Kinkstaah

I mean from V8 world there are gains to be made in intakes and such over stock items, but definitely only if you tune them. We're talking about I dunno, 10kw here and there on a 300KW v8, gains made by tuning in the 0.2 AFR that it changes so YES but also no you won't notice it other than the sound. Duct the air as mentioned 750,000 times and you will notice happier IAT's which definitely make a difference N/A. I mean my unsubstantiated guess is you'd go from 140kw with everything stock (after cams) to 145kw with everything and a tune :p

Hey, it's me! Though honestly, if I had 20M in my bank account tomorrow, I would not want to be rid of my car all of the sudden - Which makes me think this is money stuff, not "I actually hate car" stuff. I'd probably double down and buy even more trinkets and fun things for it. If this is not you, then sell it cheaper. It will sell at a certain price after all.

Of course it would be - But you shouldn't be here.

I'm going with "Just run two gates". Fix the problem conclusively. It's the only way you'd ever truly know, right?. This is all pretty much splitting hairs. Even the extreme example where it takes two whole seconds at 100kmh or something sounds monstrously dubious. And anyway, when you're punching the throttle when you 'need' this power, you aren't at 2800rpm in the wrong gear. Test it at 5600rpm in 3rd gear, when you're traction limited punching out of a sweeper. Much difference there when you account for traction?

If you want to do the wiring, the GTT engine ecu has the same pinouts extra that the seperate TCM in the NA car has. You can literally grab the wires/pins that lead into the Seperate TCM and wire them into the corresponding pins in the GTT Engine ECU. You could then in theory Nistune it. I realised this when everyone put it in the too hard basket and I actually looked at the f**kin R34 manual. This is after I had previously had a seperate aftermarket TCM controller in my original N/A chassis car and a very built gearbox from a GTT, running a seperate Haltech engine ECU. I ran into this issue when I re-shelled the car into a GTT shell, so my aftermarket TCM was no longer plug and play, because the loom/modules were not present. I was pretty livid when realizing just how simple the original fix actually was. It sat for 3+ years at various workshops trying to find a solution. In practice none of this is a worthwhile idea for a lot of reasons, generally surrounding the shitness of the NA auto, the autos in general that come with skylines, and the NA engine and lack of gains. The gearbox is specced for the 2.5L N/A and barely at that level. If you have to pay anyone any money to do any of this, that is money spent on manualizing the car and it's not even close in terms of a comparison. Learning to drive manual is simpler than going through the pain of dealing with the N/A gearbox and he'll have fun to boot.

Correct. The ECU cannot read oil temp. (Well, I think it probably can in some situations. I did have the thought of potentially repinning the ECU when I was doing oil pressure). I am using this into the MPVI dongle, so that the MPVI dongle can read oil temperature. It is attached to a VDO gauge which is obviously calibrated to whatever curve the sender actually is using. This would be easy if I could setup a table of voltage to temperature like many sensors, but it appears I cannot do this and can only setup the transform rule which appears to be Input (voltage) x Multiplier, and add an offset. This to me means it MUST be linear. So it may be a complete waste of time wiring this into the ECU. The idea was that the MPVI3 has standalone logging. I wanted to use this instead of a laptop with serial cable (for wideband) for long datalogs. Given the wideband also has electric interference, I may never trust this either in a world where the serial wideband and the analog output wideband do not agree. Last time I did a trace I could see the two wideband traces follow each other, but one was a little leaner than the other. I plan on playing with voltage offsets and actually driving the thing to see how close they correlate. If they never correlate... then, well, maybe I'll never use either. Ideally I'd like to have the Analog wideband read ever so slightly leaner than the serial one, because the serial one is 'correct'. Tuning the car to be ever so slightly too-rich would be the aim. Not needing to have a laptop flying around in the footwell connected with cables is... an advantage. About the only one from the forced upgrade to MPVI3.

It was really refreshing though... but I also agree.

I should have prefaced all of this with "I'd really like to not pull anything out of the car for this"

Yeah - I tried throwing the formulas from ChatGPT and it tried it's best as it told me that the Formula in HPTuners as requested is a Linear function, but the original data I provided it (resistance to temp) is not linear and thus it kept trying to suggest formulas that would be more accurate in regions I actually want it to be accurate in. But I didn't quite understand it at the time. I have now thrown the data into graphs and can clearly see they're all different shapes. Given it's an oil temp sensor I probably want it to be most accurate between 80 and 120c - So I don't really see much alternative other than driving the hell out of the car and letting it cool down from 120C, noting the voltage on the sensor as it chills out. But at that point if I write it down, well, I'll be able to know this from the voltage. Would look pretty stupid on a datalog or a video showing me going down the straight at 0.265V Oil temp

So to further complicate things or hopefully explain better: This is a VDO sensor. It clearly does this math inside the gauge itself... because it displays a temperature in C to me instead of a voltage. The signal wire to the gauge is in Volts, not Ohms. I have just teed into this and sent it to the ECU. ChatGPT spat this out: Temperature (°C) Thermistor Resistance (Ω) Voltage Output (V) -40 36563.56 4.973962698 -35 26284.63 4.963854097 -30 19149 4.950518086 -25 14127.68 4.933166097 -20 10504.68 4.910527969 -15 7721.35 4.879055954 -10 5720.88 4.838133512 -5 4284.03 4.786165799 0 3240.18 4.721119717 5 2473.6 4.640900563 10 1905.87 4.543692515 15 1486.65 4.429695182 20 1168.64 4.296344225 25 926.71 4.144091368 30 739.98 3.972492431 35 594.9 3.782907287 40 481.53 3.577860996 45 392.57 3.361217186 50 322.17 3.136573398 55 266.19 2.908608143 60 221.17 2.68039363 65 184.72 2.455599277 70 155.29 2.239608872 75 131.38 2.035132288 80 112.08 1.846579676 85 96.4 1.674774149 90 82.96 1.511882199 95 71.44 1.359001674 100 61.92 1.222169588 105 54.01 1.100403407 110 47.24 0.989775394 115 41.42 0.889528391 120 36.51 0.800974069 125 32.38 0.723478416 130 28.81 0.654148313 135 25.7 0.591893137 140 23 0.536380597 145 20.68 0.487551867 150 18.59 0.442640126 155 16.74 0.40213318 160 15.11 0.365841848 165 13.66 0.333073247 170 12.38 0.303758956 175 11.25 0.277572169 180 10.24 0.253917873

Alright. Exhaust has been looked at, and booked in 'soon'. I'm not 100% convinced it's going to be as good as possible but I'm going to go with it anyway. If I get a reasonable thing that works for 10 years I mean that's twice as long as I've lived with the current one. I have a more pressing issue. I have fixed my MPVI3 (by buying a new one). Excellently, one can wire in analog 0-5v inputs to the ECU itself. I had wideband already via Serial so I also wired it in via the direct input. The idea being I can use the standalone logging without a laptop and have Wideband data in it. The other wire I thought I'd use oil temp. This is where I've gone crazy. HPTuners requires you to implement a formula so you know how much volts = how much temp. This seems relatively simple to me. However I cannot find the scale for this anywhere on the internet, nor decipher how to figure it out without removing the sensor from the car. All I know is that voltage actually goes up as temperature goes down. I am using the actual gauge, so I can see what the temp is. The signal wire has been branched off into the MPVI3. EXAMPLE: 2.68v = 58C 2.7 = 57C 2.74v = 56C 2.8V = 54C 3.06V = 49C 3.18V = 47C 3.37V = 43C I think the gauge is 50-150C. It may be more. It may be less, because I can't find it for the love of f**k. It appears all the information about the gauges I have has been scoured from the internet, but the sender is VDO 320.021 I believe the resistance chart is this How the f**k do I convert this to a voltage? Once I have a voltage... I then have to perform this transform of said voltage to show it in the scanner: https://www.hptuners.com/help/VCM-Scanner/Content/vcm_scanner/defining_a_transform.htm @GTSBoy you're probably my only hope here TEST YOUR MIGHT

My idle is set at 950rpm though - Moving the timing around 20 degrees is not really what I'd call a calm idle. That said... neither is chop, by definition. The LS ECU likes to adjust timing to hold idle as opposed to air. It'd work, but generally speaking there'd be a discrepancy in the base idle and the IACV would want to move the timing around anyway to maintain said idle. I think I'm just going to keep the timing steady anyway. Preserve my engine mounts. My aircon is now officially regassed. As the guy was reversing I noticed my reverse lights do not operate, along with my reverse cam. This is a bit distressing, because 100% of guides talk about which wire to connect to backup cams as "the goes with the [other color] wire". Often when doing conversions. Unfortunately the R34 colour wires aren't documented Unfortunately I had a T56 Magnum gearbox with it's reverse switch, which also isn't documented. Unfortunately there's definitely not documentation for people with both of these in the one car. Unfortunately I forgot. After many hours of this, I have a reverse cam and reverse lights again. The wire going through the trans tunnel to the reverse switch had broken. Upon inspection, it looks like this one wire had about 7 spade terminals and extensions in it.. for reasons I cannot possibly comprehend. I also spent the 750 hours required to clean up the wiring behind my head unit which now looks like this: This is a monumental improvement relative to what used to be there WRT triple gauges, head unit, traction control, wideband controller, and whatever the f**k OEM stuff still exists there in various states of connectivity/needed. Next step is to check in at the Exhaust shop to see/confirm how much clearance I have, to decide what mid mufflers or 'resonators' (which are just straight through, narrower mufflers) I can add and hopefully cut out a lot of exhaust leaks, pinhole, v-band or otherwise. But first step will be to 'take a look' before the next step.

Take this with a pinch of salt, it's from someone (me) who got annoyed with turbos entirely. I hated aftermarket lines. If I had the option to use hardlines with whatever turbo I had - I would use them, 10/10, 100% of the time. The only reason people go larger, heat resistent, shielded lines etc is because they have to. And yes they don't last forever. Even if you spend big bucks on all the best heat shielding money can buy, with the best heat resistant, fuel resistant, oil resistant, radiation resistant hose, they get stiff and break down and just don't last the way a metal pipe will.

Welp, you've got a long list of experiences right there. I'd say you're on the right path.

I know it's an entirely different engine, but I noticed practically 0 difference removing or adding 2x 3in (5inch body) 400cell cats (one in each bank) with regards to sound. So changing the cat to change drone I suspect will have very very, very, very, very, very very minimal impact.

Yuck. But it's kinda the same principle, moving timing around to make car run bad but sound good.... I went for a more spirited tuning drive to iron out a few things. Car no longer stalls, and it loved to dip RPM low when you clutch in. After tuning this (and the 4-5 tables that HPTuners/LS1 OEM ECU wants for idle air correction) it's now behaving somewhat normal. All expected because there's a new TB, new Intake manifold and that new TB which is 102mm vs 78... has an entirely different IAC passage which is smaller because ????? Unfortunately at this point I went to make further fine tuning changes to avoid it flaring up, you know... _tuning_ the HPTuners dongle died. Well to be more accurate - The USB cable died in a fashion that anyone who has ever charged a phone will recognize. After the app demanding I resync it 50 or so times (which all 'succeeded' but all failed) the device does not want to sync and I've logged a ticket with support to see if it's fixable. US Support said it was a 'storage issue' but after removing the SD card inside it and formatting it/fixing it the issue does persist. Unfortunately usually the fix is "Turn in your old dongle and pay $700 for the upgraded one" it's cheaper because I get some free licence credits I unfortunately don't need. However I'm 10 minutes down the road from HP Tuners AUS/VCM so at least I won't need to post it, and logged a new ticket for support over here. Definitely drives different. My SOTP dyno believes it's probably making 310-320kw instead of the 280 before. It scrambles for traction a little now whereas it previously different. It drives like a bigger cam car up top even though the cam is smaller, likely due to the cam not being advanced 6 degrees. The timing is deliberately low and the fuel is very rich so who knows if this will improve on the dyno. It may, imperceptably. Also funny is removing the pineapples definitely makes the car squat more and axle tramp less. So this behavior of having more top end, squatting more, and scrabbling for traction more makes me think = more power. But I could have just been sitting on the threshold of that kind of behavior before. Time will tell if my butt dyno is calibrated right. I need the exhaust leaks fixed before dyno tune for obvious AFR related reasons - I repositioned the pipes but I'm not confident it's fully sealed even if it is better. At least the car does drive around while I cannot tweak/tune it for now. And I have aircon again. medium success!

Nah, apparently the way to do it is just mess with how much timing the engine uses to try to correct idle. So it massively undershoots, then overshoots, then undershoots, then overshoots. So timing is going from 5deg to 45deg to 5 deg to 45deg. But I kinda prefer the car to not lurch around and have a dependable idle. Given it didn't idle for shit and stalled about 7 times on the way home, still yet to drive it for the 2nd time to see if it's fixed.

Alright. Many little things have been sorted and the car successfully drove home with an incredibly huge exhaust leak. Unsure if it's simply been awhile, but new heads and cam and intake sound f**kin awesome. It might only be me that notices it though, and it's hard to tell from a 15 minute gauntlet run home and attempting to bleed the radiator. Undertrays on, tools out, road brake pads in, idle un-f***ed, time to do some road tuning. From my commute around town it sounds and drives *really* nice (with a max of like 35% throttle). It'll go to a dyno for a proper before and after once the tune is more roughly dialled in. And @Dose Pipe Sutututu I did learn how to do a proper chop tune at idle. I did indeed even do it, but the car shaking around at idle from the driverr seat made me make it smooth again.. I feared for my engine mounts and clerances to engine bay jank. . After the exhaust is fixed I may mess around with it more. I'm just happy to have it drive around without bucking or stalling which is a WIP.

Dose is unaware just how much fun 145-150kw would be in a 2.5L NC MX5. It would be one of the most fun things to drive to ever grace SAU.

MR HAMMER has said his piece. Painted up to avoid Rusty Rusty. Actually lines up well. (i.e it lines up the same as the unmolested GTR guard). Turns out the GTR Strut brace does foul on the bonnet vents ever so slightly. May need a little bendy bendy if intended to keep using with a strut brace. So spacing it out to clear the FAST102 is not an option. Annoyingly, the bonnet vents also foul on the heater lines running over the engine. Given this engine does not EVER require a heater, a delete loop is going to be used. Don't worry, the defogger uses the AC. The heater is basically "Do not use the aircon and turn the fan on". It will still be effective, I promise.... once I get the system regassed... Will have to revisit with unvented bonnet I suppose, and suitable strut brace. There's plans to do this and other things tonight and bleed brakes (there was a weep) and put the bumper back on, and take Good Friday morning - Because troubleshooting on the side of the road limping it home at midnight tonight is ... not very smart.

I actually have a replacement bosch 4.9 (from mx5mania!) to replace my current 4.2 one when/if it dies. It did weird shit once so I pre-emptively got a new kit. I also do not remember where I put it after losing it for about 18 months. I think I left it in a brake box.. which left it with brake stuff. In any case no. I much like how the OEM sensors talk to OEM ecu with OEM wiring and don't actually know if what GTSBoy said is even possible.

I mean I can be OCD'y but this is really over the top. At that point why not just run a full wideband fuel controller? Especially if you run 3 widebands. The system works pretty well, which is trimming low load stuff to be within a few percent of the base map. Pre-engine _change_ the base map was only 1-2% off, depending on ambient temp, elevation, etc. Under load the LS is really very straightforward to tune, enough that a wideband closed loop would be overkill. If I really cared (and I hope I don't) I can always just go back to the MAF system the car actually came with. Which does all those nice calculations for me (temp, altitude, etc), now that you can buy 102mm MAF's that do not cause restrictions.

In the context of cam 'upgrader' I mean generally people who upgrade headers/cams - not my specific change. I mean it makes sense that if I had a bigger cam, I may get more false lean readings. So if I went smaller, I'd get less false lean readings. To a point where perhaps stock.. I'd have no false lean readings, according to the ECU. But I'm way richer than stock. My bigger than normal cam in the past also was giving false rich leanings. It's rather odd and doesn't add up or pass the pub test. Realistically what I want is the narrowbands to effectively work as closed loop fuel control and keep my AFR around 14.7 on light sections of the map. Which is of course the purpose of narrowband CL fuel control. So if I can change the switch points so the NB's target 14.7 (as read by my WB) then this should be fine. Haven't actually tested to see what the changed switchpoints actually result in - car needs to be in a position it can idle for awhile to do that. I suspect it will be a troublesome 15 min drive home with lots of stalling and way too rich/lean transient nightmare bucking away for that first drive at 2am or whevener it ends up being. Hopefully it's all tune-able. Realistically it should be. This is a very mild cam.

The previous switchover point was 501mv. The stock value is like ~360. They now were idling at about ~880. The thing is, most people get a false lean condition. I am getting false rich conditions. This isn't a quirk of terminology, most cam upgraders get awful fuel economy because the O2's read false lean and add fuel - Mine are attempting to aggressively subtract fuel.

So... the whole idea was to upgrade the power of the motor from stock. The motor I bought with the gearbox had 'some' stuff done to it in the past, but it wasn't as well thought out/what I had wanted to do. The stock heads typically are a big restriction on LS's and need porting to unlock quite a lot of power. You can then go a bit silly with aftermarket castings to get more, aftermarket intake manifolds for a little more, and then porting those for more. <- We are here. Nobody in Australia really goes down this path (for some reason). It might* make 3kw or something more than doing things the tried and true path for 10X the cost. So that's probably why - I wouldn't even recommend it to people, the money was and is likely better spent on just CNC'ing the stock heads and putting a 6.3L stroker kit in. I didn't want to go down the 'normal' path and then think: But if I'd just done a bit more - I could have had a slightly better result. I assumed the heads were running out of flow and it always annoyed me - Turns out the previous installer advanced the cam 6 degrees so this is likely why it was coming on earlier and running out of puff earlier than advertised. The body panels were just lack of planning/no information on this anywhere on the internet and the fact they came out different was annoying. From test fitting the guard it appears I could have gotten away with GTR guards only, but I got the bonnet and raisers and everything else as well for a pretty decent package deal.