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  #1  
Old 24th March 2011, 05:07 PM
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Default mx-5 donor 1.8 or 1.6??

Hello all newbie here.

Looking to use a mazda as a donor but can't decide if the 1.6 engine has a good weight saving over the 1.8 which only has a 15bhp advantage. Obiously it will have more torque through out the rev range but.....

Any ideas anyone? Anyone know the weight advantage?
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Old 24th March 2011, 05:25 PM
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Personally speaking I went for the 1.6 vspec as you just don't need the torque IMHO but I am sure others will have differing opinions.

Matt
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Old 24th March 2011, 05:52 PM
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Yeah I think your right seems there's really not much between these engines 10lbft and 10bhp isn't going to make much difference? Is there a weight advantage though? I suppose the reciprical rotational weight will make a difference (lighterflywheel and crank etc). What's the vspec sorry?
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Old 24th March 2011, 08:29 PM
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V-spec stands for v-special. Basically the same car but with uprated suspension and LSD. The interior is also different (tan leather with high back seats) and they generally came in BRG but a few were sold in a high gloss black.

I found this engine comparison:

1.6 or 1.8?
I probably get asked about this more than any other aspect of an MX5 purchase. Lets look at the facts: when new, the 1.6 was good for 114bhp while the 1.8 produced 130bhp, an increase of 15% and had around 10% more torque produced lower down the rev range. However the 1.8 is a little heavier (50-70kg depending on exact model) so performance is not so different – an extra couple of mph on top speed and a couple of tenths of a second quicker to 60mph. Remember all these figures apply to nice shiny new cars: time and useage will have played a big part in how they drive now. In reality, a 1.8 has a little more low down power and seems to cope with motorway cruising a little more easily than a 1.6 but I reckon most people wouldn’t notice the difference. The 1.6 is a sweeter revving engine and a few well chosen modifications will significantly boost bhp and driving fun. In fact the 1.6 cars are the default choice for enthusiasts wishing to undertake serious tuning – fitting either super or turbochargers for example.
The real world answer is forget the engine and just concentrate on finding the nicest car you can. The exception to this is the late model UK 1.6 introduced in 1995: this was detuned to around 88bhp and is noticeably slower than the early 1.6 cars.
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Old 24th March 2011, 08:58 PM
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my mx5 i used for the exocet is a 1.8 it had a fair bit more poke than the 1600's i test drove
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Old 25th March 2011, 11:34 AM
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Quote:
Originally Posted by Airhead View Post
V-spec stands for v-special. Basically the same car but with uprated suspension and LSD. The interior is also different (tan leather with high back seats) and they generally came in BRG but a few were sold in a high gloss black.

I found this engine comparison:

1.6 or 1.8?
I probably get asked about this more than any other aspect of an MX5 purchase. Lets look at the facts: when new, the 1.6 was good for 114bhp while the 1.8 produced 130bhp, an increase of 15% and had around 10% more torque produced lower down the rev range. However the 1.8 is a little heavier (50-70kg depending on exact model) so performance is not so different – an extra couple of mph on top speed and a couple of tenths of a second quicker to 60mph. Remember all these figures apply to nice shiny new cars: time and useage will have played a big part in how they drive now. In reality, a 1.8 has a little more low down power and seems to cope with motorway cruising a little more easily than a 1.6 but I reckon most people wouldn’t notice the difference. The 1.6 is a sweeter revving engine and a few well chosen modifications will significantly boost bhp and driving fun. In fact the 1.6 cars are the default choice for enthusiasts wishing to undertake serious tuning – fitting either super or turbochargers for example.
The real world answer is forget the engine and just concentrate on finding the nicest car you can. The exception to this is the late model UK 1.6 introduced in 1995: this was detuned to around 88bhp and is noticeably slower than the early 1.6 cars.

Good bit of info that! LSD! 50kg! I'm sold thank you so much. Do you have plans for your chassis? how does your design vary from what Saturn are putting together?
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Old 25th March 2011, 11:48 AM
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My build has taken a little longer to do as I started mine last March so I have had to start from scratch. Generally they will be very similar. My rears are adjustable and the shock mounts low, also my diff sits much lower (25mm by eye) but apart from that I can't see a massive difference in the designs although I think comparing the geometry would show some differences.

I will be starting production of the wishbones in conjunction with some local companies soon as well as part built chassis kits and donor packages but I will be concentrating exclusively on the MX5 as it is what I know and love.

I recently acquired the most exciting bit for my build, a shiney new turbo! A little bit outside my comfort zone but the beauty of living in Cornwall is that there are plenty of retired enthusiasts with a lifetime of knowledge and time to help
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