Torsen is a good choice - 91 V spec would have the weaker viscous diff , being a 1.6
Mx5 mechanicals just dont break or wear out - so just because the bodies rust they are getting killed off at an alarming rate
Evening all, well it looks as though ill be venturing back into building another kit. Im currently perusing donor cars. Seeing as though I'm not
particularly clued up about mx5's i thought id ask the collective.
Anything in particular to keep an eye open for? Its going to be a mk1 or 2. I believe the early 1.6 is the best lump to go for if forced induction is
anticipated is this correct? If so why better over the 1.8 which offers 15bhp more in stock format?
Diffs, again i believe there is several different variants. In a 7 style is the Torsen the one to go for?
Ive found a '91 1.6 eunos type v locally that im going to hopefully see over the weekend.
Any pointers gratefully received!
Steve
What are you building ?
Bigger brakes are a bonus with the carriers fetching a premium. Mk2 has slightly different geo with the rear uprights giving a few mm extra track and
the front upright steering arms place the track rod ends 7mm different to the mk1. This is said to be desirable for a Haynes roadster.
Get the key for the steering lock as there not as cheap or easy to replace as ford.
I know nothing about engine / box or diff except I keep tripping over the diff in the garage. Oh talking of diffs I doubt they are any good for a Bec
as the one have is 4.1:1
Looking like an MNR vortx mazda, I'm heading down to the factory next week to have a nosey and no doubt leave a deposit.
If you're looking at a 1.6, Google 'short nose crank' as it's a potential engine killer.
There's not much overall difference between the 1.6 and 1.8 though, the 1.6 seems more eager as it spins up quicker, but the 1.8 has a bit more
torque. But you're right, for some reason the 1.6 is a better preference for FI, lower compression I think?
Keep the donor earlier than a 95 in order to register on an age related plate but avoid emissions.
Don't pick a special or limited edition over a standard spec, they rarely give any extra value especially as donor parts. My own 'V Spec
limited edition' turned out to be the second most common import!!
Get friendly with your local Mx5 breakers , and just buy the bits you need , rather than breaking a perfectly good car since most mechanical parts are
just not in demand to anyone with a Mx5........ And remember , any Mk1 you buy will be 25 years old - so whatever it left the factory with , may well
have been changed several times over .
Torsen is a good choice - 91 V spec would have the weaker viscous diff , being a 1.6
Mx5 mechanicals just dont break or wear out - so just because the bodies rust they are getting killed off at an alarming rate
quote:
Originally posted by clairetoo
Get friendly with your local Mx5 breakers , and just buy the bits you need , rather than breaking a perfectly good car since most mechanical parts are just not in demand to anyone with a Mx5........ And remember , any Mk1 you buy will be 25 years old - so whatever it left the factory with , may well have been changed several times over .
Torsen is a good choice - 91 V spec would have the weaker viscous diff , being a 1.6
Mx5 mechanicals just dont break or wear out - so just because the bodies rust they are getting killed off at an alarming rate
You can pick up a shell and V5 for free any day - plus you will probaly not use the brakes (1.6 are tiny) , the diff (to get a strong torsen you will
need 1.8 parts - diff , prop and drive shafts) or the engine (early 1.6 short nose cranks are a major pain.....)
[Edited on 22/5/15 by clairetoo]
The drive shafts can be hard to get out and the bolt through the lower rear upright can be very hard to move as well. See Coozers midlana thread.
quote:
Originally posted by sdh2903
Fair point but as i will be using eng, box, hubs, brakes, diff, shafts, column and probably part of the loom its just more sensible to get a donor car especially as i'd like an age related plate so need the V5.
The one i'm looking at is only 400 quid but the body is rusty, has a decent ish hood, leather interior and a bluetooth stereo so I anticipate getting a few quid back for the bits i dont need.
quote:
Originally posted by big_wasa
The drive shafts can be hard to get out and the bolt through the lower rear upright can be very hard to move as well. See Coozers midlana thread.
As it goes the 1.8 lump is the engine of choice for turboing. 1.6 was derived from the 323 GTX so was kind of designed for a turbo which is why some
places will say its preferable but the 1.8 will make better power more reliably. You also get the bigger clutch and diff which is needed even for a
1.6 turbo conversion.
Plenty of info to glean from miataturbo.net
I have a 1.6 turbo in mine. 
Cheers
Stot
I happen to have a Mk2 sport and a Mk2.5 (both 1.8) available if your looking...I also have some parts I've been collecting to turbo one of
them...give me a shout if of any use to you.
[Edited on 22/5/15 by G-sport]
quote:
Originally posted by G-sport
I happen to have a Mk2 sport and a Mk2.5 (both 1.8) available if your looking...I also have some parts I've been collecting to turbo one of them...give me a shout if of any use to you.
[Edited on 22/5/15 by G-sport]
I'm in Nuneaton, Midlands..
I'll U2U with details..
Yep, I've had the rears in the electrolysis bath 3 times and can't remove the bolts or one of the driveshafts.....
More cutting, drilling etc I reckon....
How you planing on getting the drive shaft out ?
quote:
Originally posted by coozer
Yep, I've had the rears in the electrolysis bath 3 times and can't remove the bolts or one of the driveshafts.....
More cutting, drilling etc I reckon....
Just a quick question regarding engine choices, I see there is an mx5 mk2.5 facelift which came with a different vvt version of the 1.8 lump. Are
there any differences to the exterior of the engine for mounting and fitment etc? I beleive this is the engine that roadrunner fitted the ITB's
to for 178bhp.
Also does this engine still take forced induction OK if thats the road i end up going down?
Thanks for all the replies
Steve
As far as I can see the engines are physical interchangeable and yes it's fine for boost too.
Hi its the mk2.5 1.8 with vvt. that i have used with a mini sc still building at mo but had it running see my build thread in haynes section or in
photo archive . I love yhe sound of it its running on std ecu for now till i upgrade that !!!!
Gary
[Edited on 24/5/15 by garyt]
Gary, Did you ever update your ecu? I am looking at options for a 1.8 vvt engine.
Simon
quote:
Originally posted by sdh2903
Evening all, well it looks as though ill be venturing back into building another kit. Im currently perusing donor cars. Seeing as though I'm not particularly clued up about mx5's i thought id ask the collective.
Anything in particular to keep an eye open for? Its going to be a mk1 or 2. I believe the early 1.6 is the best lump to go for if forced induction is anticipated is this correct? If so why better over the 1.8 which offers 15bhp more in stock format?
Diffs, again i believe there is several different variants. In a 7 style is the Torsen the one to go for?
Ive found a '91 1.6 eunos type v locally that im going to hopefully see over the weekend.
Any pointers gratefully received!
Steve
There are some points on which you are mistaken;
not all Roadsters have LSDs - they were an extremely popular option, but were not a standard fit
the 6 speed box is stronger than the 5 speed according to the guys running big power (AK Automotive's turbo car being one)
the only viscous LSD was the pre 1993 4.3:1 with a smaller CWP assembly, afterwards it was Torsen/Torsen based, the most common ratio being 4.1:1
In 1994 the 1.6 was dropped in Japan in favour of the 1.8, in the UK both engines were offered with the 1.6 being detuned to the 90bhp. The oil spray
you mention is the piston oil squirters.
quote:
Originally posted by S_D_C_2000
Gary, Did you ever update your ecu? I am looking at options for a 1.8 vvt engine.
Simon
quote:
Originally posted by PorkChop
There are some points on which you are mistaken;
not all Roadsters have LSDs - they were an extremely popular option, but were not a standard fit
the 6 speed box is stronger than the 5 speed according to the guys running big power (AK Automotive's turbo car being one)
the only viscous LSD was the pre 1993 4.3:1 with a smaller CWP assembly, afterwards it was Torsen/Torsen based, the most common ratio being 4.1:1
In 1994 the 1.6 was dropped in Japan in favour of the 1.8, in the UK both engines were offered with the 1.6 being detuned to the 90bhp. The oil spray you mention is the piston oil squirters.
My wife has a Eunos automatic and it has an open diff.
I built my special sevenesque using a long nose 1.6 of unknown age as it was a Jap import engine. It also has a viscous LSD and HSK turbo with
Aquamist water injection.
It goes very well and is instant and feels like a large engine with loads of torque and no lag.
The MX5 is a perfect donor methinks.
Beware, a lot of people will try and convince you all JDM cars had an LSD this is BS You'll be surprised how few actually have an LSD. UK spec only had them on a few limited editions, in Japan they were an expensive option so not that many people bought them. Up to '93 the original V spec had a 4.3:1 VLSD but they don't work the way you expect and a lot of people think they are duff. '94 and '95 some 1.8s had the torsen 1 but Mazda considered it made the car too lively and from '96 they fitted the Torsen2. Its not s straight swap to fit one as you'll need the matching driveshafts and propshaft as well as the diff which usually commands a decent price.