obliterx8

iTrader: (3)

That's a very fair question. Some very cursory research said that turbos weren't really great on the Renesis. I can't say I understand why.

My friend's aunt owned a S/C'd 8, and she loved it. She doesn't know what brand it was, and has since sold it. She bought it that way and didn't know much other than she enjoyed it.

Personally, I felt that a S/C would help more with the lack of low end torque, rather than waiting for a turbo to spool up. I've known of this Pettit kit for many years, but all I knew is it seemed to be well received and relatively reliable (I know, its a rotary, that term is relative).

I guess that's how I ended up here. I don't know of too many other S/C kits. DNA has a procharger kit, but seems overly expensive and I don't really like that they use a piggyback ECU.

If you have something else I should look into based on this information I have just written, please feel free to point me that direction.

Thank you.

OtherSyde

As far as the SC-versus-turbo thing, specifically on the RX8/Renesis, I'm no expert on the matter but there were a lot of blown engines earlier on, and I think the Renesis is already very high-compression for a rotary as it is, and hence very sensitive to turbo boost, and something about mumble-mumble-unpredictable-boost-mumble-mumble-complicated-and-difficult-to-get-the-settings-perfect-so-you-don't-****-out-your-apex-seals or something to that effect, if I remember correctly. Turbo experts should chime in here, I'm just barfing up bits of the stuff I've read on the forums over the years.


I personally do not have the automotive skills to properly get all the complicated bits involving AFM, PSI, wastegate/BOV settings or whatever else all correct without blowing an engine and I wanted something more straightforward with a more linear power curve, haence I went the SC route instead.


I do believe the turbo guys have largely stabilized the various GReddy setups at this point, and you sound like you're savvy with the specifics of these sorts of things, so turbo might be an option for you. They are more available and have more support in general, so it's something to think about.

TeamRX8

iTrader: (25)

Well you can setup a turbo to operate like an SC and get the same basic results. The difference is that you can adjust the turbo for a lot more sooner, a lot more overall, etc. and you can't really do that so much with an SC. So the issue is generally the owner smoking the moar-boost crack and never getting enough until they eventually OD. However, a turbo is way more efficient especially on a rotary engine. Most of the crap about more low end torque etc. for SC is BS from back in the 1960s that technology has overcome.



.

RotaryMachineRx

iTrader: (1)

My advice for someone looking to go FI and not push the limits as Obliterx8 is looking to do; is to find a used greddy kit and get the turbo rebuild/upgraded by BNR. Push 7-12 psi safely and be fully spooled by ~3500 RPM (how often do you drive around at less than 3000rpm anyway?).

I'm running a stock non-upgraded (oil cooled) Greddy turbo since 2010 at 9.5psi and approx 50,000kms without issue.

No offence to the SC guys but I've only seen about two builds done properly that actually run problem free for long periods of time while I'm sitting here 7 years deep on a turbo set-up that I installed once and slowly did upgrades to as the years went along.

So ya, for a street driven application where you are only trying to make a safe 280 - 320whp that's my recommendation...

TeamRX8

iTrader: (25)

Here ya' go,

https://www.rx8club.com/series-i-maj...8/#post4835801

https://www.rx8club.com/canada-sale-...-turbo-266255/



.

keck03

iTrader: (2)

Ahh the old turbo vs sc debate in the SC owners thread. Great I am glad we are debating new things. FI on a renesis is always a crapshoot. I personally know someone who went through several "upgraded/fixed" greddy turbo kits and had numerous issues. And he was a known guy on these boards for a number of years. Other than now corrected belt slippage and a right angle hose fitting, I have had no issues with the kit. I also know from riding in his car with the Greddy kit, that my Pettit kit would spool faster and felt more responsive at revs under 3k. But over 6k, his kit felt much faster. But again I am just some guy on the internet fanning a flame war that should have died years ago.

keck03

iTrader: (2)

I spent the winter going through the whole thread while saving money for my rebuild. Things have greatly changed since the beginning. I have run into a number of SC owners at DGRR and at meets and have never seen anyone still using the Interceptor kit. When Pettit brought out his AFM tube and EFI dude tune, everyone switched and it was for the better. Thats how mine was set up when I got it. But I got greedy and wanted 300whp so I wanted Stage 3. The prior owner disappeared without sending me the logger so I couldnt retune through Pettit. I went Cobb then. Cam also said he would stock parts for the kit for years. But then he didnt. So now people send it out to Kenne Bell for a rebuild. I don't think the percent of kits needing rebuild is that high. Definitely get those RRP Pulleys. You might also want to contact Ryan Rotary through FB. He is a nice patient guy who is very knowledgeable and helpful. He has been tinkering with his setup for awhile and knows the ins and outs.

That being said the support for the Pettit kit is very lacking. They didnt sell many and I am sure that number is even less now. Basically this thread and garages taking their knowledge of turbo FI and applying it to the Pettit kit. The kits make good streetable power with a unique sound. Are they a good return on investment? Hell no. Buy a FD and go to town. You can make real power for your money and get most of it back when you sell it. Its depressing when I think about the SC kit being worth much more than the value of my whole car.

200.mph

iTrader: (9)

fixed buddy

RotaryMachineRx

iTrader: (1)

Haha, I was trying to avoid getting too much into it. Just wanted the guy to know that either way you go takes about the same amount of work with nearly the same risks/rewards but one option has much more support due to quantity of builds out there, that's all. If you are going to look at SC then you may as well look at TC as well is my point.

TeamRX8

iTrader: (25)

well there was some zoom-zoom magazine car that they gave up on trying to sort out their Pettit setup that was being tuned by MM, so they didn't all end well either

those of us who've been around heavily for 10+ years have seen the good and bad for both, you won't get that same perspective just by glossing over a few threads

OtherSyde

Well **** you guys, now I'm wondering if I went in the right direction with the supercharger. Oh well screw it, I'm like $7,000 deep into my Kenne-Bell-rebuilt supercharger kit and all the accessories, guess I'm sticking with the blower for now. Maybe I'll get another 8 one day and turbo it or something.


[EDIT] - To be more exact, about $7,220 total - here's what I've bought and spent so far:


Used Pettit SC Kit from Bennett Built Performance
[$4,750]

Full SuperCharger Compressor Unit Rebuild at Kenne Bell
http://www.kennebell.net/KBWebsite/Reman_SC_pg/layouts/remansc.htm
[$750]

Ryan Racing 6-Rib Pulleys - Full Set with wider belt plus 8-PSI and 11-PSI SC Pulleys, Anodized Blue
https://www.ryanrotaryperformance.com/
[$713]

GReddy CAI, Custom-Built Version for Pettit SC Applications (slightly different from Turbo version on site)
https://www.rx8performance.com/products/greddy-turbo-cold-air-intake-1
[$365]

KOYO Radiator from Black Halo Racing, All Aluminum
https://black-halo-racing.myshopify.com/collections/rx8-engine/products/koyo-performance-radiator
[$280]

MAZMART RE-Medy Water Pump With Thermostat to Replace Shitty Stock Series 1 Version
http://shop.mazmart.com/en/rx8-re-medy-high-flow-water-pump
[$345]

12"x12" Gasket Material to cut UIM->LIM Seals From (old gaskets on SC unit are all burnt up/shredded)
https://www.amazon.com/Viton-Fluoroelastomer-Sheet-Gasket-Black/dp/B0075ZN4RE
[$18]


I still have a few more little odds and ends to get, but I've essentially bought all the big stuff. When all is said and done, total expenses will likely be around $8,000 overall. Put in perspective, I bought my 2007 RX8 for $9,500 in 2013 with 34k miles on it under a salvage title; it's probably worth half that much now. So yeah, the SC kit is worth way more than the car lol. Oh well, so is the life of the obsessive modder/HP junkie. I still love it.

TeamRX8

iTrader: (25)

well just remember that any FI kit is only as sound as the engine you install it on, same for the device you intend to tune it with, and how well you tune it. The common mistake most people make is not thinking the whole thing through in entirety regardless of what device/method is generating the boost.

There is no TC vs. SC debate; they both have good and bad. On a rotary an SC can never match a turbo for area under the curve, but then it's generally an easier install, more linear and controllable power increase, and also doesn't have the same potential for problematic issues either. It wouldn't be my personal choice, but I understand and appreciate why other people have the opposite opinion. So make your bed and be prepared to sleep in it ...

keck03

iTrader: (2)

$7k isn't that crazy honestly for FI on a rx8. The turbo kits also require a significant investment by the time you are done. The cheap kits need a rebuild or parts. Hell I dropped prob more than that on a motor and some "safety/reliability" mods in the past 12 months. Like team was insinuating. Boosting a renesis shouldn't be taken lightly. Doing it properly is a serious investment. Don't regret your mods. Trust me it will be night and day difference. You didn't cut corners. Invest now vs invest later and be chasing issues.

keck03

iTrader: (2)

Really IMHO there has been 3 significant and necessary updates to the kit. First was a redesign of the Bypass Valve. Next was the tensioner pulley mounting bracket. Last was the RRP wider pulleys. If the kit you find doesn't address these, then I would look into them

200.mph

iTrader: (9)

all you need is the picture slvr texted me (posted a page or to back) on how to tighten the pulley

keck03

iTrader: (2)

That was after the new plate. The old one bent from being overtightened

obliterx8

iTrader: (3)

First off, thanks for the helpful replies everyone.

I've spent the last couple of days reading through this thread (up to post 3,500 now lol) and looking into basically every other FI kit, turbo or S/C. Most of those turned into vaporware, as I'm sure you know. Kind of a waste of time. But, I will say, I feel this Pettit stage 2 kit is where I want to go. I could list my reasons, but it's almost irrelevant. And based on the first couple years of history in this thread, I might get eaten alive by the rest of you for being wrong (regardless of the choice lol).

I've owned this car since new (actually my first car), so I'm not going to sell it and get something already boosted (thanks though Team). I'm going to stick with this car regardless of the cost.



So, I'm looking for input on the following:

OtherSyde's part list looks like what I've gathered so far. I would add some other bits, though. Definitely need the RR pulleys.

Stiffer motor mounts might be needed to reduce the silicone intake reducer from flexing too much? Or a torque damper?

Does Charles/BHR still make the "upgraded intercooler"? I don't know if that was ever real and how it worked. Is there a suggested intercooler setup?

It seems like a water/meth injection kit was helpful... is that still the consensus? Which one is best (Snow, AEM, other)? Wire it into the MAF and control it that way?

Which is the "right" (best) BOV/BPV/DV/whatever?

It seems like I'll need a shitload of gauges... Water temp (engine), water temp (IC/charge cooler), intake air temp, boost, AFR, oil pressure (?), oil temp (?). Am I missing something? I'll probably need the RB cubby hole pod and one on top the dash where the navi would be.

I do have a Sohn adapter... Is that a good idea with this S/C?

I was going to get some headers (Racing Beat or ExoticSpeed maybe?) and a HFC/midpipe from BHR (with a GESi cat - their tech support OK'ed it for S/C rotaries). No problems there? I have the MS sport catback and OEM cat now.

Can you get me up to speed on the pulley bracket?

What was the consensus on using the (modified) Racing Beat REVi intake (with duct)? I have that on the car now - remove it???

I was thinking of tuning the ECU with MazdaEdit, especially now that the Cobb APs are gone (and Jeff/MM seemed to have some anger issues? - not throwing stones, I just don't know how it would be to work with him). Who's a good e-tuner for this Pettit kit and MazdaEdit?



...I think I might be getting the hang of this.
Not bad for 2 days, huh?


EDIT:
OH, and I forgot to ask... is 8 psi the safe route, or has 11 psi been proven to be just fine too?

Thanks guys!

RotaryMachineRx

iTrader: (1)

Definitely not trying to talk anyone out of taking the SC route.... It is just definitely the path less walked, my comments were more directed at Obliterx8 just to ensure he had looked into all his FI options as finding a used turbo kit is much easier than finding a used SC kit. Team hit the nail on the head with his last post.

RotaryMachineRx

iTrader: (1)

See my comments above.

TeamRX8

iTrader: (25)

I'd only recommend an HJS cat converter for FI rotary

https://www.rx8club.com/series-ii-af...stions-265987/

OtherSyde

Just to append that list, I do have a few other crucial mods I feel I should list for other aspiring S/C owners that I've heard really help with FI setups; I just hadn't included them in that list because I had bought/installed them long before I committed to the idea of going FI and had just installed them as basic performance/longevity mods.


In addition to the above list, I have one of the last MazdaManiac RX8 COBB AccessPorts, BHR catless resonated midpipe connected to a GReddy cat-back SP exhaust, and full BHR ignition setup installed less than 20k miles/2 years ago. So I think all in all I'm going into this about as prepared as I can, but I do have one other question: How can I tell if I have the new/upgraded type of relief/blow-off valve, as well as the second-gen tensioner pulley plate? Do they look different?




Also, tangentially - TeamRX8, why even bother with a cat when you have FI..? It's not like you're going to be passing any smog tests anyway, right? Why not just grab a BHR resonated midpipe..? Is there some advantage to having the special cat you linked to?

RotaryMachineRx

iTrader: (1)

Team I'm sure agree's that you are better off going catless. He was referring the only known cat that it meant to withstand the heat of an FI Renesis to Obliterx8; if you absolutely are required to install a cat for emissions. If you were planning on going catless then stick to that plan.

keck03

iTrader: (2)

The BOVs looked similiar. IIRC the first one had plastic parts that would become brittle from the heat. The updated one was metal. I could easily be completely wrong since its been like 6 years. I would call Cam.

The updated belt tensioner moves the bracket down and more in the "middle" of the two bolts to help with leverage. I kept cranking it down bc I had belt slippage. The bracket began bending towards the alternator belt. I'll take a pic of it tonite. I do not have the original bracket for comparison.

TeamRX8

iTrader: (25)

Not really unless you don't mind the fumes. HJS has full metallic motorsport 100 cpis cats up to a 3.5" pipe size rated for 500 hp. The 400 hp 3" version like I have on my NA car (well it just came off for the new race class change) should be fine for this SC kit.

Mark

RotaryMachineRx

iTrader: (1)

FYI HJS cat on BHR for sale here:

https://www.rx8club.com/rx-8-parts-s...s-sale-266150/