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Just read through this, what a mess! It's one of the things that has put me off getting one of my cars turbo charged by a company to be honest! I have owned a couple of turbo mx5's but these were already proven working etc.
 

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Banish a little rust a day people
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Discussion Starter · #663 ·
Looking over some settings on the tune and I'm not sure some of them are right, opinions please just to check im not going mad -
In the ECU I'm sure I set the trigger angle to 282, measured with a light, before it went for tuning but they've set it to 280. It has a 36-1 protege wheel, the miataturbo below thread states the missing tooth is 80 degreed btdc, which would be 280 atdc, but the timing points are 3 degrees wide so as the ECU is set to trigger on the falling edge you would add 2 degrees making it 282 wouldnt you?

I dont have a timing light, and the person who helped me last time has covid atm.
 

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Discussion Starter · #664 · (Edited)
I'm back.

I wanted to focus on getting to the bottom of all the issues on the car and getting it actually working and MOT’d before posting again, and I’m now at that point (sort of).

To keep it relatively brief I found someone knowledgeable on the Mx5 Supercharged Facebook group who offered to help look over the map and correct a lot of the issues I was left with. It was a lot easier said than done, there were a lot of very obvious initial problems and oddities in the map which we corrected without much hassle but the main problems were that we couldn’t get the car idling right. AFRs were way to rich and fluctuating widely, and it had a bad misfire but no matter what we tried it wouldn’t improve. We spent probably 2 months of weekends trying to work this out assuming it was a physical issue with the car, and I ran all the checks I could think of:
  • I checked and corrected the incorrectly set base timing (as I referenced in my last post it was out, and why it was changed from what I set it as with a light I have no idea).
  • I checked the injector seals a number of times
  • tried new injectors
  • tested for vac leaks using a smoke machine I built
  • checked compression (all good, exactly the same across all cylinders and peak values the same as my mk2.5)
  • swapped the cam sensor
  • tried different spark plugs
  • tested HT leads
  • new coil pack
  • etc

None of these revealed the issue and we were at a loss, suspecting the ECU was faulty. Eventually we decided to look over some of the most basic settings on the tune and found 2 issues which were the cause of all the headache. The first - the wideband had been setup wrong in the ECU, the configuration for a different model had been used….. I loaded the right configuration, tweaked the fuel map and the AFRs immediately responded and could be bought inline to something sensible rather than throwing raw fuel out the exhaust. The random misfires were the result of an equally ridiculous error in the setup, the injector angles had been set to 65000 degrees…. no that wasn’t a typo, they had been set to sixty five thousand degrees…. correcting these to a much more sane 355 degrees as per the default recommended Speedunio values immediately solved the misfire. With these issues sorted and the car actually mappable it took very little time to generate some logs, tweak the map (the previous 18:1 AFRs in some places and off the scale rich in others not being partiality desirable), and repeat until we got it to where it needs to be.

After that I threw an MOT on it (no advisories) and made a few small setup tweaks such as adding a Dayco 89269 autotensioner, a heat shield for the underside of the charger just to be safe, and a slight revision to the intake setup as it was possible there was a slight restriction (which turned out not to be the case but it also improved the mounting so was worth it regardless for the £10 cost).

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Now the map wasnt so horrendous it was throwing raw fuel out the exhaust I wanted to refit the cat, but in the on going tale of discovering fresh incompetence related issues after struggling for 2 hours with the v bands I couldn’t manage it, so I decided to put it and the decat side by side and took some measurements. Not only has cat been made up to the wrong length, but it’s not even at the right angle.

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This is as close as it gets when things are rotated to be as close as possible (bolts wont go any tighter either, and the header is under significant strain to pull in to even that). So yeh, also need to find someone to fix that.

After a fairly long wait due to availability it then went for mapping somewhere competent. The first try looked pretty good, the fuel was dialed in slowly and we started really gentle and safe and it made 185hp/150whp but promptly blew the supercharger gasket out cutting the day short. I’ve wondered about this before as the plate for the outlet doesnt match the plate on the charger very well at all, it’s a design that could use significant improvement IMO. To correct this I added some material to the corners to give the gasket more surface to seal against, had the flange milled flat and returned two weeks later. After some tweaking it made 185bhp/150whp with 10psi peak boost… again. This obviously wasn’t right, with 260bhp/220whp the ball park figure that was expected. The tuner pulled up a dyno graph of a 1.8 mk1 with an M45 kit on it and things started looking even stranger. Compared to the M45 mk1 it was making about 30hp less in the low rpm range at 3 psi more pressure. Something wasn’t right, we checked for leaks again and found none, the belt wasn’t slipping, and given it will make 10psi we are confident the charger isnt to blame (confirmed with another visual check of the blades and housing).

I again had to wait weeks for availability (a good sign the tuner is reputable I guess) and had a diagnostic run down with another compression test and a leak down test. Results were <4%, 2%, 0%, 0% leak down and 175psi hot compression identically across all cylinders which are all well within a healthy range.

I am now at a total loss. The car is making boost, there are no leaks, the engine is healthy, the timing is fine, the crank key hasn’t slipped, adding timing on the dyno makes no difference, we took some logs with the charger disconnected (2” IC pipe and IC still connected so a little restrictive for NA) and virtual dyno estimates it’s making about 90-105whp which seems about right, it idles and drives around sweet, it’s just about 50-70whp away from where it’s meant to be.

This is a bummer, I have no idea why it’s so down on power. I’ve spoken to a tonne of people both online and at a few shows (Skuzzle, Aran Large, Chaps, etc) and everyone seems to be in agreement that everything should be fine and we can think of no reason why it’s not making the power. Someone at Japfest suggested it might be spark blowout and that they had similar with no sign of breakup, that it just also didn’t make the power and a set of COPs solved it. It seems unlikely to me this would be the case with no symptoms of hesitation, misfire, or reflected in the AFRs and I don’t want to spend the £200-300 just to test.

Any or all suggestions welcome.

In the meantime I’m shifting focus onto the track car for a short time as it’s now on the road, needs the odd touch up maintenance item, and that damn 2860r installing that’s been decorating my shelf for the last year. It looks like the blue NB will probably now sit in the garage for a bit as something mustn’t be right with it, although the engine checking out healthy does make me wonder whether I could use it safely

Just for my records the Celica had an oil and filter change at 130467 miles.
 
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layabout
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the injector angles had been set to 65000 degrees
o_O

W⚓'s

:rolleyes:


After some tweaking it made 185bhp/150whp with 10psi peak boost… again. This obviously wasn’t right, with 260bhp/220whp the ball park figure that was expected. The tuner pulled up a dyno graph of a 1.8 mk1 with an M45 kit on it and things started looking even stranger. Compared to the M45 mk1 it was making about 30hp less in the low rpm range at 3 psi more pressure. Something wasn’t right, we checked for leaks again and found none, the belt wasn’t slipping, and given it will make 10psi we are confident the charger isnt to blame
cam / cam / crank timing?

Rich.
 

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Banish a little rust a day people
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Discussion Starter · #666 ·
o_O

W⚓'s

:rolleyes:




cam / cam / crank timing?

Rich.
I dont think so. It starts, idles and drives too smoothly. Disconnecting the charger so it's running without FI also nets virtual dyno figures of about 100whp, and previous logs of a virtual dyno plot with the supercharger are within 2hp of the actual dyno plot so it seems pretty accurate and im inclined to believe it.

I did pull things apart to check the timig and it all looked totally fine. The only thing I am going to double check is whether the exhaust cam gear has been rotated 120 degrees and is locating the pin on the wrong groove as I did take it out to do the oil seal. But I'd of thought I'd of noticed if it'd jumped by that much and it being a full 3rd of a rotation off wouldnt allow the car to start or run at all.
 

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Discussion Starter · #667 ·
Done the final checks on the supercharged car:
  • A maximum of 1 degree ECU timing latency between idle and 6k rpm was found, no where near enough to explain the lack of power.
  • Pre-charger intake restriction was measured at under 1psi at 6k rpm.

At a total loss as to what's going on.
 

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Discussion Starter · #668 · (Edited)
After some messing about with timing I've got the NB up to 175whp/210bhp. It's still dropping boost at the top end though. I make 11psi peak boost 3500rpm to 4000rpm, but it then tapers away to 8.8psi. I thought this might be intake restriction from the flexible hose and "space optimised, not flow optimised" supercharger inlet so I remade them both. This wasnt an easy task due to space constraints, in fact it was so difficult and needed to be so precise I made a jig for it. Looks ropey AF but it worked so well I didn't even need to adjust the 2nd throttle body cable.

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These should allow a far smoother transition into the charger and avoid a lot of poor overlap of the previous iteration. However this doesnt appear to have helped at all. Boost is still dropping near redline and the top end is flatter than it should be. A friends 1.6l M45 makes 120hp by 4500rpm, I'm making this by 4000rpm, but after 5000rpm he's making more power. I don't know whether this is due to a restriction of some form, efficiency of the charger at higher rpm (1.94:1 pulley ratio), or that my car with a decat and 4-1 header is breathing better at the top end causing boost to fall and the lack of power is due to poor timing. This seems unlikely though as the spark table appears a little aggressive here if anything.

The last dyno session is booked for the 14th, i'll let them sort the map properly and then I'll do some testing with no intake to see if it makes any difference. If it is intake restrction though I am at the limit of what I can do with the space so wont be able to change anything further. The car doesnt feel fast, but I recorded some pulls yesterday, just mashing the pedal in 4th at 2500rpm the car clears 40-70mph in 3.2s, and doing the same in 3rd it clears 20-60mph in 4.5s so it's does have some pace to it.

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(VD was accurate to within 2hp of the dyno I used, pulls have been done on flat road and I've consistently done them in the same place, I know absolute numbers aren't important but this is still relevant for comparing the shape of the graphs).

The boost graph starts to flatten near redline rather than continue to drop, it's almost like the 11psi peak is higher than it should be. It's all pretty odd. Does anyone know where VICs comes in? I wonder if that's a factor? I duno how Speedunio controls it (if it even does).
I know roots chargers arent meant to be great when spun at higher rpm so any comments from someone wiser than I am about the M62 efficiency maps are also welcome.
 
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Discussion Starter · #670 ·

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A friends 1.6l
ah, do some reserch google as the 1.6L is more efficient with comparable sized superchargers than 1.8L - something to do with swept volume iirc :unsure:

as to loosing boost @ hogher speeds, that sounds like the engine wants more than can be supplied, is there less of a restriction in the head / manifolding? (also, fi like less cam 'overlap' and even less exhaust cam to increase cylinder filling - or something😜)

Rich.
 

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Discussion Starter · #672 ·
ah, do some reserch google as the 1.6L is more efficient with comparable sized superchargers than 1.8L - something to do with swept volume iirc :unsure:

as to loosing boost @ hogher speeds, that sounds like theengine wants more than can be supplied, is there less of a restriction in the head / manifolding? (also, fi like less cam 'overlap' and even less exhaust cam to increase cylinder filling - or something😜)

Rich.
Yeh it might be related to that. It's odd it makes 11psi so low down, and that it tapers off pretty quickly before starting to level.
 
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Discussion Starter · #674 ·
Do you have any non return valves that could be failing at all, mine was a 1.6 and I had one on the idle valve, they can flutter and you’ll lose boost.
Not that I know of. I boost leak tested it to 14psi and it it held fine.
 
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Discussion Starter · #675 · (Edited)
I've been trying to find somewhere to do my clutch in the NBFL for the last few months but no one could be arsed as apparently easy work like servicing and brakes are all most places will do (was literally told this by 3 places), or no one will work on a car over 10 years old now. However, I managed to get booked in at Totalmx5repair fairly last minute and spent the day there. Not ideal that I had to travel to a different country to find someone to do it for me but I'm glad I went. Super impressed with the level of service, so much extra care went into things like ensuring all the threads were clean and wouldnt bind before bolting anything back in, ensuring the ppf was lined up, all the wiring was tucked away properly, etc, and I was allowed to help and learn how to do it. I cannot recommend them strongly enough. I'm glad I didn't try and do it myself on stands, it would have been an absolute nightmare due to space, visibility, leverage etc but Mark made it look easy. It was also nice to finally put a face to the name as Mark and I used to chat on here a while back.

So yeh, a nice bofi clutch is now in place ready to hold turbo power, just a midpipe to fabricate then I can start. I also finally put in the Mk2 RS 6 speed with 60,000 miles on it, I've only had it like 6 years now lol. I really do prefer the gearing on the 6 speeds, 1st is short but the spacing and ratios of 3rd through 6th make so much more sense to me and feel a lot better. I was able to transfer my short shifter into the 6 speed box (originally adapted from a mk1 5 speed kit) and I cannot tell any difference in shifting feel between it and the 5 speed except that the 6 speed isnt as keen to go into reverse so really happy with that

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.
 

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Discussion Starter · #676 · (Edited)
Annnnd the NB is "done". Final tune finished today, 209hp and 196ftlbs which is what I'd expect based on some feedback from people with 70mm and 65mm pulleys (mines 67mm). It doesnt feel silly fast or anything, it just feels effortless and drives really nicely. I still have the occasional very rare misfire which I need to look into, and my idle is a little high and not quite as smooth as OE but overall pretty happy. I do really need to quieten down the exhaust though so I can actually hear the charger.

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Discussion Starter · #678 ·
Cheers. Need to quieten the exhaust, coilovers, the 1000psi booster, and an ATI damper to protect the keyway and then it's done performance wise.
 

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Annnnd the NB is "done". Final tune finished today, 209hp and 196ftlbs which is what I'd expect based on some feedback from people with 70mm and 65mm pulleys (mines 67mm). It doesnt feel silly fast or anything, it just feels effortless and drives really nicely. I still have the occasional very rare misfire which I need to look into, and my idle is a little high and not quite as smooth as OE but overall pretty happy. I do really need to quieten down the exhaust though so I can actually hear the charger.

View attachment 60179

That is a loud exhaust!

Looks good though good work!
 

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Discussion Starter · #680 ·
Just one for my records really but there's some narrative below to amuse anyone who wants to read it.

I've owned the celica for about 4 years now and the rear discs were pretty ropey looking when I got it and they've not been changed in my ownership. Well the other day they started making a pretty horrendous noise, so I looked over the pads and couldn't see anything wrong, in fact they had over half wear left on them so left them and thought nothing of it. However, something bugged me about it and it wasn't until the next day that I realised what it was, that the pads had basically the same wear when I got the car. I know I've only put 20k on the car but it still didn't seem right so I pulled the wheels off to check properly and found one inside pads worn down the the metal. More worrying was all the other pads were totally fine, the cause of which was evident when I inspected the pistons..... yep, all totally seized right into the bores. I could not be arsed to mess about rebuilding the calipers and tbh I'm not even sure if they could have been saved so have just installed 2 brand new ones with new pads and discs. I coated the calipers in POR15 as they are new and spotless so it should help protect them (rated to 230C apparently). Unsurprisingly now I have 4 working calipers and not 2 1/2 my brakes are significantly better.

Fluid was bled at all corners - 131000 miles.

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