Adjusting Turbo pressure

[ian2000t]

I think I've done everything for a good basic Stage 0 tune now:

- new Cam Belt
- MLS 2 notch headgasket (with new but standard bolts)
- new IP timing belt
- IP timing set to 0.95mm
- Monark (0SD273 type) nozzles running 165 bar
- Oil flush and couple of changes (now with quality 15/40 semi-synth)
- Fuel filter
- Air filter
- calibrated boost gauge showing 10psi max boost

I have the standard factory turbo and intercooler, so I was going to take the turbo pressure to about 15psi - maybe a couple higher, and obviously up the fuel to suit aswell.


What do I need to increase the turbo pressure? Am I right in thinking I just need something like this, or are these engines a bit different to a normal turbo setup?:

http://www.ebay.co.uk/itm/Turbocharger-Manual-Turbo-Boost-Controller-Bleed-Valve-/390323680937?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item5ae11ab6a9

[IceV_760]

That is good stage zero setup. Just to ask, why semi-synth, and not full synth.?
They cost about same atleast in Finland, and are more common than mineral or semi-synth. oils in markets
and part-sellers.

The one you linked, will do its job. You control pressure same way than in gazoline engine, it dont differ.
But. You could do it even cheaper, add plastic t-hose/clamp in middle of hose going to "pressure clock",
and control max boost with amount of air your bleed to free air. Costs about 10 cents and does same,
you need pressure gauge on both ones to see your max boost anyways.

[ian2000t]

That is good stage zero setup. Just to ask, why semi-synth, and not full synth.?
They cost about same atleast in Finland, and are more common than mineral or semi-synth. oils in markets
and part-sellers.

Here Mineral is very cheap, semi-synth you can get for a reasonable-ish price, but full synth is about £25/bottle (4.5 ltrs) and 1 is never enough - couldn't afford a £50 oil change!! Plus, I think the oil has been left in there a bit too long by previous owner so I wanted to give it a few cheap changes to try and flush through and rubbish in there.

The one you linked, will do its job. You control pressure same way than in gazoline engine, it dont differ.
But. You could do it even cheaper, add plastic t-hose/clamp in middle of hose going to "pressure clock",
and control max boost with amount of air your bleed to free air. Costs about 10 cents and does same,
you need pressure gauge on both ones to see your max boost anyways.

Not sure what you mean by the "pressure clock" method - have you got an example of how I can do this cheaply?

Is there any benefit to using the "ball and spring" type, which apparently allows the turbo to spool faster?

[IceV_760]

By pressure clock meant wasteagte, couldn't remember correct word yesterday.
So, i meant you to bleed air from hose which goes to wastegate and controls opening of it.
Same idea as in the item you linked, just cheaper way.

You just named the benefit of that type of control-valve.

[ian2000t]

http://d24t.com/showthread.php?576-Boost-controller-on-stock-turbo&highlight=ball+spring

Just been reading that thread about ball and spring type. Unsure which to go for now - do many people on here use a ball and spring on their standard turbos?

[Jason]

Just get the cheapo ball and spring type boost controller. Works fine and is too simple to screw up. Still running one on my built engine, and even on the turbo motor in my 10 sec vw...

Jason

[ian2000t]

Ok cheers. Is the one I linked in my original post a ball and spring, or bleed type?

It's either that one, or this one:
http://www.ebay.co.uk/itm/MANUAL-BOOST-CONTROLLER-VW-GOLF-POLO-BORA-TURBO-GTI-GT-/250887984584?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3a6a16d5c8


What psi would you recommend for a resonable improvement, but still preserve some MPG? And are the turbo mods you mentioned in the Performance Thread worthwhile? Something about capping off the dump valve?

[Jason]

The brass one in the post above is what you want.n As for boost, I wound't go above 20 psi without having head studs. Anywhere from 15 to 20lbs of boost and the fueling to go with it will be a big increase in power. Shouldn't have any affect on mileage at all, unless you are holding it on the floor all the time. Cruising along on the highway the fuel going into the engine is the same if the pump is turned up or stock calibration. It all depends on how heavy your foot is. Did you do some kind of exhaust mods to help it breathe a little better?

Jason

[ian2000t]

Cheers will get one of them then.

I assumed turning that screw up increased the fuelling all the way through, not just on heavy throttle. Too much messing with SU carbs!! It must do something though, even at idle as the revs rise slightly with it.

Exhaust at moment is standard 2 box system, no cat, no egr. I am going to take the rear silencer box off and replace with straight 2&1/4" pipe soon though.

[Jason]

I would remove all stock mufflers and replace with 1 straight thru style diesel muffler.

Jason

[ian2000t]

Is there a difference between Petrol and Diesel style straight through mufflers? Have you got a link to one?

Just been having a read up on Bosch VE adjustments. This site actually explains quite well:
http://www.fourwd.org.uk/bosch_ve.html

Mine doesn't seem to smoke under full boost, but does seem to smoke at wide throttle low revs, and just before the turbo spools, so does that sound like my smoke screw needs backing off a bit? I'm also only getting 27MPG (UK gallons) for town/motorway/country lanes - doesn't seem to change. Was closer to 30MPG before I upped the max fuel screw a turn.

[petercz]

Hi, I plan to make a new 2,5" stainless steel exhaust for my tic, but I want it as quiet as possible, so it's better to give the muffler on the back of system or to the center section like ian or this guy http://www.fourwd.org.uk/exhausts.html ? I plan to use Simons muffler (http://www.simons.se/Katalog/Universal635.htm)

[745 TurboGreasel]

More pipe after the muffler will silence more.
The brass one in the post above is what you want.n As for boost, I wound't go above 20 psi without having head studs. Anywhere from 15 to 20lbs of boost and the fueling to go with it will be a big increase in power. Shouldn't have any affect on mileage at all, unless you are holding it on the floor all the time. Cruising along on the highway the fuel going into the engine is the same if the pump is turned up or stock calibration. It all depends on how heavy your foot is. Did you do some kind of exhaust mods to help it breathe a little better?

Jason
I've been using a ball and spring for a few years.
It feels like it cost me a little MPG, as at freeway speed, I'm load dependent at 8-14 PSI, creating needless heat and backpressure.
Without, it wold be more like 5-9PSI driving on almost flat ground
The difference in milage isn't great, but I think a 2 stage setup that allowed low boost on light throttle could net some economy improvement.
The MPG difference wasn't enough to motivate me to build that.