IronTanuki

Maybe I can eventually get an HJS high flow cat but for now I simply can't swing the $1000 + cost to weld it in vs the $150ish MIL.SPEC. My director of motorsports development [wife] would kill me if I came asking for another $1000 to dump into the exhaust system so for now I will just have to sacrifice the extra power and hope the restriction doesn't kill the engine that much faster.

It would be nice though... maybe I can fit it into my engine rebuild budget.

IronTanuki

I had a chance to install on the Tanabe GF210s and Volk GT-7s. The drop is much more significant than I had anticipated... in retrospect I wish I'd went with the Racing Beat springs instead. Well, regardless with the lowered springs the OE shocks aren't long for this world I am sure so when they blow out maybe I can justify the PSS9s that I really want.

The fenders had to be rolled to get the rears to fit but it was worth it, I love the look of the GT-7s. Traction has improved a bit but now with the colder weather the car is becoming even more beastly. I was able to hit 379g/s even with the new cat with boost peaking at 12psi (which it does not hold until redline). Under certain conditions the rear tires can break loose under WOT in 2nd gear. The tires all around don't have much tread, especially the rears, so once spring rolls around I'll probably be getting Hankook Ventus V12s to replace them.

I am also still waiting on the external signal harness for the GReddy E-01. I may break down and just install it without the harness and set that up later to be able to log AFR. I'd like to get the boost under control now that the weather is colder and spikes can be particularly nasty.

Attached some hastily taken pics with the wheels (phone camera, sorry for quality).

Edit: I also got one of these . The PC925MJT does not hold a charge well at all especially since the car has Lo-Jack installed. Normally all it takes is 4 to 5 days of not driving for the car to need a jump. I just started using it so hopefully this solar trickle charger eliminates that annoyance.

IronTanuki

The project's long hiatus is finally over as I'm fairly sure that the engine is blown. The AFRs will drop down to below 10 and lose all power if intake airflow is greater than approximately 80g/s. It also will die on deceleration unless it's eased very gently back into idle. Vacuum at idle will dip down from 17s to 14s. It starts and runs at low power just fine though. I've taken the car to Whitney Automotive to diagnose but given the symptoms I'm starting to prepare for my rebuild.

Here's my plan for the rebuild. Any feedback for other recommended mods would be appreciated.
- Ray rebuild the engine instead of a Mazda reman
- Goopy seals
- stock porting in the interest of costs if I **** up with the tuning
- Ditch TurboXS exhaust with mil.spec cat and go with a Pettit Racing modular exhaust with an HJS cat. I'll probably run it with a race pipe until the tuning is solid to minimize damage to the cat during tuning.
- Run a SOHN adapter
- Move my oil temp pickup to the oil pan instead of the filter to more accurately gauge temps since right now the temps will always plummet while driving especially in colder weather
- Flow test the turbo
- Flow test the injectors

For tuning I am going to try to tackle it myself with baseline. The amount of east cost cobb rx-8 turbo tuners seems small and it's something I've always wanted to be able to do. I've already started watching the 12 hours of tuning that Kane provided and will take things slowly.

Unrelated, since my last post was about a shitty stock shock / aftermarket spring combo also have to say I am running PSS9s now

9krpmrx8

iTrader: (46)

I ran the temp from the pan for a while and there is no noticeable difference in temps except at idle. I like my TurboXS, why bother with the Pettit?

Good luck on the rebuild, I would say you had a boost leak but if it dies on deceleration and has low vacuum then it is probably done. I also would not waste my time with Goopy seals, OEM only IMO.

Good luck.

TeamRX8

iTrader: (25)

zombie thread bump

Does it stil start and idle fine? Could be any number of other things so good luck.

Just put an HJS cat in the existing exhaust


.

IronTanuki

The reason I want to swap out exhausts is that I've had to replace 3 cats so far and each time get the mid pipe hacked up and rewelded. The pettit one has a modular section for the cat and they sell the replacement bit for $500. Each time I'm replacing the cat I'm ending up spending more because of the custom labor for the fitment.

In addition to that the turbo xs (mine at least) is the lowest part of the car and can hit aggressive speed bumps. I actually had to have it modified because it hung so low at the bend before the mufflers. The Pettit one mounts higher from their pics with their own hanger not the stock ones.

Also the reason I wanted to run it from the pan is when it's cold out my readings for oil temps dip down considerably (sub 100 degrees at temps in the 40s-low 50s) as soon as I start driving over maybe 35 mph. Isn't this the result of having the temp sender on the filter vs pan?

IronTanuki

Yes the car starts and idles fine it just has trouble returning to idle on decel, it will stall out without assistance. These symptoms happened immediately after a WOT 1st / 2nd gear run up to around 7500 RPM. I was able to drive it several times after that but had to maintain intake below 80 g/s or it will stumble and lose all power.

I had Mazda look at it and they ruled out plugs, clogged cat, ignition system and couldn't figure out what was wrong so gave me the car back since it's too modified.

TeamRX8

iTrader: (25)

How many miles now?

A bad TB (internal electronics) could cause all those things and not necessarily throw a code. But a compression check would be the next step.

IronTanuki

Just over 60k. Approximately 10k of those were boosted.

Brettus

iTrader: (2)

Sounds more like a big boost leak than a blown engine . So yeah .... compression test before you do anything else !

FazdaRX_8

iTrader: (1)

you could have made a huge boost leak after a wot run, especially with several heat cycles if you didn't tighten anything down. in turn some boost leaks can be a vacuum leak and cause the die at decleration because the maf would read 0 g/s and shut off.

I am running 2 years strong on goopy apex seals (rx-7 version milled the rx8 rotors)

IronTanuki

I got my car back today. Brettus was right, one of the couplings from the IC had come undone and Mazda failed to see it. I got it compression tested while it was over there out of curiousity and my numbers were:
7.3, 7.5, 7.5 kg/cm^2 @ 295RPM
7.3, 7.8, 7.3 kg/cm^2 @ 300RPM

It's a relief that the engine is still sound but this has given me the motivation to finally start tuning the car myself as well as plan out my eventual coarse of action when the engine does go. I'm still not entirely sure I won't swap out to a cosmo REW instead of sticking with the MSP but regardless of the coarse I take at least I'll have the time to prepare.

TeamRX8

iTrader: (25)

Not blown, but at low compression rebuild point in my book

Brettus

iTrader: (2)

Big book !

TeamRX8

iTrader: (25)

the factory manual has a lot of info

given that the line between 600 and 800 is 7.05 kg-cm^2 you can clearly see that its below Line B out at 300 rpm cranking speed