So it seems like most single turbo setups (although not all) require air pump removal, but I'm wondering if its possible to pass emissions with a single turbo.

Has no one developed an electric air pump or a catalyst that doesn't require an air pump yet?

 

The stock airpump usually will not fit with the placement of most single turbo kits. There have been a couple kits specifically designed to fit with the airpump. Some people have wired in a gm electric airpump temporarily to pass emissions.

 

So there's no permanent solutions? Doesn't the cat only need O2 at below 3500 rpms, or something?

 

the air pump is ON, below about 3500rpm (throttle position matters too), and below about 3200rpm the air pump air is going to "port air" which is the exhaust ports.

there are two permanent solutions.

1. but a turbo kit that fits with the airpump. HKS and Greddy make them, Apexi used to, etc etc.
2. use a different air pump, or move the stock one. the stock air pump has a clutch, so this signal could just run an electric air pump, or a relay for one.

simple.

 

Has anyone moved the stock pump?... By different pump you mean an electric one?

I have heard they don't last very long if I try to use them with rotaries.

I did not know the FD's air pump had a clutch. The FC pump definitely doesn't...

 

I wouldn't bother with the stock pump. Its heavy and its going to be difficult to move it and get a belt to drive it. I've seen RX8 electric airpumps adapted.

 

Why not build a custom single turbo setup with the turbo sitting back and lower than most? Its not that hard to make a manifold that can get this done.

 

Because then you can't get the ideal runner length, wastegate placement, and the kits that have the turbo hugging the block just heat up the intake.

 

Here you go !

http://www.turbosource.com/FD3S-Short-Runner-Manifold-p/ts-tbshrt.htm

 

I just wanted to know in advance if I ever bought a single-turbo FD3S. I'm not planning on building one myself. They're relatively cheap here...even with 400-500 HP. Cheap to buy, of course; I'm sure something expensive would break within a week.

 

Description says it requires full emissions removal.

 

If you only run them when the stock pump clutch is active, would they last as long as they're supposed to?

 

I don't see why not.

 

This might satisfy you from Rotary Performance, one of the leaders in the industry.


"For those needing to pass emissions, this system is definitely for you. It is the only turbo kit made today that has the ability to run the factory air pump and all other emission components. Included in the kit is a compressor charge air tube that makes an easy connection to the factory or most other standard mounted intercoolers. Of course all needed nuts, bolts, hoses, air filter and thermal protection is included. Look and compare. We know you'll be impressed. Proudly made in the USA by rotary perfectionists for rotary perfectionists".

Rotary Performance GT3582R Single Turbo Kit

 

It seems like there are catalytic converts out there that can be used to make a car without an air pump pass emissions with the right tuning.

Anyone heard of this?

 

Not many people bother with emissions because they are expensive, especially on a rotary with high EGTs.

Proper cats that will not choke power and MIGHT stand up to the heat are in the $500 or so range.
Vibrant Performance ::.

 

Actually, the kits on sale in Japan have cats that look like that, but they come with built-in downpipes (at least some do) and cost about $800... well, about $600 at the current exchange rate.

This is still less than half what a stock cat costs, FWIW (if memory serves).

 

On the other hand, could running a cat on the track damage a 500 BHP single turbo FD?

 

Description has been updated! We found out later it all would fit..

 

i live in California, so i have had to smog every car i've ever owned, every two years. i average about 5-6 smog checks a year. i think your question has a two part answer.

the first part is where does this car need to pass? i looked at the Japanese shaken test standard, and compared to CA its pretty lax. in CA the standards are set by the cars weight or something, so the numbers aren't the same everytime, but we're allowed around 80hc's, 0.06? CO, and about 450nox's. in Japan you just need to be under 250hc's and 0.20? CO.

the second part; due to the design of the engine the air pump does a LOT, but i think you could squeak by with just the cat and no air pump.

 

Yep... in Japan.

I wonder if I could hook up an RX-8 pump with a resister and a relay to the stock air pump clutch wiring, and then just pipe it into a bung on the downpipe ahead of the cat? Or would the hose simply get blown off? Or just melt?


On another note, would a car with a TO4S and 500 flywheel HP with an aluminum aftermarket radiator, FMIC, RE Amemiya aero bumper, and two Greddy 12-row oil coolers likely have cooling problems on the track? Would I likely need a vented hood?

Full disclosure... I'm thinking about buying a 92 single turbo FD for about $5000. lol. It's probably a terrible, terrible idea.

 

I would say it should be ok as long as its ducted properly.
There have been many competitive race rx7's that have run front mounts over the years.

 

the FD air pump circuit is 15A as it needs to operate an a/c style clutch. not sure what the Rx8 circuit is, but relay might not be needed.

ideally you'd go to port air, which is the exhaust ports, but the JDM midpipes tend to have the split air bungs on them which seems to work well enough.

 

Assuming the ports haven't been welded shut, I suppose I would have to reinstall or unblock a stock ACV? Does the stock main cat not have an air hose connected to it, like the FC does?

 

installing the ACV is the simplest way, although you could just thread a fitting into the port and use a check valve right to the air pump, like the Rx8 does.

it does, but like the FC its only used for transitions the bulk of the air pump air either goes to the ports or gets vented to atmosphere