Supercharging my MX5

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Discussion

MX-5 Lazza

7,952 posts

179 months

Thursday 25th June 2009
quotequote all
An Eaton Supercharge is an Eaton Supercharger i.e. the internals and much of the body are the same but they are different for different cars. There are always loads of ex-Mini chargers around but they are useless to us because they don't have a built-in bypass valve. Various people have looked into the possibility of developing a kit using them but there ate technical difficulties and it just doesn't work out financially when compared to the current JRSC M45.

Edited by MX-5 Lazza on Thursday 25th June 10:17

Legend83

9,578 posts

182 months

Thursday 25th June 2009
quotequote all
MX-5 Lazza said:
An Eaton Supercharge is an Eaton Supercharger i.e. the internals and much of the body are the same but they are different for different cars. There are always loads of ex-Mini chargers around but they are useless to us because they don't have a built-in bypass valve. Various people have looked into the possibility of developing a kit using them but there ate technical difficulties and it just doesn't work out financially when compared to the current JRSC M45.

Edited by MX-5 Lazza on Thursday 25th June 10:17
Cheers! Won't be bidding for one of those then!

Howard-

4,233 posts

162 months

Monday 27th July 2009
quotequote all
BUMP!

Starting my research into this!

So I'm right in thinking this is an easier, cheaper, more reliable solution with a smoother power delivery than turbocharging?

Are there any "kits" that are much cheaper to buy than that Moss kit? I'm happy to have a bash at doing the work myself, but £2.3k is a little steep!

That, or somewhere that details exactly what I need to buy!

And what sort of power are we looking at, with that Moss kit or similar, with the standard whatever-is-provided piggyback fueling solution?


OnlyMX5ives

1,142 posts

152 months

Monday 27th July 2009
quotequote all
No - turbo kits are cheaper.

Best go to MX5 Nutz for the best UK forum

Or Miata net / Miata Turbo are the best USA forums.

Google [bot]

5,253 posts

141 months

Tuesday 28th July 2009
quotequote all
I recently sold my Mk1 1.8 with JRSC kit, M45 etc. First thing to consider is you are not going to get massive power from a S/C set-up. Mine, though a little bit sick when dyno'd made 113kw at the wheels - I take this to be around 160-170BHP at the motor. You can get different pulleys to give (IIRC) 10psi but I think that's pretty much your limit. Maybe 200BHP at a guess? Whilst that sounds massive in such a small car, it's not that insane. If you want big power you need to go turbo. Mind you, I went out in a 320BHP at the wheels turbo 5 and I could imagine getting into a lot of trouble very quickly, IMHO it's just too much - I'm not into turbos kicking the arse out at 80MPH, but that's just me.


What you do get is the eeriest loudest shriek. Tunnels will be your friend, the looks as you squirt past people is of bewilderment - everyone's used to turbo dump valve noise but not this sound.

Turbo and SC conversions are pretty common over here in Aus and I urge you to have a look at this forum for a heap of advise:

http://mx5cartalk.com/forum/viewforum.php?f=81&amp...

Nice folk they are too.

MX-5 Lazza

7,952 posts

179 months

Tuesday 28th July 2009
quotequote all
As Mark says, a basic turbo setup is cheaper than a basic supercharger setup. Both will deliver about the same power as standard. It is then easier to up the power on the turbo but doing this can cost a bit more than on the SC as it really means replacing bits.
As a general rule of thumb I'd say for low power turbo will be cheapest.
For mid to high power they are around the same.
For very high power you really need a turbo or a 1.8 with MP62. Both will need intercooling and a stand-alone ecu so neither will be cheap.

If you buy a cheap turbo kit though don't expect it to be reliable if you tweak it for more power.

A good phrase to remember is this...
Cheap - Reliable - Powerful. You can pick only 2.

Odie

4,187 posts

142 months

Tuesday 28th July 2009
quotequote all
Im gonna keep track of this thread too.

Some good Stuff.

What kinda power gain are you looking at for a SC or TC mk2.5 1.6? What else would you need to spend money on? Brakes? Gearbox? Diff?

Is it worth getting the head flowed? (could do that myself)

what about having the head skimmed to increase the compression ratio?

MX-5 Lazza

7,952 posts

179 months

Tuesday 28th July 2009
quotequote all
Odie said:
Im gonna keep track of this thread too.

Some good Stuff.

What kinda power gain are you looking at for a SC or TC mk2.5 1.6? What else would you need to spend money on? Brakes? Gearbox? Diff?

Is it worth getting the head flowed? (could do that myself)

what about having the head skimmed to increase the compression ratio?
Getting the head flowed will always help whether it's TC, SC or NA.
Skimming the head is only for NA tuning guys. With FI you want lower compression, not higher.

1.6 engines tend to be able to hit the same peak figures as 1.8s but take a bit more work to get there.
The clutch will probably need upgrading before long (though mine has somehow lasted 4 years/40k miles).
Gearboxes & difs tend to be fine up to very high power.
On Mk1s 1.6 brakes could do with an upgrade to 1.8 brakes. Not sure if there is a difference between 1.6 & 1.8 brakes on Mk2/Mk2.5.

Not many people put FI on Mk2/2.5 1.6. Most use the 1.8 as it's a better starting point. MX5 Nutz is the best place to ask these questions - I know there are a few with FI 1.6 Mk2+ on there.

WarrenG

341 posts

157 months

Tuesday 28th July 2009
quotequote all
Is this the right place for a Pedant?
They're all superchargers, just the so called 'turbocharger' is a supercharger driven by an exhaust turbine, rather than driven by pulleys or chain drive off the engine. Which is why they are more flexible, as they are not limited by the mechanical ratio of the engine's revolutions.

I like superchargers. *want*

crofty1984

14,561 posts

164 months

Tuesday 28th July 2009
quotequote all
MX-5 Lazza said:
Skimming the head is only for NA tuning guys. With FI you want lower compression, not higher.
Related to my previous thread, Am I right in thinking the stty late Mk1 1.6 has lower compression ratio?
Could I get a decent T/C result with one of these?
I'd like to get about 150 hp, then maybe up to 200 later on. Only thing is the later 1.6 models are about £1000-1500 cheaper than the early one/1.8 here

tuttle

3,427 posts

197 months

Wednesday 29th July 2009
quotequote all
crofty1984 said:
MX-5 Lazza said:
Skimming the head is only for NA tuning guys. With FI you want lower compression, not higher.
Related to my previous thread, Am I right in thinking the stty late Mk1 1.6 has lower compression ratio?

Could I get a decent T/C result with one of these?
I'd like to get about 150 hp, then maybe up to 200 later on. Only thing is the later 1.6 models are about £1000-1500 cheaper than the early one/1.8 here
Really enjoying this thread as I am seriously considering Fi'ing the 5 someday.
My experience of fettling with FI is limited to straight sixes not MX5's so feel free to flame me if I'm wrong here smile

A much simpler way to lower your compression & start out with a decent car in the 1st place, might be to lower compression by fitting a thicker, steel head gasket IIRC we would go in 0.2mm increments (1.0mm to 1.2mm).

MX-5 Lazza

7,952 posts

179 months

Wednesday 29th July 2009
quotequote all
WarrenG said:
Is this the right place for a Pedant?
They're all superchargers, just the so called 'turbocharger' is a supercharger driven by an exhaust turbine, rather than driven by pulleys or chain drive off the engine. Which is why they are more flexible, as they are not limited by the mechanical ratio of the engine's revolutions.

I like superchargers. *want*
Feel better for that? biggrin

For simplicity sake its easier just to say super or turbo charger rather than having to say belt-driven-supercharger or exhaust-driven-turbine-supercharger. Thanks for the English lesson though wink

Odie

4,187 posts

142 months

Wednesday 29th July 2009
quotequote all
tuttle said:
crofty1984 said:
MX-5 Lazza said:
Skimming the head is only for NA tuning guys. With FI you want lower compression, not higher.
Related to my previous thread, Am I right in thinking the stty late Mk1 1.6 has lower compression ratio?

Could I get a decent T/C result with one of these?
I'd like to get about 150 hp, then maybe up to 200 later on. Only thing is the later 1.6 models are about £1000-1500 cheaper than the early one/1.8 here
Really enjoying this thread as I am seriously considering Fi'ing the 5 someday.
My experience of fettling with FI is limited to straight sixes not MX5's so feel free to flame me if I'm wrong here smile

A much simpler way to lower your compression & start out with a decent car in the 1st place, might be to lower compression by fitting a thicker, steel head gasket IIRC we would go in 0.2mm increments (1.0mm to 1.2mm).


You are correct, I used to work at a motorbike tuning shop and the bikes we used to setup for the track would have the head skimmed by about 1mm and fully flowed, including in some cases the grinding off of the valve stem guides, we would then fine tune the compression ratio using different thickness steel head gaskets. In some cases we would get handed a CNC'd head which would save use alot of work.. Just note though that the engines i used to work on where built for lots of power and a short life, they regularly used to drop valves and throw rods if they where used for too many miles before a rebuild.

OnlyMX5ives

1,142 posts

152 months

Wednesday 29th July 2009
quotequote all
Std 5's have a low enough comp ratio to run circa 250bhp on a completely std spec engine.

No point messing around with head gaskets etc.

crofty1984

14,561 posts

164 months

Wednesday 29th July 2009
quotequote all
OnlyMX5ives said:
Std 5's have a low enough comp ratio to run circa 250bhp on a completely std spec engine.

No point messing around with head gaskets etc.
Does that include the stty late MK1 1.6's? If I could get one of those for cheap enough (The early 1.6 and the 1.8 are about €1500 more expensive in Italy) and FI it to around 190-200 bhp without major work (other than the fitting of the actual turbo/SC kit) That could be an option for me.

OnlyMX5ives

1,142 posts

152 months

Wednesday 29th July 2009
quotequote all
TBH I avoid the 'low power' cars so don't remember what was done to them.

There have been big threads on them on the old OC site and Nutz.

IIRC the difference was solely in the head and I think they made more than they claimed.

I think the majority could be retrieved by simply fitting the earlier cams but I may be getting confused with the Auto engine.

A quick search should bring up all the info.

They still have loads of potential and if they have lower comp. then you won't have to pull as much timing.

maz8062

959 posts

175 months

Wednesday 29th July 2009
quotequote all
There's a Portugese poster on Nutz currently running 200bhp with a Greddy turbo, Link ECU, bigger injectors etc etc. This is on a 90bhp late mk1 1.6. - For comparison I'm running circa 250bhp (15 psi of boost) on a 1990 1.6 with the same turbo.

MX-5 Lazza

7,952 posts

179 months

Wednesday 29th July 2009
quotequote all
OnlyMX5ives said:
TBH I avoid the 'low power' cars so don't remember what was done to them.

There have been big threads on them on the old OC site and Nutz.

IIRC the difference was solely in the head and I think they made more than they claimed.

I think the majority could be retrieved by simply fitting the earlier cams but I may be getting confused with the Auto engine.

A quick search should bring up all the info.

They still have loads of potential and if they have lower comp. then you won't have to pull as much timing.
I thought the lower power 1.6 also had differences in the head so they didn't flow as well as the early engine as well as the different cams meaning it's better to just swap the head for one off an earlier 1.6 but that still doesn't get all the power back.
The auto has lower compression pistons - not sure if the low power car has the same pistons, unique but still lower compression pistons or whether they are just the same as all other manual pistons.
Do they have the oil-spray cooling under the pistons like all other MX5s do?

taff7996

2 posts

134 months

Friday 23rd October 2009
quotequote all
OnlyMX5ives said:
Hopefully this doesn't break forum rules...

But I sell used SC kits from £995

I fit them for £245

Really you also need timing retard control - from £50.

You may need an uprated pump £95.

Bad news is they don't come up that often (I have one Mk1 1.6 one at the minute).

I can also supply new kits but only for slightly less tham Moss Europe.

However I will fit any SC kit - new or used whether I supplied it or not.

I just enjoy making the little buggers faster !

biggrin
Keep me in mind if and when you get one in for a 1.8 (AC & PS)

Merlot

Original Poster:

4,121 posts

168 months

Friday 23rd October 2009
quotequote all
taff7996 said:
OnlyMX5ives said:
Hopefully this doesn't break forum rules...

But I sell used SC kits from £995

I fit them for £245

Really you also need timing retard control - from £50.

You may need an uprated pump £95.

Bad news is they don't come up that often (I have one Mk1 1.6 one at the minute).

I can also supply new kits but only for slightly less tham Moss Europe.

However I will fit any SC kit - new or used whether I supplied it or not.

I just enjoy making the little buggers faster !

biggrin
Keep me in mind if and when you get one in for a 1.8 (AC & PS)
You might be waiting a long time, it has been 4.5 months since I asked and I've not yet had an email!! I'm selling the '5 now though, so you can have my place!!!! wink