Sams TFSI turbo conversion (maybe!?)

[sambb]

Exhaust went in today. The down pipe section of the K03s/K04-001 dump was cut off and in its place a dump off the TFSI turbo was made up. From what I can gather the flange is the same between the earlier BorgWarner Mk5 K03 version of this turbo, so if I have to change to that iteration then it'll fit too. The K04-064 from the Mk5 Pirelli and Mk6 'R' has the same flange but I'm not certain its in the exact same spot. Either way I'm pretty sure 3 turbos will work on this dump/flange. So the conversion is complete.....no going back!



The orientation on these pics is a bit whack but you get the gist. So it turned out that the 90 straight off the flange did work. Its mouth had already been opened up. It just had to be cut closer to the bend to make it eliptical in the vertical plane and then the sides stretched wider. Its ever so slightly angled towards the drivers foot and then all it needed was a small little 45 degree to turn it under the car. I got it flanged too. It might be fine on a hoist to twist and turn 2 meters of one piece dump pipe out of the car but not when you are lying on your back on stands in your garage or at the track. The flanges allow me to drop the centre section straight out the bottom and then removing the down pipe is just some very accessible nuts.
I;ll probably drive it tomorrow on the stock MAF and old turbo tune just on the spring and the next mission will be upgrading the TIP for the bigger MAF and getting the juicier base map into it.

[HaydEn]

Awesome stuff Sam!

Glad you finally decided to go ahead with the swap!

Hopefully fulfils your expectations for a while.


Sent from my iPhone using Tapatalk

[sambb]

well my hand was forced. managed to damage a blade on the K04-001 at Luddenham. I thought I'd just cooked the bearing but it turned out the whining noise was a shaft not liking its new 'balance'. Lucky I didnt do the last session. This was all meant to go in with the new engine once that was finished but its getting a guinea pig run on this engine now. At least when the new engine goes in this tune will allow it to be turn key ready to run and close enough if the small port to large port conversion won't be too big a difference.

[sambb]

INLET SIDE:



You just need to cut the Forge or whatever brand turbo inlet hose (TIP) 2/3rds of the way down for a pipe off the compressor. Catch 22 is that if you cut the TIP off lower, the PRV pancake for the PCV system will be able to go in where I've plugged BUT the hose diameter will be too narrow to fit over the turbos pipe. Cut it where it'll fit and this happens. Not a biggy - I'm running as vent to atmo catch can at the moment and i'll just have to throw in a silicon tee pipe down the track to be legal on the PCV side of things. A normal 2.5in to 3in 90 degree pipe fits too but then you need take offs somewhere else for the N75 valve, PRV, diverter valve and brake booster amplifyer thingy. This was the most convenient.



If you are upgrading from the stock 2.5in MAF to a 2.75 inch I.D MAF off an S3, then you need to graduate the forge TIP's 2.75in silicon pipe opening up to 3inch so that you can fit it. I did that with some bits I had on hand and managed to get the MAF into a spot where the original cable would reach. It'll have a heat shield under it all once I'm set with where everything will go.



I could have run with the pieburg TFSI boost solenoid which is situated on the turbo itself. Access to it turned out to be easy provided you have the car in the air but what I really wanted was easy access to everything. So I ran the plumbing up from the turbo so that I could use the original N75 in the OEM mounting position. I'll need to extend the cable a bit but thats not an issue.



The diverter valve turned out sweet. I had always been running a pre-throttle body position for the diverter valve. With this setup I was able to re purpose the factory diverter valve pipe to give me a pretty straight shot at the T-pipe that I have ahead of the throttle body. Turbosmart do make a fully pneumatic replacement for the factory electric DV that comes with this IHI turbo. Its the neatest solution but again I like having everything where I can see/get to it and the pre throttle position for the DV has some boost response advantages and is how the diverters are run on the Golf 6 'R's with the bigger K04-064s.



starting to take shape. Just need to sort an airfilter/box, find some big P-clamps to hold all the inlet in place, wire up the N75 solenoid. Longer term I'll integrate the catch can into the intake when some more bits arrive.

[GRP]

If the forum back end here had likes you would be drowning in them.

[sambb]

Thanks mate. appreciate it.


Just putting the Dave base tune in now. Spent the day getting things a bit more finalised.

confirmed the upgraded MAF housing internal diameter. The MAF is off a 6.0L W12 Phaeton.

N75 wired up. Needed a a 6 inch extension soldered in to reach.
Filter on. Ready to tune!

[sambb]

Long overdue for an update on how the new Mk6 Golf GTi turbo conversion is going.
Had some problems with leaks from the oil return line I'd made up. I initially had done a cut and shut between the Polo sump side and the TFSI turbo side. It was leaking a bit through a pin hole from the welding, so the decisioon wa staken to reweld the flanges with an interference fit inside the flange and use -AN fittings with high temp pushlock oil hose that I had spare from my oil cooler job. All good, no leaks and much easier to work on.



E10 tuning:

I got a bit curious about tuning for pump E10 after watching these vids

Tuning Our Car on E10 to BEAT FUEL PRICES $$$ - YouTube
OZG S1|E10 - Fuel Testing - Octane 91, 98, E10 and E85 + Latrobe Valley Street Machine Show - YouTube

After doing a 98 RON tune I had the choice of doing a high octane E25 tune for the track or a 94 RON E10 tune for the street. Given that I'm closing in on a completing a forged engine and not wanting to up the power on the existing motor for fear of bending a rod, and seeing E10 go ok in these vids, plus 98 was 2 bucks 30 at one point.........I went for an E10 tune.

Like they say in the vids despite being 94RON you also have to weigh in the evaporative cooling effect of the 10% ethanol on the charge air temp and also the cooler burn into the equation. Rightly or wrongly I also figured that it could be that an OE engine that is designed to not run on high octane fuels might actually run well if timing could be kept in that timing zone but with more boost.

So what I found was a bit interesting. The engine made close to the same peak power all the time but with 98 ahead. Boost ramp up was the same. It was down on torque in the midrange. However this was very dependent on ambient temperature. For instance a log coming home from night shift in say 8 degrees ambient would look like a solid log compared to 98. But once it got to only 20 degrees ambient you could feel the timing pull and loss of midrange. So after initially being excited with what I was seeing, that quickly changed once it got warmer and then revision after revision of the tune had more and more timing and boost coming out of it to keep it in the safe zone. Id say that you would only want to go to E10 safely if you have very good intercooling and aren't running the turbo way outside its comfort zone, just as ways to mitigate what seems to be a really ambient temperature sensitive fuel.



you'll need to click it to open it larger. So pretty clearly you can see that boost onset was the same but that roughly 3 psi had to be dropped out of it on E10 to keep it safe. After the initial boost peak it had to be trailed slightly upwards as a way to keep some performance in the top end. What you see there was deliberate, not boost creep.
Both fuels were at 0.81 lambda roughly.
The pink lines are MAF airflow which is a pretty good predictor of power. Just think of them as 'power' for what we are talking about. So the almost continuous gap between the pink lines of 20 grams per second of air equates to 16 hp difference. So E10 in the end was significantly down compared to 98 RON. In addition to that the 98 RON tune was never trying to ring the most out of it whereas the E10 tune was trying to zero in on getting the most out of it.
BUT regarding economy the E10 was actually much better on a $ per km basis. The arguement for ethanol blended fuels is that they are cheaper but because the car uses more of it, the perceived savings are negated. Well that might be true of a car thats not tuned for it but thats not what I found at all. In commuter work with the odd log and blat thrown in, I would get 470km out of a tank (measured to when the km count down hit zero after the fuel light came on) for both fuels. In normal driving the 10% ethanol seemed to have zero impact on the fuel quantity being used. But being 25c cheaper was a good deal cheaper. In normal driving I'd say the two fuels were indistinguishable. What you see in a third gear pull is much different to how you drive on the street. Coming into and out of right angle and tight corners in the correct gear at the right engine speeds with momentum is very different to loading something up from 2000rpm in third. I'd even go so far as to say the E10 was easier to drive fast because you could take full throttle earlier coming out of corners and would actually be my choice for a track day in the wet. At a track like Luddenham or any Hillclimb other than Huntley or Panorama I don't even think you'd see much time difference between them simply because a FWD with lots of sudden midrange (98 is harder to drive than one thats more linear (E10).
So I think E10 has its place for sure given the crazy fuel prices for those that commute decent distances (economy) have good intercooling and arent running tunes that are really pushing the turbo hard ( stable low temps).

On the engine rebuild front, the head is now ready to go. The Supertech stainless exhaust valves have been fitted and lapped in. Just need to make a decision whether I run APR head bolts/studs or stick with OEM bolts and then i'll get it all together.

[Sydneykid]

Nice work Sam, like you I have had zero success with pump E10. Using pump 98 as the base DIY E10, E20 and E30 have been much more worthwhile, but E85 is my preference.


Cheers
Gary

[sambb]

yeah I think E10 will be set aside for the next fuel crisis and 98 will be the go on the street provided its not much more than 2 bucks a litre. This turbo with a brewed 98 RON/E85 @ E25 will be a rocketship on the next engine. Just didn't want to do it on this bottom end.

Gary out of curiosity does running ethanol heavy fuels cause MAF power estimations to skew. For example with E85, a large component of the oxygen that will be burnt is chemically IN the fuel and the fuel:air ratio is richer relative to petrol. So less of the O2 burnt will be taken in through the intake and the 'air' requirement is lower for a given amount of alcohol fuel. If so, does that mean that MAF g/s underestimates power on E85 cars? Or because there isnt actually that much oxygen in air, does the air measured through the MAF not actually change much?

[Water Boy]

Great updates Sam!

[Sydneykid]

yeah I think E10 will be set aside for the next fuel crisis and 98 will be the go on the street provided its not much more than 2 bucks a litre. This turbo with a brewed 98 RON/E85 @ E25 will be a rocketship on the next engine. Just didn't want to do it on this bottom end.

Gary out of curiosity does running ethanol heavy fuels cause MAF power estimations to skew. For example with E85, a large component of the oxygen that will be burnt is chemically IN the fuel and the fuel:air ratio is richer relative to petrol. So less of the O2 burnt will be taken in through the intake and the 'air' requirement is lower for a given amount of alcohol fuel. If so, does that mean that MAF g/s underestimates power on E85 cars? Or because there isnt actually that much oxygen in air, does the air measured through the MAF not actually change much?

Good question Sam, the simple answer starts with the stoich, at 1 lambda Pump 98 is 14.7 A/F whilst E85 at 1 lambda is 9.8 A/F. Around half of that extra fuel required (33%) is due to the amount of oxygen in the ethanol;. The other half is due to the lower combustion power of ethanol, as a result in order to get the same value of combustion we add around 30% more E85 (compared to pump 98 ). That's by weight (not volume) as ethanol has a slightly higher specific gravity. We can't overlook the inlet air cooling effect of ethanol, making it denser.

There's some complex maths at work, but simplistically at stoich in the combustion process there is 3.3% additional oxygen supplied by the E85 and there is 30% more E85, which totals 4.25% more oxygen. That's oxygen that doesn't get into the combustion process through the AFM. If running at richer than stoich then more than 4.25%.

Rear world about the same result, it's been over 10 years since I tuned a car on E85 that had an AFM. In general I used to see around 5% more power (E85 compared to Pump 98 ) at the same air flow meter voltage. That's just by setting the lambda for the E85 the same as Pump 98. So not a big deal. The real power increase comes about when you add the ignition timing and up the boost that you can't do on Pump 98 due to detonation.


Hope that helps
Cheers
Gary

[sambb]

Yep sure does. It just sort of occured to me during the E10 tuning that perhaps I needed to pay attention to the butt dyno rather than just maf values, because maybe the maf values were downplaying its success/or not. I remember seeing that mentioned when I was doing water/meth injection. ie the oxygen rich auxillary fuel is going into the airstream post maf so you wouldn't see all the engine power gained represented in the airflow through the inlet. It'd seems though that at 10% ethanol you'd never spot it and that even at E85 levels it'd be tough to claim that a lesser maf plot is actually making the same hp as a better looking plot because of some offset that the ethanol fueled car can claim in the maf numbers.
Well in my case I definitely don't think that the E10 plot was close enough to the 98 ron for that to even become an issue. 98 was definitely the less affordable winner.

[sambb]

So I think this is where I'll leave the TFSI turbo conversion thread. I finalised the intake the other day which has sort of ruled a line under it all. I'd toyed with the idea of moving the battery under the passenger seat and then going back to the standard airbox but but figured this way will be fine and probably breathe better anyway.
So all taken, on 98 RON fuel it made over 205g/s of air through the MAF on a tune that also wasn't looking for every last bit in the interest of keeping rods alive. With the very rough multiplier of 0.8 (which doesnt really take into account the effect of additional timing changes) that brings it to the 260 hp crank. That was when I'd deliberately had it without a cold air feed too. We were doing most of the tuning in some pretty cold weather. I simulated hotter conditions by drawing underbonnet air so that it wouldnt pull timing like crazy once summer kicked in. I think it'd be safe to say that if it'd had a cold air feed in those cooler it would have been cracking the 260hp mark pretty consistently. So at about the 195Kw crank mark, I'm more than happy with it. Best bit is that with the clutch LSD and some throttle control nearly all of that makes it into the tarmac so the car is pretty nippy when you're running up through the gears.
The other thing I would say is that turbo tech has obviously come a long way since K03s's. By going to this turbo that is standard on a 2L I always expected a bigger midrange surge and a bit more up top but thought for sure that I'd be giving away that K03s bottom end hit. I can honestly say that it is dead set equivalent down low yet has all the benefits up top. Yes, I'm running a 10psi base spring in the actuator and maybe it'd be a bit more civilised down low with a 7 psi spring and the ability of the boost control to intervene lower but I reckon you'd be splitting hairs. This car is also not running VVT as there is absolutely no need for it to infill any perceived bottom end loss. Its still a little boost freak just like K03s's. But in general its just an all round better package. The better breathing exhaust mani runners with less restriction into the hot side are a big part of that. I never have to worry about a glowing red hot side anymore and fried turbo gaskets and turbo bolts coming loose. The fact that that the turbo doesnt feel as 'big' as I thought it might makes me 100% confident that a Golf mk6 R K04-064 would be perfectly streetable on a 1.8L engine.
K04-064 donations welcome!!!! ha ha

[Water Boy]

Keen to see it in action next year mate!