04-17-2009, 02:27 PM
Join Date: Mar 2009
Location: Salem, OR
Total Cats: 0
Oregon Miata owner
Finally getting around to introduction. I've owned my 1990 white NA for a little over a year now. I bought it bone stock from the second owner. It had around 182k on the clock when i bought it. I bought it as a commuter because I drive 50 miles each way to and from work and needed a better car on gas than my piggish Durango. I made some interior upgrades like re-upholstering the seats with leather and added heaters, short throw shifter, chrome style bar, and chrome vent rings. I commuted for about 3 months before i decided I needed to make it faster.
So that began my research into turbocharging (which is the first I've ever researched it). I decided it was a viable solution to my power needs, so i purchased a china charger "kit"off Ebay (I know, I know, but live and learn right?). As you can surmise the "kit" was not exactly complete. It took me about a week of working evenings and the 2 weekends surrounding it to complete the install. I had to custom fit everything. I had not yet discovered this site at the time, so was relying on Miatanet for information, which did assist me in my install questions (since the "kit" came with absolutly no instructions or even parts manifest).
After I got it up and running, it took me several months to work out all the bugs. In that time is when I discovered this site and I soaked a bunch of info off all the knowledgable memebers on here. I have it running pretty good now and am very pleased (for the moment) with it's performance.
I have a blast on the freeway I commute on because I can drop the hammer and wail around whomever happens to be in my way! I would definitly still turbo it if i could go back in time, i would just use different parts and install it a little differently. Mostly, I didn't know about clocking, so I just cut my intercooler plumbing to work with the position the turbine was in. This caused it to be a somewhat non direct routing of the plumbing.
Heres what I'm currently running: Godspeed 20g turbo(internally wastegated to 8psi), Godspeed Intercooler, Walbro 255 fuel pump, 1.8L injectors, a generic RR FPR, a MAF from an Rx7, generic manual boost control (although I don't use it), generic RS type BOV, and a Tsudo 2.5 catback exhaust.
I adjusted the linkage on my wastegate and at redline in 5th gear, my boost gauge is actually reading 10psi. I'm not sure if that's just a margin of error in my gauge or if adjusting the linkage is actually making the wastegate open a little later and allowing the boost to get up to 10. My air/fuel gauge has me running rich under full boost and at ideal at cruising speeds (my plugs confirm I'm not running too lean). At some point, I will probably look into a fuel management system, but since I don't seem to be running in the danger zone, I havn't made it a big priority.
I've had the standard problems one can expect from an ebay charger kit, namely cracked tubular manifold (i'm on my 3rd one now, although, i had some extra pressure applied to the previous 2 because i had to block my exhuast down for a while until i figured out a solution to it's routing.). For some reason, my flange bolts on the charger to manifold flange seem to back themselves out over time, so I'm having to check them and re tighten about once a week. I've loctited the crap out of them and still have them back out.
So I was wondering if anyone knows of someone that makes a cast manifold that has the same turbo flange as the generic OBX tubular manifolds that you can find on ebay? It's a 4 bolt slightly rectangular flange (nearly a square). This would eliminate the biggest problem I've had with my setup.
And in closing, thanks to all that post information on this site because it is an invaluable tool to someone like myself who is a do it yourselfer and needs a little direction at times with something I'm trying for the first time.