BOOST NOOB tax return turbo build!
 

ok. noob to boost. not to building cars. so gonna have lots of questions and lots of research ahead of me.. a little about me and my car. im 23 and recently picked up a 94 miata. love the car. but it lacks powa! no point and trying to coax every little bit out the 1.8 while it is in n/a form as it will not satisfy me... i love working and tinkering with cars. been doing it for a while now. car i sold to buy this was a 97 cobra. not super modded but was respectable. im hearing 225ish hp will eat my old cobra up and still be a reliable dd. so im going to put that to the test :)

ok. things i know.

megasquirt. i need it. i just dont know how to tune. so thats my worry. ill get all this done and will screw up on the tune

i have a tdo5h 14b. has about 10k miles on it and i hear its a great turbo for a stock 1.8. i know its an oddball turbo and most people stick with the t3/t4 style. but i got the turbo at a good deal from a friend who is going with a 20g on his dsm.

im being told from a few friends i need a cast mani as tubular ones crack easy... i have one bud who is a professional welder and builds custom exhaust and roll cages for a living.. he says he can make a mani for it. my question is. is there a good way to brace the turbo/manifold to not crack? i dont think i can find a cast manifold for a tdo5h. and is there a certain steel and thickness that would be preferable to last longer?

intercooler. need to figure out a size that fits and has the inlet-outlet in preferred locations. not looking for a super expensive unit and im being told that the ebay coolers are actually pretty good. so if someone has a link to one known to fit that would be awesome!

rx7 injectors is what im being told i need.

things that are easy for someone who knows to explain.

do i want a higher rated waste gate spring and the boost controller will control lower pressures? or do i want a somewhat weak spring and a controller will allow it to hold more before opening.

plan is to cut corners where i can without worrying too much about reliability.

hearing i may need a restricter for the turbos oil line to save the seals?

ok. budget. tax return total came to 2100 doll hairs and i have 600 saved up. so 2700ish. bought the turbo for 100 bucks as my friend is being nice and wants to see my car turboed :p
ill be researching but anyone that can point out threads they know of that have very useful info it will be much appreciated :)

only pic of my car on my pc right now. soooo adorable :p

Welcome Trent
It's not too late to intro yourself in the noob section.
Location?
Are you going with a stock motor?
TD05 14b is a good choice.
Search "steam pipe" "weld els" for manifold parts.
Most people get the Megasquirt first so you get the car running well before boost.
Everything will take 10x longer than you think.
Cheers,
-JB

lol been on a lot of forums... forget to introduce myself on some of them. will do so in the morning as i am just checking this before bed. yes the car is bone stock down to the paper air filter. only thing i see is an aftermarket fan/radiator combo. engine wise. car has suspension work.
will do on the search thanks!

if need be i will setup the megasquirt first before installing the turbo. im buying everything up and then will go thru an installation process. guess megasquirt is first to go in :)

forgot to ask if i really need the latest and greatest megasquirt 3 or if im fine settling with an older one.

and im fine if the build takes a while. if all goes well and i like the results ill build the motor next tax return and push more boost. :)

EDIT: located in Denton TX

Start here: https://www.miataturbo.net/useful-sa...ig-post-10821/

Ah hah! Actual numbers for goals this time!

You have learned well, young padawan.


Welcome.

Diesel pointed you in the right direction.

Lots of turbo Miatas in the metroplex if you want to see examples. I'm out at MSR-Cresson frequently.

You can make do with an older MS. Heck, I run an original MSPNP (MS1 based) and it does everything I need, even AC and EBC (although I did write my own code to get the AC functionality where I wanted it). That said, each generation has better features and support than the last.

I'd say if you can find a really good deal on an older MS in known-good condition then go for it. OTW, a new one with warranty and support is the way to go.

This guy.... :p
OK cool. I'm still looking at all the mega squirt options. I might do the one you have to build. I'm very comfortable with wiring and soldering.
Will do :nice:

Welcome to the forum!

Welcome, i'd recommend getting ms2, not ms1. For some reason folks selling ms1 still expect to get the same money they paid 8 years ago... which is about 50 bucks less than what ms2 go for.

If I was going new I'd get one of Braineack's built MS's the price isn't bad considering the cost for the kit new diypnp ms3

I had similar fears about tuning, and did tons of research. I threw together a YouTube Playlist of a 10 part series that's basically a video guided tour of megasquirt, as well as a few other videos I found helpful. It's not all miata specific, but most of it is really good info.

The guy for the 10 part thing rambles a bit, but it's still pretty good stuff.

Megasquirt Tuning - YouTube

I was planning to make a new post in the megasquirt specific section with this to see if anyone else found it helpful at all.

Regarding Wastegate and Boost Controller:

A boost controller can't take your max boost below the wastegate spring pressure. So go for a low wastegate spring pressure, then use a boost controller if you want more than that.

So lets say you have a stock DSM 14B wastegate actuator that has not been messed with. That will probably crack open at about 11psi. So when the actuator gets 11 psi through that little hose, it pushes on that little arm and opens the internal wastegate on the 14B, bypassing the exhaust around the turbine wheel and keeping the turbo from making any additional boost beyond 11psi.

A boost controller (electronic or manual) can only act to restrict/reduce the pressure that that wastegate actuator "sees" such that the actual boost is higher than 11psi. So say you have that same actuator, but now the boost it sees through the little hose is routed through the boost controller. The boost controller restricts/reduces that pressure such that 14psi out of the turbo only results in 11 psi at the actuator. Now the max boost will be 14 psi. Only then will the actuator see sufficient boost pressure to move the little arm and open the internal wastegate on the 14B and bypass the exhaust gases around the turbine and keep the turbo from making higher boost.

ok. before i dish out for a megasquirt on ebay. is there someone on the forum that sell them at a good price and has a good rep? money is burning a hole in my account lol

good price?

4 750cc Injectors RX7 Civic Integra Acura All D B F H K R Series Engines ZC Vtec | eBay

DIYautotune.com is a vendor here and has been helpful. Sounds like you have a good plan. Good luck.

OK. Starting to work on a manifold. Would 1.5in piping be sufficient or should we go 1.75. Or 2

1.5" for what? for the runners?

Yes lol... Did more research and it seams miatas use 1 inch piping

750cc rx7 injectors good enough for a while? 160 a good price for the set?

meaning how much power can be made on those injectors till i would need to upgrade?

750 cc? Aftermarket?

ive read that rx7 injectors are the way to go.. so one of the first things i found on ebay when i searched for rx7 injectors was this 4 750cc Injectors RX7 Civic Integra Acura All D B F H K R Series Engines ZC Vtec | eBay

Rx7 injectors are super old technology. 440cc rx8 injectors are really cheap and are ev6 injectors, as opposed to ev1.

RX7 injectors arent 750cc though. Those are aftermarket injectors made to fit an rx7

im getting a little confused.. im looking at the diy thread that was posted here. its talking about turning the overall fuel pressure up for boosted applications.. in the mustang world we didnt turn up the pressure we just ran bigger injectors. so im confused. if i run larger injectors do i still need to turn the overall fuel pressure up? ill look at rx8 injectors. im not to familiar with flowrate but i assume 440cc is more than enough for 225-250hp?

What hes thinking when u said rx7 injectors is buying the stock rx7 injectors off of someone. The stock rx7s were about 500 cc. I think 550 but not sure.

That said if u're buying aftermarket injectors.. why not search for miata injectors?

is 750cc too much for my application? sorry for the newb questions.. i just have a large ebay order sitting and waiting for me to hit the purchase button.. but i want to be positive before i hit it that everything is right. one of the biggest purchases ive made for car parts. makes me nervous lol

Yeah its a bit much but the bigger problem is if u buy shitting injectors they wont be able to idle worth a damn because they are so big and cant open and close fast enough. That said get big injectors that are newer. Having the ability to run E85 if you decide to eventually without having to switch injectors again is a nice bonus to buying right shit the first time.

ok will do. looking at rx8 injectors.. ordering this tonight as well.MegaSquirtPNP Gen 2 MM9495 for the 1994-95 Mazda Miata, manual tranny DIYAutoTune.com

i noticed alot of talk about removing the factory maf... im guessing it doesnt do much lol. noticed this megasquirt allows for it to be removed. going to setup the squirt and tune before i go turbo. want to understand how it works before getting into boost. i really do apreciate the help on this forum. if i seem to be doing something wrong please inform me :)

I personally wouldnt buy rx8 injectors since i like to keep my options open and that 440cc will be a big limit.

so in your honest opinion. what would you go with? ive always had stock injectors on my cars. i honestly didnt even know evo injectors worked on miatas.. this new boost world has me confused.. also. the megasquirt i posted. thats a good one right? i know not to go cheap on the engine management. so i want to be sure i got a really good one

Evo injectors? U mean EV? Get a set of DW 750-800cc Miata injectors and call it done.

dw? i typed that into ebay and this came up? Deatschwerks DW200 255LPH Fuel Pump 700cc Injectors 1994 1997 Mazda Miata | eBay
these? if so ill order them tonight

That looks good. Pull the trigger.

You dont need the pump unless urs is shot but yes Deatschwerks Injectors.

Ok. I'll look at pricing without the pump vs with the pump. If I get a good deal on the pump I might pull the trigger on it

You don't need 700cc injectors unless you're trying to make 350+hp or running straight E85. I'm running RX8 480cc injectors with a cheap Walbro 255 lph and running 3 gallons of E85 to 9 gallons of 93 and making ~300 whp on 15 psi on a stock 2003 VVT engine. There's no way you'll get a TD04 to make that kind of power, so no need for the big injectors, they'll just be a pain in the ass to get to idle.

Here's your shopping list:
**Braineack or Reverant built PnP Megasquirt- Even if you're comfortable building your own, there are Miata specific modifications required to the MS that these guys already take care of for you. Plus the unit is tested and loaded with a start up tune and you literally unplug your stock PCM and plug the Megasquirt in. No re-wiring the engine bay. Spend the little extra here, it's well worth it.
** Walbro 255 lph fuel pump- get the GSL-392 version that is designed to flow well at higher PSI. They're less than $100 and will support 500 whp on pump gas.
** Yellow RX8 480cc injectors- $100 on Ebay and will supoport more HP than your turbo can flow. If they're used send them out to RC or WitchHunter or any other place that cleans and flows injectors.
** Look for a used FM or BEGi cast manifold in the classifieds section. Usually ~$200. Then have your welder buddy weld on a TD04 flange. Alternately, ditch the TD04 and by a cheap Ebay Godspeed for $150. I'm running the Godspeed 2871 equivelant and can;t complain. Full boost (15 psi) at 4k and ~300 whp.
** Choose a downpipe based on your turbo selection. Note that it is a tight fit to clear the firewall, so either buy one that's built for a Miata (no ebay BS) or have fun building your own.
** You will need a clutch for anything more than ~180 whp. I run a Clutchmasters FX100 and a Competition Clutch 10lb steel flywheel. Holds all the power I'm putting down and nearly stock pedal.
** Grab an intercooler off of Ebay or CXRacing or Enjuku/Isis etc. You can go cheap here, you're not trying to moved 30+ psi of boost and make 1000 hp. Just make sure its bar and plate, not tube and fin. And for God's sake... don't paint it! (Kills heat transfer ability)

Get the Megasquirt first, get comfortable with tuning while you're collecting parts. Then tear it apart and install the turbo. Then start tuning again. You'll be able to copy all of your non-boost cells from your original tune and then extrapolate your data for the boost cells to get started, then tune form there.

This is essentially what I did for my build, and I've got less than $1000 into the turbo set-up (not including Megasquirt and Clutch/Flywheel as I did those mods prior to turbo) Long story short you should be able to do this build with in your budget, if you buy smart. Don't buy $450 worth of shitty DW injectors and fuel pumps that you don't need.

Happy boosting!

Looks good, except it's been tested and proven that a light coat of paint does not ruin heat transfer at all. And actually, a light coat of matte black may actually make it *more* efficient.

Just don't paint it thick enough to block the fins, and don't use like plastidip or anything super thick like that.

Tube and fin is nearly as effective and flows air through it better to aid cooling the radiator... At least that's what I read.

15psi on a stock vvt? 300hp? Wow. I set mine at 10psi (dyno'd around 225) for fear of blowing the high compression vvt and am building a second motor to run the same boost your running now!

Yeah, I was making ~250 whp on 12 psi and pump 93 through stock exhaust. I've moved up to 2.5" exhaust 15 psi and E85 blend. The trick to making it last is to not hammer on it all the time. Also a bigger turbo like a 2871 or 2860 will spool a little later than a TD04 or 2560. The thing that kills motors quickly is big torque hits down low. Which smaller turbos on a lot of boost tend to do. When pistons are moving relatively slow in the bore, they tend to side load when cylinder pressure increases rapidly. It's one of the reasons nitrous motors tend to eat up bearings really quickly and also why when I tune customer's cars that are running nitrous on stock engines I instruct them not to spray until they are above 3k typically. That is unless they have a progressive controller, then I set up the controller to rapm the spray in, almost like a turbo. ;)

I did blow the first motor though, but it was because of my stupidity, not too much boost. I had flat foot shift enabled previously on 12 psi and I flat foot shifted and short shifted at the same time, so I made full boost at around 3000 rpm. Side loaded the piston and spun the rod bearing. Then I thought I could make it the 6 miles to the shop with a spun rod bearing. :rofl: I made it about 3 miles and kicked number four through the oil pan. So I put a 39k mile pull out motor in it and kept rocking. I've got a short block that I'll be building up soon as well, but the stock motor is loving the boost right now. :party:

There's a fine line between to much paint and just enough. I've had way too many cars on my dyno with painted intercoolers that couldn't keep charge temps in line for me to agree that it's a good idea. I've actually taken a painted intercooler off of a turbo Mustang, sparyed it with air craft stripper to remove all the paint, and put it back on and saw the charge temps go 20 degrees cooler. Here in Florida we have to do everything we can to keep charge temps down, and no paint is the way I go. :bigtu:

Its a tdo5h turbo. 14b for starting off and from what I've read should be good for close to 300hp. If I ever get to that point I'll upgrade to the 16g and be good for over 350. If I really wanted to push over 500 there is the 20g... I'm having a bud build the manifold. Stainless steal. He is a pro at what he does and guarantees no leaks or cracks. He will be building the downpipe also. I'll consider the lower injectors for now. And if I upgrade more I might buy a larger set. E85 is not all that common here so I don't want to have to rely on finding some.

I missed that it was a TD05... The RX8 injectors will still work well with that turbo, but you'll likely want a fuel pressure regulator with boost reference to maintain flow if you turn the boost up much past 10-12psi. Your NA runs a lower base fuel pressure than my 03 so the injectors will flow less and support less HP. But this is easily remedied by using an adjustable fuel pressure regulator and seting the base pressure to around 55 psi, then hook up a boost line to the FPR and you fuel pressure will increase 1 psi per pound of boost. This will offset the delta in pressure in the manifold and maintain your injector flow under boost which will help your injectors support more HP.

My recommendation to all of my customers is run the smallest injectors necessary to support your horsepower goals, and run way more fuel pump than you need. It's much easier to get smaller injectors to perform well at low pulsewidth (idle and cruise) and still flow enough fuel under boost with a big pump and an increase in fuel pressure. Plus the increased fuel pressure improves atomization, further improving drivability.

Still need to research that or someone explain it to me.. In the mustang world we would just sorry more fuel without really turning the pump up. But I've read a thread there the guy doubled his fuel pressure. I don't get this because I'm used to just seeing bigger injectors for more fuel. Not turning up fuel pressure.confuses me a bit lol

Injectors are rated at a set pressure. So for example the RX8 injector flows 480cc/min at 43.5 psi (most injectors are rated at 43.5 psi). If you lower the fuel pressure to say 35 psi, the injector flow will decrease. A VERY rough estimate would be to divide the new fuel pressure by the rated fuel pressure and apply that correction factor to the rated flow.

For example:
30 psi (current pressure) / 43.5 psi (rated fuel pressure)= ~0.69 <~~~ correction factor
480cc (rated injector flow) x 0.69 (correction factor)= ~330 cc/min
So if you lower your fuel pressure your 480cc injectors will actually flow like 330cc injectors.

Now if you raise the pressure to say 55 psi it looks like this.

55 psi / 43.5 psi = ~1.26

480cc x 1.26 = ~600 cc

So by simply raising your fuel pressure your 480cc injectors will flow around 600cc/min, which is a substantial amount of fuel.

The only caveat is that your fuel pump must be able to keep up with the increased fuel demand, and typically fuel pump flow decreases pretty rapidly with an increase in pressure. So if you oversize your fuel pump, a 255 lph pump to support 300 whp is quite oversized, you can run the higher pressure, support more power on smaller injectors, and gain improved idle and drivability from the improved atomization. Everybody wins! ;)

While in general smaller injectors tend to give better low rpm low load precision, modern injectors like ID1000s are just fine even when dinking around town.

It has more to do with the injector technology than size at this point.

800s dws arent hard to tune for idle. I can idle mine at 15afr all day long. Which i actually do.

Fact that in the summer i can switch to E85 without having to do any bolting is a rather nice bonus. That said DW800 or similar is a much better choice than a smaller injector.


Btw Trent, have you done any internal work on the motor? Dont remember reading that.

currently no. one reason 225 is the goal. i hear that is a safe dd hp limit. 250hp is apparently when the rods like to bend. next years tax return im planning on going forged for more power.


side question. the test pipe and aem a/f gauge came in today. when installing the gauge should i get a hole made into the test pipe for the sensor? or do you remove the factory rear o2 and just program it out of the pcm? is the rear o2 port too far back for a good reading?

guess what im asking is where is the best place to mount this sensor right now without the turbo manifold and downpipe installed? i would like to put it in a part that i wont have to replace when i get the manifold and downpipe installed. if at all possible.

What does the manufacturer say?

You can mount the wideband in the rear O2, no problem,for NA tuning as response is less critical.

Once you put the turbo on, move it closer to the engine. Usually 12-16 inches away from the turbo outlet works. That way you get good response but don't risk cooking the sensor.

You'll probably need to adjust the PID loop in Megasquirt to offset the transport delay caused by the sensor being further downstream, but no big deal.

Why is $400 worth of injectors better than $100 worth of injectors if the $100 injectors will support your power goals?

I've never had great luck with DW injectors, but most of my tuning is OEM flash programming, so injector data and response is VERY critical, but hey YMMV.

Strato, it isn't the cost that is the real issue, it's the technology.

Both the $100 injectors and the $400 injectors will work, but the $400 injectors are more likely (than the $100 set) to be EV14 or something similar. They will have better spray patterns, better dead times etc. By all means, run what works for your application but at the same time don't be afraid of running big injectors if they are newer technology. Specifically I am referring to the ID1000s that many people here run.

I agree that ID's and any EV14 injectors are great, and necessary when your power levels warrant the need for large injectors. But the OP stated he's working with a tight budget. RX8 injectors are EV6, which are still light years above the RX7 and Supra injectors in terms of control and quality, and the same in terms of quality as the NB2 OEM injectors. If he can avoid spending an extra $300 on something he doesn't need to reach his goals, then why not?

ALLOFIT

Good point. So much discussion happened that I forgot that the guy was on a budget.

I sent the OP a breakdown of what I paid for my turbo setup, but here is a link to what I think you should pay and how you will meet the budget:

Manifold, used: $175-275
Manifold, new: $400
Acceptable manifolds are Flyin Miata or Begi. Might be others but ask opinions on any manifold you find that ISN'T an ebay tubular

Downpipe, used: $150-350
Downpipe, new: $505
Flyin' Miata has a DIY manifold + downpipe kit. It's new so you are paying more but it is solid parts... Flyin' Miata : Turbochargers : Parts and upgrades : DIY turbo manifold/outlet/downpipe

Megasquirt: $450-700 depending on options
Wideband: $180
Injectors: $70-150

Clutch: $300 (approximately)

Piping and elbows and stuff for charge pipes: $120
Ebay intercooler: $100-200
Turbo: ???? all depends on what you want $100-1,800
Turbo oiling and cooling: $50-400 (anything from rubber hoses to BEGI distribution block)
Air filter: ?
Assorted other costs: $200

That is just off the top of my head.

been busy with work and stuff. finally got around to installing parts! still have a lot of parts to order and a lot of parts on the way :). just got the megasquirt installed today. took forever for me to figure out how to get it to idle down.. think i set the timing right. going to spend alot of time trying to figure it all out as it stumbles under light acceleration and i think i might be hearing it ping in low rpms under load... so going to recheck timing tomorrow. gonna spend a lot of time reading in the tuning section. would i be safe making a post in that section for me to explain things out and get advice? total newb to tuning so dont want to piss ppl off in that section for asking possible stupid questions. taking time on this build to make sure i do it right (and to keep from starving my wallet. im seeing to do this right its gonna cost a bit more than my initial plan but thats ok ill save up as im going.)

been a little while since ive posted (been a while since ive got to really work on the car...) anyways. made a quick video showing off the launch control feature of megasquirt :p


sending the two turbos i have off to get rebuilt and balanced. keeping one as a backup. getting closer and closer.. texas weather decided my car shouldnt look good.. so its gonna be an ugly "fast" car lol

more to come in the next few months as it starts coming together :)


edit.. dont know why the video is posting twice...

Ouch! We had hail like that a couple weeks back. Nearly caught a couple friends but they were able to duck under an overpass before the heavy stuff came down.

Driving me nuts seeing yellow RX8 injectors called 480cc. They are 425cc injectors. I (and anyone else who has them cleaned and flow tested) know they are 425 because I have the flow sheet that shows before cleaning and after cleaning results. And yes they were tested at 3 BAR (43.5 psi) There are larger RX8 injectors from other than the North American market that flow more. They are blue or purple depending on who you ask and don't idle worth a shit.

About the 14b, it is a great TD05 turbo, that in the stock DSM application puts out 11 to 12 psi... but this is because the DSM's have a boost control solenoid bleeder valve that ups the the boost 4 to 5 psi above the wastegate spring pressure. They did this so when some idiot put 87 octane in the car it would sense the knock from the low octane and close the bleeder solenoid to lower the boost pressure. This means that you should get 7 to 8 psi out of your wastegate actuator before putting on a boost controller.

Keith

been a while since ive posted. turbo is still happening. just might take 2 years of tax return to finish it lol. i have received 3 free turbos in the last month (pretty sweet lol) 2 need rebuilding. one is good to go. the good to go one is big though. really big. i dont mind it being big and having some lag if it is capable of spooling. so im googling like crazy trying to find out what big turbos have been used on miatas. so far the hx35 seems to be the biggest i can find. if this big one cant be used then ill just sell it and use the money to rebuild one of the smaller ones. the small ones are tr0760 garretts with .48 compressor a/r and .45 turbine a/r. ive been told i could safely get 250ish out of one of these turbos. the big turbo is a garrett. the only numbers i can find however are the a/r numbers. compressor is .60 and turbine is 1.15 turbine. any input from the guys with experience will be awesome. (pretty sure this turbo will not be usable for me)

lots of googling later the turbo is a garrett t04b