1UZ engine swap
Discussion
ikarl said:
feef said:
Fastdruid said:
Air-con should be pretty easy, just connect the compressor to the existing MX-5 system. Piece of cake. 
mine didn't come with air con as standard, that's the additional caveat 
Got the new engine on the stand and have started stripping it down to check sensors, fix a few bits that were damaged when it was removed from the donor car, and generally give it a tidy up
In the meantime, I've been pondering gearbox options and doing some ratio calculations
Stock MX5 box and diff would be good for a theoretical 138mph top speed, and cruising at 70 would be at 3100 rpm : That gearing seems a little short for my liking
A 350Z box with the MX5 diff would see a theoretical 178mph top speed, and cruising at 70 would be at 2400 rpm.
There are also plenty of folks out there making adapter plates for the 1UZ to the 350Z gearbox. However, I believe someone has already done a 1UZ/350Z combo in n MX5 and that's reason enough for me to look for an alternative
However, the curve-ball here would be to use a transaxle, which would mean I wouldn't have to worry about the engine/gearbox mounting so much as there's a torque-tube/driveshaft between them, and dropping in a Porsche 944/968 transaxle would give a theoretical top speed of 150 and cruising at 70mph would be at 2800rpm.
There's also the case that although the 1UZ is all aluminium compared to the MX5's cast iron block, it is still a little heavier (around 45kg if I'm right), so using a transaxle (and losing the spare wheel which lives in the boot) would maintain the weight distribution. Part of me is also thinking it might be easier to modify a linkage than ensure an entire gearbox lines up with the gear shift location on the transmission tunnel
The majority of 944/968 transaxles don't have an LSD (some did have, but they are expensive and rare second hand) but there are LSD kits out there for the normal versions, so would be an upgrade path for the future
Hmmm
A transaxle MX5 hasn't been done before, and that's reason enough for me to consider it
Thoughts?
In the meantime, I've been pondering gearbox options and doing some ratio calculations
Stock MX5 box and diff would be good for a theoretical 138mph top speed, and cruising at 70 would be at 3100 rpm : That gearing seems a little short for my liking
A 350Z box with the MX5 diff would see a theoretical 178mph top speed, and cruising at 70 would be at 2400 rpm.
There are also plenty of folks out there making adapter plates for the 1UZ to the 350Z gearbox. However, I believe someone has already done a 1UZ/350Z combo in n MX5 and that's reason enough for me to look for an alternative
However, the curve-ball here would be to use a transaxle, which would mean I wouldn't have to worry about the engine/gearbox mounting so much as there's a torque-tube/driveshaft between them, and dropping in a Porsche 944/968 transaxle would give a theoretical top speed of 150 and cruising at 70mph would be at 2800rpm.
There's also the case that although the 1UZ is all aluminium compared to the MX5's cast iron block, it is still a little heavier (around 45kg if I'm right), so using a transaxle (and losing the spare wheel which lives in the boot) would maintain the weight distribution. Part of me is also thinking it might be easier to modify a linkage than ensure an entire gearbox lines up with the gear shift location on the transmission tunnel
The majority of 944/968 transaxles don't have an LSD (some did have, but they are expensive and rare second hand) but there are LSD kits out there for the normal versions, so would be an upgrade path for the future
Hmmm
A transaxle MX5 hasn't been done before, and that's reason enough for me to consider it
Thoughts?
d when it comes to things like this feef said:
Scratch that idea
On the 944/968 it seems the tube that the driveshaft runs through is structural, and attaches the engine to the gearbox as well as providing a mounting point for the shifter linkage
I think that's a step too far
Alfa 75 and Alfa 90 have a transaxle according to Wiki. Not sure how available they are though.On the 944/968 it seems the tube that the driveshaft runs through is structural, and attaches the engine to the gearbox as well as providing a mounting point for the shifter linkage
I think that's a step too far
Could you use one from an MR2? It's mid engined, so I don't know if that removes the feasibility.
VladD said:
feef said:
Scratch that idea
On the 944/968 it seems the tube that the driveshaft runs through is structural, and attaches the engine to the gearbox as well as providing a mounting point for the shifter linkage
I think that's a step too far
Alfa 75 and Alfa 90 have a transaxle according to Wiki. Not sure how available they are though.On the 944/968 it seems the tube that the driveshaft runs through is structural, and attaches the engine to the gearbox as well as providing a mounting point for the shifter linkage
I think that's a step too far
Could you use one from an MR2? It's mid engined, so I don't know if that removes the feasibility.
They aren't all that common, however, and I'm not 100% sure they'd handle the torque
The most powerful engine fitted to them was the 3L V6 in the 75 Cloverleaf (Milano Verde) but even then, it only made 184lbft compared to the 1UZ with 268lbft
The attraction of the Porsche transaxle was also the availability of LSD upgrades, whereas they are thin on the ground on the Alfa 75 box
I might still pop down to the Alfa Workshop in Royston and see if Jamie has or knows of any 75 gearboxes available, as I'm sure he'd have a better idea of whether it could handle the power and torque
feef said:
Scratch that idea
On the 944/968 it seems the tube that the driveshaft runs through is structural, and attaches the engine to the gearbox as well as providing a mounting point for the shifter linkage
I think that's a step too far
Yup it is a torque tube but can be cut down shorter. A guy built a Locost in the USA based on a 944 & did exactly this. There are dimensions on the web for the adapter to the bellhousing for the LS1 transplant into the 944.On the 944/968 it seems the tube that the driveshaft runs through is structural, and attaches the engine to the gearbox as well as providing a mounting point for the shifter linkage
I think that's a step too far
tr7v8 said:
feef said:
Scratch that idea
On the 944/968 it seems the tube that the driveshaft runs through is structural, and attaches the engine to the gearbox as well as providing a mounting point for the shifter linkage
I think that's a step too far
Yup it is a torque tube but can be cut down shorter. A guy built a Locost in the USA based on a 944 & did exactly this. There are dimensions on the web for the adapter to the bellhousing for the LS1 transplant into the 944.On the 944/968 it seems the tube that the driveshaft runs through is structural, and attaches the engine to the gearbox as well as providing a mounting point for the shifter linkage
I think that's a step too far
It's still under consideration, but I'm tending towards the Toyota w58 gearbox for simplicity, availability of parts and flexibility of shifter location
The 350Z box has a 'remote' shifter which is about 7" too far away from where it ideally should be
I know this could be modified and the distance cut down by 4" but it's still quite far out compared to how the W58 would sit
Plenty of time to think things through before a decision needs to be made however
'Box sorted
I've got a Toyota W58 box en route to me
Bullet Performance in Australia also do a kit to mate the W58 to the 1UZ which they use in their MX5 based cars, so as a combination, it 'should' fit.
The W58 also has a few variations/options on shifter location so that shoud help.
Waiting for a break in the weather to get the engine and 'box out the MX5. While I can work on bits and pieces in the garage, there's not enough space to get the car in. :/
The W58 has ratios:
1st - 3.285:1
2nd - 1.894:1
3rd - 1.275:1
4th - 1:1
5th - 0.783:1
Keeping the MX5 diff (which has a final drive ratio of 3.636:1) gives the following road speeds at 6100 rpm:
1st : 40mph
2nd : 70mph
3rd : 104mph
4th : 133mph
5th : 170mph
Anecdotal evidence says the MX5 diff I have can easily handle the power and torque I'll be putting out, and it's more likely that the axles will fail before the diff.
I've got a Toyota W58 box en route to me
Bullet Performance in Australia also do a kit to mate the W58 to the 1UZ which they use in their MX5 based cars, so as a combination, it 'should' fit.
The W58 also has a few variations/options on shifter location so that shoud help.
Waiting for a break in the weather to get the engine and 'box out the MX5. While I can work on bits and pieces in the garage, there's not enough space to get the car in. :/
The W58 has ratios:
1st - 3.285:1
2nd - 1.894:1
3rd - 1.275:1
4th - 1:1
5th - 0.783:1
Keeping the MX5 diff (which has a final drive ratio of 3.636:1) gives the following road speeds at 6100 rpm:
1st : 40mph
2nd : 70mph
3rd : 104mph
4th : 133mph
5th : 170mph
Anecdotal evidence says the MX5 diff I have can easily handle the power and torque I'll be putting out, and it's more likely that the axles will fail before the diff.
Gearbox arrives tomorrow.
Not heard back from Bullet yet, so will chase them this week.
I'm tending more and more towards running with the emerald ecu as it can support the stock crank trigger wheel with cam phase sensor to manage the timing. That would mean I could strip out almost all the stock wiring, and need only the TPS, MAP, crank, cam and air temp sensors to make it work.
It also means things are more flexible on the engine's rev limit. Stock the limit is about 6100rpm I think, but they can rev significantly higher than that and remain well within safe limits. The emerald means it can be mapped accordingly.
I still need to examine how to control the speedo. The stock speedo takes its signal from a pickup in the gearbox. Obviously that's not now an option. The emerald can drive the tachometer.
Got everything disconnected and unbolted now, even have the chains for the hoist bolted into place. Just need to get a gap in the weather that will coincide with some free time so I can lift it out. (Although viewing the image reminded me I need to remove the ARB)
Not heard back from Bullet yet, so will chase them this week.
I'm tending more and more towards running with the emerald ecu as it can support the stock crank trigger wheel with cam phase sensor to manage the timing. That would mean I could strip out almost all the stock wiring, and need only the TPS, MAP, crank, cam and air temp sensors to make it work.
It also means things are more flexible on the engine's rev limit. Stock the limit is about 6100rpm I think, but they can rev significantly higher than that and remain well within safe limits. The emerald means it can be mapped accordingly.
I still need to examine how to control the speedo. The stock speedo takes its signal from a pickup in the gearbox. Obviously that's not now an option. The emerald can drive the tachometer.
Got everything disconnected and unbolted now, even have the chains for the hoist bolted into place. Just need to get a gap in the weather that will coincide with some free time so I can lift it out. (Although viewing the image reminded me I need to remove the ARB)
Fuel injector kits arrived, half of them are done
I've started fabricating some blanking plates to allow removal of the EGR valve and associated gubbins, but the motor on my milling machine has let the magic blue smoke escape so while I'm waiting for that to be repaired I'm resorting to cutting disks and grinders to make the plates. Not as pretty, but most of them won't be easily visible so I can live with that.
I've given all the top-end engine covers and manifolds a good clean and will be reassembling the top end hopefully later this week.
I need to get ahold of Bullet in Australia as I've not had an answer to my email yet, and once the engine is assembled, the project will be largely waiting on the gearbox-engine adapter kit
I can, in the meantime, get the old engine and box out the chassis, clean up the engine bay, maybe do some trimming and welding in there as well as clean up the corroded chassis legs, and sort out the wiring for the Emerald to work with the 1UZ.
I'll dig out a few photos shortly
I've started fabricating some blanking plates to allow removal of the EGR valve and associated gubbins, but the motor on my milling machine has let the magic blue smoke escape so while I'm waiting for that to be repaired I'm resorting to cutting disks and grinders to make the plates. Not as pretty, but most of them won't be easily visible so I can live with that.
I've given all the top-end engine covers and manifolds a good clean and will be reassembling the top end hopefully later this week.
I need to get ahold of Bullet in Australia as I've not had an answer to my email yet, and once the engine is assembled, the project will be largely waiting on the gearbox-engine adapter kit
I can, in the meantime, get the old engine and box out the chassis, clean up the engine bay, maybe do some trimming and welding in there as well as clean up the corroded chassis legs, and sort out the wiring for the Emerald to work with the 1UZ.
I'll dig out a few photos shortly
Got ahold of Bullet, just sorting out some bits and pieces with them and finalising pricing and shipping
As a result I've added a HiLux clutch master cylinder to the shopping list as that's the one that's compatible with the custom slave cylinder supplied with the Bullet kit
In the meantime, some progress has been made with a break in the weather and a friend with free time coinciding nicely, letting me get the old engine out
I also took advantage of having it out to inspect the damage to pistons 1 & 3
Yup, that's dead
As a result I've added a HiLux clutch master cylinder to the shopping list as that's the one that's compatible with the custom slave cylinder supplied with the Bullet kit
In the meantime, some progress has been made with a break in the weather and a friend with free time coinciding nicely, letting me get the old engine out
I also took advantage of having it out to inspect the damage to pistons 1 & 3
Yup, that's dead
Other than some cleaning of manifolds and castings, I've not made much progress. I'm waiting for the electric motor from my milling machine to come back from AES where it's having the capacitors replaced, a rewind and new bearings.
Once that's back I'll finish the EGR blanking plates I started before the magic blue smoke escaped.
In the meantime, I've taken delivery of the chassis leg repair panels from the Mx5 Restorer. There's little point in not tackling the NBFL's weak spot for rust while I have the engine out and such good access.
I've confirmed the parts I need with Bullet and have an invoice from them in my email. A credit card payment will shortly be with them and hopefully have the gearbox adapter kit with me in a few weeks.
Once that's back I'll finish the EGR blanking plates I started before the magic blue smoke escaped.
In the meantime, I've taken delivery of the chassis leg repair panels from the Mx5 Restorer. There's little point in not tackling the NBFL's weak spot for rust while I have the engine out and such good access.
I've confirmed the parts I need with Bullet and have an invoice from them in my email. A credit card payment will shortly be with them and hopefully have the gearbox adapter kit with me in a few weeks.
A bit more progress today.
I've got the motor back for the milling machine so can get on with finishing the EGR blanking plates now.
But as the weather was goood I took advantage and dropped the hood so I could get in and remove the dash as removing that plus the HVAC unit is the only way to get access to the bulkhead where the engine wiring comes in. With that removed I could extract the engine end of the loom.
Along with the wiring came the original ECU and the emerald so I have the emerald on the bench too now, ready to splice into the 1UZ loom (using stock sensors where possible) and ready program for the V8.
I also took some time to tidy up some other wiring in the engine bay and remove the extraneous stuff (eg diagnostic port) as well as remove the rest of the fuel emissions and vent pipe.
It's looking much more accommodating for a V8 now.
I'll be giving Bullet a call early next week to place an order for the adapter kit. In the meantime I can get on with the wiring and maybe tackle the chassis arms.
In looking at the bay and imagining the tubular steel subframe from Crapengineering in there, I'm wondering if I should go the whole hog and go with the tubular suspension arms from V8 Roadsters.
That would be teh seks
I think the bay is looking much tidier now
I've got the motor back for the milling machine so can get on with finishing the EGR blanking plates now.
But as the weather was goood I took advantage and dropped the hood so I could get in and remove the dash as removing that plus the HVAC unit is the only way to get access to the bulkhead where the engine wiring comes in. With that removed I could extract the engine end of the loom.
Along with the wiring came the original ECU and the emerald so I have the emerald on the bench too now, ready to splice into the 1UZ loom (using stock sensors where possible) and ready program for the V8.
I also took some time to tidy up some other wiring in the engine bay and remove the extraneous stuff (eg diagnostic port) as well as remove the rest of the fuel emissions and vent pipe.
It's looking much more accommodating for a V8 now.
I'll be giving Bullet a call early next week to place an order for the adapter kit. In the meantime I can get on with the wiring and maybe tackle the chassis arms.
In looking at the bay and imagining the tubular steel subframe from Crapengineering in there, I'm wondering if I should go the whole hog and go with the tubular suspension arms from V8 Roadsters.
That would be teh seks
I think the bay is looking much tidier now
Bit of thumb twiddling this week as work and other stuff got in the way.
I have reassembled the engine top end but just need to finish off the EGR delete plates and started extracting the wiring from the 1UZ
I've also treated it to some new plugs, cam belt and serpentine belt.
Also in the car is an air-con heat exchanger, so all I need to source now is the dash switch, condensor and custom pipework (the latter parts I'll be sourcing from carbuildersolutions.com) once the engine is in place so I can route them correctly.
Need to go get the portable MiG from our warehouse so I can do some bodywork/chassis stuff as it's easier than with the giant TiG.
Waiting on the gearbox parts to arrive from Australia and have confirmed with Claire from Crapengineering that she'll be starting work on my subframe in a few weeks.
Slow progress, but still progress.
In the meantime, I'll leave you with this..... this is how a 1UZ sounds when fitted with Kelford cams
https://www.youtube.com/watch?v=AKYg6H7yh3k
I have reassembled the engine top end but just need to finish off the EGR delete plates and started extracting the wiring from the 1UZ
I've also treated it to some new plugs, cam belt and serpentine belt.
Also in the car is an air-con heat exchanger, so all I need to source now is the dash switch, condensor and custom pipework (the latter parts I'll be sourcing from carbuildersolutions.com) once the engine is in place so I can route them correctly.
Need to go get the portable MiG from our warehouse so I can do some bodywork/chassis stuff as it's easier than with the giant TiG.
Waiting on the gearbox parts to arrive from Australia and have confirmed with Claire from Crapengineering that she'll be starting work on my subframe in a few weeks.
Slow progress, but still progress.
In the meantime, I'll leave you with this..... this is how a 1UZ sounds when fitted with Kelford cams
https://www.youtube.com/watch?v=AKYg6H7yh3k
Gassing Station | Mazda MX5/Roadster/Miata | Top of Page | What's New | My Stuff