Hello all, I've been absent from RX7Club for a while now, focusing on more pressing issues, but have now had time to get back into my S4.5 build. Let me first start off by saying that I am by no means, an expert on rotary engines. Just a simple man trying my hand at a "not so simple" car. 😅

The car is a 1987 GXL with an S5 TII engine.

Water lines: -The car is running a Turblown EWG manifold equipped with a Borg Warner EFR 8374 and twin TurboSmart 38MM wastegates.
Want to know: -Details for all the water lines to feed the turbo and both wastegates, as well as the return lines (where to where).

Wiring: The car is running an LMS-EFI harness attached to a Haltech PS1000 ECU. I'm also using 4 IGN-1A smart coils for a direct fire system. The adaptive suspension was removed and replaced with coilovers, and I've retrofitted Morimoto mini projectors in place of the factory sealed beams. The car is also fitted with an FD alternator.
Want to know: -What wires/connectors can I get rid of? Do I need the fuse block in the engine bay still? If yes, has anyone relocated it to a different location?

Feel free to PM with your responses or simply add your comments to this thread. Any help, wisdom, and opinion is welcome.

Thank you all,
Ryan H.

 

Water lines to turbo have been resolved. Still looking for insight on water lines to the wastegates, as well as help with wiring.

 

Really can't do much with the front harness. It feeds the main relay, which pretty much powers all the important stuff. Even with our engine harness, you'll still need to get power through the relay to turn the ECU and engine fuse box on. You also have your alternator wiring up there. It can be simplified and made to look cleaner. But it's not an easy proposition.

 

Mine are plumbed parallel.

Single inlet from lower radiator inlet at water pump (No paint Dual WG Asm front lower right) to brass Tee (middle of pic) which goes to each WG. Return is brass tee (upper left) back to Tee fitting behind thermostat housing (no pic).

Hose in forefront goes to turbo.

Red poly motor mount pic shows inlet tube and routing from Tee to WGs.

Lots of 4-AN hose, fittings and Tees. All routed away from exhaust manifold.

Working great, no leaks or issues.

 

This is an interesting setup. So you ran from the water pump neck to a T and then back to the water pump housing? Where did you run the lines for the turbo? I'm running off the water pump housing for the turbo feed line. Could you do a return line to the radiator instead of going back to the water pump housing?

 

Thanks, I sort of figured as much, and I'd rather not worry about the alternator if it's going to be a pain. I have been confused about the short harness that goes off the fuse block in the engine bay to the starter/alternator/ transmission. Do I need a harness from an S5 for that part, or should I just cut and re-pin the existing S4 harness?

 

I have a Tee at the water pump neck (lower hose) and a tee at the rear of the water pump thermostat housing.

The water pump neck feeds the turbo and the WGs. This water is the coolest because it is the return from the radiator.

The Tee at the thermostat housing is the return for the turbo and the WGs. This is hot water from the engine going to the radiator.

Yes.

 

Sorry for the delay and thanks for the clarification. What did you do about the nipple on the rear iron and on the throttle body?

 

Rear iron tapped and plugged. Capped the throttle body ports.

 

I actually use the rear iron to supply coolant to the WG's, and the inlet on the lower waterpump as the return for the WG cooling.

Back of the waterpump housing to feed the turbo, and then uphill to the AST. Turbo clocked 14* to get the autosiphon going when the engine is shut down

 

Would you mind showing some pic of your setup? I liked the idea of utilizing the rear iron for the wastegates, but I'm not sure how to route it yet. Also, if you don't use an AST, where would you suggest routing the turbo return to? I have plenty locations on the radiator, but here mixed opinions doing it that way.

Thanks,
Ryan H.

 

I'll see if I can find any that don't require linking... I have a whole build thread on the other forum. They basically snake around the LIM, between the DP and the block. I think there's a street tee on both wastegates, they're run in parallel.

You should ALWAYS have an AST. There are also a few spots on the waterpump housing that they can be plumbed back into, in fact, my WG's are plumbed back in that way.

 

I GOT YOU BRO. they don't wanna RCC stufff over here, plus you cant see it unless you log in...

it amazes me i have never seen your setup but i am doing all hardlines just the same for my everything.. oil.. coolant. boost/vac

 

Thanks man!



Great minds and all that.... I should check that thread to see where I left off... Some things may have changed since last pics were taken. I wanted to rock a hardline from the front WG to the WP housing but the bends we're just too tight to make it clean.... so braided line for that

 

That pic does a pretty good job of showing the difference in heat associated with the rear WG. After running the car for a year and seeing that is when I decided to go for the watercooling

 

So everyone seems to be returning the wastegate water lines to the lower water pump neck. Unfortunately, I don't have a lower neck with a return location on it (S4 N/A) water pump. Where would you return the lines if you don't have an AST or water pump location?

(This was kind of the reason for posting the thread, due to my lack of possible locations) 😕

 

Take the WP housing off and weld a bung on for either an NPT fitting or a -4AN

 

i took a 3/4 joiner and welded a 1/4 nipple on it for my FB. then put this joiner T into the heater core hose to the radiator circuit.

 

That's how I'm running the return from the AST. Plumbs into the heatercore return line on the lower WP leg.
I'm also running and FD WP and housing which makes things significantly easier over the FB/FC WP housings.

 

Can I return all the lines to the same port? If I use -6AN return for the turbo and a -4AN line for the turbo. Could I use a Y adaptor and return them to the same location? I have a location on my lower radiator hose that is big enough to handle that. Would that work?

Here's a pic.

 

Maybe You could get a rad hose adapter that has a threaded port on it.
like this one?
You'd have to be sure that the port size is bigger than the one I has (for my temp gauge sensor)

 

You can, but it's not ideal