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Ok here goes. I have a 1999 1.8L miata with 175000 km. The engine is stock inside and out. The car is currently apart as the suspension is being rebuilt. I am on a tight budget and as such must do all the work myself. I cannot get all new shiny parts as I have a family and other priorities. Currently I have in my possession , boost controller, bov, turbo timer, AN fittings and lines, oil cooler, 440cc rx8 injectors, toyota COPs, water injection setup and some other bits. I also have at hand half a dozen or more turbos from various projects. I am planing on running a cast manifold for ease and reliability. The turbos are as follows, Rb20 hitachi bb ceramic turbo max boost 14psi, RX7 fc turbo, Evo7 TD05HRA-16G6-9.8T (RS/RS2). I can also get my hands on an Rb25 hitachi bb ceramic turbo max boost 14psi. I live in Japan in a mountainous area. The roads are narrow and winding. I need a respnosive agile setup which will produce power through the band. I do not want it to be too peaky or lag too much. I am hoping to get between 250 to 280 hp at the flywheel. Which of the aforementioned turbos do you think would best fit my needs and what are the benefits and shortcomings of these turbos. Any and all help, comments personal experience and links are welcomed.
Putting the effort in to reading a few of the stickies specifically geared towards new members goes a long way in getting you the information you need.
Thanks for the tip. I went through it. Some funny stuff in there. I would think some of the things would be obvious, but I guess not. I will do the into thing soon. It is a good Idea. It is rather late now and I am about to pass out. I have been reading hours on end for nearly two weeks. My eyes hurt and they feel like sandpaper (a quick cut and buff is called for). I am all hyped about getting this project going.
After weeks of reading, you should have found that building a set up around a somewhat random turbo, is a bad idea. So is not using a stand alone computer. 440's probably won't make 280.
I plan on using Megasquirt, but not the plug and play. Insofar as the turbos being random, I don't really take your meaning. The rb turbos are T3s and the Mitsubishi dsm turbos are very well supported and have many incarnations. As such if I have to swap out the turbo there are other variations and incarnation of the same housing type that will bolt in with little if any modification. The exhaust system will be v-band so that in such scenario the process is made easier. I plan on running higher fuel pressure somewhere in the 47lb range so that should give the needed flexibility to reach the power goals of the build.
:
I am planing on running a cast manifold for ease and reliability
:
If you're not making/using a custom manifold and want to use a cast manifold, this is where you should have STARTED!
ie. Find out what cast manifolds are available and what turbos they support, then based on the supported turbos, choose the one that supports your goals.
For years the only available cast manifolds were from FM and the OEM Mazdaspeed manifold (eBay knock-offs too but they don't count if you want reliability). Now we have the track-proven TSE cast manifold and the promising new Kraken cast manifold.
It's expensive and takes time to develop a cast manifold so they typically only support a specific turbo range.
Once you've settled on the manifold and turbo, the downpipe is the next big issue and it's usually cheaper and way less hassle using the one recommended by the manifold manufacturer than coming up with your own solution (unless you live overseas and the S&H is a killer) .
For years the only available cast manifolds were from FM and the OEM Mazdaspeed manifold (eBay knock-offs too but they don't count if you want reliability). Now we have the track-proven TSE cast manifold and the promising new Kraken cast manifold.
There's also the pretty nice looking g19 engineering (subaru turbo flange) cast manifold from the UK. Plenty of options now.
Once you've settled on the manifold and turbo, the downpipe is the next big issue and it's usually cheaper and way less hassle using the one recommended by the manifold manufacturer than coming up with your own solution (unless you live overseas and the S&H is a killer) .
Well put. I do live overseas as a matter of fact. I am looking at a T3, however I have found T3 to td05 bolt on flange which will enable me to run the Evo turbo. On the other hand I can bolt on the Rb turbos right up as they have a T3 flange.
The specs of the turbos at my disposal are as follows:
Rb20 Hitachi T3glange T28 centre ball bearing ceramic shaft and blade max boost 14psi
Comp
inducer= 42.5mm
Exducer=58mm
55 trim.
50 AR.
answer: none of them.
or which ever you want, if you wanna do it the hard way
Please elaborate. As I see it the MHI evo 7 turbo does not bolt up and requires extra work. As such I can see how that is indeed more difficult and can be problematic. However, the T3 is a direct bolt on to the manifold, so fitments is not an issue. There is no doubt that buying a prefabricated kit is easier, but it is not an option that I can afford. I am hoping to find a practical and reasonable way to do this. All of the parts that I currently have are quality brand name parts. The only compromise here that I am making is the turbo. I am not keen on getting some Ebay chinese turbo. On the other hand there are many oem turbos here in Japan that fit the bill both in terms of ability to produce the desired power and reliability.
The rb20 turbo is a good size and has t3 inlet. Run it. Should be fine.
I was thinking much the same. I have access to both the rb20 and rb25. They share housing, flange and centre section design. Naturally, there are differences. Both are 55 trim on the comp side. The inducer on the rb20 is 42.5mm while the rb 25 is 48.5mm, exducer 58mm vs 67mm, A/R .50 vs .60. Here is a pic the illustrates the difference.
09-02-2017, 04:01 AM
Which of these turbos to use?
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