nlsolja123

So I seems some people with mzr swaps and a 2.5.

As Ford has recently sold out of their mavericks, and restarted orders. It's a big fact that there will be so many 2.0 Ecoboost in junkyards in the near future.

As much as I want raw power out of the rx8 I have given up on it for a while now. It had a fresh rebuild that *I didn't take my time on* and only lasted 6 months. No internal damage just no compression due to side seal springs. I have everything to have It rebuild to oem with a street port. And soon will be doing that.

But the point of this post. Since I have all rotary rebuild parts to have it put back to spinning Doritos status I will. once I have the rotary alive again I do plan to start gathering the parts for a Ecoboost swap..

As I've decided. The rx8 doesn't need to be crazy fast. But a reliable 300hp that gets good gas milage sounds very rewarding.

Has anyone done mock ups of a 2.0 Ecoboost or is the dimensions pretty much the exact same as the mzr?

John V

iTrader: (1)

The Ecoboost is similar to the MZR (it's part of the same family of engines) but has significant disadvantages for swapping into an RX-8. The main issues are the direct fuel injection and the high pressure fuel pump. The fuel pump is on the rear of the cylinder head and space is at a premium when installing this engine into an RX-8.

It's much easier and cheaper to start with a vanilla MZR and turbocharge it than to start with an Ecoboost.

Laminar

^^^
Ford sold about a bajillion Fusions with the 2.5 MZR/Duratec. Junkyards are basically giving them away, you can find low mileage examples for $200-300 all day every day. You're going to struggle to find a good EcoBoost for under $2k.

John V

iTrader: (1)

Yep. I mean not to rain on your parade or anything but there's a reason the Ecoboost isn't a commonly-swapped engine. If you have the fab skills to pull it off I still say give it a shot, it would be unique and should work well if you can get everything to fit.

UnknownJinX

Also, if you want an EcoBoost, why not just use the Mustang 2.3T? Should be quite a few in the junkyard right now. Better yet, there is the Focus RS 2.3T, but that's harder to find. Focus ST came with a 2.0T engine, too.

But from the cost perspective, yeah the 2.5 Duratec/MZR is a dime a dozen. I have seen people directly swapping them into 2.3 Mazda3/Mazda6 when their original engine dies since the block is identical and everything just bolts up. Those engines cost a couple of hundred dollars and are pretty robust.

Snox801

So I brought this up a while back as I have a 4K mile 2.3 and the whole turbo setup out of my 16 rs I built. First post was correct with space issues for the fuel pump. I love the idea but you are selling the power short. Stock engine and turbo I was at 398awhp and 420trq. That was maxing out the stock turbo but it’s proven to last a long time at that power.
It was crazy good also started low and pulled almost to the top.
Would be amazing In this car and could be done but as I was told the steering rack and then making the fuel pump fit would be a bit tough.
2.0 or 2.3 would work fine the run the same bore.
2.0 is solid and the 2.3 is open deck. Stock 2.9 block will hood about 600whp but I believe the proper 2.3 with brace will cool better. If it was me and you haven’t got the engine yet I would do a 2.3.

Snox801

Also it’s not the complexity that keeps them from being being swapped because it’s much easier than making all the parts and fitting it.
The problem was the ecu. It was taking inputs from the chassis that was almost impossible to get past and make work correctly. So guys doing it we’re using syvec.
Now I believe juts recently ford started selling the ecu that can be used to swap without that parameter in the ecu.

John V

iTrader: (1)

Yep, the non-Ecoboost swap can just use an unlocked NC Miata ECU very easily. It will even drive the stock RX-8 gauge cluster with no issue.

Snox801

I still some day dream of a rx powered by a 3.5 ecoboost.
But like was pointed out it could be done with lots of money. Ten years ago I would have jumped at it. But with a family now I need to plan for long term care for my oldest. So adulting got in my way of dumb spending. Imagine 500+whp and 600+trq with a relative light motor.

Federighi

iTrader: (7)

The 2.5 MZR + aftermarket turbo is very popular among diy enthusiasts these days. I even know of a few miata guys who've completed the 2.5 swap on their NC's (some with ITB's, some FI, etc) with promising results. Depending on turbo selection + fueling etc you can make serious power (imo). I'm planning to upgrade to the 2.5 swap when my Speed's 2.3 eventually gives out. No specific power goal(s) but I estimate a 'mild' build with no ethanol / aux fueling will easily produce around 450whp.

This shop is very reputable within the MazdaSpeed community and 'TunedbyNishan' is the shop tuner. I only have positive things to say.

https://www.speedperf6rmanc3.com/pag...anc3-2-5l.html

Laminar

Snox801

wait wtf? 2.7 when is this gonna be done. I have a yard of hard right now.

Snox801

Why do a 2.5 over a 2.3? I know some guys were going that route on the rs but none seems to pan out as good as a built 2.0 or a build 2.3.
Now you have me curious.
I’m very aware of that company.
I actually consulted with them for a few builds.
Ended up using Livernois instead.

Federighi

iTrader: (7)

Snow- 2.5 mzr short blocks can be sourced cheap and easily while the 2.3's are more expensive and less commonly found by comparison. Also a direct swap. Check out SP63's little write-up on the topic.

But my personal reasoning for this is primarily cost effectiveness. Basically just throwing on a GTX3576R w .82 A/R and calling it a day.

Snox801

That’s makes sense. Just the direct bolt up.
I wasn’t aware the price my new block for my built 2.3 was very inexpensive. Was cheaper to do that than use my stock one and tear it all apart.
2.3 should start to become cheaper with everything running them now.
I’ve toyed with selling my stock long. Lock out of mine. I only had 4K miles on it. But I keep holding onto it and my stock rs turbo in hopes of putting it into something.

kovalmax

Not to brag, but I got lucky with my wife. I too have long dreamed of an RX-8 with a 3.5 ecoboost engine. And on my 30th birthday, she made my dream come true She is incredible and pleases me to this day.
By the way I couldn't decide which to use 5w-30 Oil for 3.5 Ecoboost engine. I wanted it to be perfect. On the advice of some guys I chose Pennzoil. I do not know if I did the right thing, but for many years everything works well and without particularly heavy failures. Maybe you use a different oil?

Snox801

I’ve run 5w30 amsoil in all my ecoboost engines. Currently have two of them over 300k zero issues.
My work truck has over 300k on it and it’s at 500whp and has been since about 300 miles.
I drag race it several times a year. And pull all my equipment for the farm with it. Pulls my 24’ car trailer all over the country for work. Things never skips a beat even in the Rockies.
I’m completely sold on the amsoil and Livernios motor sports tuning.

Snox801

So you were able to get a 3.5 in the rx8?
If so I need more details. Pictures and dyno runs.
I’m might have a new project now.

Laminar

Finishing up engine mounts now. Controls are 90% figured out, fuel system is 95% figured out. Should be running this summer.

Snox801

That is fantastic. When your done I’m gonna be able to Picking your brain a lot. I think I’m gonna do one. Those 2.7 ecoboost are amazing.
FYI not sure who you are using for tuning but Livernios is the only company that has access to the flex fuel tables form ford. You can’t run that motor on e85 because hpfp restrictions but, if you are wanting to max out stock turbos you can do e30. If you choose them they still use flex fuel settings so it’s flex fuel up to the limits of the hpfp. So you eliminate the need for content gauge and no messing around trying to get it perfect.
That was the big reason I used them for my 2.0 and 2.3. My wife can pump in a close enough guess of e85 then top off with premium and not worry. Been 125k carefree miles tuned on e30 with them.

Federighi

iTrader: (7)

Snow- the 2.5 should also broaden the power band a fair amount. Leaning towards the SP63 'internals kit' as opposed to their 'stage 1' build block but I'm not sure what to do about the head but at this time. I don't plan for anything too involved like porting, cams, etc and ultimately just changing the intake manifold and turbo. Plan is to keep it more mild than wild and would be more than happy with 450whp.

My stock block fbo 2.3 is currently running a BNRs4 @22psi on 91 pump gas with the ACT 'pro-lite' kit and estimate it's putting down somewhere around 350whp. It's a very fast hatchback.

Oh and there are a few 'e85 safe' HPFP rebuild kits out now. I recently had my AutoTech HPFP serviced after 60-70k street miles; no issues just preventative maintenance, etc. Corksport and Graveyard performance are 2 that come to mind.

Snox801

That’s cool I like hatchbacks. My stock block 2.3 stock turbo rs put down 398awhp on 93 with meth injection.
It’s not the hpfp that can’t handle the actual e85 it can’t pump enough fuel.
stock pump could only handle about e30 stock turbo. I use and upgraded hpfp in my rs that allows me full flex fuel tune. So if I can’t find e85 93 works and no need to retune.

Snox801

Guess I should have said I have multiple ecoboost. Most run on e30 or meth because of cost but my rs has a full long block big turbo, upgraded hpfp for flow. And currently sits at 528awhp if running e85.

John V

iTrader: (1)

I would warn anyone using the 2.5 for a boosted application, you should really go in and inspect the ring gaps before doing that. I have had four 2.5s through my shop since I started this build in 2018 and every one of them had factory ring gaps that were too tight for any meaningful boost.

The factory pistons are pretty weak so ultimately I decided on forged rods and pistons but for street cars, a stock 2.5 with the ring gaps opened up should be fine. it will be pretty hard to get to 450whp with stock 2.5L cams, though.

UnknownJinX

Also, earlier naturally aspirated 2.3 MZR had oil consumption issues. Lots of people with BK(1st Gen) Mazda3 go for the 2.5 engine when their 2.3 fails because 2.5 fixes the oil consumption issue, as well as being more readily available, as mentioned.

The 2.3T MZR in the Mazdaspeed cars and CX-7 at the time has a slew of design issues, mainly the noodle timing chain that will stretch over time. Doesn't help that it's direct-injected which adds more stress to the timing chain from the mechanical fuel pump.