Loss in BHP T32 204ps 2016 swb Manual [Resolved]

[Mupp3tt]

Is anyone able to point me in some direction.
I have a 2016 SWB T32 Kombi 204PS BMT (65K miles) and it has been on the rolling road for a check up to find only 175BHP and 312 Ft/lb Torque, everything seems to be running smooth and no real hiccups pleanty of pull in the turbos to red line[ from low down, smoke tested, maf tested. not yet had the egr off or the pipe (already replaced but with the old style not the new style, VW dealer at thier best) that was replaced before, but that will be next. intended on a tune up and remap but no point with this hanging over my head, any advise help or otherwise direction is welcome.
I have a lot of confidence in the garage, far more that VW dealer so I'm happy on that front.

Just had a service,
Running propr oil ( after flushing)
running on Supermarket fuel but that said loss of 25bhp seems too much
reading taken from crank
suspention been lowered (recently, but not yet had tracking done)
dpf seems health, and regens fine.
K and N filter in the box
some possibilityies...

new plugs needed? (would that be a loss of 25bhp?)

 

[DaveD]

I'm curious why it was on a rolling road / dyno for a check up, you seem to have been satisfied with the way it was running, or have I misunderstood?
I guess you told the person carrying out the dyno procedure that you were disappointed with the result, did he / she make any observations or suggestions?
How was the MAF sensor tested? (There's more than one way).
How was the reading taken from the crank?
Is the air filter new, i.e. was it replaced at the recent service?
Sorry to ask so many questions but the more you can clarify the more likely it is that people can help.

 

[Mooncat]

Lose the K&N as that contaminates the MAF with oil and gives a lower airflow reading.

 

[Mupp3tt]

Not a problem with the questions the more I learn the better.
So was going in for a service then remap tune up for more economy.
So I guess they were taking a base line figures.

One mistake I may have made, I was given a KnN PANNEL airfilter as a gift and I put it in, could the oils in the filter do damge to the maf?

They put a standard one in and checked the maf, I didn't ask the ins and out of how.

They told me it was down on power, I had sent really noticed, I don't tend to drive it that fast. They had done tuning in one weeks before and it was 200bhp stock.

As for the other tests you suggest I don't really know the answers but if you could provide advise on different testing techniques I can pass it on. Although as they did a van prior to mine I expect they already know it.

 

[VanDamMan]

Not use one...but terraclean do an engine clean Process...go back to basics use nice clean oem filters .....the only real things that engines suffer from is carbon build up and restricted air flow.....once you get it sorted. ...be nice to know the outcome

 

[Mupp3tt]

KnN has been ditched and MAF cleaned, terraclean is a good shout. Will get back if I find a solution

 

[DaveD]

Lose the K&N as that contaminates the MAF with oil and gives a lower airflow reading.

It's possible / likely that oil from the K and N filter has already contaminated the MAF sensor, causing your low power.
MAF sensors are critical in the engine management, you can buy MAF sensor cleaner or use electrical contact cleaner, I wouldn't use anything else, it's a 5 minute job to disconnect the wiring, remove the MAF sensor and spray clean it, don't touch it with anything.
Or just buy a new MAF sensor, they don't last forever, they go out of spec over time anyway.

 

[Mooncat]

Ditching the K&N is a good choice, if you've ever seen how much dirt gets through these high flow filters you'd never fit them to a road vehicle.

 

[Insert Coin]

175 at the wheels? That’s about right isn’t it?

I’ve run a few cars on Dyno’s over the years and never had much success, everything I’ve ever run has been down on factory figures.

 

[DaveD]

175 at the wheels? That’s about right isn’t it?

I’ve run a few cars on Dyno’s over the years and never had much success, everything I’ve ever run has been down on factory figures.

You should certainly expect losses in the transmission, no transmission is 100% efficient. The 204 figure is probably from the bare engine at the flywheel and I think some manufacturers even measure the engine power with no alternator, power steering pump etc, so the figure won't be the same as when the engine is running ancillaries.
Somebody on here will know what a 204 should show on a rolling road, it won't start with a 2.

 

[Insert Coin]

Isn’t there a rule of thumb, circa 10-15% losses at the wheels?

 

[Village]

i thought that generally in the UK, the figures you get from a dyno aren't whp, but at the fly wheel

Edit: it says reading taken from the crank!

 

[DaveD]

Isn’t there a rule of thumb, circa 10-15% losses at the wheels?

I've heard 15% quoted before, it will differ from vehicle to vehicle, and 4motion vans will lose more than 2wd vans.

i thought that generally in the UK, the figures you get from a dyno aren't whp, but at the fly wheel

Edit: it says reading taken from the crank!

I was a bit puzzled by "reading taken from the crank".
A rolling road can only measure power delivered by the wheels to the surface, or the rollers. I don't know how you'd measure flywheel horsepower with the engine in the van!

 

[Village]

I've heard 15% quoted before, it will differ from vehicle to vehicle, and 4motion vans will lose more than 2wd vans.

I was a bit puzzled by "reading taken from the crank".
A rolling road can only measure power delivered by the wheels to the surface, or the rollers. I don't know how you'd measure flywheel horsepower with the engine in the van!

Yeah it's cobblers! As you say, not possible. You can only measure whp and then factor back in the (estimated) drive train loss. But my understanding is all (most?) UK dynos do this automatically, which would surely make them inherently inaccurate from the start, as they must assume a standard % loss from power at the fly to the wheel

 

[Lukavell]

Yea, it must just be an algorithm based on the wheel reading

 

[Mooncat]

The easiest way to get a better rolling road output figure is to fit skinny tyres and pump the pressure up to the max recommended on the tyre.

In reality a rolling road graph is just used as a reference - Graph A is the vehicle as originally presented and Graph B is after a repair or some sort of performance modification has been applied and even this assumes atmospheric conditions are similar. You then compare the shape of the torque curve and the delta between the two to see what the real improvement is.

What I do find interesting is that even the rolling road operator recognised the K&N is junk and fitted a standard filter - they must see a lot of issues with these things doing the opposite to what they are supposed to do on engines with a MAF.

 

[Mupp3tt]

Guys Guys Guys,
I may not be precise in my wording, not an automechanic.
All I know at the momnet is that the Power reading of 175BHP was at the Crank power, If that is an algorythm I will find out today hopefully.
What I have found out that the KnN to OEM Filter Change made no difference.
The MAF has been cleaned, Not sure with what fluid I didnt get into that side of it. (so may need to order one up to see if it makes any difference.
The Pipe Typically replaced to the ERG was done by VW is the OLD style not NEW style.
There are no dash lights warning of any issue
Could be the ERG but it hasnt been removed yet to see if it is clogged, stuck etc.
Tires are relitively new (less than 1000 miles, pressures have been done before I went to the garage.
Suspention was changed about 2000 mies, not yet aligned, but definately not going to put itout that much,
Brakes have never been changed, not needed it and not sticking.

not sure on anything else, but seems a good wee thread so will kep you up to day.

if anyone has any experiance similar, it would be great to hear thier outcome. issues and resolutions.

 

[DaveD]

Ha ha, we do tend to go off on to specifics, speculation and theories!
Anyway, I look forward to finding out how you get on.
I had two previous turbo diesels which got to 80k miles, both seemed to be less powerful than they used to be but for no obvious reason. I changed the MAF sensors and both made a very noticeable return to full power as well as better economy and smoother running. Hence I'm very quick to point out the importance of MAF sensors, which do deteriorate over time and use, even if an oiled air filter isn't fitted. I have cleaned MAF sensors in the past with limited success, replacement is best.

 

[Mupp3tt]

I have cleaned MAF sensors in the past with limited success, replacement is best.

Seems the best point of advise.... Cheers fella.

Specifics will come, some folk get right ratty when they read things on here ,

 

[Mupp3tt]

So here is the lowdown,
First, apparently changining out components is not the best idea, the ECU learns how each of the MAF, EGR,MAP,HPFP,TPS,CPS etc work together as a unit and chaning one out can affect the whole system forcing it to relearn and will take time. Makes sense, with everything being more complex and clever.

On the Van it has shown several Regens that have failed on the DPF so it has been foreced into a regen a couple of times. and awaiting feed back on the outcome....

Also I was thinking a 5 hour drive would be bound to kick the van into doing this is not the case.. it really depends how you drive.
I'm a highlander, I drive quick but maybe not fast, what i mean by this is, I will happily sit on corners in excess of the speed limit and dont slow down becasue i know the roads, which aslo means i dont really change gears a lot and there fore the revs dont fluctuate a great deal. so even driving at say 90mph (not saying i have been, just a suggestion ) will mean that i am not getting the engine hot enough for the DPF to kick in...... face palm.

I've been advised by a well known VW transporter tuner that you need to drive with the engine above 3k revs for at least 30 min to get the 204ps spec vans to regen correctly.... which is surprising but makes sense, so this issue could be down to my good driving, at least that how i read it not sure if this helps anyone or if it is totally wrong but there is my advise collation for now.....

more to come ..... when i get the van back, I hope , today, maybe , possibly......