Need help with DIY turbo parts
 

I have been working on putting together a Garrett T25 based system for my 97 Miata and I have been having trouble finding a few of the parts.
So far I have a HKS manifold, T25 turbo, BOV, bipes acu, coolant/oil/vacuum lines, and an O2 clamp.

I still need an intercooler (preferably 2.5 in/out, but 2.0 will work), but I can't seem to find one that will fit a 97 w/ ac.

I need to find a flange for the exhaust side of the turbo so I can make the downpipe and exhaust. I also need advice on a cat to use.

I also need advice on injectors, at best I have found that part of the DIY cryptic. I am looking to get about 10-12 psi boost and can't figure out what size injector I need.

Any advice or words of wisdom would help, this setup is on a budget where cheaper is better, but I do not want to have to replace/rebuild parts right and left.

IC: http://www.cxracing.com/mm5/merchant...ry_Code=IC30CO

Flanges: www.atpturbo.com

Cat: Universal high-flow that matches the exhaust diameter

Injectors: go to DIY > FAQ , read my section on injectors and what ones will fit.

Thanks, I think i finally started to some what understand the whole injector bit.

So I am looking at using a bipes acu and an O2 clamp, is this correct or should I just use the bipes?

The two serve completely different functions. The ACU is a variable ingition retard, designed to allow you to run stock ignition timing but reduce advance under boost thereby preventing detonation. Has no effect on mixture.

The O2 clamp is there to prevent the ECU from noticing that you've gone rich when on boost and trying to reduce fueling to compensate.

Which brings up the fueling question- I didn't see anything in your list that addressed this. Assuming you are keeping the stock ECU (and not installing a piggyback such as an eManage) there's a practical limitation to what you can do in terms of injectors. Some folks report that they've been able to get injectors in the high 200s / low 300s to work by adjusting the AFM, but no personal experience here. At a minimum you'll also need an adjustable fuel pressure regulator such as the old FM / Bell kits used to have to get anywhere near 12PSI safely.

A "better" solution would be to get some injectors in the 440-460 cc/min range and use an eManage ultimate, Megasquirt, or some other ECU that can manage them properly. This will eliminate the need for the fuel pressure regulator and the ACU.

ok so I cant run that much boost then, I just don't have the money to get either of those, I have managed to find the bipes acu and the o2 clamp for 180 total.

But I was under the impression that the bipes could also set pulse width, guess not. So dose anyone know of any references for modifying the afm?

http://www.diyautotune.com/catalog/m...f79095ab1b6e5b
if you don't have enough money for that, forget about turboing your miata.

I'm not going to say that you *need* an AFPR, as people have clearly demonstrated that you also don't technically need beer to survive (thus disproving many of my theories) but I personally would not turbo a Miata without a fuel pressure regulator at an absolute minimum. It doesn't necessarily have to be a fancy Bell regulator. Ask around here (search the classifieds, post a WTB) and you'll probably find someone who has upgraded their Greddy kit and has a Vortech for sale.

No on the Bipes. It connects to the ignition system only. Does a good job of timing control, but that's it.

There are two adjustments that can be made to the AFM. The first involves the clock spring which is under the big black plastic cover. Tighter = less fuel (to compensate for those big 'ole squirters). The second adjustment is the adle mixture- it's a screw under a small round cap which you'll probably have to drill out. This is a fine-tune to try to get your car to idle after you've done the above.

Disclaimer: You're going to kill your car. I can feel it. I take no responsibility for that, and furthermore I call dibs on your transmission. :bigtu:

wow, ok well apparently i suck at finding things properly and have just been owned, but i have made sure to put good mechanical parts in with the plan to eventually upgrade to an ecu replacement, but if that is what i should be looking at, along with a pressure regulator, then i will just do it right since i wont be looking at around 500 to do a piggyback system, thanks Al Hounos.

is there anything else i should be looking at

so far i have a garrett t25, hks manifold, GFB BOV, cxraceing IC, MegaSquirt-I (with harness, simulator, and all other needed parts), all the vacuum/coolant/oil lines/parts needed for install, and i found some RC 560cc injectors for 150 from a local shop, i will be doing my own dp/exhaust and looking for a pressure regulator

well you surely got well on your way in one day.

ya, thank you soo much, so is there anything else i should consider?

the only thing you need to go with that MS is an IAT sensor, a WBo2 sensor like an LC-1 (which you need on any turbo car for tuning, even without a standalone), and those injectors you mentioned. you don't need a FPR

read a bunch on here about MS and decide if you want to build it yourself (8-10hrs) or buy it prebuilt.

... and a MAP sensor, unless he's already got one as part of his ACU purchase.

Also, cocide, if you can find some 440-460cc injectors, they will probably work better for you than the 550s.

the ms has a MAP sensor built in... and 550s would be better for a 1.8.

awesome, I think I got it now, I should be fine building it since I design and assemble new motherboards for servers.
so I'm adding a LC-1 and a IAT then, thanks again guys.

Imagine an image of me slapping myself on the forehead right about now, saying "D'oh!".

Not sure I'd agree on the 550's being "better" but they'll certainly work.
Plenty of folks running 'em even on 1.6s, I just prefer to go as small as possible.

OP has a 97 so there is not an AFM to adjust.

With just the Bipes and BEGI AFPR and a cheap fuel pressure gauge you could run 5-6 psi, depending upon your pumps capability fuel pressure, a lot of us started that way.

You'll need to devise a way to connect your EGR to your HKS Manifold (BTDT)
IIRC FM sells the specific fitting for ~$20.00

yes, but if I do the MS wouldn't I be able to just cap off the EGR at the intake and remove it or should I leave it and 'adjust' the manifold.
I do not have an emissions test to pass and do not think that it is needed to pass inspection.
so basically is it needed and will it/dose it have any affect if I use the MS?

no, block it.

cool, works for me.

You'll have to live with a CEL then...