colincoon

iTrader: (1)

Well this is only my second post, so I guess I'll put my flamesuit on just in case.

I more or less want to turbo my Miata and while I've been considering it since I bought the car I decided I wanted to do it after running it on the 1/4 last weekend. 16.7XX at 81mph is almost fun...almost.

I actually want to go the ghetto/chinacharger route with this one, as I paid next to nothing for this car and it's my "fun" car that I daily drive and whatnot. I know my way around a car, I've been working on Mercedes for years now and so far have not had an issue working on the Miata. I don't want to sound like an idiot doing this for $300 or whatever, I'm more than willing to put money in to this project, just not a ton. I will definitely be using MSPNP for engine management.

My experience and knowledge of turbo's and forced induction isn't that great though, but I've done some research. So here is my plan/what I need advice on.

Turbo: Like I said I want to go with a Chinacharger, and have been told that the Godspeed turbo is the best one to get in this category. In terms of which one though is where I am confused. Should I go with a T3/T4 or a T25? I know I sound like a n00b asking this but I need advice.

Manifold: It seems that the most common 1.8L manifold on ebay is one that looks about as solid as a wet napkin. I really want to go with the "log" style manifold, but don't want to pay $500 for it from FM. Any suggestions on where to find one of decent quality for cheap?

Wastegate: Obviously internal is the easy way to go, and what I'm leaning toward, but would external be worth it? I guess finding a manifold with an external wastegate port would be nice, but if not what am I losing out on by having an internal wastegate? Obviously I would have it ported out on the turbo prior to installation.

Intercooler: This I am more or less in the dark about. I know the function of the intercooler and everything else, but what SIZE and shape should I be looking for for the Miata? What have you had good luck with in the past?

That's about all I've got for now, once I feel completely comfortable with what I'm going to get I'll probably start collecting parts.

Thanks guys

skidude

iTrader: (3)

You missed the most important part for us to help you: Power goal. If you want 150whp, that is a very different set of parts than 250. Given the "low cost" thing, I doubt you will want to go higher than 250.

I will assume you want 250whp.

Go with the T25, given those two choices. T3/T4 is huge.

I built a decent log manifold out of weld els and a flange, I think it was only a couple hundred for the parts. This requires a friend who can weld well though. Don't bother with the tinfoil ebay manifolds, I have yet to hear anything good about them.

Internal wastegate should be fine for this, what are you doing about exhaust?

A generic intercooler kit from ebay should work nicely. I forget the dimensions of mine, but something like 22x8x3, give or take a couple inches.

colincoon

iTrader: (1)

I guess that is sort of important isn't it? Yeah somewhere around the 250 mark would be preferable. I don't really want to have to do pistons and rods unless I have to and am making big numbers.

T25 it is, seems to be the right size for this engine and what I'm trying to achieve.

I don't really have access to anyone that knows how to weld, but I'll keep an eye out for one. No way am I going to go with the shoddy looking ebay manifolds, I too have not heard anything good about them.

Okay good, that's what I was hoping for. How about manual/electronic boost control? Is the little ball-valve boost controller frowned upon or is it decent? As far as exhaust goes I was thinking about doing 3" or so all around, would that be too big for the turbo? I know they like to breathe as much as possible but do they need back pressure as well?

Okay perfect, I'll keep an eye out for one in those dimensions.

Thanks for the advice thus far, I'll keep posting questions as I come across them.

skidude

iTrader: (3)

3" exhaust will be perfect. Turbos want no back pressure, so the bigger, the better. 3" is what most people here run at those power levels.

The little ball-and-spring boost controllers are great. I don't see the point in EBC. I have tried it a couple times on each of my cars and it just never works quite as well as the simple MBC.

Keep an eye out on the classifieds, you can often get good deals on manifolds, injectors, intercoolers and the like when people give up part way through their builds and sell everything. Also, don't forget about all the little crap that will add significant amounts to your final budget. Oil supply/return lines, odd couplers that won't come with your intercooler kit, random nuts and bolts, new spark plugs, clutch (I guess that's not minor, but you'll need it), etc.

BTW, put some info in your sig and your location in your info.

colincoon

iTrader: (1)

Okay awesome. My exhaust is starting to show its age right now anyway. It is beginning to look like cheese. What are people running for Cats (if at all), resonators, and mufflers? I really don't want a fart can, I like the way the M-Edition exhaust sounds low and raspy. I know turbos eat a lot of the noise too.

Okay awesome, that's good to know. I guess that leaves me with more budget for a wideband.

Yeah I've been keeping an eye out for stuff I'll need and whatnot, seems like there isn't a short supply of used turbo components. I was smart and bought a brand new Excedy clutch when I got the car because I was told it was having issues, but alas it was just the MC and nothing else. Sucks that the clutch is stock though, so I'll just have to resell it. The F1 Stage 3 looks to be right up my alley, and I don't think I'll be making much more than 250 ftlbs so I might just go with that.

I'm updating it now, I need an avatar and whatnot.

Thanks for the help thus far!

Wildanimal

iTrader: (2)

The magnaflow high flow cats are a decent setup. I'm going to be running twin magnaflow mufflers (dinan style) and the magnaflow cat. It sounds like it would be a bit louder than you would like though.

As far as turbo parts go, you need to be patient. I bought my unused HKS 1.8 Manifold and a used sr20 turbo from the classifieds here.

thirdgen

iTrader: (26)

Buy my sr20 turbo and my cast outlet. Then you'll need a manifold and the DP and you're set.

skidude

iTrader: (3)

Exhaust: I have a 3" enthuza and I love the quality but I wish it were quieter. Mine has an 18" magnaflow, and I wish it had the 22" and maybe even a resonator. My '94 had a home-built 2.5" with an 18" magnaflow and it was actually a lot better. That extra half-inch makes a huge difference in noise. Both have a high-flow cat. Always stainless.

I had the F1 6-puck in my 94, and for the price it worked but when it came time to do it again I was more than happy to spend the extra on the FM clutch, and I would do it again and again. The FM clutch is amazing.

Nice sig and picture.

RattleTrap

Years ago, one of the best welders in the area worked at Takash Racecraft.
I think he was aerospace certified. Did some motorcycle parts for me. Goood welds. Pretty.
IDK who's there now. You could give 'em a shout.

Go to local shows, ask people who they had do their work.

colincoon

iTrader: (1)

I was thinking Magnaflow too, and I don't mind loud, just not annoying sounding like a civic or something. From what I've heard it provides a low tone which I'm a fan of.

Yup this is not a "lets get some boost quick" project, but rather a "lets take my time and learn about this" project.

Send me a PM!

Do you have the "turbo street racer" or whatever it's called? I looked in to that too, seems affordable. How loud is it? I'm still going to go with 3" all around but would like it to be tolerable in terms of noise.

I looked in to the FM Level 1 clutch, but will have to decide if it's worth throwing down that much for it. Did you have any issues with slipping or anything with the F1 clutch? What were your numbers when you had it in? If this was a car I was going to turn in to my pride and joy I would go with the FM clutch, but so far it's not.

Thanks, took it today when changing my oil/valve cover gasket. Felpro brand is crap btw, I have had three of them split on me since October! B&A from now on. Here is the actual picture:



Wow, aerospace certified is pretty good. I used to fly a bunch when I was in high school so I know how hard that is to get. Might have to check them out, thanks for the tip!