Sam's build thread

[simon k]

brilliant - you guys are awesome

next sprint is in a month, so I'd better at least have the rear bar done by then

I'll quote this stuff into my own thread so I don't lose it

[sambb]

Had a bit of a win tonight with my boost/wastegate springs/logs etc. Since I put the new turbo in I haven't been fully happy with the boost delivery and as a result of that the power of it either. My turbo has had the wastegate port taken out and the mani ported which means more pressure on the back of the wastegate flap. If the psi is acting on a bigger area then it has to be exerting more force making the standard wastegate actuator spring a bit weak. After testing the standard spring it cracked almost immediately and went to full stroke before even 5psi so I'm not sure how that can be called a 6psi spring and it wasn't up to the task. I then ran the turbosmart actuator with a 7psi spring but had to back off the preload to nearly zilch. Because the mani and turbo are flowing more and combined with the 7psi spring it was tending to overboost (1.5bar - 1.6 bar) and backing off the preload got that under control, but then I found in the logs that the boost control solenoid was all over the place in its duty cycle trying to keep the boost stable at high rpm. So then I went to the 10psi spring. I needed the full solenoid MBC bypass to get the peak boost under control and then had a nice flat boost curve. The problem was though that in having slightly too much boost in the higher rpm range when normally it would tail off, it was puling bits of timing above 5000rpm but not below, not even at the boost peak. So I was high rpm timing limited which meant I couldn't get any real timing into it to pep up the bottom end. The car suffered for it at Bathurst where obviously on such a fast track the car was living at higher revs yet timing was being pulled - I was noticeably down on power + it was hot which didn't help.
So what I remembered was a story I read ages ago about the earlier WRX's and how Subaru was using restrictor pills in the solenoid feed tubes to tailor the boost curves to the many different wastegate springs those cars had. Maybe their mapping was different but the were using a hardware mod to to set the boost levels. Not only did they put restrictors in the line that feeds the boost signal to the solenoid to raise boost, but they also used them in the line that leaves the solenoid and empties into the TIP to drop boost levels (probably for stiffer wastegate springs). I dug out the list of cars/wastegtae springs/restricter sizes and their locations. If you look at the first line, the 93-96 WRX used a 2.0mm restricter pill inserted into the line between the solenoid and the TIP.

MY93-96 ... 3 port solenoid 2.0mm restrictor fitted into the vent pipe between solenoid lower port and intake
MY97 (Euro) ... 2 port solenoid 1.2mm restrictor fitted between the turbo and the tee piece
MY97 (JDM) ... 2 port solenoid 0.9mm restrictor fitted between the turbo and the tee piece
MY98 (Euro) ... 2 port solenoid 1.2mm restrictor fitted between the turbo and the tee piece
MY98 WRX (JDM) ... 2 port solenoid 0.9mm restrictor fitted between the turbo and the tee piece
MY98 Sti 4 ... 3 port solenoid 1.5mm restrictor fitted between the turbo and the solenoid adjacent to the solenoid top port
MY99 (Euro) ... 2 port solenoid 1.2mm restrictor fitted between the turbo and the tee piece
MY99 (JDM) ... 2 port solenoid 0.9mm restrictor fitted between the turbo and the tee piece
MY00 (Euro) ... 2 port solenoid 1.2mm restrictor fitted between the turbo and the tee piece
MY00 (JDM) ... 2 port solenoid 0.9mm restrictor fitted between the turbo and the tee piece
MY01-05 (Euro) ... 2 port solenoid 1.2mm restrictor fitted between the turbo and the tee piece
MY01-05 STi ... 2 port solenoid 0.9mm restrictor fitted between the turbo and the tee piece
MY06/MY07 both WRX and Sti 2 port solenoid 0.9mm restrictor between turbo and tee piece

By doing this, at the time when the solenoid is trying to bleed boost away from the wastegate to keep it closed or less open, a restriction in the line to the TIP will have the effect of holding residual pressure against the solenoid so that when it opens again a bigger burst of pressure will get through onto the wastegate to help open it. The bigger the restriction the lower the boost curve will run.
I put an adjustable flow control into the line and closed it right down which put me onto spring pressure = 7psi. As I then opened it up the boost went up and I was able to get it bang on. This proved that it would work so I then removed the flow controller, found a pneumatic fitting at work that had about the same restriction as the flow controller when you blew through it and pushed it up inside the line from solenoid to TIP. Things normally never work first go but this did. The boost curve is bang on. I set up the 7 psi spring/actuator as you should with 2-3mm preload this time on the nut and with the other bypass junk removed and a little restricter pill hiding in one of the pipes went for a drive. It smoothly rises to a 1.4bar peak, caps for a bit and then trails down just like the tune had it doing on the weaker spring. If it had been lower than where I wanted it then I'd have had to drill the restrictor piece out ever so slightly, bit by bit till I got it. If it had been overboosting still I'd have had to find a slightly smaller restricter.The restricter has just taken the boost curve from where it rose to cos the turbo/mani was flowing better ,and has adjusted it down to where the tune wants to see it, but the kicker is it is running with a stiffer spring now that is better suited to the tubo hardware and feels sweet. I'll start adding timing/logging over the next few nights and see where it ends up but thought it was worth mentioning as a tidy, undetectable, factory utilised and effective way of getting an elevated boost curve back in line with a tunes specified boost values if needed. Obviously i'll also have to check the injector duty cycles especially at peak torque to check that I have headroom. anyway we'll see how it ends up!

[simon k]

that is very, very smart... impressive as usual

what are you logging with? and using to adjust your timing? nefmoto?

[sambb]

logging with VCDS. To get any resolution I just run the particular lines I'm interested in rather than doing the big logs you can with nefmoto that capture everything. Still not good enough though. Then I'm altering global timing with Lemmiwinks. You can adjust globally in 0.75 degree increments.
If the turbo starts to look better now that I've got the boost curve to where it needs be I may hang onto it. I was thinking that if I do the fuel pump, injectors and a 3in MAF, water injection and finally get the exhaust done properly (all the way through not just the dump + cat) it might be enough if I get it tuned via Eurodyne or nefmoto. I still think a punchy little torquer turbo can make a bloody quick car on the track so maybe i'll see how far the K03s can be taken first.

[simon k]

Then I'm altering global timing with Lemmiwinks. You can adjust globally in 0.75 degree increments.

MORE tuning software??!! sigh...

[sambb]

lemmiwinks by REVO - REVO Lemmiwinks

its a free download but I cant actually find any current links to get it.

here is unisettings tough which is much the same GUI:

---

http://unitronic-chipped.com/downloa...gsBoschME7.zip
Unitronic

If you're already using nefmoto then your cable will run this stuff.

[simon k]

lemmiwinks by REVO - REVO Lemmiwinks

its a free download but I cant actually find any current links to get it.

here is unisettings tough which is much the same GUI:

---

http://unitronic-chipped.com/downloa...gsBoschME7.zip
Unitronic

If you're already using nefmoto then your cable will run this stuff.

Cheers Sam - I wasn't looking for a copy of it, I just can't get over how much hacking people have done to these ECUs. They're almost open-source

The way I read it, it's more-or-less normal runtime adjustments they might do in a VAG dealership (maybe to cheat emissions!)

there's a download here that works (VWFixx Adjustable Software Tuning Guide - General Discussion Forum - Gulf Coast Euros Forums) but like you said, the UI looks the same as Unisettings - Unisettings looks better with load & save options...

[sambb]

You're right. I just wish you could do real timetunng with it. ha ha Re emissions. Bonnet up + wheel speed sensors ticking over + no lat/long G sensing active + sustained fixed speed running = I'm on an emisions dyno: activate said program........ naughty naughty!

[sambb]

I had laid the N75 over onto its side so that I could run the parallel solenoid bypass (red) when I was using the 10psi spring and had a sizeable boost spike to get under control. Once back onto the 7psi spring though, I turfed the red bypass circuit but kept the N75 on its side like it is in the pic. That way there is a hose running from the solenoid to the TIP rather than the solenoid being mounted directly into it like OEM.
This is the adjustable series flow control that I used in the solenoid to TIP line to test that adding restriction there would help get the elevated boost curve down where I wanted it. To work it cant be a vent to atmosphere flow control which acts as an air bleed and vents unwanted pressure to atmosphere. This works differently - because it is a closed circuit flow control it builds pressure on the upstream side of the restriction against the N75. A bleed wont do this. Once dialled in it could have stayed but I'd have no reason to increase the boost again past the specified thresholds in the tune (unless maybe for water meth) so it was deemed neater/safer to run with a fixed restriction instead. So the adjustable flow control was removed and a restrictor pill of about 1.5mm orifice (to mirror the controllers restriction) was put up the hose and sits about where the pink dot is. The downstream hose joiner piece obviously prevents the pill from making its way into the TIP although it was very tight in the hose. As mentioned adding restriction to the solenoid to TIP line lowers boost but the same cant be said for the N75 inlet pipe running to the solenoid from the boosted induction pipe. Restriction there will elevate boost, so be careful that you have it in the right line if dropping boost is what you are trying to achieve.

[Sydneykid]

It smoothly rises to a 1.4bar peak, caps for a bit and then trails down just like the tune had it doing on the weaker spring.

Is this what you want? Or is it something you don't want, a symptom of waste gate creep?

If the latter, back in the manual boost control days we used to fit a pressure relief valve in the wastegate hose before the pressure regulator (the common valve that allows adjustment of boost pressure).

The order, in series, is pressure relief valve ----> pressure regulator -----> wastegate actuator.

The pressure relief valve can be set to open at, say in your case, 7 psi. This means that absolutely no pressure at all will get to regulator and hence to the wastegate actuator at boost pressures lower than 7 psi. So there's nothing "pushing" on the wastegate actuator, just the actuator spring holding it in place. This means boost can build as quickly as possible at lower rpm, but it also ensures at higher rpm that the only drop in boost pressure (below 7 psi)will be due to the turbo running out of airflow.

The airflow restrictor works differently in that it slows down (dampens) the airflow but ultimately the pressure either side of it equalises. Whereas using a pressure relief valve stops any airflow (below 7 psi) at all. Make sense?

Cheers
Gary