in what we call "The Death of 77 Gloves" the old turbo came off.
i think its the first time the manifold has been off since i put the car together, i want to just slap the new turbo in, but i had to take a breath and do some inspecting.

first, the old manifold had been dying a slow death, the part where it looks like its sagging is because its sagging


next is the port match, the HKS manifold is a 48mm circle, and interestingly the stock manifold was oval, its about the same size, but its about 50mm wide and i think 44mm tall?

i decided it was close enough and left the HKS alone

also since i was in there, i test fit the HKS log manifold and 60-1 turbo,
i thought it wouldn't fit with the air pump, but it does, so fail-boat there


why didn't i run that setup? well i thought the air pump wouldn't fit, and then i would need to find a wastegate, or really the money for one
and then i would need to fab up a downpipe, or a dongle that would let me keep an unmolested stock downpipe.
the Greddy kit had something like that, so that would be an option

if i knew it fit with the air pump, i probably would have run it, lol

the Greddy kit gets funny, its like the adaptors have adaptors. although it did let them sell it in California legally, as you keep the stock exhaust and you can run any turbo from a TD05, TD06, TD07 and T78's

 

i have it in, its WAY down in there, there is more room between the turbine housing and the intake too, which is kind of awesome
heat shielding is on the agenda, but in part 2

its hard to get a picture, its dark down there

 

Since Sevenstock is so close i decided to do a bunch of work at the last minute

first: when it rains the spare tire well fills with water. usually this isn't a problem, as it doesn't rain here, but the last three years it has.
it was actually kind of hard to figure this one out, it wasn't really obvious where the water was coming from
i ordered and replaced the 3rd brake light gasket, but the lock cylinder was really loose, i kind of wonder if it was that.
while the lock was out, i pulled it apart, greased and painted it, tightened the clip and maybe we're ok?
who knows, i didn't check



i also polished my pipe. i installed the very rare one of one K2RD AFM block off plate. i had the AFM in there the whole time, even though it wasn't hooked up
polished the HKS RS pipe and filter, and it got a new air filter and wow, it makes the rest of the car look dirty and old, lol

polishing the filter cage was, um awkward

 

As part of this turbo install, i redid all of the intercooler piping, except the one i really wanted to re-do, lol; i don't know either.
on the turbo the FC rubber 90 degree boot got replaced with a little Greddy elbow.
i've been wanting to do this for a while, the FD uses a hose for the injector air bleed, and on a stock car hooks up to the Y pipe (it sees boost)

the Greddy part had enough meat to drill and tap for a fitting. previously i had it teed into the boost solenoid, which worked but basically made boost control impossible
i put it there, because when i change my mind, it can go the other way, lol


then i had to shorten the other pipe, ive got a hacksaw with a dull blade so it sucks


but turned out like this


the IC pipe i want to redo is this one,

instead it got a coat of paint, so you can't see it. it lives in the drivers wheel well
and its V shape makes the brake duct not fit. the HKS kit has one that looks more like a big mustache

i sort of ran out of will to saw more piping, lol.

the next hurdle was the turbo oil drain. which has been one of the hardest parts of the whole project. the FD uses a T2 flanged drain at like 16mm and the FC is T3 flanged with a 19mm.
i was hoping the drain on the turbo would fit, but not surprisingly it didn't. it was too high and too long, cutting it would be easy, but bending it down, maybe not

i ended up with a generic AN style kit, which its a huge pain to install, but is working, so i'm kind of happy with that.
on the engine side there is a front cover bolt right there, and you can't tighten the AN fitting because the non flat parts of the AN fitting hit the bolt. so you need to put the fitting on first, but then that fitting kind of blocks the wrench.
i think a 10mm wrench got ground down to fit better (and a 13mm got ground to be able to get to the CHRA bolts)

 

The IC pipe on the cold side got redone too. i tried to swap to a Greddy intake elbow, but it slightly points up, and puts the IC pipe in the hood, which is pretty annoying
the blue coupler over by the battery can be eliminated later, i can have those pipes welded up
main goal of redoing the IC pipes was that i think i had them too tight, so the pipes were basically butted together, now they have some room. hopefully things can move around a little more

the turbo heat shield is the same one as before, and since the turbo is clocked differently, it took a while to get it to fit. i moved the brackets so many times, i'm not even sure what i ended up changing!

and done! net difference in looks? zero, lol

 

i drove it, and was surprised. i think i was hoping that the divided manifold would offset the bigger turbine, on the compressor side the T04E-46 and T04B-V Trim, flow about the same ~40lbs min
i guess i wasn't expecting a big change up top, also the silencer in my exhaust keeps power to like ~300.

boost response is crazy, it feels like an NA. the previous turbo felt like you stepped in mud and maybe wouldn't get your shoe back.
i get 7psi at 1800rpm, which is way faster than the old turbo (i think it was ~2800?)
it goes to 13psi at 4100rpm, the old turbo needed 5000 to get there.

then boost falls off to ~11psi, but it holds to 7000rpm, the previous turbo would kind of peak at 6500.
also, its early days, but new turbo is ~300hp at 11psi and old turbo was ~300hp at 13psi, so maybe bsfc is better?

so it really changed the car, but who would have thought bigger turbo would spool faster?

 

Lines up with my experiences too. Big exhaust wheel coupled with big exhaust= low rpm boost.

I'm going to try 8" diameter downpipe (precat in downpipe fits stock FD).

I've read wherw a 240 guy kept trying bigger and bigger downpipes and spool kept increasing. He ended up with a box/fabricated guppy as a downpipe.

Not only does blowdown accross the exhaust turbine increase, but the post turbine exhaust flow is so turbulent it takes time/distance for it to organize to laminar flow.

 

i only have the one data point, but the Big Dumb Exhaust works
the other part that i'm shocked about, is with the silencer in there, its totally silent.
who would have thought i could have a 94mm exhaust AND have it quiet?

 

Thats impressive!

 

it must be close to 10 years ago, i bought a set of really manky East Bear mirrors.
bad paint, over really bad paint, and then the passenger mirror was just broken.

i got off my butt and sanded it and sanded it and sanded it. then glued it back together, and painted it
i'm working on a deeper dive on mirrors, they turn out to be more repairable than my dealership just replace it thing.

but anyways, since they are RHD mirrors, i mocked it up to see if i could get it adjusted right, this is a thing with RHD mirrors on a LHD car
and i think its kind of funny

 

And here it is with the shells on, its got the right look, but i'm not sure i like it.
the East Bear mirrors have about the same profile as the stock mirrors did when they were folded, which isn't something i would have thought about, but i guess they would need to be



the rear tires are a 225/45/17 on a 17x8 inch wheel, and i'm thinking they don't look meaty enough, thinking about a 225/50/17
and or a set of the same wheels in 16x8 and 16x9, which i think would look kind of awesome, also thinking about stickier tires

 

 

The trip to Sevenstock went really well, it was by a lot the furthest i've driven the car. in fact just to go from my house to Fungus Mungus's house (~90miles) was the furthest, i have ever gone, and then we went another 330miles
car had a couple of quirks, but basically made the trip without any trouble. gas mileage was around 21, which is fine. i forgot to reset the trip odometer on one leg, and then it didn't work for a part of another (?)

we started by getting rained on, i did wash AND wax the thing, so we're lucky it didn't snow, it rained two more times on the way(!) and the hotel sprinklers chipped in too

i randomly took this, and that dark cloud was rain



i'd say Rx7's in their natural habitat, but we stopped at this gas station and it had no power, electricity. we ran into some odd stuff on the way down


but we got there, we drove down Friday, and the show was Saturday

 

and a few more, i almost forgot to take pics of my own car!

Rob's engine looks like something out of The Terminator, or maybe Johnny 5 is alive







the trip back was pretty uneventful,
besides the trip odometer not working once,
the tach also decided to not work on Saturday. the tach has been intermittent sometimes, so its not a new thing, it just acted up more than usual
all the bearings in the back are LOUD, i used earplugs, lol
and i think my thermostat is dying, it didn't really get hot, but on the long downhills it would almost cool down completely, like 60c!


on the list of stuff i learned;
its quick, 60-90mph, is like a squeeze of the gas pedal away
it rides really well, dare i say except for the bad bearings in the rear its more comfortable than the miata was
also if you're just cruising down the freeway intake temps are steady, at a little over ambient, which tells me my heat soak thing might actually be heat soak, so i need more turbo heat shielding

so i've got some stuff to work on, but i'm really happy with the thing

 

@j9fd3s What are you running for shocks?

 

Really wished I was able to attend Seven Stock, it looked like there was a lot of nice cars.

 

including yours, if i'm not mistaken.

the last two sevenstocks have been really great, LOTS of really great cars, and irwindale is nice because everyone is parked together, its easy to see everything, and bump into people

 

ive got a set of Tein HA's. i bought Teins, because they rebuild them in LA, and you can get parts.
they were $65 + $150 overnight from Japan + $300 to have the fronts rebuilt.

i'm pretty happy with them, although i've been mulling over something softer. the HA is 8/6, and i'm wondering if 7/5 is more fun

 

Really love your FC! A clean FC rivals an FD all day in my book. We'll done on the trip, too

 

so it rained and my spare tire well is dry, so 3rd brake light gasket worked, which is great

not so great is that the inside of the back window is more wet than the outside, lol. really at a loss for that, but i guess i'll try to seal the rear washer nozzle

 

so i fixed it, its dumb too. not the dumbest thing, i think that was on the last page.
anyways, i was looking at some stuff. in 2025 i'm looking to make it a little more better. and i noticed that i didn't have these little plugs installed.

the parts catalog is hopelessly vague, depending on which catalog you look in (JDM S5, or the US 89-90, or 1991) the quantity of these changes, but its really hard to tell why


i poured out my box of clips and plugs and suspiciously i had just two of these.
i put em in, and it rained next couple of days and inside of the car is dry.

so pretty dumb

 

i made a pipe! the old IC outlet pipe, was just a 90 degree pipe, and it was really awesome it fit, because it didn't need any fab work.
the trouble is that the brake duct didn't fit, and the fender liner can't go on. this wasn't a big problem, its lighter!
but i've been getting little up dents on the fenders(!) and even though i kind of doubt that the brake duct does anything, it kind of bugs me its not there

soOOoo i made a pipe!



i chopped up a pipe i had lying around, test fit, and then took it to a hot rod shop we have around here to weld it up





i'm not sure why it looks like i've been driving off road, but its super filthy, and i did nothing about it!
that can come later

 

i always kind of wondered how something like a 2 stroke expansion chamber would work for a rotary, given there's no valves to control backpressure. it would make sense rotaries could benefit from a really large chamber to collect exhaust pulses. mazda of course built the cars just well enough to drive on the street. space being the obvious limitation as well as heat, the turbine being a buffer and acting like a one way valve i figured the benefits would be rather minimal.

 

i think it kind of depends on what you start with, like its the combination. for instance with a stock turbo going from stock (60mm?) to like 76mm is huge, but going from 76 to 94 probably wouldn't do much.

when i put the HKS turbo on, i changed the manifold, turbine housing, and both turbo wheels, which is a lot at once. i did think about swapping the guts of the turbo, so it would have just been manifold and turbine housing. but i do feel like the divided manifold was a big improvement. i just didn't prove it. what did happen though, is that i added the divided manifold, larger turbine wheel, and slightly smaller compressor = WAY better turbo response. power went down by about 5hp but boost is also lower. its less peaky too. the S4 turbo with the V trim would peak around 6000rpm, and then it was done by 6500. the HKS is pretty flat from 6000-7200, its got a broad peak (also i haven't done as much logging).

i think my point is that if you do a little testing you can find a combination that works really well pretty easily. i would say divided manifold, and giant exhaust. for like 300-350hp turbo can be pretty modest.
cooling is then the next thing, one of my projects this year are some better heat shields for the turbo. (stock radiator is fine, although its old.)

 

i haven't been up to much, with this car, just enjoying it really.

i did decide to paint the hatch frame black, again. when i had the car painted, they painted the frame, and since Brave Blue is so dark, going back to black is going to be pretty subtle.
if the car was white, i think i would have painted it black right away.

anyways paint the frame black = chip some of the blue off and make it look worse, lol.

and then issue #2 is that idle mixture is richer when the car is hot than when its cold, so i have been doing a little playing with the Air Temp map, first pass made it worse, of course. pass 2 is really close.
change #3, is that the auto tune gives you a choice of idle mixtures, and i guess a year ago, i went to the richer one, cause the leaner one was too lean. (you can also edit the target AFR map if you want)




BUT the new turbo is divided, and the engine REALLY likes it. so i decided to try the leaner setting again, and its better. so that is pretty neat.
basically less stinky, the way i drive i might see better mileage too, lol.

this might sound like a thing, but FC Tweak is so easy, this was like a few key strokes and a 25 minute drive.