SamM_UK

Hello folks

A few weeks back I bought myself a Japanese Domestic Market 1998 Mazda Eunos Roadster RS in chaste white as a base for a turbo project.



The RS has a torsen LSD, 6speed box, AC, PAS, lightweight flywheel and tweaked inlet cam giving approx 145hp from the 1.8l engine.

At the moment she has the following mods

Gaz coilovers
Drilled and grooved discs
EBC pads
Michelin Pilot Sport tyres.

I had an FD3S RX7 for 5 years and it reminds me of a miniature version of that. It's a great little car to thrash around in but it really does need some more torque!!

So to deal with that I have the following plans

Revent Turbo and Intercooler Kit
Borg Warner EFr 6258 T25 .64
ME221 ECU
Coolant reroute
Mishimoto radiator
Mishimotor oil cooler kit

Longer term I will forge the engine and fit a meatier clutch to really make the most of the EFR.

I wanted to ask about fuelling. I'm looking at EV14 440cc injectors, but do I need a fuel pressure regulator tied to MAP pressure? i seem to find different views on this depending who I'm talking to!

Cheers

Sam

jonboy

Welcome!

Personally, I would go for bigger injectors (550s / 640s etc) - there's no real benefit of smaller than that, and you will probably run out of headroom, although it's dependent on what your power goals are... Beware of cheap RX8 injectors from ebay, it seems there's a lot of fakes about which aren't any good (if that's why you were after 440s)

There's two routes you can take with the fuel rail - either convert to the earlier style return fuel system and a pressure referenced regulator, or put a different regulator and up the fuel pressure on the returnless system (and likely a bigger fuel pump too). Swings and roundabouts with both options...

As for the ME221 - be prepared for the hate for that on here! I would research ECU options carefully - have a look on mx5nutz.com at how many people struggle with cold / hot starts and general niggles with that ECU. The thought on here is that MS3 is a much more mature solution...

SamM_UK

Thanks for the reply.

For the injectors I'd be looking to buy new EV14s and will consider going larger. I'm not aiming for massive power, probably a safe 300-320 once I get the engine upgraded. It'll be a road car 95% of the time so I really don't need huge power in a 1000kg car!

I assume going returnless means I need to run a line back to the tank? If so the latter option of just increasing the existing rail pressure seems like it'd be the easier route?

Just looking at the MS3 site, it does look like a good ECU. I'd read a few things about hot/cold start on the ME221 but had put that down to bad tuning. Are they that bad with hot/cold starts?

I assume for the MS3 I'd need to look at the 99-00 model?

That seems to be a common thread with the car, whenever I'm looking at parts its 90-97 and 99-00. It's like they skipped the 98 cars!

jonboy

I'd be looking at 600+ injectors - the Flow Force injectors from here are highly regarded, as are the Injector Dynamics.

If you swap to the earlier fuel system yep, you'd need to run a line back to the tank. I think might be OK with a bigger fuel pump and a higher pressure regulator (which would probably not be on the fuel rail any more). I'm sure there's some posts about it on here somewhere - I've got an NA with the return fuel system so it's not something I've paid much attention to

For the ME221 - I'm not sure if it's just the way that they are mapped, or it's a quirk of the ECU, but it seems a lot of people are complaining of starting issues. Due to past history there's a lot of negativity towards ME as a company on this forum, so don't expect the same level of fanboyism for their ECU that you get on the UK forums!

For the MS3 - you'd need to have a look at your ECU plugs and figure out which model is plug and play, but there should be an option available. I have a feeling yours will be the same as the 99 - it'd be a 99 (very early) model year NB, as the 97 would be the very late model NA (mk1) that had different ECU plugs to the earlier ones that nobody caters for... There should be PNP options from both MSLabs and DIYAutotune if you go down that route..

SamM_UK

Thanks again

I'd like to go Adaptronic modular in an ideal world, I just can't justify the extra expense!

jonboy

I was on Adaptronic, but the old e420c until a few months ago. I did toy with going to the newer adaptronic kit, but got a really good deal on an MS3 second hand so swapped to that.

The adaptronic was good, and their support forums etc were really helpful, but you can't beat the level of MX5/miata specifc MS3 knowledge that you can get on here.

SamM_UK

I had one of the pre-modular plugin units on my RX7, was a nice bit of kit but I hear what you're saying about experience!

Mobius

iTrader: (2)

For eventual 300+ whp I'd go straight to ID1000's or Niglet's 960's.

You definitely want to upgrade the fuel pump.. I can say from firsthand experience that the stock NB regulator and fuel system, with ev14 550cc injectors and a DW300 fuel pump, has no problem with 250whp with some headroom left.

Your emissions / roadability regulations - how do they affect your ability to run an aftermarket ECU? You'll need to in order to run bigger injectors, and for that kind of power the add-on bandaids are really not optimal.

Mobius

iTrader: (2)

That's probably because for the US Domestic Market there was no 1998 model. It went straight to 1999. If it's an NB then anything for 99-00 should work with it.

You specify the 1.8l, so that's good.

The MS3 can run any NB from any year. I recommend to you the MS3 variants from MSlabs (reverant). I have one with the optional canbus/obd2 module, and having that output from the ecu is very helpful.

jonboy

It looks like the OP is in the UK the same as me, so as long as the emissions (CO / HC) from the exhaust are low enough, which would require keeping a cat (or a dodgy test centre!), there shouldn't be any issues passing...

MSLabs/Reverent is also based in the EU (Greece) - so no import duty.

SamM_UK

Thanks, that's good to know

Those seem like huge injectors, would idle quality be sacrificed going so large? 550s with an upgraded pump seems like a good combo. When I'm talking about 300hp I'm talking flywheel, so a setup that supports 250whp would be ample I think.

Yep indeed! I plan to have a removable cat supplied with the Revent kit.

For now. :

Mobius

iTrader: (2)

The whole point of miata guys running EV14 injectors is that the idle quality / drivability is still ok. I think you'll be fine.

The point of doing the fuel pump first is one of priorities. You want power? We all want power. But do you want to run your motor lean and destroy it, and then have to rebuild it? That is why we are here, and reading posts such as yours. Edit: stock USDM fuel pump runs out of fuel ~190whp. Best to replace it now with a more robust unit, I recommend DW300.


Your first priority should be brakes. Do you, will you, have enough brakes to stop what you plan?

If not, we can't help you much. Because that's the primary attitude here at mtnet - survivability. You want 300whp, that's fine, a lot of us want 300 whp. But will you do the necessary mods to support 300whp? That is our question.

So start with brakes. If you truly want 300+whp, stock brakes, even sport brakes, are not enough if actually pushed. As in, on track with power, driver pushing hard, calipers bend. This is a real life scenario from a 250whp full weight mazdaspeed msm (factory turbo car, ~180whp).



I

SamM_UK

Good info, thanks.

I know the current setup is track friendly as the previous owner used the car at Silverstone and Spa, but with 100-150 more HP I totally take your point.

I've been eyeing up Wilwood kits, but I wonder if there are any other perhaps off the shelf OE items that'll retrofit easily? I had an EG6 Civic which I upgraded using larger MG Rover discs and pads, all off the shelf but a decent upgrade to the little Civic.

What's the path most followed here for a good turbo brake upgrade?

jonboy

I've got 620cc EV14s in mine, and with a crappy 'making it up and learning as I go along' tune on my MS3, the idle is pretty much as good as standard, and I've not got as far as turning on the advanced features like Idle VE or Ignition based idle control. The ID1000's are supposed to idle just as well - if I was going to buy new this time around I'd go straight with ID1000s.

The previous owner of the turbo kit that's currently on my car had it on a mk2.5 and was running into fuelling issues with 620's and higher fuel pressure (on a non return system) at about 240whp..

I'm running mk2.5 sport big brakes on mine, with Carbotech XP8 pads and I've not run into any problems on track, but I'm hardly a competitive track driver like a lot of people on here who push stuff *really* hard... Does the JDM RS come with the sport brakes on it? Looks like it might from the pic...

Where abouts are you in the UK Sam?

SamM_UK

Honestly I'm not sure if they are sport brakes or not, how could I tell? Are they larger diameter than non sport?

I'm in Sussex, not far from Gatwick, how about you?

Which tracks have you used the car on? I did Brands Indy, Bedford GT and Cadwell Park in my RX7.

jonboy

Sport brakes are bigger diameter. Easy way to tell for the factory setup is if the rear discs are bigger than the fronts (unless someone's been mixing and matching!)

I'm out the other side of Swindon.

I've had the car for years, done Brands Indy quite a few times, Castle Combe, Donnington, Cadwell, Anglesey, Abingdon Airfield, and a few sprint tracks like Llandow, Haynes Motor Museum, Curbourough... It was off the road for a long time while I sorted the engine out, then a better turbo setup came up for sale locally, now I'm sorting out all the little niggles ready to get it mapped...

SamM_UK

I plan to keep the car for a while too, tend to keep my projects for a minimum of 5 years. Had my Charade GTxx, MR2 GTS and RX-7 each for 5 years.

I hope to complete the first stage of this project within 6 months, then enjoy the car whilst I evaluate it and upgrade as needed.

Who will you be using for mapping?

SamM_UK

Just thinking about order of work

1. Cooling - radiator, coolant reroute
2. Fuelling - ECU, pump, injectors
3. Turbo, turbo kit, mapping

jonboy

0. Brakes?

I've had this Roadster since late 2007, and had a different one for a few years before hand!

For mapping - not 100% decided at the moment. Half of me thinks I should do it myself, the other half says use someone like Horsham Developments and get it done properly...

I'm trying to get all of the time consuming stuff (idle, closed loop target table, cold starts etc) sorted at the moment, and have let autotune do a half decent job on the fuelling side. I have det cans so may slowly turn the boost up and see how it goes...

SamM_UK

Haha yes possibly.

HDev have a good rep for sure. I've used Ed@Fusion Motorsport in the past too, he's really good.