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To burn the fuel needs oxygen, at full chat and perhaps 9:1 afr you have used all the oxygen in combustion and have water carbon dioxide and a few toxic pollutants plus the excess fuel so the fuel can't burn. In your case you were missfiring and pumping both fuel and air in, you basically had combustion in the exhaust rather than the cylinder. Misfires are one of the easiest ways to damage a catalyst.
Its a while since I worked on catalyst development but i think the basics are still the same, you have a basic ceramic brick which is coated in a rough oxide washcoat surface layer which under a microscope looks a bit like a scourer pad. This washcoat acts as the carrier for the precious metals platinum, paladium etc. which on turn are the catalysts for the chemical reactions which clean up the gases. The washcoat massively increases the surface area so there is more area to react with the passing gas and therefore clean up the exhaust. I suspect you have damaged the washcoat, from memory this starts around 900 deg C which is also when steel starts to glow bright red.
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Last Edit: Apr 14, 2020 12:43:07 GMT by kevins
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gryphon
Club Retro Rides Member
Posts: 330 
Club RR Member Number: 157
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To burn the fuel needs oxygen Oh so it does. It all fell into place after 6 words!
Really interesting info, thank you. I was indeed chucking fuel and air into my catalyst, and the steel casing was giving off quite a glow at one point so I imagine the insides were a fair bit hotter again. |
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gryphon
Club Retro Rides Member
Posts: 330
Club RR Member Number: 157
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Apr 13, 2020 22:13:43 GMT
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I'm really lucky in that I can work from home through this lockdown which means I should have extra time for projects and the like, especially with the long evenings! In reality it seems to leave me totally drained of energy though, and I find myself sitting in my 'office' (spare bedroom) after work watching 4 or 5 episodes of M*A*S*H without any will to do anything at all.
Thankfully Easter weekend has woken me up a little bit though, and we took advantage of the weather to get on with some painting on my girlfriends Honda Benly she's been restoring. As you might have seen earlier in this thread painting isn't a strong point for me... Functional, yes; Pretty, no! I was pretty happy that I started to get some good results over the weekend though. Lots and lots of sanding and getting a feeling for how thick to apply the paint - So I'll just leave one of the side pods here. Still needs a final sand and polish once the lacquer has fully cured.
On the Sunday morning while we were waiting for the day to warm up for more painting we had a wheel cleaning session. The superleggeras were clean, but covered in tar spots:
Somehow the camera hides most of them. Out with the Tar Remover, and I sat there for hours cleaning them! Why did I ever think 12 spoke alloys were a good idea?! Once they were all de-tarred I gave them a coat of collinite 845 (those 5 spoke Enkeis are looking better and better...) and buffed them down. Huge improvement.
You get to know things very well when cleaning them. I have two very nice wheels. I have one wheel with a very slight flat spot in it, and I have one wheel that's been repaired in the past, the details of which are hidden under the powdercoating so I'll keep an eye on it. They've all been recently powderoated to a pretty good finish, but it's softened all the text around the rim - I was aware of that last bit before buying them though.
With the wind today ruling out more painting (as well as getting low on paint) today was an MX5 day. Other than emissions, the only other note on the MOT was that I was missing a split pin in a track rod end. The tester liked the engine swap though, and was complimentary about how solid the car still was underneath.
As I can't go out to get a split pin and couldn't find any I rummaged around the garage and found a length of stainless steel from a windscreen wiper blade that was about the right width. A few minutes later:
It's a bit sad to include a picture of a home made split pin, but I was pretty happy with the result - it came out better than expected.
Next on my list of to-dos for the day was to see if the old undertray would fit to try and keep the engine bay a little cleaner. No doubt I'll curse it every time I need to take it off again, but it feels like something I should put on.
Bingo! It actually took a fair bit of faffing re tapping bolt holes and finding the plastic screw clips, but it did fit. It also holds and protects the low coolant and power steering hoses.
Next up was another black plastic addition:
Spotted it?
One front splitter. Fitment isn't amazing, and it took ages to get it as good as it is, but I much prefer the look with it on. The front bumper ends about an inch or so higher than the sills - this levels the car off a bit. Should looks better again once I've re-done the bottom of the wings and sills in black to match.
Last job for the day was looking at the headlights. I like the pop up lights, and while the novelty has worn off a little after 5 years of 944 ownership, the biggest issue is that the lights on 944 are far better placed than on the MX5. From the driver seat in the 944 you see the top inch or so of the lights appear over the bonnet as you turn them on. I don't have a picture from the drivers seat, but this gives you an idea:
By comparison the MX5 lights are very up and in your face... In the long term I'd really like to try and fit some small LED projectors in the existing bumper mounted side lights/indicators, but that's going to take a while to do right. The smallest aftermarket LED projectors that are readily available are 2.5" which is still a little too big. There are smaller projectors in the headlights of cars coming out at the moment - the new F-Type lights look promising but I've no chance of affording a pair of those to cut up... but I'm digressing a bit. A nearer term solution is to put some 6"x4" rectangular H4 lights, and a while ago I bought a second hand Jass Performance kit with a pair of Hella lights to do just that.
I made a start on dismantling one of the lights to fit the new one, only to find that the second hand kit I'd bought is missing a few crucial pieces. In order to reduce the height the light rises to you need a shorter rotating arm from the motor (just visible at the bottom of the picture) and to relocate the connection point on the light a corresponding amount further back... and I am missing all the parts to do it! This job just got a fair bit longer.
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Last Edit: Apr 29, 2020 8:19:36 GMT by gryphon
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gryphon
Club Retro Rides Member
Posts: 330
Club RR Member Number: 157
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Fixed the pictures  |
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gryphon
Club Retro Rides Member
Posts: 330
Club RR Member Number: 157
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Apr 15, 2020 11:17:43 GMT
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More bits and bobs... When the engine was getting rather hot I was getting a lot of what looked like steam from the radiator - and I had seen exactly the same in the previous radiator. To see if I had a pinhole leak in the radiator I borrowed a coolant pressure tester and pumped the coolant loop up to 16PSI (That's when the pressure relief valve would activate) and left it pressurised.  40 minutes later it had dropped 0.5 PSI and there was no sign of wetness on the radiator or on any of the joins... So hopefully I'm ok on that front! Now while I've got the tester I need to diagnose the never ending coolant leak on the 944...
The soft top has some stitching that has been slowly (or not so slowly) unstitching itself. Unfortunately it's white contrast stitching, so very visible, and I was going to get it done professionally as I don't think I'll be able to do a great job of it. Unfortunately the 'hole' is getting bigger and bigger and I need to do something about it as when it rains it now lets quite a lot of water in. So, I found by biggest needle and doubled up the best thread I could find... and made a right dogs dinner of it!
This stitching holds two layers of material plus the zip for the window in place... none of which seem to want to line up.
So the end result was... The aforementioned dogs dinner - so I stopped there and will either give it another shot or get it done by someone a little better than me!
Next job was the headlights... While I work out hows best to sort the hella lights I put the original one back together and spent some time aligning the light covers: Loosen off the 4 bolts, add some masking tape tabs so you can pull them up easily with the bonnet closed and spend ages aligning and bending them back into shape. It's so easy to lean on them when the bonnet is open and bend them out of shape. Didn't get them perfect, but was pretty happy with the end result: |
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Apr 15, 2020 12:05:42 GMT
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splitter makes a big improvement on the front end.
And that is a very nice split pin, be proud.
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goldnrust
West Midlands
Minimalist
Posts: 1,887
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Apr 15, 2020 12:13:13 GMT
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Liking the new splitter. When I was but a lad in my early 20s and owning an mx5, I was all about the Garage Vary type lip, but as an older and wiser gent in his 30s, I think think the factory style splitter is much better, even on a heavily modified car.
I believe they designed the car to come with the factory splitter, but then left it off as a cost saving? Either that or I've just perpetuated a myth...
With the sewing repair, I feel your pain as I've spent the last few days trying to repair my seat covers by hand and struggling to get neat even stitches. Though my stitching isn't going to be as 'on show' as yours, it will show it's inconsistency as wibbly wobbly seams. It looks like you're getting neater. and straighter with every stitch? So maybe just some more practice?
Presuming you haven't already done this, I suggest releasing the roof tension by popping the clamps off at the front. Normally I'd suggest pinning the pieces would help, but I presume you don't wanna do that for the risk of putting hols in your roof! Could you clamp the pieces together somehow? Finally chalk lines along the line you wish to sew helps keep things straight.
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Last Edit: Apr 15, 2020 12:14:09 GMT by goldnrust
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Apr 15, 2020 13:39:06 GMT
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Great thread👍 I'm running a AJ30 in my kit car,coupled to a RX8 6 speed gearbox. Really pleased with the engine👌 I'm running a ST200 mondeo upper inlet manifold,mated to the AJ30 lower with some alloy spacer plates I've made. Running MS ECU using a Mondeo wasted spark coil pack with custom leads. We've altered the VVT on and off points,as the standard Jag VVT came on at 5200rpm,and stayed on to the rev limter.This actually reduced the engines power output at higher revs! Mine now comes on at 1800rpm,and goes off at 5800rpm. Power is still climbing at the 7100rpm rev limiter and it made 286bhp😎 I'd like to see more on your car coskev, have you got a build thread anywhere? |
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gryphon
Club Retro Rides Member
Posts: 330
Club RR Member Number: 157
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Apr 15, 2020 17:38:36 GMT
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splitter makes a big improvement on the front end. And that is a very nice split pin, be proud. Thanks. I tried to make a second one today... looked terrible! Must have been beginners luck. Liking the new splitter. When I was but a lad in my early 20s and owning an mx5, I was all about the Garage Vary type lip, but as an older and wiser gent in his 30s, I think think the factory style splitter is much better, even on a heavily modified car. I believe they designed the car to come with the factory splitter, but then left it off as a cost saving? Either that or I've just perpetuated a myth... With the sewing repair, I feel your pain as I've spent the last few days trying to repair my seat covers by hand and struggling to get neat even stitches. Though my stitching isn't going to be as 'on show' as yours, it will show it's inconsistency as wibbly wobbly seams. It looks like you're getting neater. and straighter with every stitch? So maybe just some more practice? Presuming you haven't already done this, I suggest releasing the roof tension by popping the clamps off at the front. Normally I'd suggest pinning the pieces would help, but I presume you don't wanna do that for the risk of putting hols in your roof! Could you clamp the pieces together somehow? Finally chalk lines along the line you wish to sew helps keep things straight. I've never really liked the GV splitters. They're certainly more of a nod towards an actual functional splitter... But I much prefer the OE one too. Hadn't heard that bit of trivia/myth before but it would make sense given that the factory bumper finishes higher than the rest of the car. I don't envy you the seat covers! I had de-tensioned the roof, and the old stitches had left a guide that I could kinda follow, but coming back up from underneath through three layers of material it was really difficult to come out in the right place. Each stitch ended up as the closest of about 3 attempts. It was too thick with not enough free movement to pin properly so I pinned vertically through and tried to use them as guides for where the needle needed to come back out with some success - that's where it got neater. Looking forward to seeing your seats - your thread's bookmarked, I just don't generally have much to add Great thread👍 I'm running a AJ30 in my kit car,coupled to a RX8 6 speed gearbox. Really pleased with the engine👌 ... I'd like to see more on your car coskev, have you got a build thread anywhere? I think found it when he posted here, but I can't seem to find it again... Seem to remember it was on the locostbuilders forum. Here's one with engine content, not CosKev's though. www.locostbuilders.co.uk/viewthread.php?tid=214370 |
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gryphon
Club Retro Rides Member
Posts: 330
Club RR Member Number: 157
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Apr 22, 2020 21:41:44 GMT
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Thanks to goldnrust 's seats and petervdv who reminded me that an awl was the right tool for my soft top stitching (Thank you both!) and there was plenty of choice on eBay - one arrived a few days later with some white waxed thread and I took a trail run at a few stitches on the other side of the soft top that had come loose: Other than a slight thread mismatch, much better! The awl arrived with a pre-aged affect on the wood too.... End result and after rubbing a slightly grubby thumb over the threads to take the brightness out of the white: Definitely happier with that (other than the top stitch) - lets tackle the big section! I picked out my last attempt and had a go with the awl: That'll do nicely. Ideally the thread would be a little thinner, but once it's aged a little I think it will blend in ok - and having a heavier thread in what is apparently the heavier wear area right where it bends as it folds down can't be a bad thing. It did take me a little while to get the hang of the awl, keeping enough loose thread around it to push through with it etc, but the biggest was really making sure I pulled each stitch tight. Near the end of the long section I realised I had a loose stitch half way up so spent a while pulling it through a stitch at a time to tighten it all properly. That done I turned my attention to some other cosmetic bits at the rear. Both the rear numberplate panel and bumper had some poorly painted or scratched areas that will need some proper attention at some point, but for now I rolled on some paint with a cotton bud and the results were pretty good. Once it's dry I'll give it a sand, probably a couple more layers in the scratched areas and a polish but it's made an excellent 2 meter difference (or maybe I'm just colourblind... In which case it looks better to me at least ) Before: After: Not too shabby, although a shame it all looks very pink again! Also did the door edges and a few other little chips, and took the mazda security stickers off the windows too. On a slightly more oily note, I've finally got around to replacing the jubilee clips on all my fuel lines for proper hose clamps: I say proper hose clamps... The design is right, but they seem a little bendy as I tightened them up, so I may not have spent enough money on them. Disappointingly the end of some of the fuel pipe was already cracking - only on the fuel pipe supplied with the kit, the Gates pipe I bought was still good thankfully - but I don't have enough spare to replace the cracking pipe right now so I cut it down to un cracked pipe before reattaching it. I also finally bought a battery for the mx5 so I can give the other one back to the 944. This one fits in a plastic battery tray and the vent is piped to outside the car so hopefully the rust that I ground off the battery tray won't come back too fast... Finally I've been playing with the electronics a little. I had previously been told that the ECU didn't follow any OBD standards or put out any standard CAN data... Turns out they didn't know their own ECU particularly well. First up I checked the CAN wires with an oscilloscope and saw that they were busy outputting CAN data so figured I'd plug in a standard bluetooth ELM327 OBD adapter... and hey presto! ^Need to sort out a proper J1969 connector...
I had a suspicion that it might work - the ECU is made by MBE who supply a few UK low volume automotive manufacturers which means they make ECUs with the legally required diagnostics, and the Rocketeer is an A9Ab, which looks to be a variant of their top end ECU... so the can coming out in the standard J1939 format wasn't too surprising, I was impressed that it also has standard self diagnostics though.
So Torque app on my phone, connected to the bluetooth and I could get some nice information:
The first screen is all the good information that I can see from the ECU - although the actual numbers there are mostly junk as the screenshot was after an engine shutdown.
The graph is the engine RPM at idle. Every now and again - both when idling and under power - there is a split second cut out. When idling it normally catches itself as the graph above shows, sometimes stalls. I was hoping to get some ideas from the data of what was causing it. That I got a continuous data stream through it rules out the power being cut to the ECU. As the RPM didn't drop to zero it might rule out the crank sensor having a momentary drop out, although that could also just be signal smoothing. The cut out is very abrupt and recovers as quickly and I haven't found a trigger for it yet... Doesn't seem to be getting worse though so I have time to diagnose it.
The last screen is the DTCs... I was impressed the ECU responded to the diagnostic scan, but only two of those codes relate to things the ECU actually has plugged into it. (I did clear and re scan a couple of times to make sure I had active DTCs). The two possibly relevant ones are the Injector 2 error, and the cooling fan error. The cooling fan definitely doesn't work and I haven't worked out why yet. Injector 2 might be worth taking a look at to see if the code has any rationale behind it or if it's another spurious one. Another point to investigate is that the AFR jumps between 0 and a reading that looks rich every 0.5 seconds, not sure why!
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Last Edit: Apr 23, 2020 6:58:46 GMT by gryphon
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Apr 24, 2020 16:57:46 GMT
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Great thread👍 I'm running a AJ30 in my kit car,coupled to a RX8 6 speed gearbox. Really pleased with the engine👌 I'm running a ST200 mondeo upper inlet manifold,mated to the AJ30 lower with some alloy spacer plates I've made. Running MS ECU using a Mondeo wasted spark coil pack with custom leads. We've altered the VVT on and off points,as the standard Jag VVT came on at 5200rpm,and stayed on to the rev limter.This actually reduced the engines power output at higher revs! Mine now comes on at 1800rpm,and goes off at 5800rpm. Power is still climbing at the 7100rpm rev limiter and it made 286bhp😎 I'd like to see more on your car coskev, have you got a build thread anywhere? Hi I haven't got a thread anywhere tbf,got loads of pics on my phone. Should do a thread really. I would do one now if I was furloughed but actually working more atm!🤦♂️ |
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gryphon
Club Retro Rides Member
Posts: 330
Club RR Member Number: 157
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Apr 29, 2020 12:23:58 GMT
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When I put the front suspension back together I put the tie rod ends back to as close to their old positions as I could, and set all the eccentric bolts to their mid positions - not that that really achieves anything. Unsurprisingly the car didn't go in a particularly straight line, and the steering wheel was far from straight (Steering wheel was fitted so that 12 o'clock is mid point on the rack). The plan was MOT, then straight to a hunter rig for some fast road geo settings... As this isn't happening particularly fast I figured I'd take a shot at improving things with some string.
The idea is to get perfectly parallel strings down each side of the car, then centre them around the car by measuring from the centre of each wheel to the strings. Once the strings are central around the car you can measure the distance from the front and rear of each rim to the string to get a decent idea of which way the wheels are all pointing. Previously I've done this with heavier string and needed wights at each end to hold it taught etc... This time I bought a roll of cheap 0.2mm bright pink fishing line to try and it's excellent for it. It has a decent bit of stretch to it and the weight of the axle stands is enough to pull it a little stretched and taught, no getting caught in the wind, and very accurate for measuring with the ruler.
First off I measured where the wheels were with the steering wheel straight ahead.
Rear Right: 1mm toe in Rear Left: 2.5mm toe out Front Right: 15.5 toe in (Very visible to the eye) Front Left: 1mm toe in.
Due to doing it on the ground the eccentric bolts are difficult to get to and I'll leave the rear as it is for the short time until I can get it to a hunter rig. The front on the other hand could obviously do with some improvement. I adjusted the front right to 1mm toe in on the track rod and the car drives much better for it, although the steering wheel is still points right a little. Ideally the adjustment would have been made with the tyre on a low friction surface. I could have lifted the car or rolled it backwards and forwards to neutralise the tyres but then I'd have had to spend a while re-setting the strings each time and I only wanted a quick improvement.
I also spent more time looking at the ECU and trying to work out if there was a reason other than the cat that my emissions weren't great. What I found was one very suspect O2 sensor, unsurprisingly on the bank that had been cooked. When the O2 sensors are first started the controller takes a few seconds to heat up the heating element and gives out a reading of about 1v while this is happening. Once it's up to temperature it switches to reporting the sensor output. What you can see in the graph below is both O2 sensors getting up to temperature then switching to sensor readings with the engine off... One is not like the other!
 
I'm going to go out on a limb and say that Sensor 1 is a little dodgy - after flirting with 0v a couple of times it gives a dead straight line at its maximum output voltage forever. Happily as the old engine in this car had been supercharged with an aftermarket ECU before I bought it, I had a spare wideband sensor to chuck in. That done, the engine sounded noticeably better and the O2 graphs looked far more realistic.
The really good news? This done, the car just squeaked through a (safely socially distanced) MOT emissions test  Clean sheet, zero advisories.
Now I can drive it!! For the essential shopping runs 5 min down the road 
First impressions on the road - power is good, noise is great but a little too loud, the diff sounds pretty grouchy - I've got oil for it, not got round to changing it yet though - and there are a fair few knocks and noises to work out. The mx5 gear ratios are too high - 3.5k @ 70mph is not pleasant, especially with the current exhaust. After some damping rate tweaks to the coilovers the ride is actually pretty impressive for an mx5 and much better than I was expecting from HSD coilovers and cheap polybushes. It definitely helped to have a vehicle dynamics engineer (girlfriend) in the car for the damper tweaks, got it pretty much nailed over a couple of miles on the way back from the MOT. |
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eurogranada
Europe
To tinker or not to tinker, that is the question...
Posts: 2,556
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Apr 29, 2020 14:50:11 GMT
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Well done! Good news for sure!
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gryphon
Club Retro Rides Member
Posts: 330
Club RR Member Number: 157
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Didn't take very long at all for the noise from the back (my presumed grouchy diff) to get rather bad... The car's done about 30 miles with the new engine!
When everything's cold, the only time it's noisy is pulling away while turning. When hot it's anything below ~20mph with low torque. accelerating is ok, just pootling back to the house trying to keep the exhaust noise down results in a loud CLACK CLACK CLACK. Didn't seem to be gear related but I have been trying to diagnose it without any non-essential driving and I don't trust it for the occasional commute. Probably related it feels like there is a lot of lash in the drivetrain - a poorly rev matched shift results in a clack and some jerking. The really odd bit is that under load and at speed it sounds and feels spot on. A 0-60 pull sounded absolutely fine. (6.7s with a late start and two fluffed gear changes... I was on form!  )
A first peek under the car revealed what I thought was far too much play through the rear diff - Gearbox in neutral, handbrake on, the prop shaft has a lot of free play in it:
For reference, that bolt head is 14mm.
Ooh, got gifs working 
There was no detectable play in the driveshafts, so I figure all that play is in the differential... Which is annoying because the Torsen diff was a big contributing factor to be buying this car in the first place! However, googling it the diff looks quite rebuildable (not the torsen innards, just the CROWN and pinion), and I could take the opportunity to swap in a 3.6:1 ratio CROWN and pinion - which it turns out are quite difficult to get hold of because they were sold on Europe spec cars and all the breakers ship any they get straight out to the States where they are very sought after!
So gathering parts and some specific tools for the diff rebuild will take a while - but there is an open diff for sale very locally for £30. Seemed a no brainer to pick that up, and fit that. It keeps the car on the road and cheaply verifies if the problem is actually with the differential.
I was about to swap them out this evening, when I noticed that the oil seals on the new diff have been damaged... so the cost of the diff just doubled and some new seals are in the post!
I went ahead and removed my old diff anyway to see what I could find.
Top bolt out of the rear uprights and pull them out to get the driveshafts (mostly) out of the differential:
I didn't do very well on pictures, but exhaust off and rear chassis brace off, prop shaft off, and PPF unbolted from and 'inserts' hammered out to allow it to separate from the differential. A bit of wobbling and it dropped out easily enough.
Once out I cracked it open and got it on the bench... and couldn't find any of the play that I expected to!
In fact everything I can see looks pretty healthy... Backlash was barely detectable by hand, and there was no play I could feel in the output splines.
Checking backlash with the dial gauge gave me readings between 0.08mm and 0.13mm, checking it at multiple points on the CROWN wheel. Spec is 0.09-0.11mm.
Using two needle nose pliers held open I can get a decent grip on the output splines, but can't feel any play in the internals. The splines look good, as do the mating ones on the driveshafts... so I'm stumped!
I'll put the open diff back in anyway to see if there's any difference, and (assuming there isn't) hopefully find a 3.6:1 CROWN and pinion to rebuild the torsen core with...
I'm really not sure where all the movement on the prop shaft going into the diff came from, it felt more than the sum of what I've found! One thing I did note was that the play between the prop and differential was quiet - none of the noise I had been hearing. The play into the gearbox on the other hand sounded eerily familliar - although there was far less movement. I'm thinking that the noise I'm hearing is somehow caused by the propshaft 'vibrating' at low loads, and the noise itself is actually from the gearbox.
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It's not aged failing mounts is it? Diff carrier or gearbox?
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gryphon
Club Retro Rides Member
Posts: 330
Club RR Member Number: 157
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Nope, diff mounts are relatively new polybush, engine mounts are brand new... (Gearbox doesn't have any mounts of its own)
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Thanks for all the updates...the diff backlash is certainly a problem. I have an MX 2.5 S-VT and it had a noisy 6 speed gearbox but it got quieter as you went up through the box...Swapped it for a much better one now though.
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goldnrust
West Midlands
Minimalist
Posts: 1,887
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Shame to be having the drivel one issues so soon after swapping the engine in, hope you get to the bottom of it soon. Regarding the amount of pinion backlash, I've noticed a similar situation on some other diffs I've owned, notably the diff from Spitfire recently. I also noticed what seemed like a lot of backlash at the pinion, but them pulling the diff apart and measuring the backlash at the CROWN wheel also found it perfectly in specification. I guess the nature of the small pinion Vs large CROWN wheel means the backlash if magnified. The play into the gearbox on the other hand sounded eerily familliar - although there was far less movement. I'm thinking that the noise I'm hearing is somehow caused by the propshaft 'vibrating' at low loads, and the noise itself is actually from the gearbox. One thing that crosses my mind here is the old PPF alignment on Mk1 Mx5? I know from experience just how much noise the standard Mx5 gearbox can make when it's not quite aligned right on the PPF. |
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OGDB
Part of things
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What a fantastic build thread. I don’t know if I’ve commented in here before but I’ve certainly followed with interest.
How do you find the handling of the car now your conversion is installed? I ask because I visited a company down my way called TDI south located next door to AMD. When I was in there they had a few MX5s with various engine conversions, from memory a F20C, SR20 and I can’t remember the others. The owner said he struggled to get the centre of balance correct to retain the great handling and driving experience he had with a standard car. This was nearly 10 years ago now, so I suppose far more research and development has gone into the conversion you have installed but it would be interesting to hear. Sorry if this has already been covered.
Do you still have your 944? How do you feel the MX-5 compares? I was recently watching a “Smoking Tyre” episode on YouTube with a modified 944 turbo, the presenter described it as “it feels like a faster Mx-5” which I disagreed with. Would you say the two are comparable? Obviously I understand your 944 is not a turbo model and your MX-5 statistics are far greater than that of the 944. It would be interesting to hear your opinion. I’ve owned both and felt the Mx5 was far more nimble.
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I have the same issues as you with an MX5 4:1 torsen, ive adjusted mine back into limits, the remaining play is inside the torsen worm gears, and isn't really serviceable. Might be better to find a new core, mine isnt as bad as yours even after some 90,000 miles and serious abuse.
The cabin diff noise, will be caused by the poly diff bushes, i run them, but mines a track car so who cares.
Rubbers are quieter, and you can limit play with super pro limiter donut inserts.
0-60, should be in the 5's.
I run 5.1 to 60 with 240hp/250ftlb, so you should be equally as quick!
Great to see the rocketeer kit go together! I still really want a V6 mx5!!
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Clean sheet, zero advisories.
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