VR power curve looks v. wrong.. (NOW WITH DYNO PLOT) :(

[HiAsAKite 0]

Got my VR rolling roaded today... and can't say I'm overjoyed with what came out...

 

138BHP @ wheels (estimated 174 @fly)

126lb.ft @wheels (estimated 163@fly)

Bit annoyed about this.. and trying to figure out what may be sick with it.. :( :shock: :(

 

However what is interesting is that it gave peak torque at approx 4700 rpm, and peak power at 6400rpm.....

 

This confuses me slightly since I thought peak power was at 5800 and peak torque at 4200... :?: :shock: :?:

 

What the f'k is going on?

 

 

The torque curve also looked like a chunk was missing out of it between 3100 and 4000 rpm..

It rose up till 3100rpm and then flattened out until 4000 at around 108lb [email protected] rose 4000 and 4600 to peak at 4700 and 126 lb ft @wheels...

 

I would welcome any suggestions as to what may be going wrong here...

I would also be interested to know what the curve looks like if the cam sensor is out..(though last time it was VAG-COM'd it was ok.. but this was over a year ago..)

[Supercharged 2]

Does it feel down on power??? I would have thought you'd notice if the CPS was dead if it was ok a year ago as it knocks off 30bhp!

 

Get it on VAG COM again!

[smarkham 0]

was just think cam position sensor myself they are only about £30 as well

[HiAsAKite 0]

I can't say it feels that down on power... but then it is still giving 138BHP at the wheels...

[HiAsAKite 0]

Anyone have any other suggestions?,... and does anyone have a VAG-COM I could use in the SW London/Surrey/Hampshire area?... I have the 2x2 PIN connection...

 

Thanks,

 

Al

[Kevin Bacon 5]

The torque curve also looked like a chunk was missing out of it between 3100 and 4000 rpm..

 

You're cam sensor is down mate as the other guys have said. This rpm range is where it suffers the most.

 

If yours is anything like mine, then it should jump back up to 200bhp and 193lb/ft torque with a new sensor :D

[Guest]

Hold up on the engine re-build, just for a second. :roll:

 

As you're a CCGB member, I'll add some questions:

 

1. Was the car RR'd at the one on the Yorktown Ind. Est. Camberley by any chance?

 

2. Does the car feel lethargic pulling away from a standstill at light/part throttle?

 

3. Have you noticed a drop in fuel economy or if not, what sort of average are you getting?

 

I'm sure there will be someone with VAG-COM at the Dorset meet should it be required. :wink:

[HiAsAKite 0]

It doesn't seem noticeably lethargic pulling away...but then I don't really 'boot it' until I hit 2nd.. and then there's a very definite 'coming on cam' feeling around 3000+ RPM.. which increases progressively through the rev range up to 6K (I don't rev it beyond 6)

 

 

Average fuel economy tends to be around 10-12 l/100 km (its a left hooker) on A-road/M-way cruises.... can get this down to 9l/100km in the 50mph part of the A3 which equates to 28/23 and 31 mpg respectively..

 

I did three runs... first gave 171BHP, second gave 174 and 3rd gave 158 BHP (estimated flywheel) :0

 

EDIT:

The shape of the overall torque curve gives a broad 'flat' between 3000 and 6800 rpm, with a peak rise between 4700 and 6800 (a little bulge if you like)..

It the 'missing' torque between 4700 and 3000 that concerns me most.. plus the fact its giving peak power 100rpm below redline! (6400)

 

I will post up the RR plots when I get them... does anyone have a standard VR torque curve for comparison?

[Jim 2]

I'd go with Dr Haywires diagnosis!

 

Cam position sensor is a cheap fix from a labour AND part point of view!

[HiAsAKite 0]

That was my thoughts last night.. expecially when I remembered the 158BHP run!...

 

Just need to get this confirmed with VAG-COM with a 2x2 pin connector... anyone?

[Joe M 0]

I will post up the RR plots when I get them... does anyone have a standard VR torque curve for comparison?

 

 

Heres mine when it had just a ss exaust and k+n filter on it:

[Guest]

I'd go with Dr Haywires diagnosis!

 

Cam position sensor is a cheap fix from a labour AND part point of view!

 

I'm sure you would given your vast experience of fault finding on VR6s.

I on the other hand, would prefer not to gamble with HAAKs money on an unsubstantiated guess. I'm sure you see the irony of a forum that regularly lambasts VW technicians, having a fault-finding methodology amounting to little more than listing parts to swap out?

 

Perhaps a little more digging is required before we send HAAK off, wallet in hand? The reason I mentioned SRR is because every car that I know of that has run there has had an owner come away saying "It's really down on power". :roll: Read into that what you will...

 

HAAK, were these dynoruns conducted in quick succession or was the car left idling for a while between them? What fuel do you use : 95UL, 97SUL, Optimax? The simplest way to check the car over is to get it on VAG-COM and if you remember when I last scanned your car, you can use an OBD lead without a 2x2 adaptor.

 

In the meantime compare these, obviously not the VSR plot.

[CazzaVR 0]

I'm sure you would given your vast experience of fault finding on VR6s.

I on the other hand, would prefer not to gamble with HAAKs money on an unsubstantiated guess. I'm sure you see the irony of a forum that regularly lambasts VW technicians, having a fault-finding methodology amounting to little more than listing parts to swap out?

 

Erm, people are just offering their opinions and trying to help. Calm down :roll: .

[dr_mat 0]

He's got a point though...

And when did Haywire steal my PhD? ;)

[Kevin Bacon 5]

Just need to get this confirmed with VAG-COM with a 2x2 pin connector... anyone?

 

Have you looked here to see if anyone is near to you? http://the-corrado.net/.archive/forum/viewtopic. ... 09&start=0

 

Hope you get it sorted.

 

K

[HiAsAKite 0]

Blue Nothelle..

 

It was 3 successive runs (ie no substantive idling in between)...

 

Your non VSR torque plot is not that disimilar from mine in shape.. at least below 4000 rpm.. above that you have around 7lb ft @flywheel estimated more mine which is fairly flat till 6000rpm.. mine peaked atv 4700 and then sunk down to give 150lb ft at 6000 (approx)..

 

I need to find a VAG-COM.. and yep. when it was last checked around a year ago there were no fault codes (other than an ABS fault fromsomepoint in the distant past..)

 

It was running on a mixture of optimax and BP ultimate..

 

Thanks for posting the curve!

 

 

Kev.. thanks!

[Phil K 0]

I'm sure you would given your vast experience of fault finding on VR6s. I on the other hand, would prefer not to gamble with HAAKs money on an unsubstantiated guess. I'm sure you see the irony of a forum that regularly lambasts VW technicians, having a fault-finding methodology amounting to little more than listing parts to swap out?

 

Perhaps a little more digging is required before we send HAAK off, wallet in hand? The reason I mentioned SRR is because every car that I know of that has run there has had an owner come away saying "It's really down on power". :roll: Read into that what you will...

 

Little over harsh there I feel, this is a public forum and everyone is entitled to their opinions but there is no need to get at or slate other forum users.

 

Also, are fly wheel differences on a RR more to do with what is being calculated as transmission loss? Therefore you may find some RRs are a bit optimistic and some a little low - could it not be that the cars you know of have all been led to believe optimistic readings? For example a calculation of 25% transmission loss would mean 100bhp at the wheels and would be 125bhp at the fly.. so make that 35% loss and you get 135bhp ATF... which implies that the only real way of getting fly wheel figures is to bench test it.

[Guest]

Blue Nothelle..

 

I need to find a VAG-COM.. and yep. when it was last checked around a year ago there were no fault codes (other than an ABS fault fromsomepoint in the distant past..)

 

It was running on a mixture of optimax and BP ultimate..

 

Thanks for posting the curve!

 

Ok, next thing to check - engine off, bonnet open. Hold the accelerator flat to the floor. Look (through the gap in the bonnet if possible), or get a helper to look at the throttle mechanism - ensure it's hard against the end-stop. If it's not and you find there's a car mat preventing the pedal reaching the floor stop - feel free to take that mat out and beat yourself around the heed with it! :lol:

 

When you get it VAG-COM'd, in addition to scanning for fault codes, check your TPS is reading ~90 Degs or more at WOT, check your IAT sensor value is (a) realistic and (b) drops under WOT, check your lambda probe is switching either side of 1.00 every second or so (once up to temp), check your lambda & ISV adaptation trims for outlandish values. Finally do a 3rd gear, WOT, 1500-6500RPM datalog of blocks 001, 002 & 003.

[Guest]

Little over harsh there I feel, this is a public forum and everyone is entitled to their opinions but there is no need to get at or slate other forum users.

 

Conceded, I'll withdraw the remark towards Jim, who I regard as a decent bloke.

 

Also, are fly wheel differences on a RR more to do with what is being calculated as transmission loss? Therefore you may find some RRs are a bit optimistic and some a little low - could it not be that the cars you know of have all been led to believe optimistic readings? For example a calculation of 25% transmission loss would mean 100bhp at the wheels and would be 125bhp at the fly.. so make that 35% loss and you get 135bhp ATF... which implies that the only real way of getting fly wheel figures is to bench test it.

 

I place little store in chassis dyno figures full stop. I've lost count of the amount of people who've spent time & money searching for 'lost power' when there's nothing wrong with the car. Take them as a diagnostic aid, not gospel absolute.

[Kevin Bacon 5]

Little over harsh there I feel, this is a public forum and everyone is entitled to their opinions but there is no need to get at or slate other forum users.

 

Agreed and despite his pomposity last night, he still hasn't brought anything to the forum that we didn't already know.

 

HAAK - If you struggle to find VAG-COM, PM me and we can work something out :wink:

[HiAsAKite 0]

Thanks everyone.. I'm now out the ocuntry until next week, but I'll follow this up then..

 

Once again, thanks all..

[Guest]

Agreed and despite his pomposity last night, he still hasn't brought anything to the forum that we didn't already know.

 

If the basic checks I outlined were old news, why didn't YOU suggest them? Did it slip your mind during the headlong rush to make a snap diagnosis? Were you going to let him follow your example and replace half his engine bay before you revealed them?

 

Want something you don't already know ? Try these :

 

http://www.mmm-five.net/Corrado/Manual.txt

 

http://hometown.aol.com/DVAndrews/ems.htm

 

Note the use of the word BASICS on the bottom link. Strange, they've both been on the net longer than this forum yet they're clearly not common knowledge to some :

 

I've driven my VR with the TPS disconnected and it used the MAF for fuelling.

 

That's the easy-level stuff, there's no way I'm going to post up details on doing your own (re)maps or an idea I'm working on for REVO-style user-selectable maps on Motronic M2.9 cars.

That along with the other 'uncommon knowledge' I've got is for my own and my friends benefit, not every VW-owner who can't be bothered to do his own leg-work.

[Mike Edwards 0]

Handbags at dawn required I feel.

 

Only in this case maybe if the the one with poor choice of words and an irritable streak beats himself senseless for the entertainment of the rest of us.

 

You may well be God's Gift to VW fault diagnosis and tuning (you do appear to know what you're talking about) but your attitude sucks.

[CazzaVR 0]

Totally agree, Mike. There's no room on this forum for people with such a pompous attitude to others who he doesn't even know. He has indeed raised some interesting points, but he is clearly very socially inept.

 

This is a great forum where people offer excellent advice and opinions- this is only what Kev and Jim where doing- they weren't pointing a gun at HAAK, they were just offering friendly advice. Fine, if Mr Nothelle disagrees, he can say so, but next time try to do it in a diplomatic fashion instead of using unnecessarily cutting and supercilious remarks which are most unwelcome here.

[Kevin Bacon 5]

If the basic checks I outlined were old news, why didn't YOU suggest them? Did it slip your mind during the headlong rush to make a snap diagnosis? Were you going to let him follow your example and replace half his engine bay before you revealed them?

 

Well because his engine had mysteriously shed 30hp, which funnily enough correlates with a knackered CPS. So that was the intial suggestion based on our experience. One of my RR plots was almost identical to his when my CPS went down. If that wasn't the case in HAAK's instance, then we'd move onto the next list of items to check....

 

We are not going to stop offering advice because YOU feel we are under qualified to do so I'm afraid.

 

I haven't replaced half my engine bay, two thirds actually :wink:

 

Have a nice day :D