Mx5 Rocketeer V6 Conversion Project
Discussion
Another small update to upload and fascinate you all with!
I've had a new roof fitted, due to torrents of water pouring into the car. The roof was a little bit worn aside from this issue anyway, so a new roof it was. Plus, as time goes on, I've got used to spending sums of money that would have given me pause earlier!
Mid roof change:
IMG_2740 by Jon Fellows, on Flickr
And fitted - It does look nice, and I'm pretty pleased with it.
IMG_2741 by Jon Fellows, on Flickr
I also spent a few hours today getting my new diff ready to be fitted. Although my car does come with a Torsen LSD, it had much backlash in it. Plus, I wanted a lower ratio final drive to lower cruising revs. This shouldn't adversely effect performance once the V6 goes in, so it made sense to do the swap now. So here is my new 3.6:1 Torsen LSD having a few bits swapped over:
IMG_2744 by Jon Fellows, on Flickr
And lastly, another picture of wishbones I took and forgot to post last update...!
IMG_2742 by Jon Fellows, on Flickr
I've had a new roof fitted, due to torrents of water pouring into the car. The roof was a little bit worn aside from this issue anyway, so a new roof it was. Plus, as time goes on, I've got used to spending sums of money that would have given me pause earlier!
Mid roof change:
IMG_2740 by Jon Fellows, on FlickrAnd fitted - It does look nice, and I'm pretty pleased with it.
IMG_2741 by Jon Fellows, on FlickrI also spent a few hours today getting my new diff ready to be fitted. Although my car does come with a Torsen LSD, it had much backlash in it. Plus, I wanted a lower ratio final drive to lower cruising revs. This shouldn't adversely effect performance once the V6 goes in, so it made sense to do the swap now. So here is my new 3.6:1 Torsen LSD having a few bits swapped over:
IMG_2744 by Jon Fellows, on FlickrAnd lastly, another picture of wishbones I took and forgot to post last update...!
IMG_2742 by Jon Fellows, on FlickrEdited by Lewis's Friend on Thursday 1st February 21:33
Nice project, enjoying the thread so far. Is there anything more satisfying than seeing grungy rust turned to shiny black? How much did it rush you for all the powder coating if you don't mind be asking? I'm in the process of restoring and tackling rust on my '6 and am interested in getting some parts done but am on a tight budget...
Great effort for doing this all on the driveway too, I've been there before but found it harder to be motivated when it's all open to the elements...
Great effort for doing this all on the driveway too, I've been there before but found it harder to be motivated when it's all open to the elements...
MX6 said:
Nice project, enjoying the thread so far. Is there anything more satisfying than seeing grungy rust turned to shiny black? How much did it rush you for all the powder coating if you don't mind be asking? I'm in the process of restoring and tackling rust on my '6 and am interested in getting some parts done but am on a tight budget...
Great effort for doing this all on the driveway too, I've been there before but found it harder to be motivated when it's all open to the elements...
Worked my on the drive certainly adds a layer of discomfort and frustration when the weather is inclement...!Great effort for doing this all on the driveway too, I've been there before but found it harder to be motivated when it's all open to the elements...
Happily at the moment, if it’s wet I can carry on inside pressing bits and bobs in.
In terms of powder coating costs, the whole lot was £500. No idea if that’s exorbitant or not really. That’s blasted, zinced and powder coated.
Another minor update. Progress has slowed a little, due to work, cold and my central heating packing up (not happy with that last particularly)...!
But, having swapped bits over on my diffs, it was time to fit it. On MX5's there is a PPF (power plant frame) that ties the gearbox and diff together. This can be taken off before removing the diff, but I couldn't see a way of putting it back on when the diff was installed (not in the Haynes 'installation is the reverse of removal' tradition). So I fitted it in the back garden to the diff, which made a very meaningful monument - it was a shame it couldn't stay really...!
Diff by Jon Fellows, on Flickr
But it couldn't stay, so I fitted it.. It was a bit of a faff doing it by myself, but by no means impossible. I just had to make sure it was balanced on the jack nice and centrally and up it went.
Diff2 by Jon Fellows, on Flickr
Diff3 by Jon Fellows, on Flickr
I then had to align the PPF, which basically just involves setting the gearbox tail height in relation to the chassis rails before torquing up the PPF bolts. All done and in spec, so next step is to fit the suspension bits and build up the brakes.
But, having swapped bits over on my diffs, it was time to fit it. On MX5's there is a PPF (power plant frame) that ties the gearbox and diff together. This can be taken off before removing the diff, but I couldn't see a way of putting it back on when the diff was installed (not in the Haynes 'installation is the reverse of removal' tradition). So I fitted it in the back garden to the diff, which made a very meaningful monument - it was a shame it couldn't stay really...!
Diff by Jon Fellows, on FlickrBut it couldn't stay, so I fitted it.. It was a bit of a faff doing it by myself, but by no means impossible. I just had to make sure it was balanced on the jack nice and centrally and up it went.
Diff2 by Jon Fellows, on FlickrDiff3 by Jon Fellows, on FlickrI then had to align the PPF, which basically just involves setting the gearbox tail height in relation to the chassis rails before torquing up the PPF bolts. All done and in spec, so next step is to fit the suspension bits and build up the brakes.
Some more work now going on. Vexingly, I only really have time to work outside on the car on Saturdays, and it has rained without fail every Saturday...! But some progress has been made regardless.
I'm getting to the slightly more photogenic point of the refresh, where bits are getting bolted back on and it looks like progress is being made.
So after fitting the diff etc, I have started putting the rear suspension back together.
IMG_2756 by Jon Fellows, on Flickr
IMG_2757 by Jon Fellows, on Flickr
I must admit it is very nice working with clean parts and new/refreshed bolts etc. It all goes together much more easily.
IMG_2759 by Jon Fellows, on Flickr
IMG_2760 by Jon Fellows, on Flickr
I also fitted the prop shaft and mid-heatshield with new bolts etc. In an extremely nerdy way, it was really nice to see all new bits on against the fresh underseal and the cleaned up PPF. I tried to capture the look, but frankly, failed hard! Nevertheless, this is my best effort. I think photography will not be a fall-back career of mine...!
IMG_2758 by Jon Fellows, on Flickr
I'm getting to the slightly more photogenic point of the refresh, where bits are getting bolted back on and it looks like progress is being made.
So after fitting the diff etc, I have started putting the rear suspension back together.
IMG_2756 by Jon Fellows, on FlickrIMG_2757 by Jon Fellows, on FlickrI must admit it is very nice working with clean parts and new/refreshed bolts etc. It all goes together much more easily.
IMG_2759 by Jon Fellows, on FlickrIMG_2760 by Jon Fellows, on FlickrI also fitted the prop shaft and mid-heatshield with new bolts etc. In an extremely nerdy way, it was really nice to see all new bits on against the fresh underseal and the cleaned up PPF. I tried to capture the look, but frankly, failed hard! Nevertheless, this is my best effort. I think photography will not be a fall-back career of mine...!
IMG_2758 by Jon Fellows, on FlickrWas having a browse through to see if anyone else was shoving big engines in MX-5's while mines tucked away for the winter and this one popped up! I love the work you've done, essentially a new car, really great job.
On the engine conversion I looked into the V6 before I did mine but went with a Rover V8, mainly because my first car had one and there are so many upgrade choices from superchargers to 5.4 litres etc. I got a 4.6 from a running P38 Range Rover with all the ancillaries for £550 delivered. Spent around 1k on megasquirt with a custom loom and another £1,500 on bits like stainless steel headers and so on. There was some welding but nothing that would scare most competent mechanics. I put a diff from a 323i E36 and used the lt77 gearbox, they cost less than £200.
Once I was done I had it tested and it puts out 240bhp and 250 lb/ft. The nonsense about the V8 being to heavy is just that, it may be slightly heavier but it's not noticeable and the engine sits slightly further back. It sounds great and goes like stink. The part which pushed me to the Rover engine are the upgrades. I bought another set of heads for £90, I'll be doing the heads and cam next winter and and winter after that the pistons and supercharging it. I always have something to look forward too. The only negative seems to be the sniping when you go to meets "so much work for so little power", never sure why people feel the need to put down other people's work. Anyway best of luck!
On the engine conversion I looked into the V6 before I did mine but went with a Rover V8, mainly because my first car had one and there are so many upgrade choices from superchargers to 5.4 litres etc. I got a 4.6 from a running P38 Range Rover with all the ancillaries for £550 delivered. Spent around 1k on megasquirt with a custom loom and another £1,500 on bits like stainless steel headers and so on. There was some welding but nothing that would scare most competent mechanics. I put a diff from a 323i E36 and used the lt77 gearbox, they cost less than £200.
Once I was done I had it tested and it puts out 240bhp and 250 lb/ft. The nonsense about the V8 being to heavy is just that, it may be slightly heavier but it's not noticeable and the engine sits slightly further back. It sounds great and goes like stink. The part which pushed me to the Rover engine are the upgrades. I bought another set of heads for £90, I'll be doing the heads and cam next winter and and winter after that the pistons and supercharging it. I always have something to look forward too. The only negative seems to be the sniping when you go to meets "so much work for so little power", never sure why people feel the need to put down other people's work. Anyway best of luck!
daveinhampshire said:
Was having a browse through to see if anyone else was shoving big engines in MX-5's while mines tucked away for the winter and this one popped up! I love the work you've done, essentially a new car, really great job.
On the engine conversion I looked into the V6 before I did mine but went with a Rover V8, mainly because my first car had one and there are so many upgrade choices from superchargers to 5.4 litres etc. I got a 4.6 from a running P38 Range Rover with all the ancillaries for £550 delivered. Spent around 1k on megasquirt with a custom loom and another £1,500 on bits like stainless steel headers and so on. There was some welding but nothing that would scare most competent mechanics. I put a diff from a 323i E36 and used the lt77 gearbox, they cost less than £200.
Once I was done I had it tested and it puts out 240bhp and 250 lb/ft. The nonsense about the V8 being to heavy is just that, it may be slightly heavier but it's not noticeable and the engine sits slightly further back. It sounds great and goes like stink. The part which pushed me to the Rover engine are the upgrades. I bought another set of heads for £90, I'll be doing the heads and cam next winter and and winter after that the pistons and supercharging it. I always have something to look forward too. The only negative seems to be the sniping when you go to meets "so much work for so little power", never sure why people feel the need to put down other people's work. Anyway best of luck!
Thanks for the kind words. I wasn't initially planning so much work, but one thing has lead to another...!On the engine conversion I looked into the V6 before I did mine but went with a Rover V8, mainly because my first car had one and there are so many upgrade choices from superchargers to 5.4 litres etc. I got a 4.6 from a running P38 Range Rover with all the ancillaries for £550 delivered. Spent around 1k on megasquirt with a custom loom and another £1,500 on bits like stainless steel headers and so on. There was some welding but nothing that would scare most competent mechanics. I put a diff from a 323i E36 and used the lt77 gearbox, they cost less than £200.
Once I was done I had it tested and it puts out 240bhp and 250 lb/ft. The nonsense about the V8 being to heavy is just that, it may be slightly heavier but it's not noticeable and the engine sits slightly further back. It sounds great and goes like stink. The part which pushed me to the Rover engine are the upgrades. I bought another set of heads for £90, I'll be doing the heads and cam next winter and and winter after that the pistons and supercharging it. I always have something to look forward too. The only negative seems to be the sniping when you go to meets "so much work for so little power", never sure why people feel the need to put down other people's work. Anyway best of luck!
I ended up chosing the V6 option, basically as that what what the kit was for. I'm not sure I'd back myself to fab stuff up to get another engine to fit. Plus the original gearbox etc could be retained for ease of install. I do like the RV8 though - a friend has a TVR Chimaera with the 4.0 and had that up to a rolling road verified 240bhp with work on the exhaust, intake, carbon trumpets in the intake plenum etc. Though now it has a large turbo strapped to it!
Part of me would like a V8, just for the noise. That said, the V6 in the demo car does sound good too, and I have some experience with the Jag V6 from my XJ (though in a totally different setting). There are tuning options with them too, though I would imagine at greater cost that the RV8. Mountune can build an engine to about 330bhp I believe, though I would need to remortgage for that probably, and I'm not sure if the gearbox etc could take it either!
Lewis's Friend said:
Thanks for the kind words. I wasn't initially planning so much work, but one thing has lead to another...!
I ended up chosing the V6 option, basically as that what what the kit was for. I'm not sure I'd back myself to fab stuff up to get another engine to fit. Plus the original gearbox etc could be retained for ease of install. I do like the RV8 though - a friend has a TVR Chimaera with the 4.0 and had that up to a rolling road verified 240bhp with work on the exhaust, intake, carbon trumpets in the intake plenum etc. Though now it has a large turbo strapped to it!
Part of me would like a V8, just for the noise. That said, the V6 in the demo car does sound good too, and I have some experience with the Jag V6 from my XJ (though in a totally different setting). There are tuning options with them too, though I would imagine at greater cost that the RV8. Mountune can build an engine to about 330bhp I believe, though I would need to remortgage for that probably, and I'm not sure if the gearbox etc could take it either!
It's a bit splitting hairs really, either engine is awesome and with such low curb weight I'd be more than happy in either! I was a bit surprised the original gearbox and diff stay in on the conversion, more so the diff as they range anything from 3.6 to over 4 on ratio. I've currently got mine on a 2.93 which is a little low(removes wheelspin though) but couldn't imagine using much above 3.2 especially as the mx5 box ratios are low. Be interesting to see the speed in each gear, really you should be able to get a much stronger top end on the V6 and a much more relaxed cruise at 100mph I ended up chosing the V6 option, basically as that what what the kit was for. I'm not sure I'd back myself to fab stuff up to get another engine to fit. Plus the original gearbox etc could be retained for ease of install. I do like the RV8 though - a friend has a TVR Chimaera with the 4.0 and had that up to a rolling road verified 240bhp with work on the exhaust, intake, carbon trumpets in the intake plenum etc. Though now it has a large turbo strapped to it!
Part of me would like a V8, just for the noise. That said, the V6 in the demo car does sound good too, and I have some experience with the Jag V6 from my XJ (though in a totally different setting). There are tuning options with them too, though I would imagine at greater cost that the RV8. Mountune can build an engine to about 330bhp I believe, though I would need to remortgage for that probably, and I'm not sure if the gearbox etc could take it either!
Just another mod I made, I vented the front wheel arches as when you build up speed the air pressure seems to build up. That seemed to solve it.
daveinhampshire said:
It's a bit splitting hairs really, either engine is awesome and with such low curb weight I'd be more than happy in either! I was a bit surprised the original gearbox and diff stay in on the conversion, more so the diff as they range anything from 3.6 to over 4 on ratio. I've currently got mine on a 2.93 which is a little low(removes wheelspin though) but couldn't imagine using much above 3.2 especially as the mx5 box ratios are low. Be interesting to see the speed in each gear, really you should be able to get a much stronger top end on the V6 and a much more relaxed cruise at 100mph
Just another mod I made, I vented the front wheel arches as when you build up speed the air pressure seems to build up. That seemed to solve it.
I understand the gearbox and diff are good for the power. Quite how much more they could take over the approx 260bhp that the demo car runs I couldn’t say though. Just another mod I made, I vented the front wheel arches as when you build up speed the air pressure seems to build up. That seemed to solve it.
In terms of cruising revs, I calculated that with the 3.6:1 diff and wheel/tyre combo I’m after it should sit at a hair over 3000rpm at 70mph. Which is not super relaxing, but should be fine. In fact it’ll be almost exactly the same as my daily driver, a 52 plate Seat Leon Cupra R.
Also, do you have any pics of your arch vents st all?
I think you'd get away with quite a lot, the weight of the car is so low plus even with the higher bhp the torque is likely to sit around the same figure. And as you're unlikely to daily drive it 3,000 rpm is fine. I often leave mine in 4th, it sounds better. I'll grab some pics when I'm over my parents next, it's in their garage until the spring 
Love this, following with interest! Your driveway is very similar to how ours was a few years ago - I had a red Leon Cupra R and my wife had a MX-5, although hers was silver, an NC and just a standard 1.8. Really interesting choice of engine for this, keen to read about the finished article.
Again, thanks for all the positive comments - always appreciated.
Some more progress as I bolt more bits on. It feels like a lot of headway all of a sudden as the pile of bits diminishes, but still a ways to go...!
Front suspension started to be built up here:
1 by Jon Fellows, on Flickr
And at the back, droplinks attached to the ARB, and the reinforcers bolted onto the rear subframe:
3 by Jon Fellows, on Flickr
And lastly, a thrilling picture of a fuel filter! Just to show that I was sad enough to get even the little brackets coated...
2 by Jon Fellows, on Flickr
So next step is to lower the car to ride height and torque up the suspension bolts. Then it should be brakes on and bled, oil in the gearbox (diff already filled with Fuchs Syn 5), exhaust on and then trying to get it started and fault finding. There will be faults...!
Some more progress as I bolt more bits on. It feels like a lot of headway all of a sudden as the pile of bits diminishes, but still a ways to go...!
Front suspension started to be built up here:
1 by Jon Fellows, on FlickrAnd at the back, droplinks attached to the ARB, and the reinforcers bolted onto the rear subframe:
3 by Jon Fellows, on FlickrAnd lastly, a thrilling picture of a fuel filter! Just to show that I was sad enough to get even the little brackets coated...
2 by Jon Fellows, on FlickrSo next step is to lower the car to ride height and torque up the suspension bolts. Then it should be brakes on and bled, oil in the gearbox (diff already filled with Fuchs Syn 5), exhaust on and then trying to get it started and fault finding. There will be faults...!
Paddy_N_Murphy said:
Re-iterating - the "Lovely Thing" I am loving what a brand new fresh look the MX5 is having / will be - never mind the V6 up front.
I'd love to have a project / place to potter like that.......
Thanks. I do like to have a project to play with, as it keeps me out of trouble. I'd love to have a project / place to potter like that.......
I think I’ll have to be careful not to assume it’ll drive like a new car when I’m done, and then be disappointed that it doesn’t straight away. In the flurry of getting the underside sorted, there’s still the window that doesn’t really work, wing mirrors that don’t adjust, awful sound system, suspect immobiliser and other things that I relegated to the back of my mind as being ‘minor’...!
I’ll get there with it, but it won’t be perfect for a while yet!
Paddy_N_Murphy said:
Not a bad thing 
Just given mine a run out - there is a charm that a new car can't get near...
To be fair, I’ve never owned a new car, or even close to it so I don’t have much to compare it with...! I tend to only start being interested in a car after it gets to about 10+. Just given mine a run out - there is a charm that a new car can't get near...
Paddy_N_Murphy said:
Lewis's Friend said:
Paddy_N_Murphy said:
Not a bad thing
Just given mine a run out - there is a charm that a new car can't get near...
To be fair, I’ve never owned a new car, or even close to it so I don’t have much to compare it with...! I tend to only start being interested in a car after it gets to about 10+. Just given mine a run out - there is a charm that a new car can't get near...
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