all carry over from other tests.

 

Wow the numberplate is so close to what mine was.... mine used to be R240 SLU, also a Golf VR6

 

May have been registered at the same dealership on the same day maybe .

 

So same inlet temps on both runs then, or is the new graph IT data actually November's with the latest run superimposed on it?

 

I will not do things like that. The green box on the graph I posted up is the intake temperature on the day the vehicle measured 192bhp.
What I did here was to prove that the clutch torque has increased since performing the hardware changes post CGTi day rather than be subjective and say it feels better or my mate says it is faster.
This new baseline can now be further improved with calibration tweaks.

 

Ah, I wasn't suggesting any alteration, merely asking which parts of the peripheral graph data related to which day.

So the box inside the graph above is for the day you got 192.

Back in Nov, the data was:

BP - 1013.2
RH - 60
AT - 25
IT - 16
RR - 125
TN - 3.480
20091107 - 153810
CK - 49
CF - SHOOT_6
Tyre Pres. - std
Gear - 4th

(whichever bits are relevant!)

 

I got what you are saying. And I am be wrong on this occasion on my Intake Temp at 16 deg based on that plot.
The 192bhp run was added to the 181.5bhp plot for data comparison. Thus the green box defaulted to the enviromental conditions on the CGTi day as seen by the 2009 11 07 date.
On that day of the test the ambient temp was 6 or so degs. So the inlet probe in the airbox would be approx 11-12 deg C. I do not have the raw data for this run on me at the moment to confirm.
Does not influence the result on the day but well spotted though.

 

Hmm.... sounds like the plan is changing!


Have you managed to crack the code yet?

 

Code cracked

Just trying to get all those boat anchor torques under control for now.

 

Soon you'll be saying there's no replacement for displacement

 

Never...
But there is no replacement for Boosted displacement though!!!
Only a small huffer will do (GT35 anyone lol)

 

See if you can get the hammer to swing round a corner too