texastboneking

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

Chilicharger665

iTrader: (2)

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

triple88a

iTrader: (2)

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

texastboneking

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?

triple88a

iTrader: (2)

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?

texastboneking

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

triple88a

iTrader: (2)

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 **** the first time.

texastboneking

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

triple88a

iTrader: (2)

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

texastboneking

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

triple88a

iTrader: (2)

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

texastboneking

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

2manyhobyz

iTrader: (4)

That looks good. Pull the trigger.

triple88a

iTrader: (2)

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

texastboneking

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

StratoBlue1109

iTrader: (1)

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 *** 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!

mlev

iTrader: (5)

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.

carnut169

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!

StratoBlue1109

iTrader: (1)

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. 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.

StratoBlue1109

iTrader: (1)

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.