Ready to start build, but a few questions?
 

Hey guys,

First off thanks to everyone for all the help so far and for all the help with my last build on my 1993 Miata.

Here's a list of what I have for the build:

- 1994 Miata "C" package with torsen, A/C & P/S
- BEGI Shanghai Kit with crossover pipe delete, FMU delete, Stainless DP & Stainless braided lines.
- Used TDR intercooler for a Greddy [I will have to adapt it a little]
- Megasquirt [built by Brainiack] with AIT sensor and harness to run it Paralell with the stock ECU
- LC-1 WBO2 sensor and digital gauge [On the way]

I am going to have a place up the road build me a 3" exhaust and I will use a metal core 2.75 or 3" cat.

I still don't have any injectors, and therein lies one of my questions:

I have the instructions from Brainiack, but unless I missed something, most everything I have read everywhere refers to Megasquirts running standalone. Should I have just run mine standalone too?

What about injectors? From what I can determine from my calculations, if I want to keep the stock fuel pump, and the stock FPR, I will need the 440cc injectors to get me to my goal of about 200rwhp. Does that sound right?

Are there any special considerations when running a MS in paralell to the stock ECU? Or is it basically the same tuning as if you were running it stand alone?

Is there a discussion or a thread that I am missing covering the MS piggyback operation?

I have a pretty good handle on everything else except for this, because my last set-up I just ran a Bipes, 1.8 injectors, Walbro 190hp and a RRFPR.

Sorry, but I have searched and I couldn't find any clear answers regarding MS running piggyback.

Thanks for any help... I'm ready to get started on this thing. I'm tired of going down in the garage and fondling all of the pieces. ;)

I would, well, it's what I did. MS is well capable of handling everything in our year NAs. And it's kinda fun having the stock ECU as a paperweight. My favorite part was when I went to my uncle's shop to use a lift for the clutch install. I handed him the stock ecu after sitting down in the car...as he's holding it in his hand I fire the car up, and enjoy the look on his face, and the Q&A session.

Yes, I'm using 460s, and I hit 85% duty cycle, which is widely agreed as the upper limit you want to put your injectors at. Maybe go a little bigger. I haven't had any problems with fuel pump or regulator, one of the nice things about MS and it's ability to control injectors twice the size of the stock units. If you go too big it can be hard to tune idle.

I think deliverator still has some RX-8 injectors for sale that would be perfect. I originally tried to get them since they have a better spray pattern, and are 20yrs newer than all the RX-7 injectors us turbo guys keep passing back and forth.



If you are going to run standalone you probably need to decide quickly as it involves Scott building a different harness. I know he actually prefers the standalone harnesses as the parallel (not piggyback, piggyback intercepts and modifies signal post ECU like a PowerCommander) ones are supposed to be a bitch.

I forget the special considerations, just a different looking VE table, and stock unit controlling AC, maybe fans. Since I went standalone I can't help here.

I know the feeling.

You've got a good setup going, I'd just get cracking on it. Doesn't look like you've missed anything major, and your BEGi kit should have most of the small bits that usually send us searching every auto parts store in town.

It looks like that is what I'm going to do. After thinking about it, I PM'd Scott, and I ma sending my MS back to him and getting it rewired and getting a standalone cable. He was very fair.


I will PM him. I called the dealer just for fun and even with my Miata club discount thet are $175 each. I also calld a friend Tom Neel at The Parts Group, and he has a few, but he is hanging on to them for his RX-8 race cars.


Thanks for the reply and the help.

Now that I am shipping the MS back to Scott to be retrofit, all I need is the LC-1 from BEGI, a high flow cat, and I think I am going to talk to the guy at the exhaust shop and go ahead and order some 3" stainless mandrel bent pipes and I should be good to go.

Hopefully I will be starting a build thread soon if anyone is interested. I can't wait to start on my second turbo Miata build... And apply all my lessons learned from the first one. ;)

I'd say go 550s. I scored a fairly good deal on ebay (or maybe it wasn't a good deal?) for under $100 for my RX7 550s then sent them to injector rehab for rebuild/cleaning for 64 bucks.

I went standalone on my MS as well. I had no reason to go parallel. It'll take a bit to get the hang of idle controls on the standalone but should work just fine (although I never did figure it out on mine).

Cant wait to check out your build thread!

I'd say go 550s. I scored a fairly good deal on ebay (or maybe it wasn't a good deal?) for under $100 for my RX7 550s then sent them to injector rehab for rebuild/cleaning for 64 bucks.

I went standalone on my MS as well. I had no reason to go parallel. It'll take a bit to get the hang of idle controls on the standalone but should work just fine (although I never did figure it out on mine).

Cant wait to check out your build thread!

There is enough support on this forum to get the car running well enough to drive around in minutes, not hours.

550cc injectors are big enough to make 300+ on a stock pump/regulator, yet can still idle perfectly on the low-res MS code.

Looking forward to your build, since my Chinacharger from BEGi is on order.

Thanks for all the replies so far guys. I have considered 550's, but in order to hit those power levels, I will probably need to swap out the Chinacharger anyway.

I have found a set of remanufactured RX-7 460's with new seals and they have been flowtested for $149 including shipping. Does that sound like a good deal?

If seller can give you a copy of the flow testing.

You'd pay about as much to get "dirty" injectors and send them to your specialist of choice...and then you'd be assured of the numbers and the new o-rings, seals and screens.

I concur with wayne curr...I cheaped out and didn't get mine cleaned, and would have done so if I could go back in time. Part of my issue was being set back nearly two months by a scammer, and NEEDING injectors fast. But it's one of those things that eats at you in the back of your mind. I got lucky and rharris gave me a really good set, and no issues so far. I did run some chemtool through the first tank of gas though.

So... Go for the injectors if they flow properly?

It would save time and shipping.

Those injectors usually go for around $80...so by the time you ship them and clean them, it's an equal dime, and less of a headache.

Again, go for those injectors if they can provide proof that they were flowtested etc. If they dont have the proof, I wouldn't chance it...would be a waste of money.

Well... I bought them and I am shipping the MS back to Scott this afternoon. So that should be the last pieces to the puzzle other than a few odds and ends.

Here's the injectors I bought:

eBay Motors: RX7 460cc Civic Integra Miata non turbo Fuel Injectors (item 190304977904 end time May-08-09 04:03:12 PDT)

They have flow test results and the guy has fantastac feedback, so we'll see.

Just a little update on this thread...

I was fully intending on building a custom 3" exhaust, but I found a good deal on a slightly used Flyin' Miata 2.5" S.S. turbo exhaust and highflow cat for $200 and I just couldn't pass it up. Those items on FM's site are $742 and $199 respectivly and even though their stuff it pricy retail, $200 for a complete system including cat is a pretty good deal even though it is only 2.5".

I got the RX-7 460 injectors in and they are very nice. they have the flow test printouts and they all flow 472 cc's at 43.5psi, so they should be good to go.

The only thing I am still waiting on is the damn LC-1 wideband. I ordered it from BEGI back on March 20th when I ordered the modified Shanghai kit and it still isn't here. Steph told me that it was "on it's way from LC-1" 11 days ago and I still have not seen it. They are great people and all, but I am glad I am not in a hurry for anything. Oh well... I sent her another nice emil today and ask if she knew anything about my wideband.

I still need to decide on a clutch. The F1 ebay 6 puck racing clutch seemed to hold well on my last Greddy kit, and it was a 1.6 clutch. I would assume that a 1.8 F1 clutch would hold a little better because it is bigger.

Has anyone run the F1 clutch at 200+ rwhp? How is it holding up?

Right now I am doing pretty well on the budget. I am at $2500 including: the Shanghai kit with SS downpipe and lines, Megasquirt, TDR intercooler, FM exhaust and cat and the LC-1 wbo2 snesor and gauge. I have a leftover a pillar mount and JR boost gauge left over from my abandoned JRSC that I sold to a forum member.

If I sell the Nissan Turbo I can take that money and buy the clutch and I will stay at my $2500 budget. I know that many have done it cheaper, but still it is not bad for the set-up that I will have.

I will probably start the build this weekend if i can get some confirmation from BEGI on the wbo2. I don't want to start if it is going to be next year before I get a sensor.

Comments... Suggestions?

You did well on the exhaust, I wouldn't beat myself up over the 2.5", as long as it is mandrel bent, and has a quality cat.

I ordered my sensor from DIY, very little waiting. If you can't get a tracking number from BEGi, see if you can't cancel and order straight from them. Or you can order one, and see which one arrives first, and sell the other one if you want to make sure you'll be tuning in time.

Glad to hear the injectors ROCK (of FLOW). If you can afford for the car to be down I'd go ahead and start bolting stuff on as you may find fitment issues, or need hardware, although this is less likely with a kit from BEGi.

Looking forward to progress pics.

It's just like the one on the FM site so I assume that it's a pretty decent set-up. For my horsepower goals I think it will work great.

Stephanie emailed me back this morning and it was shipped out yesterday, so I should be good to go. I had thought about ordering from someone else, but i had already paid them. No biggie. They have been great to work with.

If it looks like I am going to have some time this weekend I will start. My lovely bride has exectutive passes and arm bands for the golf tournament this weekend, so that means free food and free beer at the corporate tents.

I don't know if I can pass up watching the pros play, eating and drinking and hanging out with my Baby.

But the forcast is for some nasty weather so we will see how everything plays out. Like I said in an earlier posts, I will start another thread with pictures and then everyone can see detailed documentation how NOT to install a turbo. ;)