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-   -   Boost and PCV niggles on track car (https://www.scoobynet.com/general-technical-10/1058987-boost-and-pcv-niggles-on-track-car.html)

Jonny Cut Corners 21 May 2019 03:19 PM

Boost and PCV niggles on track car
 
Background:
1999 Turbo 2000, with FMIC, TD06-20G, 380bhp (Too many other mods to mention, really must get a project thread started!)
Standard PCV system still in place

My friend Andy and I built & run this car between us for summer track days and the odd weekend blast.


Just done a TD at Kendrew Barracks where we encountered a few niggling issues, that I’m not sure are connected or not… hoping for some input from the learned scoobynet folk.

Here’s a quick run down of how the day went and what we found:
  • About mid morning we noticed we’re using a bit of oil (put 1 litre in over the day, doesn’t normally need anything) From early on in the day there was oil residue visible from the ends of vacuum pipes going to the boost solenoid. At this point the car had been giving the odd misfire when it was hot
  • After lunch Andy came into pits complaining that the car wasn’t running right. Found that the boost reference pipe had come off the nipple on turbo housing. Secured it back on with a ziptie and it was running ok again. Also noticed oil residue in the intake/intercooler piping so gave the MAF a wipe clean. Miss fire seemed to have gone.
  • A few sessions later and a developed a slight boost leak via an intercooler pipe clamp not being quite tight enough (Could hear it screaming out). Oil residue was clearly visible where air was escaping (made finding the leak easy!) Nipped that up and it was running ok again. AFR reading 10.0 on WOT like it should.
  • Swapped drivers shortly after this (without turning it off) Andy heads out and finds the AFR reading 12.0 on WOT and it not feeling right. Plus oil was getting low again. As it was basically the end of the day we decided to put the car on the trailer and vow to investigate later.

The next morning we found that the pipe to the PCV valve under the throttle body had worked its way off.

Questions:
Would that disconnected PCV pipe manifest itself in the increased oil consumption?
Or at least why the MAF & intercooler pipe being coated in oil residue?
Do you think we should look into a oil catch can / air-oil separator seeing as it generally gets driven on track or fast road use? Rarely driven in a city.

If you've read this far, thank you!

Jonny Cut Corners 23 May 2019 07:52 PM

I guess this was a bit TLDR then?
Good to know Scoobynet is a vibrant, helpful community.

Henrik 24 May 2019 12:19 AM

Hmm would the pvc pipe have created a vacuum leak before the turbo by any chance?

If yes, it could we'll throw the afr readings off.

I don't have enough experience of oil in the inlet to say if it would make the car run lean (would have thought the opposite), but a vacuum leak can definitely make it run like poo.


I'm interested in your td06, though... What rpm do you see boost by? I've got a 2.1 with a billet td06-20g, but not really driven it in anger yet.

Jonny Cut Corners 24 May 2019 11:37 AM

Thanks Henrik .
I think that under boost the loose PCV pipe would have let unmetered air into the intake (after the maf) so would explain the AFR being off. Might not explain the oil use though.

Our TD06 was originally an Andy Forrest build, which we've had rebuilt by AET with a 7 blade billet compressor wheel.
Our boost curve goes like this:
3000 - 0.25
3500 - 0.55
4000 - 1.0
4500 - 1.5
5000 - 1.45

This on a stock EJ207, with ebay headers and harvey trick up pipe.


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