Rolling Road Test - essential or not necessary?

[berg]

Hi guys, as I have had my Mk 5 ED 30 for nearly a week one of the first things i thought of doing was to get it rolling road tested so that a.) i can see the power at the wheels b.) if anything needs a slight adjustment the test will highlight it. Am i correct on point b.) and so it is a worthwhile exercise to make sure everything is running right? Also, what is typical cost of the above?

Cheers, Berg

[Hurdy]

You need a diagnostic on the rolling road then. These cost a little more, but are worth their weight in gold for ensuring that the car is running correctly.

Bank on between £70-£100, depending on the time spent on the RR. 

[Janner_Sy]

Its a good idea but alternatively  you could get your car logged on the road with VCDS by someone on hereand save yourself some money..

[vRS Carl]

^^^^

Was just going to say the same thing.

No RR will ever replicate the real road so VCDS Logging would be better. Having said that you can get the car running very well if you go to a decent tuner.

[berg]

Its a good idea but alternatively  you could get your car logged on the road with VCDS by someone on hereand save yourself some money..

VCDS - i presume this is where someone will plug a laptop in to ECU whilst the car is driven along and collects data?If so who might have such equipment and be willing to give my car a "going over" so to speak in the north west area?

Many thanks for the input though chaps.

By the way for the purposes of pub gossip what are the official 0-60 sprint times for a manual box for Gti and ED 30? Am I right in thinking it is 6.7s for the Gti and 6.6s for the ED 30 because the extra 30 horses dont come into play that much low down?

[vRS Carl]

Have a gander at the VCDS owners register.

http://www.mk5golfgti.co.uk/forum/index.php/topic,120.0.html

I am sometimes up in the northwest as thats where im from originally and my parents still live there. But im not going to be up there for a while im afraid.

[R-tech-Nick]

^^^^

Was just going to say the same thing.

No RR will ever replicate the real road so VCDS Logging would be better. Having said that you can get the car running very well if you go to a decent tuner.

A rolling road logging session is a much better way of VCDS data logging.  A 3rd run on a road will not replicate a 6th gear full load pull.
On a eddy current rolling road you can dial in load or acceleration rates to allow for a more refined data point and more readings per log.
You also have the options of holding the engine flat out at whatever rpm you want and check every measuring blocks real time reading.

Nick

[vRS Carl]

A RR will never replicate real world so will never be better. You will never get the same airflow, downforce, changing road conditions etc from a Dyno.

For example on a Dyno my car can sit with timing set at 9 and produce no timing pull whatsoever. Put it on the road and the timing pull goes to dangerous levels and i can't safely run timing any higher than 7

So while you can do a lot of things on a RR (i did say a good tuner can get the car setup well) it will not replicate the real road.

[R-tech-Nick]

A RR will never replicate real world so will never be better. You will never get the same airflow, downforce, changing road conditions etc from a Dyno.

For example on a Dyno my car can sit with timing set at 9 and produce no timing pull whatsoever. Put it on the road and the timing pull goes to dangerous levels and i can't safely run timing any higher than 7

So while you can do a lot of things on a RR (i did say a good tuner can get the car setup well) it will not replicate the real road.

Sounds like the dyno your using is not adding the correct amount of load or ramp rate during the logging session? Done right using a rolling road to log in steady state mode is the best way to log any car.

  The only issues with a rolling road is charge cooling and heat soak (if only one fan being used) but this should be down to an educated tuner who can monitor these and relate them to the readings they are getting.   And part of a logging or remap session should be to heat soak the engine and get the intake temps to the upper limits of 70+degrees to make sure enugh timing is pulling out and the fuel is rich enough to cope

Nick

[vRS Carl]

Sounds like the dyno your using is not adding the correct amount of load or ramp rate during the logging session? Done right using a rolling road to log in steady state mode is the best way to log any car.

  The only issues with a rolling road is charge cooling and heat soak (if only one fan being used) but this should be down to an educated tuner who can monitor these and relate them to the readings they are getting.   And part of a logging or remap session should be to heat soak the engine and get the intake temps to the upper limits of 70+degrees to make sure enugh timing is pulling out and the fuel is rich enough to cope

Nick

It's a Dyno Dynamics one and the tuner knows there stuff (not just my opinion).

So for my own education then.

How do you replicate downforce & aerodynamic lift. I know you strap the car down but that applies the same force to the wheels no matter the speed? Or do the Dyno Straps increase in tension the faster the car is going? Or do you alter the ramp rate?

[PDT]

I second everything nick said, many people will knock dynos in favour of on road logging but unless you have first hand experience of datalogging and mapping on a good eddy current dyno you cant really comment on how one method is better than the other.

I.e you want to map/check a data area for  boost, ignition timing and fuel. This data area is at 65% throttle at 6000 rpm. You go out on the road with one person driving and one checking the data and correcting the map and as you hit 6000rpm at 65% throttle you have a fraction of a second to look at the 3 required parameters and before you know it you are at 7000rpm.

On a dyno you can hold the car at an exact rpm amount and it wont allow it to accelerate further so you can analyse the data, correct it, move onto the next data area etc... then at the end of this process you carry out a sweep (dyno run) through the modified data area and compare the power output and emmissions to see if the alterations have improved the cars performance.

[R-tech-Nick]

Hi.

Downforce & aerodynamic lift will not even come in to the factor while logging, why would it??    A logging session is not to replicate road going conditions the idea is to apply load to the engine to monitor all the outputs at every load site.

During a power run  on our rolling road Hurdys ed30 made 357bhp with the simlar load ramp rate to the dynamics rolling roads in F4 shoot out mode, then straight afterwards we did a WOT steady state test which fully loaded the engine to its extream and made 367bhp@6800rpm, and to replicate steady state test on the road the car would have needed to drive up a steep hill with the boot and backs seat stacked with added weight at around 130mph.
If you fancy having a play with logging under steady state your more than welcome to come and have a play down here.

Nick

[R-tech-Nick]

I second everything nick said, many people will knock dynos in favour of on road logging but unless you have first hand experience of datalogging and mapping on a good eddy current dyno you cant really comment on how one method is better than the other.

I.e you want to map/check a data area for  boost, ignition timing and fuel. This data area is at 65% throttle at 6000 rpm. You go out on the road with one person driving and one checking the data and correcting the map and as you hit 6000rpm at 65% throttle you have a fraction of a second to look at the 3 required parameters and before you know it you are at 7000rpm.

On a dyno you can hold the car at an exact rpm amount and it wont allow it to accelerate further so you can analyse the data, correct it, move onto the next data area etc... then at the end of this process you carry out a sweep (dyno run) through the modified data area and compare the power output and emmissions to see if the alterations have improved the cars performance.

+1 sums it all up 

 more refined data the better the end result or a visual picture on how safe well an engine is performing.  With the added load a vcds log  can be as long as 2mins from 1500rpm to 7000rpm, with 1000s of data points, on the road run you limited to around 14 -15 seconds with only a fraction of the data.

Nick

[berg]

mmmm, lot more complicated than i thought

[R-tech-Nick]

mmmm, lot more complicated than i thought

Hi
Its not complicated m8.
Just find a company local to you who understand the TSFI engines and who have a rolling road and ask them to do a power runs and a datalogging health check, PLUS a visual inspection.

Nick