Some of y'all may remember my project updates back in spring/summer 2007, when I bought a pristine 1992 Sunburst Yellow Miata and proceeded to give it the Greddy treatment. During the install, I also did an intercooler, 2.5" exhaust, among other things. Here's a few pics from my original Greddy install thread.
After the first round of mods, it was making great power, even at 5psi. (BTW - when I posted this video, I never dreamed that YouTube people would call it fake/sped up, but they do, constantly. Sigh.)
As time went by, I continued to make small improvements, many inspired by my experience playing with Mitsubishi 4G63s for many years. After a new clutch I finally got it to the dyno.
I really enjoyed the car like this and drove it all the time, rarely missing an opportunity to tap into the extra (and much needed) power. But as many of you can relate to, work got much busier, the family was growing and in January 2009 I decided to sell all of my turbo stuff. I sold it all because I planned to sell the car. What can I say? As you get older, a weekend toy car like this just seems impractical and a luxury that I could do without.
I posted it for sale locally and had great offers, but something told me I'd regret it years from now. At the 11th hour I decided to keep it. I still drove it all the time, but the stock 1.6 was just a terrible soul-sucking horsepower void that could no longer be tolerated - which is why I'm talking to y'all today.
After de-Greddifying my Miata, I'm now re-turboing it with some different goals in mind. I've still got a super-tight budget and my plan is set - now I just need to get to work! Last but certainly not least - I've been lurking for some time soaking up tons of knowledge from all of you. Thanks for openly sharing so much info - it has been extremely helpful.
Oh snap, it's you. I've seen your video quite a few times, and it's actually the only Miata related video in my favorites. I'd like to hear/see more about the car. Kind of inspiring me to go outside of the BEGi box and piece together something, seeing that ebay manifold.
Thanks for the warm welcome back and kind words fellas, I appreciate that!
Speaking of Ebay turbos, mine showed up just the other day. I chose this completely based on the positive feedback that others have shared here. I went a little bigger than I wanted, but the low cost of this turbo means that I now have room in my budget for something smaller if this is too big and laggy. I am going to give it a try and see how I like it. That's the beauty of this manifold - a million affordable (and not-so-affordable) options are out there.
Also, just as an FYI - the buy it now price is listed as $152 plus shipping. I offered $132 and the seller accepted immediately. Here's a link to the one I picked up and some pictures.
Made a little more progress last night. I made a few tweaks to the turbo before bolting it up. First off, I decided to check out the internal wastegate mechanism and saw some room for improvement. An old DSM trick is giving the flapper arm more room to travel/open. Here's how it looks out of the box - not much angle there.
So by grinding out a little divot in the wastegate housing...
The flapper can now open at a much wider angle.
I've never met an internal wastegate port I liked. This one was no exception.
Here's the flapper diameter:
And here's the wastegate port diameter. There's just a little room for improvement there!
It's hard to capture this kind of thing on camera, but here's the port after enlarging it and smoothing it out.
On the internal wastegate DSM turbos I've modified in the past, I really concentrate on the flow from the turbine inlet into the wastegate port. Again, hard to tell here, but this has been smoothed and opened WAY up.
Hell yeah. I'm all about optimization of the waste gate form. I had to do similar with one of my RX7 turbos once to cure boost creep. Ground down some of the surrounding material to make room for a larger puck, ground down the floor for more open room, and welded the new puck on (stationary, welded in place so it would contact flat, and not wobble around on that pitiful pivot). Enlarged the port itself by about 3/8'' and never had trouble again.
Looks like you are on the right track. I'm watching this VERY closely, as I may likely go the ebay chinacharger route to save $$$.
Also, might I inquire as to where you got that manifold? And also, it looks like it would give clearance to work with a/c. Is this the case that you know of? I like the placement of the turbo with that manifold though, very much what I want (I think). Probably one of those deals that is only for the 1.6, which makes no sense to me.
Also, might I inquire as to where you got that manifold? And also, it looks like it would give clearance to work with a/c. Is this the case that you know of?
I have A/C and there is tons of clearance for the manifold. It puts the turbo in a pretty darn good spot too, allowing for plenty of downpipe room. It will be tight with the internal WG/V-band setup I have, but still doable. I may end up with an external wastegate setup when it's all said and done, I just wanted to see if an internal was even possible.
Is there a reason, other than to **** me off, that they don't make 1.8 versions of these decent cast manifolds? I see so many DAMN good priced 1.6 manifolds like the one you have, but then I can never find an equal in the 1.8...
Seriously though, If I can find a manifold like this for 1.8, for under $200, I can high chances of me stockpiling turbo build parts as soon as this weekend. Turbo for less than $200, and a $100 manifold, why not give it a shot. Sure beats the $3000+ I was going to save for a BEGi system. Tinker on it a bit, weld up a decent v band downpipe, ebay intercooler, rx7 550cc injectors and my ms pnp and I am about good to roll. I have been thinking about just running with the stock block for now. Run super conservative timing and fuel, and low boost, shoot for 200whp area. Surely a stock rebuild with 20k miles, good compression and a decent tune can hold up to 200hp easily enough, without too much fear from me.
Sorry, I realize I am hijacking your thread a bit. I guess I have to go make my own, I have many questions!