FabiaGonzales

Yeah exhaust needs upgrading, the backpressure from the stock cat hurts spool and increases cylinder pressure and temps alot, its bad for the engine and the turbo, free flowing exhaust reduces those temps so you can oush it further. 180bhp is about as far as you want to go on the stock exhaust, you can force more through it but the car will start pulling power cos of it, i suspect that's partly what the surging was all along, trying to push too much gas through the exhaust, backing everything up, o2 sensor would detect its too hot and itd pull timing and boost, the whacky wastegate probably didn't help either. 200ftlbs region is safe for the rods, beyond that is kinda untested in terms if reliability, mine made 230-240ftlbs before without spontaneously ejecting themselves out the side of the block lol

I doubt 99 octane would gain that much. You gain a couple degrees extra timing but that's about it. The exhaust is what holds everything back past about the 180 mark. The JBS hybrid can push considerably more than the 206 ftlb / 280nm that JBS gave it, we only left it at that for the longevity of the rods and to reduce stresses while i get a sport cat downpipe sorted for it. Its torque also comes in around 1800rpm, though it's limited to about 170ftlb until 2200 to try keep the stock clutch happy (i've done 10k on the stock clutch and it feels no different to when i first had it done, but then again, i don't hard shift or flat foot shift like some do.. 😂 ) The RTMG is based off the smaller 1.4 turbo which is a much similar design to the 1.2 turbo, the wastegate behaviour is much closer to the 1.2 turbo as a result so it shouldn't really have any issues with that. I'm surprised the RTMG only made that much considering how massive the turbine / compressor are, what's spool time like? Once i've got my exhaust sorted i should be making around the 200bhp region and a tad more torque through the mid range since the clutch seems ok with it.

181bhp on 99 octane. I recently ran short and had to put a little bit of BP 95 to get by, out of curiosity i watched timing pull from knock and it was pulling 10-11 degrees of timing on 95 octane, on 99 only 3-4 degrees which is normal. It definitely felt sluggish and boost came on slower. BP 97 octane had pulls of between 6-7 degrees, and didn't have the same slow boost buildup, but it lacked power in the top end, struggling to get to redline in 4th, with 99 it can reach the rev limiter (136mph @6500 rpm ish) in 4th.

Got 16mm Forge spacers on the rears on mine today, Gives it a far more agressive look from behind. 20mm would probably look ever so slightly better still but i didn't want to risk rubbing on big bumps given i'm not on stiff coil or anything, plus i got the spacers + bolts from someone on facebook for fairly cheap compared to a new set lol.

Who with and what did you go for the exhaust? Just the downpipe or a full system? Also do you have a dyno graph of yours? The exhaust is holding mine back a lot, i can get to 140 but as i only have a 5 speed i'm already at 5300 rpm by that point where im losing power because of the exhaust it takes damn forever to get to 140 haha, of course with a bit of a tow from a rather confused range rover driver it gets there and beyond quicker.

What size spacers do you have and how does it look? Looking to get spacers for mine

Ooh, any hints of how the sport-cat will handle an MOT? I'd love to get a better exhaust on mine, i've a feeling the back section is a restriction too, not just the cat(s), if it's a dusty road and i plant it, the stock exhaust kicks up massive clouds of dust 😂 might see if i can get the map upped a little once it's got an exhaust on it too, ive done about 6-7k on the hybrid so far and it's solid as a rock.

I disconnected & reconnected it like that (same as in the user manual), no change. I don't see anything that's changed, or at least i didn't see anything different before i started poking.. 😂 I was curious to see whether changing the battery serial would have any effect (to make the BMS see it as a "new" battery) type was set to efb (i left that alone) manufacturer was set to JCB (eh? I left that alone too) serial was 1111111111 (which i just zeroed out) The result? charging voltage dropped to about 14.4v, and now once it hits 75% ish, it drops to 13.3v ish (previous 13.6v ish) unless on overrun. No return of stop/start yet. The battery has been disconnected before (and as far as i can remember, stop start worked again straight after). Recently after being a little deeper drained a few times (when having the hybrid turbo tuned in sat with ignition on engine off etc), it's taken a few days to recover and resume stop/start functionality. The other wierd little thing it does is when lifting the clutch (in neutral) it raises revs as if it expects me to pull away. It's done that previously when "recovering" too but it's a little random thing ive noticed I've ordered a Yuasa YBX9027 AGM battery. Whenever that comes i'll code that in properly with the actual serial and manufacturer code (does anyone know the manufacturer names-codes references?) and see how i get on with that. I have a feeling this battery is on its way out. Even with a good 1hr+ drive out, shutting off and leaving for 12hr the battery is usually sitting around 11.8v ish and it drops to 9v (and possibly lower) the cars not complaining about it or anything, just stop/start not functioning. Edit: previously it only used to drop to ~10.5v when starting the car (and even after prolonged cranking by disconnecting fuel pump it stayed above 10v)

Yeah i've checked that. If i unplug that, the charge % reading doesnt work and voltage sits at a steady 13.8 ish, no fluctuation for overun or anything. Might disconnect it and reconnect it again to see if that changes anything.

So, recently my top right engine mount (the one next to the coolant reservoir) split (and made a right mess), I ended up swapping all 3 engine mounts for Polo GTI ones. Anyway, to do this i had to remove the battery (albeit only temporarily). I disconnected the +ve first, and connected it up last. Stop-Start was working properly beforehand, but since the mounts have been replaced, stop-start no longer works, it simply states "engine must be running", i've a bluetooth OBD module which shows the battery gets to ~85% charge via flat rate 14.8v, once it hits that point it drops to overrun-only charging. Still no stop-start though. Any clues?

If you ever crash it, let me know, i'll swap seats with yours, been wanting these for a while now but haven't seen any pop up anywhere;

Shuddering at idle with EPC sounds like some sort of timing issue. A possbility it could be clutch/dmf. Take it to someone witha code reader to see what the actual issue is.

True, the BMS does use a standard charging scheme to get the battery up to somewhere around 80% or so, after that it drops off to basically the battery doing nothing and the alternator is powering all the car functions. But still standard batteries aren't too fond of being even that low, they prefer being full all the time and being trickled constantly.

Then that's how our BMS handles it, so it shouldn't overcharge on overrun. That still leaves the main issue with the fact that as standard batteries have higher internal resistance, they won't be able to take on as much charge from regenerative braking and overrun, that'll leave the battery in a constantly low state of charge that's going to encourage the formation of sulphur crystals on the electrodes. EFB and AGM batteries don't have such issues by design, but they don't like being constantly charged (standard ones like being trickle charged, agm prefer a pulse maintenance style of charging).

Yes, but it would depend on how the BSM handles the overrun charging. If it's designed to throw (for example, actual charging currents and voltages would be much lower) 100 amps at 15v at an EFB battery, A standard battery being given that voltage, would only soak up approx 50 amps or so due to its higher internal resistance, the BMS might try and compensate by increasing the voltage (to say, 16v), and the current would rise somewhat accordingly. The heat generated by charging is dependant upon the internal resistance and the current being accepted. This theoretical EFB battery has 0.15 Ohms internal resistance, and the theoretical standard battery has 0.30 Ohms internal resistance. The EFB battery would be seeing 0.15 Ohms * 100 amps, so it would see 1500 watts of power going into the battery. Because the internal surface area is much larger, this doesn't really pose an issue. The standard battery would be seeing 0.30 Ohms * 50 amps, so again it would see 750 watts of power going into the battery. No issues there yet, the lower surface area means it can accept less power. The standard battery being forced a higher charging rate (if the BMS were to try such a thing, perhaps to try compensate for the fact the battery isn't charging up enough between stop/start events), that increase to 16v charge voltage would only net 53 amps charging current, but it's now sucking in 853 watts. The overcharged standard battery just isn't going to last as long, it's going to get considerably hotter than it's designed to and it will slowly boil off the acid over time, futher reducing surface area and accelerating the issue till it's dead. Obviously real life values will be considerably lower, as internal resistances are nowhere near that low, but you get the idea. It's like a 100w light bulb vs a 50w light bulb, you can make a 50w bulb output the same amount of light as the 100w one by increasing the voltage (and therefore current), but that small fillament is going to melt very quickly.

It's difficult to find useful into, but EFB (and AGM) have considerably higher charge current acceptance than standard batteries. Here's one source; https://www.yuasa.co.uk/info/technical/agm-efb-explained/ Standard cells have limited electrode surface area due to their design (efb and agm fix that) and a battery can generally only accept so much current per the surface area at a given charge voltage. Depending on how the BMS is set up, it may keep the voltage low on regeneration (and therefore the current will be low too), in which case the battery will struggle to get charged up sufficiently before the next stop/start event, and will slowly become deeper discharged over time and fail quickly (standard batteries dont like low charge states, they sulphate), or it might try to push the same current as it would do for an efb or agm battery, it would do that by ramping up the voltage considerably which as we know can overheat and damage the battery by effectively boiling the acid off. With agm due to their design with lower internal resistance than standard cells they will pull more charge current at a given float voltage, that's why they need a lower float voltage, else they sit there sucking up all that current and overheat. It's easier to simply hold the battery at a lower state of charge (usually 80-90%) as the battery is still able to put out plenty of power, that charge level is fine for an agm battery and it also stays away from any overcharging.

A standard battery doesn't like the higher currents and voltages that the regenerative braking provides, EFB and AGM batteries don't like the constant charge voltage that a standard system provides. Ideally you should replace the battery with whatever type came with from factory. Nowadays it's generally safe to upgrade the types via coding the BMS (battery management system) which alters max charging currents and float voltages accordingly for the battery type installed, while going backward is also doable by the same methods, you're putting extra stress on a battery that wasn't designed for such activities. My factory installed EFB battery's going on toward 6 years of service now, not missed a beat. Why you want to replace a standard battery multiple times when a properly looked after correctly matched battery may not need replacing at all during the time you own the car? There are a lot more metrics to look at other than "engine starts" when it comes to car batteries. Standard cells don't like the deeper charge cycles that stop/start involves, for example, they prefer to be fully charged all the time, but stop/start is rarely going to allow that kind of condition. AGM doesn't like being sat on charge all the time when it's full, like when installed in a non stop/start car, rather they prefer the constant charge cycling of a stop-start system.

Some people have a thing for diesels lol. Standard batteries do not like the higher charging voltages and currents that the stop/start system uses. It can cause the acid to boil over and make the battery fail far sooner. Yuasa AGM 096 battery i found for something like £120 on amazon, are you sure yours is 096 size? That CCA sounds more like the larger 027 or whatever it is, i'm sure the diesels use a larger battery.

I do fairly mixed driving nowadays, some longer 30-40 mile trips but usually 5-10 mile ones with occasional shorter less than one milers, and i generally leave stop/start enabled. My car's coming up to 6 years old now and the original battery is still going strong, every now and then i take it to halfords for their free battery tests and it keeps coming back flying colours, usually performing a little above it's ratings. My battery has definitely done more than its fair share of cranking. Back when lockdown first started, my car sat for just over 3 weeks, i got in it, it started up straight away, i got to the end of the street and to my surprise, stop/start kicked in. When i'd had my hybrid turbo done it'd been sat with ignition on for a lot of time having maps altered etc between dyno runs and had drained the battery somewhat, stop/start didn't function for 3-4 days after and reported "engine must be running". Still didn't have any trouble starting and no warnings on the dash or anything. Once it'd got back up to an acceptable charge level stop/start started kicking in again.

Decent branded batteries in the key fob last quite a long while. My Duracell CR2025 bought from amazon nov 2019 is still going strong at the moment. Cheaper ones you may have lying around often only last a couple of months or sometimes even less, i had some energiser ones which didn't even last a single journey before suddenly dying completely. CR2025's seem to be a very mixed bag but people have had good experiences with the Duracell ones, some grab em from Amazon, some from supermarkets etc.

Toe camber and caster are all somewhat adjustable on the front. When i first did the wishbones on mine all the adjustments were wayyy out, and like yours within about 150 miles i'd completely trashed the 3mm of remaining tread down to about 0.5mm! Good job i didn't get stopped by police... After the alignment the whole lot felt so much more incredibly precise and responsive, was like a new car haha The rear is pretty much non adjustable without the aid of shims, that's why being lowered can cause wear irregularities on the rear tyres (and why it's suggested to swap them back to fronts more often and in a cross pattern if the tyres are non directional).

I queried JBS about it when i had the hybrid done. You can very easily swap the boxes out and shouldn't need to change anything else. For coding in for the gear recommendation (and cruise in 6th) i'm not too sure what's needed, best to message JBS about that i imagine. The 5 speed box is PED, the 6 speed box is PRQ, they are drop in replacements.

I originally had 16" wheels and I went from Bridgestone Turanza's to Avon ZV7s and it was a night and day difference. Huge increase in comfort too. Quite sticky too, probably owing to their softer compound. Then i changed to 17" wheels which came with Dunlop SP Sport Maxx's, and by eck they're awful, known to be a noisy tyre though, i'll be switching to a nice set of four Pilot Sport 4's (not 4S, they don't do them in this size) next month so should be better than these.

Perhaps! Surprised economy hasn't suffered with it being out that badly

For the price and how long they usually last anyway, i don't think it matters too much whichever you get. There's not a great deal you can do wrong with simple linkages. More load bearing functional parts though i'd recommend Skoda, though the OEM wheel bearings are FAG parts so just grab those if you're going for that.