engine ideas take 2

[Moggy]

Have you actually done this swap Warpspeed? I'm just asking as there are a couple of things in your post that confuse me. You mention fitting the mx5 distributor as the GTX one won't fit. The mx5 runs coil packs though not a dizzy so I assume that is what you meant. You also suggest fitting the GTX ecu, but this only has one ignition trigger while the mx5 coils need two to work. How do you get around this?

I personally think there are benefits to fitting the GTX engine instead of turboing the B6. If you fit the B6T you get the stronger rods, lower compression, bigger injectors and oil feeds with an engine designed to have a turbo. If you fit the BPT it is more awkward but if you source the parts first you get the benefit of bigger displacement along with the lower compression and bigger injectors.

There is no doubt it is a lot more work to change the engine to a GTX one but I think it sets you up better for future modifying.

To anyone doing this conversion I would recommend getting the engine only, without the loom and ecu, and not in a half cut...

[sabretooth]

IMHO it's not a good idea if the engine and ECU's going to cost you an arm and a leg. It's a great way of getting a block and selling bits off (as I did - linked in my sig). Also, if you want to do some power upgrades, you'll probably ditch the ECU in favour of something aftermarket anyway.

The NA BP block has the same coolant and oil feed lines as the turbo BP block. It's not any more or less awkward as the lines are all there - they're just blanked off. See here. That's my Familia block with the MX-5 stuff swapped onto it. Turbo and non-turbo cams may be the same but they bear different part numbers. I haven't yet established why and don't know how to measure camshaft lift etc.

Unless you're buying a new engine, I'd have some big questions about an import engine that's been sitting around for how long. Also, the GTX flywheel is huuge. It's a rather significant rotating mass. Me, I tossed the old clutch, flywheel and pressure plate. Will a clutch designed for the FWD/AWD Familia gearbox fit to an MX-5?

In any event, I would say that if you really want to purchase another engine, start with an MX-5 engine, get an AVO/GReddy kit, stick that on, drill the oil return in the sump, use the feed from the block that the Familia uses. Get an ECU such as a Haltech, Link, Hydra or Megasquirt and use that. And seeing as you now have 2 MX-5 engines, you'll have sufficient bits and pieces to use as spares such as coil packs, CAS, sump, etc.

I think that using a Familia engine with the included turbo etc is going to leave you with a crappy, ugly setup which you'll face difficulty upgrading easily - and you still won't have enough MX-5 engine bits to sell off the original engine as a complete item. That's an expensive way to get lower CR pistons, some injectors and an ECU you can't tune.

[Moggy]

IMHO it's not a good idea if the engine and ECU's going to cost you an arm and a leg. It's a great way of getting a block and selling bits off (as I did - linked in my sig). Also, if you want to do some power upgrades, you'll probably ditch the ECU in favour of something aftermarket anyway.

I understand what you are saying but I think a GTX engine is a better starting point for modifying than an mx5 engine. If you just want a basic turbo setup then you are probably better off using the existing engine. But if you are intending to go a bit further than that then starting with a GTX block is the go IMO.

A GTX engine can be had for about $1200 (and you would only get the engine, you don't need the ecu or loom etc) and this isn't much when you are going to have to buy an aftermarket ecu, turbo, heavy duty clutch, exhaust manifold, radiator, diff, intercooler and piping and lots more. So for this level of modification it is not too much effort or money to put in a more turbo friendly base engine.

I guess it all depends on how much power you are after...

Also like you said you would ditch the GTX flywheel, clutch, exhaust manifold and turbo.

[sirbob]

Why bother fighting with the GTX? Just do the stock motor with a small turbo or bite the bullet and go SR20DET, if your talking about full engine swaps, and the like, then you may as well go the whole hog...

I dont know much about nissans, but these motors seem to really go seriously hard...

But for the sake of dreaming...

I would really love to see a rotor in my mx5... An almost impossible task, but hey, at least then the car is still a MAZDA and not a Nisda-Frankenstien half bred monster!

[kitkat]

I would really love to see a rotor in my mx5... An almost impossible task, but hey, at least then the car is still a MAZDA and not a Nisda-Frankenstien half bred monster!

what planet have you been on bobby??? the rotor conversion is always being done... ive seen one on the gold coast not to long back aswell.

about the sr20 in an mx5, the red mx-5 at dutton had an sr20 init and it was blisteringly fast... ill post up footage when i get the chance.

[Sean]

If you want to stay Mazda then why not get a FE3? They are good for 400 ish bhp.

I'd not bother if you're only chasing 400hp - Plenty of B6 and BP cars making 400 at the wheels


As for teh rotaries, ther's at least two members on here with them...

[Woo]

300 kw is pretty big at the wheels Sean
Are they in Australia?
What sort of specs?

It seems like a lot of work modding an FEDOHC to fit when/if a BP/6 will do the task.

Wòó

[Sean]

300 kw is pretty big at the wheels Sean
Are they in Australia?
What sort of specs?

It seems like a lot of work modding an FEDOHC to fit when/if a BP/6 will do the task.

Wòó

It's not particularly cheap to get 400hp - but it's basic and straight forward - Much easier than custom fabicating the gear required to fit an FE into an MX5.

AFAIK there are 2 FE3 MX5's in Australia, I've personally met and discussed the conversion with one of the owners, he is pushing about 400hp, but has had just about every part of teh engine replaced, rods, pistons, machined crank, BIG turbo etc.

When you add up his costs, betting Flyin Miata to build you one of thier 2 litre BP engines would be a cheaper option - It would also be a direct bolt in cause it's still a BP block...

The FM setup has the goods to handle well over 400hp.

To my knowledge there is only 1 possibly 2 in Australia that have made this sort of power from a B series mazda engine - but it has been done...

In teh US 400hp is often achieved from B6 and BP engines, there's actually quite a few B6T cars running STOCK bottom ends in the US making over 400hp... Stock bottom ends, ported and valved heads, BIG turbos.

Really though, it's a futile arguement, once you get over 250ish hp in one of these cars, there is no real need or use for any more power...

http://www.cardomain.com/ride/354836

[Woo]

Really though, it's a futile arguement, once you get over 250ish hp in one of these cars, there is no real need or use for any more power...

http://www.cardomain.com/ride/354836

Thats one hell of a kick ass MX3
Lotta money and time spent there. Is that a T6 ? It'd be really lazy down low but when it wound up it'd be fingernails in the steering wheel time

225 is fun, 250hp would be a blast.
Wouldn't it be difficult not to keep turning up the boozt? Getting traction would definately be a problem, but once there it'd be ballistic.

[Moggy]

I'd not bother if you're only chasing 400hp - Plenty of B6 and BP cars making 400 at the wheels


As for teh rotaries, ther's at least two members on here with them...

I agree with the not bothering bit. Personally I wouldn't bother trying to install a FE3 either, but moggy seems determined to do a lot of unnecessary and expensive work to his car by doing an engine change, so I just added another possibility to his list.

Me?

I'm not thinking about changing my engine - I've already done it. It probably cost me an extra $1200-$1500 over just fitting a turbo, with the benefits I've outlined in earlier posts, plus a displacement increase from 1.6 to 1.8...

I was originally intending to put an SR20det in but I calculated this out as being around $3000 or so more and a LOT more work (I did it all myself) so I went with the BPT. And I'm very happy with it, as it produces over 2 1/2 times the power of the standard engine, and spools up quite early thanks to the fairly big but light turbo I put on.