Performance upgrades

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Snoggledog

Original Poster:

7,073 posts

218 months

Sunday 15th June 2008
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Apologies if this is becomes a long post but here goes.

The chaps at P5 (Steve) and I have been thinking about doing something to the old girl to help her move a bit better. At the moment it's running the good old faithful 1.6 4 pot but in all honesty it's a bit, well, weedy. So... Both Phil & Steve reckon that turbos are the best way to go for a 1.6 as the supercharger technology has only really been made to work effectively on the 1.8.

At this point I have two options. Slap a turbo on or change engines (to the 1.8) and put on a supercharger. TBH , I've never really been keen on a turbo as I've heard all the old stories about lag and my old car had a supercharger which I liked... A lot. So that means an engine change.

This is where the discussion started to head into the realms of fantasy a little.... Ok.. So if I'm going for an engine change why not go the whole hog and put in something different. Does it have to be a 4 pot Mazda block? Well, according to Steve the answer is no. Within reason it can be almost anything I want.

V8 conversion? This isn't my favourite as I don't think that it goes with the car. The engine needs to fizz rather than thump, so that idea is quickly binned..... Unless I can get hold of a V8 with a flat plane crank which does fizz.... Which means I have to buy something like TVR / Ferrari blocks. Could be pricey.

V6 conversion? Fizzy engine. Mazda make one as do Peugeot. Ok so I might have problems with the drive as it's transverse as opposed to longtitudenally mounted.

Straight 6? Nice sound and plenty of power.. BMW (M) engine or TVR Speed 6.

Flat 6? Old 3.2 911 engine?

OK.. So a flat plane V8 will cost the earth to buy but will almost certainly be any alloy block so won't screw the weight distribution up too much. The V6 would end up being longer (fractionally) than the 4 pot that I currently have. But again I believe that these are alloy blocks. The straight 6 on the other hand is likely to be weighty (and longer) and therefore upset the balance to a degree. The flat 6 might potentially be a major headache as the gearbox (we think) is mounted in front of the engine.

So does anyone have any thoughts? Is there any experience out there? Please don't say mx5oc.

Caveat. This is fantasy land and is based on the fact that I've just won the lottery (No I haven't)

anonymous-user

55 months

Sunday 15th June 2008
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Well, the first thought is that a 1.8 swap is very simple as the engine mounts are available to mount it to the exact same subframe, gearbox is the same, etc. etc. Any other engine will need fabrication which will put the cost up. AJP V8 engines can be had for a few grand and are fab engines IMHO. Not sure about physically fitting one into the engine bay though.

If it were me, it'd be a rotary. Get the weight down and even more centralised, revs to buggery and makes good power. NA 13B can see 280bhp ish IIRC, turbocharged the sky's the limit.

Snoggledog

Original Poster:

7,073 posts

218 months

Sunday 15th June 2008
quotequote all
LexSport said:
Well, the first thought is that a 1.8 swap is very simple as the engine mounts are available to mount it to the exact same subframe, gearbox is the same, etc. etc. Any other engine will need fabrication which will put the cost up. AJP V8 engines can be had for a few grand and are fab engines IMHO. Not sure about physically fitting one into the engine bay though.

If it were me, it'd be a rotary. Get the weight down and even more centralised, revs to buggery and makes good power. NA 13B can see 280bhp ish IIRC, turbocharged the sky's the limit.
I've been warned off Rotary as apparently it's an absolute pig to fit. But considering that I was looking at pretty much anything other than a 4 pot, it's back on the list thumbup

MX-5 Lazza

7,952 posts

220 months

Sunday 15th June 2008
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Are you looking for suggestions about conversions that others have done before or purely fantasy-land?
For existing conversions, the best place to look is miata.net. Most conversions that are realistic have been done over there before.
I'm not so keen on rotary conversion myself as while it does give a good weight saving, the stock MX-5 has close to 50-50 weight balance and all the saved eight is from the front so that will spoil that weight balance, moving the centre of balance backwards making it much trickier at the limit.
Similarly, heavier engines will move the weight balance forwards which will encourage understeer = no fun.

So really you will need an engine that will fit in the engine bay but isn't too much different in weight from the Mazda lump.

I like the sound of a V6 - Alfa V6 is superb but I have no idea if that's feasible (probably not).

How about - a Mazda 1.8 with an intercooled MP62 supercharger? It'll be as powerful as most other engines that fit and without having to chop up the engine bay!

Snoggledog

Original Poster:

7,073 posts

218 months

Sunday 15th June 2008
quotequote all
MX-5 Lazza said:
Are you looking for suggestions about conversions that others have done before or purely fantasy-land?
TBH, a bit of both. I've never been particularly good at doing the same as everyone else.
MX-5 Lazza said:
For existing conversions, the best place to look is miata.net. Most conversions that are realistic have been done over there before.
Ok. Thanks. Will have a look there. At the moment it's just getting a feel for what's possible. Hence why I was speaking to Steve. He seems fairly in favour of the S6 idea.
MX-5 Lazza said:
I'm not so keen on rotary conversion myself as while it does give a good weight saving, the stock MX-5 has close to 50-50 weight balance and all the saved eight is from the front so that will spoil that weight balance, moving the centre of balance backwards making it much trickier at the limit.
Similarly, heavier engines will move the weight balance forwards which will encourage understeer = no fun.
Yeah.. That's the problem I'm trying to grapple with. It's a cracking little car with brilliant handling and I'd like to retain that if I can.
MX-5 Lazza said:
So really you will need an engine that will fit in the engine bay but isn't too much different in weight from the Mazda lump.
And that's where I think the challenge will lie.
MX-5 Lazza said:
I like the sound of a V6 - Alfa V6 is superb but I have no idea if that's feasible (probably not).
I think, although don't hold me to this, that the Alfa V6 is a cast iron block with an alloy head. So could be a tad weighty.
MX-5 Lazza said:
How about - a Mazda 1.8 with an intercooled MP62 supercharger? It'll be as powerful as most other engines that fit and without having to chop up the engine bay!
Yeah.. But that's the sensible option and the one that I'll probably end up doing. frown


I just mentioned the idea to my wife.... Her initial reaction was "Are you trying to kill yourself?", but when I mentioned the idea of the Speed 6 with a couple of Tuscan cherry bombs a smile crossed her facewink

If I had free reign and a bottomless pit of cash I'd like a sleeper that instills fear in other drivers, growls, barks and spits flames at passing BMW's

iguana

7,044 posts

261 months

Sunday 15th June 2008
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My 1.8 had little turbo on it, spooled up very low & was pretty lag free, litle turbo so much lower power than the big buggers, all except the turbo soundtrack it felt like a nce torquey 3 litre n/a engine.

I ran the stock injectors so was a bit limited to under 200 but should potentially have been touch over that if I changed them (& re-mapped to suit) new owner is planning that so will be interesting to see how he gets on.

I like superchargers too but my turbo was pretty darn good.

anonymous-user

55 months

Sunday 15th June 2008
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This would go some! scratchchin

skinny

5,269 posts

236 months

Sunday 15th June 2008
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i know you're just dreaming about what could be at the moment but before you go too far down that road, i'd try and get a passenger ride in an FM2 1.6

then if you don't fancy it, what about scooby flat 4 or jap(lexus soarer or something) V8? biggrin

kevham

118 posts

274 months

Sunday 15th June 2008
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I know you've said you don't want a four-pot but for me the engine of choice would be the Cosworth YB from the Sierra RS turbo and 4x4.

Turbocharged you can get to 500+ bhp - albeit with a little lag ;-)
But you can also take it back to N/A and get over 200bhp.

It has been done in an MX-5 before!

Herman Toothrot

6,702 posts

199 months

Sunday 15th June 2008
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To get 500bhp from a cosworth lump it'd need a rebuild, if you rebuild the 1.8 mazda lump you can get 500bhp+

576 whp (about 600@ the flywheel) at 29.6psi

0 - 60 in 2.35sec


Snoggledog

Original Poster:

7,073 posts

218 months

Sunday 15th June 2008
quotequote all
LexSport said:
This would go some! scratchchin
You sir are a bad bad man hehe (Hunts behind cushions to find winning lottery ticket)


Arghh... You're all trying to tempt me with too few cylinders. biggrin

I know that some people (P5 included) have been pushing out silly, even mad BHP & Torque figures. Steve's is pushing out something like 325 bhp & over 300 ft lb of torque from a 1.8; so I know it can be done. I'm not knocking the Mazda 4 pot and all the equipment that can be bought to enhance it. It's a cracking engine. The Cosworth is a novel idea and one that I'll think about. The Fiat twin cam (a la Lancia Delta Integrale) could also be worth a look if I went down that route.

But.. I'd like more cylinders. If I could live in cloud cookoo land I'd have one of these...



1.5 litre. Blown.. 600+ bhp. Granted. Economy might take a small hit. Read gallons per mile and the HSE might have something to say when it can be heard 5 miles away.

In an ideal world I'd like to avoid forced induction as I feel (incorrectly I might add) that an engine should be able to stand on it's own merit and not need to be pushed.

But. Great ideas all. Keep 'em coming. thumbup

GravelBen

15,695 posts

231 months

Sunday 15th June 2008
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http://www.pistonheads.com/gassing/topic.asp?h=0&a...

smile A previous discussion on V6 conversions - its been done but wasn't particlarly easy, I think the Mazda V6 would still be one of my choices in a lotto-win situation.

Rotaries are compact but are actually not that light at all. And besides, would you really want your MX5 to sounds like a chainsaw?


Edited by GravelBen on Sunday 15th June 22:48

Snoggledog

Original Poster:

7,073 posts

218 months

Monday 16th June 2008
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GravelBen said:
http://www.pistonheads.com/gassing/topic.asp?h=0&a...

smile A previous discussion on V6 conversions - its been done but wasn't particlarly easy, I think the Mazda V6 would still be one of my choices in a lotto-win situation.

Rotaries are compact but are actually not that light at all. And besides, would you really want your MX5 to sounds like a chainsaw?
Thanks for that link. Hadn't considered it would be something that had been discussed on PH. I tend to agree with you regarding the rotary engine. My other concern it rotor tip wear and the maintenance associated with it.

Munter

31,319 posts

242 months

Monday 16th June 2008
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I'd be tempted by the high revving Honda engines. Still NA. Still have to rev it to get the best out of it.

GravelBen

15,695 posts

231 months

Tuesday 17th June 2008
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On the topic of superchargers, a thought occurred to me today:

Why not use the supercharger from a Toyota 4AG-ZE 1600? (Came from the factory in the Mk1 MR2 and various versions of the Sprinter Treuno/Corolla Levin). Surely it can't be that hard to find a way of mounting it, and where I am anyway they're readily available second-hand for around $200NZ (compared to $2.5-3k for a basic Greddy MX5 turbo kit).

Anyone know of it being done, and if not any particular reason why? It wouldn't be the best option for big power but should see 180 bhp easily easily enough.

Snoggledog

Original Poster:

7,073 posts

218 months

Tuesday 17th June 2008
quotequote all
GravelBen said:
On the topic of superchargers, a thought occurred to me today:

Why not use the supercharger from a Toyota 4AG-ZE 1600? (Came from the factory in the Mk1 MR2 and various versions of the Sprinter Treuno/Corolla Levin). Surely it can't be that hard to find a way of mounting it, and where I am anyway they're readily available second-hand for around $200NZ (compared to $2.5-3k for a basic Greddy MX5 turbo kit).

Anyone know of it being done, and if not any particular reason why? It wouldn't be the best option for big power but should see 180 bhp easily easily enough.
thumbup Added to the pot of ideas. When my tame techie gets back from his holidays I'll see what he has to say.

(Personally if I go down the route of forced induction I'd prefer a supercharger over a turbo)

GravelBen

15,695 posts

231 months

Tuesday 17th June 2008
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Snoggledog said:
GravelBen said:
4AG-ZE supercharger
thumbup Added to the pot of ideas. When my tame techie gets back from his holidays I'll see what he has to say.

(Personally if I go down the route of forced induction I'd prefer a supercharger over a turbo)
yes Same here (not a fan of lag), I'm starting to think quite seriously about that supercharger idea myself actually so let me know if you find out anything useful about it.

But its a case of first things first for me - this weekend I'm (all going according to plan) mounting a 4-point rollbar into mine and replacing the gearbox gaiters, also found a well-priced shortshift kit for it which I'll install at the same time smile

MX-5 Lazza

7,952 posts

220 months

Tuesday 17th June 2008
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Does that supercharger come with a bypass? That's the main reason we don't use the MINI supercharger; finding a way of mounting would be relatively simple but designing in a bypass would be a royal pita.

Munter

31,319 posts

242 months

Tuesday 17th June 2008
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I'd have thought a 2nd hand jackson racing kit would be just as cheap and easier to fit than playing with a supercharger from the MR2.

GravelBen

15,695 posts

231 months

Tuesday 17th June 2008
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MX-5 Lazza said:
Does that supercharger come with a bypass? That's the main reason we don't use the MINI supercharger; finding a way of mounting would be relatively simple but designing in a bypass would be a royal pita.
Not sure about a bypass, I don't know a lot about them tbh. Apparently they have an electromagnetic clutch in them so only drive when they're needed, but more research is needed I think smile