Maybe another slight engine tweak...

<tuffty/> said:
That said there shouldn't be any reason why the N75 can't be mapped
Click to expand...

I'd rather it be that to be fair, it makes part throttle driving much nicer.

I am also considering putting a kill switch in for the N75 to run actuator pressure...
 
Welly said:
I'd rather it be that to be fair, it makes part throttle driving much nicer.

I am also considering putting a kill switch in for the N75 to run actuator pressure...
Click to expand...

I have an idea for that... use an N249... its what it does (switching valve) and means you won't have it throwing fault codes etc all the time when the N75 is electrically disconnected

<tuffty/>
 
<tuffty/> said:
I have an idea for that... use an N249... its what it does (switching valve) and means you won't have it throwing fault codes etc all the time when the N75 is electrically disconnected

<tuffty/>
Click to expand...

Yeah, maybe long term. We discussed this before. But short term, a kill switch will do... lol. That way I might get better than 0.0 MPG on my Facebook... lol.
 
Welly said:
Yeah, maybe long term. We discussed this before. But short term, a kill switch will do... lol. That way I might get better than 0.0 MPG on my Facebook... lol.
Click to expand...

Maybe a brick under the accelerator maybe more suitable? ;P

<tuffty/>
 
jojo said:
Welly, I have to say that your are MAD! 400+ bhp and standard braking system!! :respekt:
Click to expand...

It stops me just fine, I have had this discussion several times with many people.

I hit the stop pedal, the thing stops. Happy days.
 
OK, so beginning to wind up for another go on this one now. Turns out my easy and quick horsepower boost wasn't either easy or quick...

So, a week has been and gone, and I once again have a complete turbo.

It turned out to be a bit of a saga after all.

The hotside came back on Wednesday morning from CR. They had done a lovely job of installing a nice new wastegate control arm and penny valve. Sadly, they hadn't done the other important thing - skimmed the manifold flange.

Bill, having spotted this straight away, sent it back the same day to have the remainder of the work completed...

So, now the hotside is all nice and clean, and looks brand new. Came back with 3 nice new studs, all skimmed :). It is currently sat on my desk at the office. I must say it looks somewhat out of place in an IT Support company's office...

19.jpg


The wastegate arm now has an original style Mistsi stud on it, meaning that I have had to get a new turn buckle for the actuator from Forge today to fit properly. This may have needed a slight heat up and bend operation to get it to sit properly, but now fits like a glove which is nice :). A good fit now though - working well. Crack pressure is about 9 psi. Free sir-clip blagged from Forge... :)

20.jpg


Finally, the last problem to overcome is the blowing from the manifold flange. I'm not convinced that it was due to the original hotside being warped in fairness, more of a less than perfect fit to the manifold's spiggot.

The hotside now has about .2mm skimmed off of it, meaning that the spiggot should fit in the counterbore much more snugly.

Also, Bill has suggested that the use of a small amount of copper wire should help the turbo actually seal when clamped down. Photo below shows the principle. I need to get it to sit in the outer ring all the way around so that it seats properly on the manifold.

21.jpg


The idea is that the compression of the wire here will fill up and gaps that may exist, producing a nice tight seal to the manifold.

Fingers crossed I will be able to crack on with this - planning on getting on Wednesday night hopefully all being well.
 
Afternoon all.

Well, turbo bolted back to the engine last night.... and I've come across a whole new set of problems sadly.

Firstly, worth saying that it's all fitted together really well, and we are all blow free and happy, which is a nice start.

Was a breath a sigh of relief moment when it started up and didn't sound like a tractor :).

However, the success has been marred by some annoying side issues...

The turbo doesn't produce quite as much boost as expected.... which sorta sucks! lol.

Now I wouldn't mind this so much, if I had any idea as to why. But I don't. Spent most of my evening last night messing about with actuator preload, testing this, testing that - all to no avail.

Popped into Bill's to gather some more knowledgeable thoughts. Found some issues whilst we were looking at it, but none of these caused this problem either. Anyway, on the plus side, he was suitably confused as well, so that made me feel better in a way :).

So, how is it currently? Well, it will make a MAX of about 22 PSI as it stands currently. This pulls VERY well I must say, producing the same sort of airflow that the PE used to produce at a much higher RPM.

There is also little to no timing pull on boost, meaning that there is some room there for improvement if this is ultimately what this turbo will do on this engine.

I really think there is more there, I just can't figure out what is stopping me accessing it.... :(
 
Adding to the above - things to try to see if a little more can be extracted...

1. Red actuator spring. May help, may not. There may be the possibility that the wastegate is opening slightly from exhaust gas flow under heavy go go.

2. Increase size of oil pressure banjo bolt to allow a bit more flow through. Tuffty's idea - the journal bearing may be dragging which won't help.

3. Remove and dissassemble Jonny 5 - I mean the FP and have a good look at the insides. They are an **** to put together without things catching.

I've come to the conclusion though, that there was nothing wrong with Bill's previous wastegate bodge - looks like it was never that!
 
that's very strange Wellyboots.....

It's not something stupid like the wastegate being forced open against the actuator is it? No amount of pre tension will stop that from happening if it's a weak spring.

perhaps time for a brave dyno run with the WG jammed fully shut? to see if it's a compressor issue or a WG issue?
 
good news! nice one bud Im sure you'll figure it out.

does it get to 22 psi and stay there, or get to 22 psi and then drop off?
 
Prawn said:
that's very strange Wellyboots.....

It's not something stupid like the wastegate being forced open against the actuator is it? No amount of pre tension will stop that from happening if it's a weak spring.

perhaps time for a brave dyno run with the WG jammed fully shut? to see if it's a compressor issue or a WG issue?
Click to expand...

I'm leaning towards that myself mate to be fair, I don't see what else it could be. I know they are finnicky to put together, so there is the possibility that something inside is catching on something else causing mechanical drag.

On the plus side, it goes like hell for 22 PSI. 280 g/s. Thats what the PE would do at 26.5 PSI.

Half tempted to leave it as is, and whack some timing in there instead. Less boost will keep it cool and happy.
 
Last edited:
Dane said:
good news! nice one bud Im sure you'll figure it out.

does it get to 22 psi and stay there, or get to 22 psi and then drop off?
Click to expand...

Hard to say, but looks to me like it's dropping off, but only really slightly.

Here is a log excerpt:

RPM Boost (Mbar -1000)
3440 1320
3800 1480
4240 1730
4760 2130
5560 2450
6360 2480
6960 2460
7240 2470
 
audi upgrades
Westy said:
Well that's not dropping off! It's climbing through the rev range, lovely.
Click to expand...

It does tail a tad, but only a tiny tiny bit.

Peak boost there was at 6360, but it is pretty stable - almost like the actuator is allowing some gas to bypass the turbine and keeping a steady boost.... :think:
 
Westy said:
I'd be happy with that considering you've just had to bolt it on. Imagine it's potential though :faint:
Click to expand...

This is what bugs me. Imagining it''s potential, and not actually being able to produce it. I don't like it when things don't work at their best. I KNOW there is more in it, it's been extracted from the very same turbo before.

To be fair, it wasn't as easy as just bolting it on. If it wasn't for Bill and a stroke of his charateristic genius, I don't think I would have ever stopped it blowing!! That, the oil lines, all the other problems. Booo.
 
yeah its not like its getting to 22 psi and the penny valve is opening and letting all the boost out.

A stiffer spring is a good plan :)
 
yeah it'll tell you one thing or another to move on from
 
ps only 280 g/s pah :) ;) :thumbsup:

you know you wanna be in the 300 club lol
 
****** good result! Decent amount of torque there too and the power delivery looks nice and smooth.
 
A few posts ago hes talking about being unable to get it to boost past 22psi, but the graph shows it up above 25, even without the MBC?
 
I believe Welly changed the spring in the actuator to a stiffer one and all was well(y) again...

Prob being blown open with the increased flow...

<tuffty/>
 
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