Sam's build thread

[sambb]

some footage of the event that I missed: YouTube

[simon k]

I sorted out why the car wouldnt go into closed loop. I knew the N249 delete could affect fuelling if its solenoid wasn't resistered properly. What I didn't know was that the same is true for the SAI delete. Id thought that If you had the SAI delete as part of your tune that there was no need to resistor the solenoid so I'd left it unplugged/ open circuit. Well doing that means that the o2 sensor for some reason never gets full readiness as seen in VCDS block 030 - you need the last digit to be a '1'. O2 sensor mixtures will appear ok in block 031 which is commonly logged for power runs (which made me think everything was ok), but these values become just read only and do not update fuel trims because you are permanently in open loop. So if you've deleted the N249 and SAI then check that you've resistered BOTH or youll be locked in open loop. One the resistor went in, short term fuel trims started changing immediately and once the car hit about 70 or so degrees the long term fuel trims started compensating for the extra fuelling.

that's good to know... there's so much conflicting information about the N249 and SAI delete. I'm leaving mine on there until I have an actual reason to remove them - like when the SAI craps itself

[sambb]

Yeah the SAI pretty much has to stay put until its written out in the tune. The N249 does help though. The ECU actually uses it with other control measures like throttle cut, timing pull etc to keep things as per the tune. What you find though once you are tuned is that the ECU gets pretty active at activating the solenoid to allow the vacuum stored in the canister to pull the diverter valve open as a boost limiter. In a stock tuned car its a non issue though. The N249 system can be removed though. The solenoids plug gets cut off and a 330-380 ohm 6watt+ resistor soldered across the wires. Then the hardware can be turfed and the DV run straight off the vacuum line that will now only run to the SAI solenoid.

[metalhead]

Sam should've kept going... you could have made 1 good car out of the two

Haha... The real bummer was that I also forgot to throw in the fuel injection handset, so I couldn't lean out the targets to compensate.

Glad you found your issue Sam.

I've chucked up some videos as usual too. You can see the black fuel smoke billowing out in the video where I'm warming the tyres...

[sambb]

Yeah yours did look like it was chugging in the burnout area in that vid. Next round is Kempsey yeah. Now that the championship as a whole is a bit compromised I'll just do rounds closer to home - Tamworth will be the exception though, I love that track. Kempsey + the VW Nats in the same month was going to lead to divorce so maybe its better this way and my Yoko softs will live to fight another day. VW Nats allows other makes! are you brave enough to rock up at a hot hatch festival in a chevy!! Otherwise we'll cross paths at Tamworth, Ringwood or Huntley or Wakefield I suppose. I'll check out the vids.

Car is going better by the minute. Now that it can actually read the mixtures and adapt the ECU is dialling it all in and the car feels great. I've pulled the timing right back yet it did a 182 g/s (MAF) run which is only a whisker off the previous cars best and its still running rich everywhere and has no timing in it. Just a stop gap though before the proper tune with left foot brake, linear throttle, maybe launch control etc. Have to start getting Nefmoto logging happening.

Seriously considering E85 for when I get it tuned if I stay K03s turbo OR if a K03 hybrid turbo pops up real soon i'll do that on petrol. I have E85 down the road and half way to/from work so the urban side of things is ok, but need to find out about its availability up the freeway towards Newcastle and out to Tamworth etc. I'll have to hit up Louis and find out what parts of the fuel system need to be sorted to run E85 long term.

[Sydneykid]

In Newcastle the Mayfield East and Merewether Uniteds have E85.

In Tamworth the United near the Golden Guitar has E85. That was pretty marginal non stop in the Evo, so we used to carry 10 litres just in case. Filling up at the Uniteds on Rookwood Road now we wouldn't have to.


Cheers
Gary

[sambb]

Hmmm really wondering about E85 now. If not too much hardware needs to be changed then I may do it. I have 3 and 4 bar fuel pressure regs, both the 2.5 and 3in MAF housings so can go up to the bigger housing if they think the MAF will top out. A bigger fuel pump in there already (but not sure if its E85 safe). I'll have to find out if audi S3/TT 225 380cc injectors would have enough headroom (stock is 315cc) for a modded K03s or if bosch 550cc's would be the go. I guess we could do the 380cc ones on the 4 bar regulator for E85 and then I could always go back to the 3 bar reg and retune for petrol if E85 proved to be a pain.

[Sydneykid]

Some very basic (ie; rule of thumb) maths for injector size versus bhp (that's at the engine, as on an engine dyno);
At 12 to 1 air fuel ratio for petrol 1 x 300 cc injector (at its rated psi) will provide enough fuel for around 50 bhp, so 200 bhp in a 4 cylinder.

315 cc = 210 bhp
380 cc = 250 bhp
550 cc = 360 bhp

Keeping in mind that that's petrol, 12 to 1 AFR and standard (rated) fuel pressure. Obviously the flow increases as we add more fuel pressure and we need around 25% to 30% more E85 for the same bhp output. That's not allowing for any increased bhp as a result of being able to tune it higher as a result of using E85 (ie; more ignition advance etc).

If they are rated at say 3 bar fuel pressure and we increase that to 4 bar and allow say 30% more fuel for an E85 friendly air fuel ratio around 9 to 1, the result is;
315 cc = 215 bhp
380 cc = 260 bhp
550 cc = 370 bhp

That still allows enough flow for acceleration enrichment and cold start enrichment.

Since fuel injectors cost pretty much the same regardless of how much they flow we use the biggest ones we can (eg; 2000 cc injectors for a 280 bhp N/A 2 litre). That way we can move the injector timing around within the combustion cycle, which is important when we use up to 10,000 rpm.

Remember, just rule of thumb calcs and that every engine is different.

Cheers
Gary

[Sydneykid]

I guess we could do the 380cc ones on the 4 bar regulator for E85 and then I could always go back to the 3 bar reg and retune for petrol if E85 proved to be a pain.

Separate thoughts on this one;

In theory (that rule of thumb again) you could drive to an event on pump 98 on the 3 bar FPR. Drain the tank and fill it with E85. Then swap the FPR over to the 4 bar one and do the event. Then drain the tank, fill it up with pump 98, swap to the 3 bar FPR and drive home.

Not suggesting that you should do that, but you that could. Or in an emergency when you couldn't find any E85, it might save your ass, maybe close enough AFR's to get you home.

Cheers
Gary

[simon k]

how about swapping ECUs? e85 on one and 98 on the other

though loading a tune only takes a couple of minutes, as long as you carry a laptop everywhere

[sambb]

actually that's a very good idea the swapping of ECU's. Have an E85 one ready to go, with a defeated immobiliser on it, and a separate one for the street/petrol. An ecu swap now that the airbox and battery are out of the way takes about 2 minutes. For the time being most of it has been settled on. Initially at least i'm going to do a 98 petrol tune. I'm buying 550cc bosch ev14's (that can do both although they may need a 4 bar fpr on a hybrid if I go that way but will be fine on the current turbo). Judging by Gary's info (thanks for that) they should be fine for what I have on the 3 bar and maybe even for a hybrid if its not too extreme. S3/TT225 380cc would have worked but would give me no headroom for even e85 on the existing turbo so I discounted them. I'll use stock 3 bar fpr and the 7psi wastegate spring. Its still up in the air whether a 3in MAF housing is needed. Once I've got the 4 bar fpr which is in there now tuned enough to do some WOT runs, i'll be able to see what the max MAF g/s flow is. I think anything that is approaching 200g/s is meant to be topping it out so if that happens then the bigger MAF may be needed for the proper tune but that's up to the tuner. First things first though I need to find the correct length 550's for the right price and surprisingly domestic looks to be the go. But yeah I'll be keeping an eye out for a spare ECU from now on - regret selling my old one now.

[simon k]

I'll be keeping an eye out for a spare ECU from now on - regret selling my old one now.

maybe talk to Louis - I was going to hit him up now that he's replaced it...

[sambb]

Ordered my Bosh EV14 550cc injectors today - 53mm o-ring to o-ring, with the connector adapters for our loom. A tad over 300 bucks delivered from VPW in Melbourne was pretty good too.

[sambb]

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!

[sambb]

Question for you Gary. Hankook TD r spec only have 195/55/15's. I'm after 215/50/15 to put on my 7in rims on the fronts or 205/50/15 if you think that's a silly thing to try. The only two I can see that do it are Yoko A050's in medium and Dunlop Direzza D03G. In previous posts you mentioned that you rated these Dunlops yeah? They are R2 compound. Is that their medium? Do you know how that compares compound wise to a Yoko medium, because it would probably have to double duty as a hillclimb and rallysprint tyre too. Don't have the dollars anymore for a soft and a medium set - thinking Ill end up on mediums for everything.