RX7Club.com - Mazda RX7 Forum - 13B turbo R5/Y Nikki build

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13B turbo R5/Y Nikki build

Jeff this is Jeff your my turbo hero right now and that looks really nice.

I figured you'd like what you see.

Jeff can you let me know what parts you used I am doing something similar but on a 12a

Quote:

Originally Posted by Jeff20B (Post 11811132)

I figured you'd like what you see.

you bet I do if only I was up closer to Washington I would probably ask to meet up but I live in lower Idaho so its a no go

would be one of those times I ask to be shown how to tear down and time a motor from someone who has been doing it a lot longer.

but nothing a junk motor can't solve for practice.

by the way is that going in your REPU can't remember what you said from before?

awww icy...I missed you. Looks good Jeff!!

What Nikki manifold is that?

It's a 13B Hitachi manifold drilled & tapped for a Nikki.

I needed an assembled short block to test fit parts. Icy is a test rig right now. :)

This was just to test fit parts. Most of them went into the brown car for test running. Enough power to break them loose in gear on dry road. Even managed to do it in 2nd gear. But there is a bog when the secondaries open that I'd like to solve before a turbo goes into the REPU.

A 12A is going to have different clearances and spacings. Plus there is a search function on this forum. Oh and the carbs were hogged out to work on a 13B and boost prepped. You might not need to hog yours out, but it's still a good idea for better off-boost performance. Search.

One small piece of advice I can provide, however, is look for a 79 intake manifold and learn how to put quicksteel in the intermediate plate's ACV port. You're on your own for figuring out a manifold spacer and grinding down the ACV area to fit the compressor housing. You might cut into the water jacket. I didn't, but that's probably because I was pretty careful. I also installed brass freeze plugs in the rotor housings for easier manifold removals/swaps for testing.

Get a MOOG idler arm, obviously. You could probably do a 1" spacer if you have a Moog. I get plenty of room with my 7/16" spacer and the 13B width of the secondary runners. Turbo install/removal is easy enough. Yours might get interesting though with a thicker spacer.

Have fun everyone!

i really like that light blue

Thank you for your help and advice jeff

So I got a rebuild kit for the carb pictured above. Replaced the usual stuff like site glass window rubber seals and new paper gaskets, accel pump diaphragm etc. Cleaned up the housings and stuff. I made a new base gasket because the ones that come in the kits are too thin. Still a little damp around the secondaries so I threw on the thin gasket too. Must be a warped housing. I'll have it fly cut later.

So the carb is all back together. Then I tested it with the turbo. https://www.rx7club.com/images/smili...y-evilgrin.gif The first jets I tried are ideal on the other carbs but were too lean here so I swapped to the richer ones usually reserved for NA (yes NA wants richer jets than turbo for some reason). Ok, now it seems right. But when I get on it going up a hill, just taking it kinda easy and not going into boost or opening the secondaries, it goes pig-rich and floods itself badly. Sputters. 10.0 on the wideband. Could it be floats? Needls and seats? Probably.

You see, I swapped some Grose jets in and I think they don't like boost. The float levels were perfect at 2.5psi at idle but when the mallory sees anything above atmospheric, it lets more fuel pressure into the carb at a 1:1 rate. So 1psi of boost gives the carb 3.5psi of fuel. Anyway none of the other (boost prepped) carbs with regular needles and seats do this so I'm going to say Grose jets don't like boost.

So it's going to be an NA carb. To tune this carb for NA, I'll leave the current 130 primary jets in place as they seemed almost perfect with just a little bit of leaness with the 90 air bleeds before, so all I gotta do is swap from 90s to 80s and I think it will be perfect.