IHI VF34 down on power, any ideas why? Dyno Graph included / video

[shantybeater]

ok I bought the cupra a month or two ago as a bit of a project, and luckily ive been looking at it that way as its costing a fortune at the mo!

Anyway it felt not a massive amount faster than my k03s & as some of you may know i made a thread a while ago about the lack of turbo noise...

Ok i decided to get it RR'd to see if it was running right & the outcome shows a problem somewhere, the car has no faults on VAGCOM at all & is still fast dont get me wrong! It has an IHI VF34 with a chargecooler & all the usual mods....apparently the guy put it on a low map of around 330-340ish.

When the car reached high revs on the dyno whitey/blueish smoke started coming out of the exhaust, and as he let off quite a large ploom came out....if you rev the car at stand still there is NO smoke at all....on the way home i did notice when booting it in 5th i could see some blue smoke in through the back window....

Any ideas what it could be? i was thinking worn turbo? but would that explain such a massive loss of performance

The overall result was

- 283.5 bhp @ 6600rpm & 256lbft of torque...
- 1.2 bar of boost from 3700rpm - 5200rpm then tails off to around 1.1 bar

http://s141.photobucket.com/albums/r65/shantybeater/?action=view&current=Dyno-2835bhp.flv



link for large pic: http://i141.photobucket.com/albums/r65/shantybeater/DSC00112.jpg

 

[MIkey kc]

Blue smoke! means your burning oil somewhere! that for sure will make you loose alot of power! It just finding how the oil is getting into the cylinder?

Posible faults

Turbo like you said,-seals worn?
Piston rings?
valv stem oil seals? (i think its unlikey them, you usually get blue smoke on start up)

 

[shantybeater]

well i'm kind of hoping its the valve stem seals or piston rings because its going in over the next few months for rods & valves etc.. so i dont think it will be alot more trouble to get them done at the same time?

 

[stewbie55]

Well I think you've got more than one issue...

Blue smoke is almost certainly worn valve stem seals - ideally need fixing but shouldn't account for loss of power.

Only making 1.2 bar falling to 1.1 bar at redline is the problem - from my experience you need at least 1.3 bar at the redline to make the 320-340HP mark.

Do you have an adjustable boost controller on the car and do you know what the boost is meant to be set too?

I'd guess you either have a boost leak, dodgy N75 valve or DV.

My advice would be to get yourself along to JKM in Portsmouth. Jim there really knows his stuff and has worked on my IHI'd Leon.

 

[shantybeater]

Thanks for the replies

Well i know the car was originally supposed to be running around 360ish & then was put on a lowish map, i do have an adjustable boost controller but its just an on off volume switch style thing...I will phone jabbasport on monday as all the work was done there & ask what its 'supposed' to be putting out and post up what they said on here

 

[stewbie55]

Same controller as mine then...
Mine is set to give 1.5bar fully clockwise and 1.0 bar at minimum "volume", but it will depend on how Jabba have set it up - I assume you had it set to max?
However the fact that your boost drops as the revs increase would suggest you have a boost leak or something - with mine set to 1.4 bar or less it will hold that value to the redline, it's only if it's set to 1.5 bar that the boost drops a bit as the VF34 is maxed out at the limiter then.

 

[cus]

i take it that its the ex jabbasport car?

 

[Madmile]

I would do the basics maf and plugs. And go from there 95% of all issue mainly come back to the maf.

 

[shantybeater]

ok ill look into maf etc.. cheers ppl....as for holding boost stewbie if the turbo was on its way out would that explain the lack of power?

oh and yeah it is jabbasports ex demo car...big plans for it

 

[stewbie55]

Would really be worth doing some proper logs using VAGCOM - preferably someone who knows what they are doing, looking at MAF readings, actual vs requested boost, timing pull and fuel trims etc.

TBH even at 1.2 bar you should be seeing high 200's maybe near 300 lb/ft of torque and you're a fair way off that, something other than the turbo will be causing that...

 

[Madmile]

I lost 40-50bhp through an intermittent maf a few years ago at awesome, sometimes it would make a perfect power run. It would boost to 1.6bar and then hold 1.2bar at high revs then it would boost to 30psi anf hold 12psi at the top end. Simply for the price of a maf I would rule it out they cause all kinds of weird and wonderful faults.

 

[MIkey kc]

I cant see how a Maf can create blue smoke tho? I mean i agree with you on the power side of things it will make you loose alot of boost! but if hes getting blue smoke then hes burning oil somewhere which will make him down on power! if hes burning oil is he low on cylinder compression?

 

[MIkey kc]

sounds awesome on the vid! ripping the rollers up!

 

[Madmile]

White'ish blue ish smoke, is it over fueling for safety at the top end to make up for the fact the Maf is breaking down under high load/air flow. Mine did.

For £75 I would rule the maf straight out before I went any further. This is only what I would do after many hard learned experiences with IHI and Bosch Mafs.

Its certainly not making decent power it sounds flat on the rollers.

 

[caveo]

Are you running the 16g or 18g ?? but as said 1.2 bar wont break the 300bhp mark . 1 other thing are you using the std actuator as I am and my waste gate is blowing open at 5500 - 6000 rpm so iv ordered a forge one with a red spring to hold 1.5 bar.
ps your tourqe is quite low too ( look at mine , IHI 18g )

 

[shantybeater]

stewbie - id love to do some logs but dont have VAGCOM and my understanding of it goes about as far as reading & wiping fault codes..unfortunately there doesnt really appear to be anyone that nearby either.

madmile - i'll order a new maf asap just to see if it helps, as for the whitish blue smoke, im no expert but i thought if it was overfuelling there would be black smoke?

mikey - I get the feeling it is the valve stem seals (although would that account for such power loss?) as on startup i get quite alot of smoke although its no bluey! im sure its more than the usual condensation as well..

caveo - i have no idea if its an 18G/16G how can i find out? as far as im aware i am running a standard actuator, the spec list i was given was a little basic to say the least..

 

[pj1985]

I remember you posting asking if anybody knew about the car when you were looking at buying it and people posting about it possibly having problems. You have posted the turbo you have in your first post- IHI VF34. Not sure about your smoke. Fuel or Oil being burned is its bad but you say sometimes its blue and others its not. I think your boost level has alot to do with the power you are getting but it sounds like you may have some other problems.

Also with this 360bhp on a hard map...it wont do that for long as you will either crack/warp your exhaust housing or the bearings will go from what I have seen and been told about.

 

[Wilko]

Look
You don't have any power loss. A 1.8T running 1.1 bar boost at the top end will make 280ish hp. I bet your maf reads around 220g/s peak.
Turn the boost up so that you maintain 1.5bar at the top end, and you'll make 250g/s and 320-330hp
The turbo you have is maxed out at 320-330hp.
If you do however, the turbo exhaust housing will crack to buggery, and eventually the bearings will fail.

The only people that will tell you that a vf34 will make more than 330 are either trying to sell you one, or trying to inflate the power numbers of their cars.

Basically there is nothing wrong with your car. Just turn the boost up.

Your smoke on the over run is more than likely doown to oil from the crank case breather system being sucked through the intake on the ever run, which is exactly what it is designed to do.
If your car doesn't use copious amounts of oil, then don't worry.

 

[shantybeater]

Pj - i only ever see blue smoke when booting it in 5th / on the rollers when the car is doing the equivalent of 110mph , it started coming out then as he let off a lot came out...otherwise none...i get some smoke in the morning but i dont know if thats just condensation. Also it isnt running "360" anymore, apparently he got it turned down to 330-340 as the exhaust housing had cracked to shite...

wilko - so you think a VF34 will produce 340 at the very most??? and at those levels my exhaust housing & bearings will die??? whats a safe level to run them at then? i would assume its more than 280 as whats the point in spending so much on an IHI when you can get similar figures from a k04???!?! lol, i've seen a few cars on here quoting more but like you said they could be lying...i just always heard more was possible

also i cant just 'turn the boost up', the boost controller is a simple on/off switch & i highly doubt he would have got it mapped to run at 280???!?! so there must be something wrong!

finally if i get a hybrid capable of more power will the housing just eat itself just as quickly?

 

[caveo]

Your in the same boat as me mate the IHI is good to the point of needing new rods etc so if you want 330+ then it gets really expencive ( iv been quoted almost 3 grand for full internal work ) .
From our turbo 320 is a good topend ( "safe" ) figure , but if you can hold 300+ from 3500rpm to redline then you,ll have a quick motor.
Ill post my most recent graph up later.