RX7Club.com - Mazda RX7 Forum - Non-Seq Twins Question about turbo control

Most weld the pre-control gate open.
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Beyound the standard non-seq conversion but not the rich man's:

To optimize a non sequential stock turbo system only takes a little time, and simple die grinder or Dremel "Tool" with carbide bits. This will be in addition to what is done at: http://www.fd3s.net/non-sequential.html.

You do not need all the parts listed as many do not apply to doing only the conversion.

Step 11, you should get a new "O" ring seal if yours is older than 2 years.
Step 13, make out of a piece of aluminum about 2-3mm thick.
Step 26, no need to remove the lower intake manifold unless you engine still has the original paper one and you upgrade to the metal gasket. If you also do this,
it is a good time to port match the openings where the upper intake manifold
bolts to the lower manifold. Use the metal gasket for marking the metal to be removed.
Steps 33-34, only remove both turbos if sending the turbo housing out to have the wastegate opened up. Anyway, mark the turbos to housing for alignment for reassembly. If porting the WG yourself, only remove #1 turbo and the front third of the turbo housing.
Step 36, open fully and weld it there.
After Step 37, also grind the air pipe intruding into the #2 exhaust port, down flush with the exhaust manifold.
Step 40 is not part of the non-seq conversion but is a throttle body mod.

The next section about making the WG 1.24" wide is wrong (too large). You can do this by hand with the mentioned tools without removing the flapper. Make the opening so that there is at lease a 1/16" (1 mm) lip for the flapper to seal on.
Look at how the gases flow through the opening and round off the interior edges of the port inside away from the flapper. After all the work is completed on the exhaust manifold, bolt it to the turbo assembly with a few loosely tighten fasteners. Then look through the #2 port in the exhaust manifold to how the gases flow into the tubo assembly housing. You will see a very flat area where the now removed turbo control gate use to seat against. This obstruction to
exhaust flow can be modified to flow better which makes more power. You can mark it with white paint or something else. After removing the manifold from the turbo assembly, use the tool to round off that sharp 90 degree edge. Be careful that you do not remove too much and make a hole in the housing. You "can not make it perfect" but only improve it.

You can also make shims to go around the 4 fasteners that keep the "Y" pipe attached to the 2 turbo compressor outlets. When loosely attached, see how much play there is. This causes poor alignment with something that fits poorly to begin with. The shims that fit into the holes where the fasteners go through, will reduce the "SLOP". This will keep the parts aligned better. Then using the metal gasket that goes between them, port match all 4 openings.

Use a rubber cap to cover the pipe on the back half of the "Y" pipe where the hose for the charge relief valve was.
It looks like a bov.

Doing simple obvious things like this will increase intake and exhaust flow for more power. I do my own work so it was free power for me. If you pay someone to do these little extras, it probably is not cost effective to gain the extra power.

But as you know, "attention to detail" is what makes a car faster!

If you do not need to pass emissions testing, then also remove the air pump.
If you do this, then while cleaning up the rat's nest, also remove the air control valve and install a cover plate over it. I was non-seq with a working air pump and air control valve to just help keep the exhaust gases cleaner.