power loss at 4800 rpm ?

[GIXXERUK 0]

thanks for the offer of the supersprint but if i travel 320 miles for it, i might aswell pop to demontweeks and buy one

i cant see it being the cat tbh , if the gases were having problems escaping at that point then surely it would show by being difficult to rev past there

[dr_mat 0]

Well maybe..? But air flow volume at 50% throttle is less than at 100% throttle, so it might well rev freely(ish) past a certain point, but it won't be able to flow enough air to sustain the power.

What oil are you using? Does the engine and oil temp run up to normal?

[GIXXERUK 0]

i'm using quantum silver, the oil temp runs up to normal , doesn't use any oil or water

by air flow , do you mean as in the air filter or the exhaust gas flow ? we did a run with no air filter just the maf and i think it made 2bhp difference

the RR referenced the air/ fuel on the dyno butdidn't show any glitches at the loss of power point

its very odd thats why we changed the dizzy as we thought the timing must be going off at this point , to no avail though

 

i always run super unleaded

[GIXXERUK 0]

i've just spoke to vince who said its a tough one, could def be the cat or maybe a crank/cam pos sensor, so i'll go with a decat first and see what that does

he said the other option is to wait until whatever is breaking down at 4800 gives up the ghost completely but patience isn't my thing :twisted:

[dr_mat 0]

You said yourself you'd never really noticed it ... you could just keep your wallet in your pocket ..!

 

 

 

 

 

 

 

 

 

No, sorry, I know that once you've found a problem it's got to be fixed. Don't know what came over me there for a second .. sorry .. ;)

[GIXXERUK 0]

no no no .. dont throw that into the equation , i know common sense screams WAIT !! but its bugging me !

[GIXXERUK 0]

bwwaahhaa :-)

 

i thought i'll put a new dizzy cap and rotor on just for the hell of it as they aren't usually expensive - WRONG :-(

 

dizzy cap - £33.31

rotor ( two types) - £41.13 or £33.65

all plus vat

so i''ll give my old one a wipe :-)

[dazzyvr6 0]

ive got a brand new dizzy cap somewhere,if i knew i would of given it to you

[GIXXERUK 0]

:-(

[Kevin Bacon 5]

Maybe that's just the way your engine is and has always been?

 

Look at it from a mechanic's point of view..... it does 32mpg, flies round to the rev limiter, doesn't hit a wall as such as isn't far off factory power. Not being funny mate, but this could drag on for ages!!

 

I was going to get Vince to drop the decat in the post btw!

 

It's got to be that or fuelling. A partially blocked cat will effect the top end but not necessarily the bottom end. Try breathing slowly through a tea towel.... you can do it but it's not especially comfortable. Do the same at a faster rate with bigger gulps of air and it becomes very uncomfortable......too restrictive..... hope that analogy works, LOL! :-)

[GIXXERUK 0]

lol sounds like the hamster and clarkson last night .... and breath ! :-)

 

when we overlayed the graph over a 2.8 it showed a higher bhp all the way up to 4800 but then drops off so it has the potential to get there

 

wheres that tea towel --------------------------->>>>>

 

ps do you know what size your decat was kev ?

[Kevin Bacon 5]

Wouldn't be clutch slip or something silly like that?

 

Yeah it's a 730mm one mate..... the 'long one' if that helps, LOL!

[GIXXERUK 0]

Wouldn't be clutch slip or something silly like that?

no mate i'd hear it or see it on the revs and it would be unusual for it to do it consistantly at those revs on 20 dyno runs :-(

 

i know i should wait but how do you feel when somethings not right ? it eats away at you causing sleepless nights and a break down of your marriage and the children being taken into care , unable to concentrate at work so you lose your job and end up penny less on the dole wandering the streets , going through the bins outside mc donalds

[Kevin Bacon 5]

Yeah that's true!

 

LOL, I can just picture you in the black leather chair explaining to the shrink that you're depressed and losing sleep because your VR is losing power at 4800rpm :-)

[RW1 0]

was a 2.8 block rebored to 2.9, i've got the receipt

 

I expecting to see you Sunday to talk about this one.

 

It's funny but the bhp plot follows exactly a "AAA" engine (2.8ltr) bhp factory dyno plot to a tee all the way up and over the top. Low end torque is up a bit - build variation only though. What is it supposed to be chipped with? Is it physically there inside the ECU?

 

What is running through my mind is that it's a 2.8ltr block not rebored and thats why you are struggling with it (despite the receipt). And also why it runs so well.

 

.

[Supercharged 2]

Is it running the AAA cams then??

[GIXXERUK 0]

RW1, sorry i had to give sunday a miss unfortunately, hope to make the next one

afaik the bottom end is a 2.8 bored out to 2.9 by awesome gti , the guy who dyno'd it last week remembered the car and the work done to it , he said it was definitely a 2.8 that was bored out, all the other ancilleries were as was

It isn't chipped and is running a standard ecu, we replaced this with another rado vr6 ecu and run it on the rollers and it made no difference

he overlay my dyno graph over a previous 2.8 graph he had done and it showed it to be up on that all the way to 4800 rpm where mine dropped off and the 2.8 continued to make power

 

without taking the head off and vernier the bore, i dont suppose there is any way i can tell ?

would a 2.8 run ok with all the 2.9 ancilleries ?

 

tia

[dr_mat 0]

So you have a 2.8 throttle, and a 2.8 inlet manifold, and 2.8 cams, and a 2.8 ECU on your 2.9 .. ?

[GIXXERUK 0]

dr_mat, no afaik everything is 2.9, only the block was a 2.8 which was bored out to a 2.9, it was burning an excessive amount of oil so a 2.8 block was sourced and bored out

[dr_mat 0]

Ok. Still don't know what might cause it...

[Kevin Bacon 5]

So it's got the 2.8 cams and throttle then?

 

Sorry, just p'ing about....I wanted to see if you'd lose your rag and say "FFS, how many more times.....it's BORED OUT 2.8, EVERYTHING ELSE IS 2.9" :-) :-)

 

It's a funny one for sure..... give the decat a bash and see what happens then.

[GIXXERUK 0]

So it's got the 2.8 cams and throttle then?

 

:onfire: :onfire: :2gunfire: :x-mas: :joker2: :salute:

[GIXXERUK 0]

is this actually a cat ? (looks small to me ), i was just measuring up to order a decat - 76cm i think

[Kevin Bacon 5]

That's a cat alright and yep, 76cm sounds right, same as mine. Thought it was 73. There's only 2 on the VR, a short one and the long un (our 76 ers).

 

Yours doesn't look OE though mate.... it's a pattern one IIRC isn't it?

 

I have the OE VW one (cells perfect) if you want it. Just pay the postage and it's yours....but wait and see if yours is OK first.

[GIXXERUK 0]

kevHaywire,

I have the OE VW one (cells perfect) if you want it. Just pay the postage and it's yours....but wait and see if yours is OK first.

cheers kev, what have you got on yours atm ? if you want to sell your supersprint pm me , i thought i'd ask before i order

 

cheers

 

paul