borka

iTrader: (1)

For a gt2560r forget about pistons, arp studs, oil pump, head job...

just get ANY rods, even eBay rods, new rings bearings and seals, with a hone and mazda head gasket. Done.

this is exactly what I have and I pushed my 2560 to 17-18 psi with zero problems and zero oil consumption.
Did 4000 miles, 2 track days and 4 autox events with zero issues.

I have about $700 in my block, it held 264hp with zero issues.

with the money you have left over buy an ms3 ecu and proper 640cc ev14 injectors.

Mazdaspeed_Miata

Thanks for this chart but of course I know that more displacement results in more power and especially in earlier higher TQ and HP. That don't need to be discussed.

I am driving a 300whp 2.0l Turbo hot hatch as my daily and of course this pushes so much earlier than my miata does. The miata has a total different engine characteristik but I like it a lot that its get stronger and stronger with every rpm.



As displayed in my dyno chart above it gains power till the limiter above 7000rpm.

Again, if I would change to BP engine I would need to buy a new exhaust manifold and downpipe, need a different ECU etc etc...don't want that.

I have already written that in my second reply but it looks like that there are no build NA6 engines in the US. :(

I just hoped to get some answers to my questions written down in the first post...

Monk

iTrader: (3)

You did get answers to all of those questions.
Perhaps you didn't read anything you wanted to hear?
Upgrade rods and rehone.
Everything else is unnecessary and futile if you aren't going to properly tune what you have.

18psi

iTrader: (76)

Bastian,
You seem like a smart guy so I'm going to be really honest with you.
You have bad plans and plan to waste a ton of money on a garbage engine, because you want to save a fraction of the cost retaining parts that fit this crappy engine. You came here hoping we would tell you the plan was good. We won't. We don't lie around here

It's not just about displacement. It's about head flow, manifold flow, everything.

If you are required by law to have that engine, then ok. But if not, then don't waste money on it.

It only feels like it makes lots of topend power because it makes little down low. Compared to the newer BP's its worse everywhere. Compared to other modern engines its a complete turd.

Mazdaspeed_Miata

Ok guys, you won't stop preaching the NA6 is "garbage".
Propably it is really much worse than a BP or modern engine. But that is not surprising, because the design of the NA6 is more than 30 years old, so of course it can't be that good like more modern or modern engines. Because the development moves on. My EMU is also far also not that good like the latest stand alone ECU. Thats also not surprising.

BUT: As written, I like the current engine characteristik of my NA6 a lot, because it is NOT ONE OF THAT MODERN ENGINGE, that kicks your *** at around 2000rpm, and runs out of power at higher RPM. It is more like an N/A engine, that always needs to keep at high rpms.

As the post #20 shows, the BP characteristic with T25 in comparison to the NA6 with T25 is totally different.

While my current set up reaches his max. hp at the limiter (7200 rpm), the BP with T25 (like shown in post #20) reaches his max. hp at around 5500 rpm, holding this maximum till 6000 rpm, and then start losing power with every rpm.
Of course the areas under the graphs of the BP engine are a lot of bigger than the areas of the NA6 engine, which means that it is stronger in total, especially at lower rpms, but again, I like the characteristic of the NA6 far more, although it is accelerating slower.

In the fact that I am using my miata 100% for pleasure and NOT for winning any trophys, the total amount of areas under the graph is not that impoertant.

But to be honest, I don't know how the characteristic of my current NA6 set up with GT2560R will change, if I increase the boost from 9,5psi to 19psi.
I am pretty sure, the graph will more looks like the BP graph from post #20 because the turbo will run out of efficiency at higher rpms, so the power can't increase till the limiter.

But because of you are also preaching it is not economically to upgrade my engines with forged pistons, lets compare three scenarios:

1st: only upgrade rods, bearings and new rings and rehone cylinder

working hours:
- engine needs to take out
- bottom end needs to get stripped completely
- piston and old rods need to take apart
- old pistons needs to get cleaned
- assembling old pistons with new rings and new rods
- assembling bottom end and head
- put engine in

material / engine builder:
- head gasket 50$ stock / 100$ cometic
- head screws/studs 120$ stock / 120$ ARP
- main studs ARP 100$
- plan head and block 150$
- flexhone cylinder 50$
- new oem rings 200$
- forged rods 400$
- acl rod bearing 50$
- acl main baering 80$
- new timing belt, gaskets and seals (like oil pan, valve cover, intake/exhaust manifold etc) 300$ (?)

TOTAL = ~ 1550 $ + a lot of work




2st: upgrade rods AND pistons, bearings and new rings and rehone cylinder

working hours:
- engine needs to take out
- bottom end needs to get stripped completely
- assembling new pistons with new rings and new rods
- assembling bottom end and head
- put engine in

material / engine builder:
- head gasket 50$ stock / 100$ cometic
- head screws/studs 120$ stock / 120$ ARP
- main studs ARP 100$
- plan head and block 150$
- bore and hone cylinder 250$
- forged pistons 600$
- forged rods 400$
- acl rod bearing 50$
- acl main baering 80$
- new timing belt, gaskets and seals (like oil pan, valve cover, intake/exhaust manifold etc) 300$ (?)

TOTAL = ~ 2200 $ + a lot of work



3st: upgrade to BP engine, new pistons and rods, bearings and new rings and rehone cylinder

working hours:
- search for a BP engine and pick it up
- NA6 engine needs to take out
- BP bottom end needs to get stripped completely
- assembling new pistons with new rings and new rods
- assembling bottom end and head
- put BP engine in
- integrate downpipe to current 3" FM exhaust
- integrate BP engine to my car, don't know if it also works with EMU?

material / engine builder:
- head gasket 50$ stock / 100$ cometic
- head screws/studs 120$ stock / 120$ ARP
- main studs ARP 100$
- plan head and block 150$
- bore and hone cylinder 250$
- forged pistons 600$
- forged rods 400$
- acl rod bearing 50$
- acl main baering 80$
- new timing belt, gaskets and seals (like oil pan, valve cover, intake/exhaust manifold etc) 300$ (?)
- new downpipe and new manifold 800$
- BP engine 800$
- BP conversion parts 200$

TOTAL = ~ 4000 $ + a lot of more work


Have I done any mistake in my calculation?

For me, option 2 looks like the most "economic".

Of course option 2 will never reach the efficiency of a BP set up.
But I have a bottom end thats good for 400rwhp (which not mean that I am planning to realize such an amount of power), so I never need to get worried about my engine and at the moment I don't need to touch the electronics/ECU.

Just a further "story". The current installed exhaust manifold is my 4th because the others were crap and cracked all the time. I am happy that Begi finally has sent me manifold, that has a durability of more than 3 month....
That is also a reason, why I don't want to start with a new BP manifold and downpipe. Moreover I like this bottom mount system. I don't know if there is a bottom mount exhaust manifold for BP engines available at the moment?!

I have some money left over, that I would like to spend in my miata, more concrete in my engine. It is also a many years dream of mine to totally renew and forge my own engine.

But there is some difference between 2200 and 4000$...

Maybe you can understand my thoughts a bit better now?

nitrodann

You cant be saved.

der_vierte

my BP engine was 250€ in RUNNING condition - even if it wasn't, if you rebuild anyway, get a cheap one.

i think turning up the boost that much with an EMU is going to be even more expensive than your option #2
and you end up with #3 anyways

18psi

iTrader: (76)

Agreed

viperormiata

iTrader: (24)

Don't give up. Maybe a hurricane will force him to change, like me :-)

Most cost effective route would be to fly to my house, buy my pre-built LNC 1.6 and return home with it in overhead storage.

Savington

iTrader: (31)

We understand your thoughts just fine. Don't insult us by assuming otherwise. You are about to make a bad decision and you're looking for our approval. You won't be receiving it. If you aren't going to heed the advice you ask for, I'm unsure why you felt the need to ask for it.

concealer404

iTrader: (3)

Scenario #1 sounds a lot better to me if you MUST do something. That way you can save $700 towards an eventual Scenario #3, or better yet, put the $700 towards real engine management.

Alternatively, presenting a BP swap as only costing $1800 more than the option that you're illogically wanting to do, really just makes a point FOR the BP swap. The end result will be at least $1800 better. Maybe even $5000 better.

But hey, if you're just looking for someone to agree with you and parrot your own ideas back at you, i'm your guy for that, too. Just tell me and i'll start doing it. I charge one Like Cat per post.

ryansmoneypit

iTrader: (6)

Just remember guys, in the last two years we get one retard like this, for three others who listen to good advice.

sixshooter

iTrader: (12)

.

Mazdaspeed_Miata

Ryan, stop offending or whats wrong with you?

Because really everybody in this thread is recommending to swap to the BP, I am thinking over it!

What exhaust manifold and downpipe would you recommend?
Also, what ECU would be the easiest one to handle?

It should be possible to control the BP engine with 1.6 ecu and EMU in beginning with the FM swap kit?

sixshooter

iTrader: (12)

The best ECU choice for the Miata is the Megasquirt. I recommend the MS3 Basic from MS Labs in Greece. They are forum vendors here.

FM makes a good cast manifold for the 1.8, since you are already looking at their site.

borka

iTrader: (1)

Kraken makes good manifold and downpipe kits. Good prices and quality. Plus he is in Europe

ridethecliche

iTrader: (2)

If you want to keep the 1.6, just do rods and hone/re-ring and move on with your life. The 2560 at like 16-18ish psi is plenty of fun and you're going to get out of its efficiency zone past that. Given the 1.6, I doubt you'd hit 300. Stock pistons will be fine. Run that for a while, blow it up, and use those rods for the 1.8 build provided they survive.

Or just enjoy the current setup without any of this headache. Totally up to you.

The folks on here are very much of the 'do it once, do it right' mentality, which is why folks aren't telling you what you want to hear. If you're spending that much money anyway, the 1.8 shouldn't add that much to the cost. I'm sure you can recoup a fair amount of money selling the 1.6 turbo setup you have there.

This is what I'd do.

Mazdaspeed_Miata

Hey guys,

thanks for your answers again!

I checked out some things the last days. And I am still not sure, what to do!

I got offered a 1.8 Kraken downpipe (1 piece SS) and manifold, together 650$. Sounds good.
I also found a BP engine, out of a 10th anni NB, for ~ 470$.
I also read a bit about stand alone ECUs and come around, that a MS3 mini would be a nice solution for my application. What do you think?

And or better but finally I have done a 100miles trip on small and curvy country lanes that has demonstrated once again to me, that actually my car is fast enough for its current field of application.

So maybe I should really only upgrade my B6 with rods and ARP studs, which both could be reused at a BP. (if I do that step sometime in the future)

And before I put that rods in, I install a MS3 mini with 550 cc EV14 injectors and COPs, which should result in a better driveability of my miata.

In the step of chaning the rods, what would you recommend to renew?

- hone cylinders
- new oem piston rings (where to purchase them? in germany I find one adress that offers them for around 285$.... )
- new acl rod bearings
- new head gasket
- new arp head and main studs
- new timing belt
- QMAX coolant reroute
- Anything else you would recommend to renew? Should I renew the main bearings?


Sorry for beeing still that undecided!!

I have really also thought about a BP swap intensively as shown above, but I think I don't want to spend 5000$++ (BP engine, manifold, dp, MS3, injectors, piston, rods, seals/bearings/gaskets, new reroute, money for engine builder, hydraulic ramp use etc etc) for such a complete upgrade at the moment.

Thanks for further responses.

jonboy

If it was me, I'd stick with the current motor, leave it totally as it is apart from some larger injectors and probably replace the EMU with an MS3. Turn the boost up a bit, to whatever is considered a reasonably safe level (13-14PSI?) for a 1.6 with stock rods and your turbo and enjoy it as is with an eye on doing a 1.8 swap in the future.

With the thousands of Euros you've not spent on the 1.6, watch the for sale sections and hoard 1.8 bits that you are going to need, get it all built up over time and then maybe swap over one weekend in the future. Keep an eye out for high mileage/mildly broken engines (blown head gasket, low compression etc) that can be picked up for very little money - you save a fortune and it doesn't really matter on previous condition (as long as it's not too broken!) as you are rebuilding it anyway. Other option would be to buy a rusty NB, keep the bits you need (engine, gearbox, diff etc) and part the rest out, you will probably pay for most of the engine build selling off a good hood, wheels, brakes, interior etc..

ryansmoneypit

iTrader: (6)

All you listed for the 1.6, will cost more and yield less than a 1.8 swap. Your new list is not any more smart than your first ones. You say the power now is good. then you want to put rods in a 1.6 and ARP hardware on a NON TURBO engine WITHOUT MEGASQUIRT 3.

Save yourself here. tell us how much power you want, and we will tell you the cheapest, most reliable way to get there. But i can save even more time. You said you dont want to spend 5k. so that leaves pretty much one option. a 1.8 swap. then add small things over time; header, intake, megasquirt 3 etc.

I dont see any indication that you need rods or any other internal mod for what you want, other than it sounds cool to say " I have a forged rod I have forged rods"