Sam's build thread

[Sydneykid]

In Dunlops they have 4 compounds - S (wet for very light cars), M (wet) , R (sprint races & light cars) and H (long distance races & heavy cars). I think the 205/50/15 D03G in the R compound would suite your car very well, they are similar to Medium compound in the A050's.

On the Sprinter (you've seen it) we run 215/50/15's on 7" rims. Some of the guys run 225/50/15 on 7's but I think they are too baggy. Can you fit 215/50/15's on the Polo? I might be able to find a 2nd hand pair/set of A050 Mediums.


Cheers
Gary

[sambb]

Yeah it appears that 215/50/15 will fit. I run 15mm front spacers so that can be paired back to 10mm if the guard becomes an issue. I've got my taller 200mm springs now too (to sort that coil bind - lack of bump travel issue) and when they go in i'll raise the front even more, so 215's should be ok. If you happen to find second hand 215's that would be absolutely brilliant as I've been trying for ages to source some second hand and can only ever find ones that are 4 years old etc.

Was IPRA on the weekend?

[metalhead]

MY MATES AR-1 TEST: So my mate was out at the Eastern Ck south circuit today with the Renault car club testing a new set of Nankang AR-1's. He has two sets of Rega's and so had a very fresh set of same size 195/50/15 Yoko A050 mediums on hand to compare them to. The Yokos had been oven baked by Gordon Leven and had done only two 7-9 lap sessions at Wakefield when we were there in January (22-25 degree day though). The Nankangs were bought new 2 weeks ago (late 2017 build) and he'd done a street scrub on them a day and a half before the event. He said based on finger nail duro test they were softer than his Yoko mediums. Today was about 26 degrees on the coast so could have been nudging 30 degrees at the track I'm guessing.
His car is a W172 renault Clio 2 litre atmo. Standard 4 into 1, W182 inlet manifold, W182 cams with some cam timing changes and a plug and play aftermarket ECU. It has nearly 160hp at the wheels but wouldnt have our low rpm torque. Car is road registered engineered 2 seater with 4 point cage. 6kg front and rear springs. Stock front bar, big rear bar. Toe out everywhere, 3 degree front neg, 2 degree rear neg and roll centre/steer correction kits. weighs 1050kg with 1/4 tank, no driver. Rear beam, mac strut setup just like ours and close in weight.
He said his first session was taken easy so that he could sight the track and get the tyres up to temp and see how they were going with pressures etc. He said he then did the next three sessions and really struggled with the car. He said he was fighting the car struggling to get it turned in, despite the quaife he was getting straight linepower on wheelspin out of the slower corners and found that the car was sliding laterally a lot. He said he actually wasnt enjoying himself and was wondering whether it was because he was on a new track and was getting the lines wrong, or if it was the stiffer 6kg/mm springs that we'd put in the back. He said he could feel them go off a bit to in the later sessions. Not sure if that was pressure related - forgot to ask. He said he tried 32psi hot, 34 psi hot, 30psi hot and came in on one session and set them to 29 psi front 31psi rear to see if that would help get the thing turned in. Throughout all this he said his times were all within 5/10th of 1:09.50's.
So in the last session he thought he'd go out on the Yokos. They were stone cold so he set the fronts at 24 psi cold and rears at 27psi and he said immediately it was like they were an old friend. The car was balanced sharp and doing what he told it. He said his laps for that last session considering also that he was coming up from stone cold low pressures were same deal all within 5/10ths of one another but 2 SECONDS quicker - all around 1:07.5's.
Glad he was the guinea pig because I was going to do it myself, so its a bummer that a nice cheap semi that had had good reports on small cars doesnt seem to hold a candle to the Yokos', and a double bummer that it seems to be that once again you get what you pay for and pay for Yokos you surely do! Whether any of this holds true for bigger cars I dont know but as a good basis for comparison against our car. He said they are still better than his 'street semi' Yoko AD08R's would have been, but markedly off the Yoko's. They'll be on gumtree if you want em cheap!

Wow... That's a bummer for me! In examining my in car videos of my performance at Canberra the other weekend, I was fairly confident that the Nankangs were quite a bit quicker than my street Continental ExtremeContact Sports (which are an excellent street tyre, quicker than Michelin Pilot Supersports), but again it was hard to tell in poor weather on an unfamiliar track. My brother has also recently run them on his mx5 in some supersprints and gone a decent amount quicker than he has previously on Dunlop StarSpecs - again a great street/track tyre but not an R spec. Definitely didn't notice any issues with turn in on my car, but my car tends to be very good there anyway. Very interesting!

I had a chat to James Pearson at Canberra about them too actually, as he had them on his very quick rx7. He said he thought they were ok, not the best he's used but good for the price.

So yeh, maybe not up to some of the reviews we were reading early on. Good for the money perhaps, depending on the car, though sounds like they didn't work well on the Clio.

[Sydneykid]

Yeah it appears that 215/50/15 will fit. I run 15mm front spacers so that can be paired back to 10mm if the guard becomes an issue. I've got my taller 200mm springs now too (to sort that coil bind - lack of bump travel issue) and when they go in i'll raise the front even more, so 215's should be ok. If you happen to find second hand 215's that would be absolutely brilliant as I've been trying for ages to source some second hand and can only ever find ones that are 4 years old etc.

Was IPRA on the weekend?

Round 2, next weekend at Eastern Creek, race engine rebuilt from rocker failure, installed it last Saturday and we'll run it in on Friday. Hopefully not having to come from rear of grid to 4th with a standard engine this Round. Driver is getting a tiny bit disheartened, need to get him on the podium to spray some champagne.

I'll ask around about the 215's and check the workshop, there might be some. The problem with A050's is that they are pretty good until bald, so people don't tend to change them while they have any life left.


Cheers
Gary

[sambb]

Don't worry Andrew. From what he said they'd absolutely kick his street semis (and AD08R's are pretty damn good tyres) and they were better than a second hand set of Toyo R1-RR that he'd run in the early sessions at Wakefield. Just not up to the A050's. It think amongst those tyres for sprints that the yoko's are the kind of tyre that you don't want to try unless you are certain you can afford them in the future because the others just aren't quite as good and there's no going back. The only reason I ever had that set of softs that I've been running at the hillclimbs was because I found a dodgy grey importer who was selling them CHEAP. Wouldn't have run 55 profile if they weren't only 125 bucks each! But there's no such off the back of a truck deals on them that I can see at the moment. Unfortunately my mediums are basically done (should be enough to get me through at DubNats and that's it) and the softs are pretty mutilated. So it'll be mediums from now on. Hopefully provided I'm putting 215 vs 195 width rubber onto the road, the mediums should be ok for the hillclimbs. All up though, you'll be much much quicker on the AR-1's than street tyres.

not R1R's sorry R888RR's which are definitely an R spec

[sambb]

The car is going to get changed over to different hardware and a tune very soon - hopefully sorted by VWNats, so I thought I'd just show how I've been running around lately. Going back a bit I realised I was well and truly out of injector duty cycle. I'd been a bit lazy in looking because the mixtures weren't too bad (0.84-86's) and it wasn't pulling timing really. I'd crunched the numbers by using vcds injector open times(ms) and the rpm I was at and put it all into this little calculator: Stealth 316 - Injector Duty Cycle Calculation
I was up to 95% IDC which meant I had zero room for error eg bad fuel batch, fuel pump starts to struggle etc and I'm in trouble.
First up I thought it could be the pump. Big thanks to Louis who sorted me out with his uprated pump from his previous tune, but the issue was still there so it wasn't a fuel starvation problem. I got my stock 315cc injectors cleaned/flowed to make sure they were in good condition but problem still there. Seb from eurorevolution then sorted me out with a 4 Bar fuel pressure regulator. Basically for a given open time this will force more fuel through. The ECU then adapts and starts to shorten the duty cycles on the injectors until things come under control again. Well this worked a treat. The specified ambda of 0.83 was met almost exactly. Once I got my silly stuff up with not resistoring the SAI solenoid plug sorted, my O2 sensor was able to go into closed loop and I suddenly had long term fuel corrections in VCDS block 032.
TUNING WITH LEMMIWINKS: Basically this block had an idle (secondary/additive) and a partial throttle (primary/multiplicative) fuel trim %. The FPR will determine the wide open throttle fuelling, but next you need to look at the partial trim = all things between WOT and idle from what I could tell. A negative % shows that the ecu is trying to pull fuel out of it (shorter duty cycle) because it is running rich. This is what I had which makes perfect sense because of going from a 3 bar to a 4 bar FPR. So I basically obeyed what it said and would go into Lemmiwinks and subtract/lower the primary /multiplicative fuel trim by the same percent. I'd read that lowering by 80% of what the trim in 032 says is a safer way to sneak up on the right mixture but I found that like for like did the same anyway without any overshoot. So once I got the partial % sorted with Lemmiwinks CH10:primary/multiplicative, the idle % in VCDS block 032 more or less fell into place. It still needed ch08: secondary/additive trim to be decreased from its 100% starting point right down to 60 something %, because it was rich at idle too.


But in the end both fuel corrections in block 032 stabilised and WOT fuelling was bang on what the tune wanted but with 80-85% IDC (much much safer) and it was driving great and making some good power. It still needed some start up fuel enrich and cold start fuel enrich fuel removed with Lemmiwinks but given the fact that its about to be all redone I never bothered. Here is a log from a third gear pull. I think I'd only added 5 or so degrees of global timing in Lemmiwinks. You can see there is stuff all timing pull but it was making 185g/s through the MAF at about 6400rpm which was pretty solid - about 235HP I think.

So this little chapter proves a few things. If you are stage 2 and port your stock manifold and run a ported K03s wastegate tunnel in the turbo your boost peak will jump up due to the better breathing being able to spin up the turbo further compared to a stocker. This needed a pneumatic fix to get the boost peak under control but isd proof that there is gains to be had in creating a sort of stg2 ++. But, in doing so the stock 315cc injectors are maxed out. Short of going to 380cc S4/TT injectors on the 3 bar and retuning I went for a 4 bar fuel pressure reg and used Lemmiwinks to adjust the fuelling. Yes Lemmiwinks is ghetto but it does have some capability with fuelling, so what I did above shows that it can work until say you get your other bits together for a proper tune.

edit: each time you read off the fuel trim in block 032 and make a concurrent adjustment in Lemmiwinks, you need to go back into VCDS and clear fault codes. When you open fault codes there will be non there, but click "clear fault codes" and what this does is reset the short and long term fuel trims. So if the LTFT said the partial fuelling was 13% too rich (by showing -13%), you would go into Lemmiwinks and subtract 13% from Ch10 primary/multiplicative fuel trims. Then you would go into vcds and clear fault codes. Straight after you would check block 032 again and the fuel trims should have all reset back to 0.0%. Drive the car again for an extended period and then at the conclusion of that go back in and check your trims to see what they are saying to do. eg they may still be slightly negative meaning you need to continue to pull fuel out or they may be saying its a touch lean now with a + %. All the while the timing is backed fully off. Only once I had WOT fuelling, partial fuelling and idle fuelling sorted, and in that order, did I do some power runs to check that all fuelling was ok and then I started adding timing. Another point is that because ME7.5 is a load based ECU, from what I could see if you up the boost then load goes up and so soes fuelling. I found it best to be doing the fuelling adjustment at spec boost. I found that if I got fuelling correct with the boost turned down, that I would need more later once the boost went up. So right or wrong I had boost at spececified levels, sorted the fuelling with timing way down, and then only had to find the timing thresholds later too. Again right;y or wrongly I'm not into the whole push it till 6-7 degrees of timing pull happens. To me that's insane because the ECU is basically seeing knock. What if then you run in 35 degrees on a heat soaked intercooler up a hill or you're on the track with 130 degree oil temps, I think you're just asking for trouble so I look for the beginnings of 0.8-3 degrees of pull here and there and then come 0.75 degrees back from there.

[simon k]

this is very clever stuff - really really clever - I'm continually impressed with the way you work through problems, and then document it for us to learn from

it's time I started tweaking things in the ECU instead of just reading about what you're doing

[sambb]

thanks mate. Lemmiwinks is totally kosher for timing adjustments or idle speed tweeks etc, but these days pretty ghetto for tuning. In the past it was pretty heavily used for that though. It worked for me luckily because of all things it does give you control over fuelling and that was my particular problem. I've always wanted to have a play with it and finally had the need to and it worked well, but now I'll be getting into the proper tune - next week or so.

[sambb]

added a little edit to the end of the Lemmiwinks post

[simon k]

thanks mate. Lemmiwinks is totally kosher for timing adjustments or idle speed tweeks etc, but these days pretty ghetto for tuning. In the past it was pretty heavily used for that though. It worked for me luckily because of all things it does give you control over fuelling and that was my particular problem. I've always wanted to have a play with it and finally had the need to and it worked well, but now I'll be getting into the proper tune - next week or so.

I figure it's the right thing to use for minor adjustments once you have the ECU tune set up - the way you've been doing it. The more little tweaks you put in through there, the less 'correct' the ECU tune will be, so it'd be a matter of adjusting the ECU tune and zeroing out the adjustments in lemmiwinks.... is that the right way to think about it?

so what's the hardware change? same as Louis?

[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