Forced induction fuel economy and durability

[MX-5 Lazza]

skinny said:

MX-5 Lazza said:

Filled up today. 260 miles on 45 litres so pretty much 26mpg. Not bad considering I've been "testing" my new Hankook RS2s

[OT]how are you finding them mate - wait until it warms up a bit outside and you get the chance to really lean on them these on your 15's? to me, they were a noticeable step above F1's and T1R's on a dry road, and fantastic on track - they *love* getting a chunk of heat into them[/OT]

They were only fitted last week and so far I've just been scrubbing them in. Went out earlier today for a run to the DIY shop and had a chance to lean on them a bit on a couple of roundabouts. They do seem to have great grip in the dry. It'll be interesting to see how they perform as the weather gets warmer and especially when I get the car to a track!
[further OT]The rep said that they were stopping production of RS2s and there were no plans to produce a replacement[/further OT]

[Chris71]

Another question out of interest - with only 200cc between them and as much boost as you dare is there any preference between the 1.6 and 1.8 for forced induction?

[OnlyMX5ives]

There's a very telling Dyno on FM's site comparing the two.

Its a BIG difference.

I currently own a 1.6 and 1.8 FM2 not really a fair comparison as they have different specs but the 1.6 is FAST.

The 1.8 is SCARY.

But TBH much is down to tuning if YOU don't want to learn how to tune you won't get anything like the best set ups as it takes lots of time to get them right.

[GravelBen]

I seem to recall reading somewhere that its easier to turbo the 1.6 but easier to supercharge the 1.8, any merit in that?

[MX-5 Lazza]

GravelBen said:

I seem to recall reading somewhere that its easier to turbo the 1.6 but easier to supercharge the 1.8, any merit in that?

With the 1.6 just about all of the turbo kits are available but only the M45 SC kit will fit (I think the MP62 1.6 kit is about to be released).
With the 1.8 most of the turbo kits are available but with SC you have a choice of M45 or MP62.

One isn't any easier than the other, it's just the availability of parts/kits.

Something to keep in mind though is that the 1.8 comes with a bigger clutch & flywheel and bigger brakes, both of which are desirable. They can both be fitted to a 1.6 though. The 1.8 LSD (Torsen) is stronger than the 1.6 (viscous).

[Chris71]

MX-5 Lazza said:

GravelBen said:

I seem to recall reading somewhere that its easier to turbo the 1.6 but easier to supercharge the 1.8, any merit in that?

With the 1.6 just about all of the turbo kits are available but only the M45 SC kit will fit (I think the MP62 1.6 kit is about to be released).
With the 1.8 most of the turbo kits are available but with SC you have a choice of M45 or MP62.

One isn't any easier than the other, it's just the availability of parts/kits.

Something to keep in mind though is that the 1.8 comes with a bigger clutch & flywheel and bigger brakes, both of which are desirable. They can both be fitted to a 1.6 though. The 1.8 LSD (Torsen) is stronger than the 1.6 (viscous).

Ah, interesting. So if you could pick either as a donor it'd probably be a 1.8? Must admit I've always wondered what the split between Torsen and viscous LSDs was. I'm told the viscous ones can unlock after a while, but the Torsen ones don't?

[MX-5 Lazza]

Viscous wear out and end up as open dif. Torsen is mechanical and is stronger.