Nice! I've got some aluminum that needs welding when you you're ready. :)

I wouldn't trust my skills on anything you care about. So you make the call on that one. :lol:

If you need help on something mission critical though, Larry Casey does amazing work.

More TIG practice. The 3" aluminum tube running from the intercooler outlet to the TB inlet never fit well because the junction was at a ~ 20 degree angle and I made up the difference with a silicone joiner. I decided to fix that and bought a 22 degree bend and welded it to the (shortened) tube from the intercooler. You can also see the little box I fabbed up to shield the ECU from heat and moisture (though the Haltech is supposedly waterproof)

https://lh3.googleusercontent.com/pw...-no?authuser=0

Definitely getting better at this but I still need lots of practice. The more major stuff I have planned (fresh-air anti-lag) will require stainless welding and backpurging, and I don't have a second argon bottle and reg so I'll have to go to Larry's to do it.

Want to let me know when you do that? If possible and you don't mind another body around, I'd kind of like to observe (without directly watching certain parts).

That sounds great. I'll keep you posted.

I've been doing a lot of welding. Mostly aluminum, but I started a new project that will require welding of 316 and 304 SS.

I've decided that I want to add anti-lag to the RX-8. This will be a huge learning experience on the engine tuning side, but that's kind of what this car is about.

https://lh3.googleusercontent.com/pw...-no?authuser=0

great looking fabrication.

Does this take air pressure from somewhere else and feed it into the exhaust manifold when there's not a lot of exhaust pressure to keep the turbo spooled?

Turbos work based on heat energy, not gas flow. So the key to anti-lag is making heat in the exhaust when the throttle is closed. The cleanest way to do this is to plumb a pressurized air source into the exhaust runners at their hottest point (near the cylinder head) when the throttle is closed, cut spark and add fuel. The Haltech has this capability programmed in with the appropriate safeties, so in theory all I need to do is add a valve and air tubes to direct boost pressure to the exhaust manifold. Combustion then occurs in the exhaust manifold instead of in the cylinder. The key is adding enough fuel and controlling the turbo speed because this is effectively a positive-feedback loop that can cause Really Bad Things if left unchecked.

Well, so this took a long time. I'm not done, but it's very close. This has been an interesting problem to solve. I needed to keep access to the manifold fasteners, clearance to the cylinder head, water pipes, turbo, and various other underhood thingies. And then there's an order of operations to drilling the manifold and welding each of the pipes to the runners. I think I'm in the clear still but I'm burned out and my neck hurts from being under a helmet all day. Not sure how professional welders can do this every day.

https://lh3.googleusercontent.com/pw...-no?authuser=0

https://lh3.googleusercontent.com/pw...-no?authuser=0

https://lh3.googleusercontent.com/pw...-no?authuser=0

https://lh3.googleusercontent.com/pw...-no?authuser=0

It's looking good!

Awesome!

I need to make the connection from the anti-lag valve to the boost pipe, but other than that it's done. Definitely the most ambitious project yet on this car, and I'm happy with how it turned out. The manifold was tricky to weld because it had been exposed to oil, coolant, and other contaminants, but the welds seem to have penetrated well. I've kind of fallen in love with TIG welding.

https://lh3.googleusercontent.com/pw...-no?authuser=0

https://lh3.googleusercontent.com/pw...-no?authuser=0


https://lh3.googleusercontent.com/pw...-no?authuser=0


https://lh3.googleusercontent.com/pw...-no?authuser=0

Looks pretty cool. Test driven yet?

Waiting on a couple of aluminum bends for the boost side so no, not yet

I've been working the car a bunch. I built an exhaust extension to add a muffler and move the tailpipe from a simple dump under the car to an exit at the rear bumper. Dumping the exhaust out the bottom of the car seems like a really bad idea when it will likely be shooting out some fire when the anti-lag is active.

https://lh3.googleusercontent.com/pw...-no?authuser=0

My TIG skills are getting better, gradually. Throughout my winter projects I've spent about 20 hours welding, which seems crazy.

https://lh3.googleusercontent.com/pw...-no?authuser=0

I did some street tuning on the car yesterday and the exhaust noise is almost nonexistent now. Not that I could really hear it over the gearbox.

I have not enabled the anti-lag yet. I probably should but I'm not sure how to tune it on the street - it really wants to be set up on a load-bearing dyno where you can stare at the laptop and see how turbo speed reacts to changes in fueling and airflow on throttle lifts. I can certainly go out on the road and get some logs, come back and make changes, etc, but it's tedious.

As a reminder of what the RX-8 should NOT have been... I bought a $900 non-running automatic RX-8 more than a month ago. It's just been sitting on my trailer since then. Marisa is out of town so I spent an hour fiddling with it. I think this might turn into a daily driver for me once I swap the drivetrain, or I might sell it to a friend to build into an endurance race car, who knows. Either way I wanted to get it running so I could drive it up to the shop vs. backing the trailer up there. The previous owner sold it because it wouldn't start and a mechanic said it needed an engine. I probably overpaid by a couple hundred, but it was clear the guy I bought it from needed that couple hundred more than I did so I bought it. It's actually in really nice shape, no rust, etc.

It was super-duper flooded and had two spark plugs that were broken (!). After replacing the plugs and de-flooding it, it fired up and actually runs okay.



It's a bit of a rare bird, it has a 6-port engine and an automatic. Most of the autos were the early cars with the shit 4-port engine. Being a 6-port means I can actually sell this engine for parts. The engine and catalytic converter alone are worth about $3k.

So... what to do? I have a 2.5L to swap in, and I now have "off-the-shelf" engine mounts of my own design so I could swap this in a weekend... though I don't have a gearbox that will work with the 2.5 at the moment. I think a high-revving 2.5L with a BMW E46 6-speed would make a nice daily driver. Maybe eventually turbocharge it? What say ye?

"Automatic, bad."

No "Rotary, bad"?

Which is worse? :dunno:

It also sounds more interesting with a cat sitting next to the speaker purring up a storm.

Automatic is worse than Renesis. The combination of the two is truly sad, though. This thing is positively gutless from a stop. It's fairly sprightly around 4,500 RPM, but I think the CX-5 (which I'm driving this week) is most certainly faster.

I was thinking I'd immediately tear the drivetrain out of it, but now I'm kind of tempted to get it inspected and slap plates on it, just so that process is done and I don't get questions about the drivetrain swap if I wait until that's complete to get it inspected.

That's...depressing, but not surprising.
I think that's the right path.

I think it would be pretty cool to build up the street version of the race car.

An rx-8 lacks torque - but for me - it would make a great daily driver with a stick. Something about that light weight, balance and smooth handling.

Recognizing that I drive an E90 M3 (glass houses and all), I couldn't imagine driving something daily that gets such incredibly poor fuel economy for so little reward. A real engine would make such a difference.

I'm not really clear why JV would want a BMW transmission for this, though. What's pushing you in that direction, JV?

I was okay with the RX8 15+ years ago. So much so that I briefly put a little effort into finding another one a couple years after that.

But it was a stick. No way I'd want to have anything to do with a slushie RX-8 unless it was to pull the engine and put something else in.

I defer to JV and what he's learned, but I'd imagine that almost anything else will put more weight on the nose and probably have a negative impact on balance. I don't think it would be that big of a deal, though. And the benefits of power and torque (and probably long term reliability) would more than offset.

I'm looking forward to seeing what it turns into.

I'm not set on using an E46 6 speed, but it's the best option. The gear ratio spread is good, it's compact and relatively light, they are available for not very much money, and there is an existing solution to mate it to this engine. The other option is to do what the race car originally had which was an FD 5 speed. I like how those shift, but they are getting very hard to find and relatively expensive. An RX8 6-speed is also an option, however it would require a lot of custom work to make the shifter fit in the stock location. The idea with this car is to be a more streetable version of the race car

Fair enough. I just wish it shifted a little better.

Sure, same here. But it is the easiest solution that will work. I guess I wish I hadn't sold my last FD 5-speed. Those gearboxes shift well and I already have the clutch parts I would need. I don't love the gear ratio spread, though.

Cool, good luck with this one!

So, I borrowed a real-deal rotary compression tester and did a compression test on the gray car. Mid 7's across all faces on both rotors. That's not bad at all. A well-built broken in Renesis should do low 8's, and they start to have hot-start problems around the high 5's.

It has a stumble off-idle when it's cold, but it runs perfectly once it's slightly warmed up. Seems like the low-speed injectors might be a little unhappy, so I dumped an entire bottle of seafoam into the nearly empty tank, ran it for a bit and shut it off. I just took it to get fuel and it seems to run just fine.

Perusing FB Marketplace, it looks like I could pretty easily get $3500 for this thing so I'm going to flip it after putting new brakes on the front (I can't in good conscience have anyone drive this away with the brakes that are on it now). After digging into it, it's going to be a pain in the ass to convert this over to a manual - the brakes are wrong, the rear axles and hubs are wrong, and I need to find a bunch of other parts. I think it makes more sense to send this one on down the road and find a car that was a 6-speed to begin with and swap that.

Sounds like the smart choice. Unfortunately.

I'm shopping around for 6-speed cars again. Bombing around yesterday in the gray car, I'm reminded what a phenomenal chassis is baked into these cars. Even with the auto, even with the soft stock suspension and wimpy 16" wheels and tires, it's just perfectly balanced. Lots of body roll to be sure but the balance is lovely.

I drove the turbo 2.5 car while running errands on Friday and while the brutal power is addictive, it's way too stiff and loud to be a good street car. And darty with the 315mm tires.

Gray car sold for $3500. I don't hate that. I probably should have asked for more, but I feel okay not trying to eke out every last dollar.

Congrats! What’s next?

Well, I still want an engine-swapped RX-8 as a daily driver. Driving this automatic car only reinforced to me what a good car they are. Very solid structure, compliant suspension that also handles well (i.e. what BMW used to be), good visibility and a playful personality.

I found a nice white 6-speed non-sunroof car (almost a twin to my race car, but it has the factory ground effects kit, which I kinda hate) in NJ that I might go look at this weekend. And by look at, I mean bring 5 grand in cash and my trailer :). The best part about this one is it's a non-smoking car. The gray one had been smoked in at least once. Very faint smell, but even just a hint of that smell is enough to make me feel gross driving it.

The plan would be to do an engine swap on it. Easy button is of course another Duratec 2.5 swap, was thinking maybe a high-revving NA motor might be fun this go-around. I've also thought an S54 swap might be fun, though those engines are so heavy I think it would very negatively affect the dynamics. Honda K-series swaps are also getting to be popular, but I don't really know those engines very well so there'd be a learning curve.

John

From an engine architecture standpoint, what advantages does the K series give over the Duratec? Higher revving? But is the basic design better?

You should do something really off the wall, like a Volvo 4.4 V8.

I'm less interested in doing something "cool" and more interested in doing something usable.

The K-series is better supported in the performance aftermarket than the Duratec. It is a shorter-stroke engine and has a cylinder head designed for big airflow, so it makes great NA power out of the box. The Duratec requires quite a bit of work to get to 230-ish wheel horsepower, but then again it's work I'm very familiar with. The K is also just a better-looking and better-sounding engine. Not big factors for me, but it's something. The Duratec is quite a bit cheaper. Pluses and minuses to both. I also like that with the Duratec, I know exactly what I would need to do if I eventually turbocharge it.

A popular swap now is the LFX out of the newest Camaros. But it's a V6, and I really don't like how they sound.

I think the LFX sounds decent enough. Better than a K-series for sure. But I'm not the one driving it and don;'t live close enough to you hear it comeing going every day. ;)

I’ve been thinking about what you want to do and really have to say that is pretty amazing you have the ability to do this type of thing, the biggest downside today(being these are not new anymore) with the RX8 is the engine, as a reminder I had one when new and then inherited one years ago, The problem with the inherited one was the engine, you just knew it was a ticking time bomb and not only that, to mod the damn thing was so limited.

I would love an RX8 with a decent engine, that is just so cool, looking forward to what you end up with.

After getting the gray one running properly with new plugs and coil packs, I was reminded what a joy a properly-running Renesis can be. Even with the auto, it was quite fun to blast around in. They are pretty easy to keep running, but unfortunately the fuel economy is so abysmal that they're just not practical as a day-to-day car

Maybe it is worth considering a V6 swap. I don't know. I need to contemplate.

So do you have a nice white one in your driveway and 5 grand less cash in your pocket?