Sam's build thread

[sambb]

yeah I used to read about guys that had standard ECU's and they'd be putting garrets on and just 'tweaking' Lemmiwinks/unisettings/etc and that would make you wince a bit. But if you have a tune and then you deviate slightly from the hardware that the tune is written for eg porting a manifold, a big TIP + enlarged intake, straight piping the exhaust on a stage 2 tune or what I did - freeing up flow in the really hot bits..........things that make it breathe better and demand a little more fuel then yeah I think Lemmiwinks can cover off things like that.

Yeah what I did was basically throw on a 4 bar and luckily fluked it for where I needed to be. The tune was asking for 0.828 lambda at WOT and I ended up on 0.813's. Rich but safe. The best way would be to use the ECS adjustable fuel pressure regulator. You'd then manually adjust the reg to get your wide open throttle fuelling correct, and then use Lemmiwinks to adjust out the surplus fuel at all the other load points which will be running rich as. Left as is the ECU will be be going "WHAT?" and adjusting out as much fuel as it can but it can only do this within limits eg I think anything outside of -25% in ch10 and it cant pull more out, so you have to keep checking and adjusting until you firstly pull the fuelling into a window that the ECU can adjust for, and secondly into a zone that is bang on for mixtures.
From what I understand if what you do is within those limits its ok to do it that way. I ran around for days on end watching block 031 which is real time mixtures and it was pwrfect at idle, in partial throttle acceleration until it dropped into the tunes WOT maps etc - couldn't fault it. Is it possible that that's how the factory made tweaks to different cars maps? not sure. plenty have said so - probably people trying to validate their results with tuning this way, but it is amazing to watch how the ECU firstly and within a couple of runs adapted the WOT duty cycles to the new fpr.
But yeah with partial and idle, it can only adapt within limits so you look at what % its pulling or adding with the fuelling, zero that, and then go in with lemmiwinks and make an adjustment which basically tells the ecu that what you have been doing until now is not an adaptation, it is in fact normal and what you do from here on in is a 'new' adaptation based on a new benchmark that I'm giving you. Then you scrutinise the next adaptation the ECU does, respond to it with a lemmiwinks tweak and go again. Eventually you zero in on the right mixtures and the ECU thinks all is fluffy because behind the scenes you've added or subtracted offsets that it doesn't even know about. Your reference for all this though is you o2 sensor feedback. You might be fooling the ECU but the O2 sensor (which is a wideband in our car) tells the truth, so you do need to rely on the fuel trim blocks as a guide for the magnitude and direction of the adjustments you make, but it pays to be always watching the actual o2 sensor readings in real time in block 031 while you are driving around 'learning' the new settings to the ECU which is watching all the time, just in case you go the wrong way with a channel change, or make a change in the wrong channel etc etc

What I'm going to be doing with my car is a tune for my existing ported K03s turbo/mani with a 3inch MAF and Bosch 550cc EV14 injectors. It'll go back to a 3 bar FPR with the 550cc injectors obviously and will run a 7psi actuator spring. The reasoning behind the 3in maf was mostly so that if down the track I go to an E85 tune, then the 3in can definitely do that whereas the stock 2.5in maf which will do the 98RON petrol tune ok would likely run out of flow potential with E85 - not 100% necessary for the petrol tune I'm about to do, but if later I go to a situation where I can just swap an ecu to be able to run E85, then the hardware will be common. For injectors I had looked at 380cc audi S4/TT ones but they were close to the EV14 Bosch injectors in price new and again while the 380's could probably cover me for the petrol tune they definitely wouldn't for an E85 tune. The EV14 550's are meant to be very good at small opening times (which i'll need them to be say at idle on the petrol tune) but they will open like taps when they need to. I agonised over the actuator spring. I can go 7psi or 10psi with my turbosmart actuator. 10psi definitely works better at flattening the boost out through the higher rpms than the 7psi does, and from what I've found doesn't produce an overly aggressive boost ramp because the K03 naturally boosts like a little mofo anyway. But where I think it does matter, and the tuner nudged me in this direction too which was the clincher, is when you are on the track and need to make little throttle corrections, or a deliberate lift to change the way the car is rotating, the 10psi can be a little like a light switch with the K03 whereas the 7psi is that little bit duller and user friendly on the limit in that respect.
As part of the tune i'll be getting left foot brake capability, 1:1/linear throttle that will moderate how manic the turbo is at reacting to small throttle inputs, and maybe a 2 step. I've heard that 2 step can turn stock cast rods into noodles though, even on K03s's so I'll have to ask about that, but I'm pretty sure the guts of the tune will have to be worked out before we get to that anyway.

[sambb]

The old airbox/filter arrangement wont work with the 3 in MAF. It was perfect for the 2.5in where its bellmouth exit fed directly into the MAF with the correct IDmm, but its way too small for the bigger housing. So I made a new base plate to accept the 3in MAF housing. All that's left to do is make a bellmouth/velocity stack/.... that will slot into the throat of the 3in MAF yet also fit inside the filter. You have to use the 3in housing from an Audi S3 or TT mk 1 225. The VR6 ones will not accept our MAF sensor.
original setup.
I found some 3.25-3in progressive silicon reducer and then a 3in pipe will link the filter airbox to the forge 70mm TIP for the smoothest possible step downs.
Bosch 550cc EV14 injectors with the adapter plugs for our loom fitted.
- bosch injector part# BOS0280158117
- need to order 53mm +/- 1mm (O ring to O ring) version as there are many different lengths of this injector. Then they are a direct fit with no fuel rail spacers needed.
- proflow injector plug converter part#PFEFI-003

[sambb]

A nice little run down of the 9N Polo Cup cars that competed in South Africa's Engen Cup before they went to the newer cars. 4 door and NA 2L (bored out 1.8T blocks from wat I can gather) but our chassis.

YouTube

YouTube

[sambb]

Finished my inlet set u ready to transfer over in place of the 2.5in MAF once the new tune starts getting logged. I didn't like the way the 3in MAF housing had all sorts of ugly steps etc at its throat. The 2.5in MAF is fed by a bellmouth in the standard airbox. I hunted through a couple of wrecking yards and noticed that a golf 4 had an even better bellmouth. I spoke to a VW person who surprised me by saying that the 3in MAF cars S3/TT/bora did not have OEM bellmouths inside their airboxes and I looked at a Bora one that confirmed this. The MAF just sits in the top cover and has no contoured lip or anything. After reading so much stuff about how critical air stream conditioning is for MAF sensors and seeing bellmouths/stacks/curved lips on just about every other cars airbox while I was down at the wreckers I decided to make my own. I had a 2.75in belmouth which I cut at the correct height to give me a 74.5mm ID. This matches exactly the inner throat diameters of the MAF screens that are in the 3in MAF. It was a reasonable tight fit but I managed to neatly silicon it in there so it wont budge.

So now its a nice entry to the MAF housing and should breathe nicely from within the K&N filter that I swap onto this plate. A 3.25 to 3in contoured reducer runs off the back of the housing into a 3in pipe. I cut the rolled edge off the trailing edge of the 3in pipe so that it'll go into the 2.75in Forge pipe. All up its a really nice smooth reduction that'll feed the existing TIP as a swap n' go.

[Sydneykid]

Looks good Sam, nice job, but I'm not sure that it was worth the effort and time. At the other end of that pipe is 100,000 rpm "vacuum cleaner" sucking away and providing airflow to the engine (making boost). If you have a boost target of say 1.5 bar and with the "super duper inlet mods" the turbo can achieve that at, say, 100,000 rpm (shaft). Compared to no super duper inlet mods it might need 101,000 rpm to make 1.5 bar. The engine doesn't care as it's still getting the same airflow and the increased shaft rpm (to overcome the slightly higher resistance) will be so minor as to be inconsequential.

This is why we find some manufacturers bother with "super duper inlets" and some don't. Quite often I suspect that they use whatever is in their parts bin, if they have a suitable one they use it, if not they don't bother engineering one.

On a normally aspirated engine the inlet is very important and we go to great lengths to maximise the airflow, we chase every single horsepower. But a forced induction engine, no so much, we can easily increase the airflow using the turbo and pick up 10 bhp.

Cheers
Gary

[sambb]

ha ha yep total OCD taking over. Just couldn't put it in there how it was. It just looked rough. To be honest I wasn't expecting that I'd see gains I just wanted to make sure that there was the least possible turbulence going through there so that I could get nice stable sensor reads which would kick on into nice stable fuelling. If I had an OEM airbox I wouldn't have bothered because in that case I wouldn't second guess what the VW engineers had decided on but since I'd modified the air filtering setup and the MAF would be drawing at close range within a tight filtered 'plenum' space compared to an OE airbox, then I figured I didn't want to upset anything. Weird though that all the 2.5in maf cars from the factory had bellmouths but not the 3in maf cars. All I can think is that the "2.5in" maf which is actually pretty far from it in reality eg closer to 50mm ID but the '3in' maf is actually a true 3in ID. They say that the maf sensor can reach its metering peak inside 2.5in housings quite easily (ive seen 190-200 g/s given as the max and one of my stage 2's was certainly maxing the sensor if that is the case, so maybe because its running closer to the wind in the smaller housing, they need the bellmouths on there to condition the air as much as possible. The 3in just looks massive compared to the 2.5in and maybe since the sensor is not topping out inside that housing they don't bother with the bellmouths. Yeah all along I thought the making of the bellmouth was overkill. But at the end of the day its now the best it can be and will flow anything I need it to.

[Sydneykid]

I do lots of things on race cars just because they "look better", it's a bonus if they also "work better". I know next to nothing about VW AFM's, but in general all AFM's have some form of air flow director around/before the sensor to ensure that only non turbulent airflow gets to it. For the Skyline AFM's we take the sensor out of a 90 mm Q45 AFM and stick it in a 100 mm alloy pipe. That gives us metering up from around 600 bhp (in a 90 mm housing) to 800 bhp (in a 100 mm). Although it does need tweaking we don't have to rebuild the AFM voltage table from scratch.


Cheers
Gary

[metalhead]

Nice work Sam, whether required or not! So you're not going to be heading up to Kempsey next weekend?

[sambb]

No unfortunately. The car is in the middle of being tuned. Just did some runs/logs with the existing hardware so he could build a picture on what the wastegate is doing and then the base tune will go in with the injectors and MAF probably this weekend. The aim is to have it ready for VW Nats on the 26th track day, so didn't want to delay things by doing events around now.
If I'd been able to run at Canberra and come away with some good points I'd have weathered the wife storm and committed to the whole 8 rounds of the championship but since I missed Canberra it pretty much put me out of the picture for a good overall result. I wont do Grafton either, but will look to do Tamworth, Huntley and of course Ringwood. I'd like to do the Tamworth 3 lap dash too maybe.
I will do Kempsey one day. Looks like a really fun track. I missed it the first year I was hillclimbing which wasn't a bad thing because that's the year the guy in the mini hit the bank and was killed which was horrible. They only did that one run and forfeited the round I think. Last year I missed it after I was hit by the 4WD. Next year probably, and Grafton too - everyone says that'd be a great track for my car.

[sambb]

Pete's upset that there is literally no one in the under 2.5L road reg class. I reckon he should just go into improved production but keep his road reg (if that's possible) so that he can compete. Instead he's focused on track stuff for now. He really needs Graham in the CRX to come back and then he'll be at every round again. We're opposites - he started out and was getting podiums left right and centre because his class had good guys and was very competitive but was small. As you know our class is very tight and other than the couple of guys that were guaranteed podiums it was very very competitive for third/fourth. So Pete's a bit demotivated when there's no one to compete against but I'm still super hungry to try and get a class win. I've told him he should supercharge and then he'd be in our class but I do agree with him that his car is better as an NA.
Did you get the header fixed? Want to hear how it goes up there.