blackenedwings

The AEM intake is good because its designed to OEM spec in terms of the flow past the MAF sensor. As mysql said the GReddy one has a foam mushroom cap right next to the sensor resulting in wacky behavior which could cost you an engine. The cooling aspect of the car is very important, but the intercooler, turbo blanket and meth injection should be more than sufficient. From what I understand unless you are in constant very high temps the stock radiator is fine. Racing Beat reported almost no benefit from a larger radiator under non-track conditions.

Brettus

iTrader: (2)

Greddy kit
+ intake
+ AP or Pro tuner
+ Upgraded turbo
+ better couplers
+ a few tweaks here and there
+ BOV
= excellent bang for buck ........reliable 300 + RWHP and double the factory torque

click link below

Red Rex

iTrader: (1)

Upgraded turbo? MM upgrade isn't available anymore soooo..

And whats a few tweaks here and there? A reason I would want FI is the torque you get from a turbo which broadens the cars powerband instead of just improving on the existing band like a supercharger does. And I've driven a supercharged and turbocharged car. The speed from the supercharged car was fun but being able to go in and out of boost made the actual turbocharged car fun. I forgot about torque when I sold my T-bird and realized it again when I drove my dad's vette. Its nice if I went FI I'd like to go turbo but a blower wouldn't be out of the question.

JinDesu

iTrader: (2)

You've sold me on the turbo, Bret..

That's looking at around 5k min though, right?

Red Rex

iTrader: (1)

Turbo = $3,500
Intake = $320
AP = $700
Couplers = ?
Tweaks here and there = ???
BOV = $250
Having a turbocharged rotary = priceless

Oops almost forgot the shipping and installation fee's if you don't know how or don't have your own place to install. And an upgraded turbo is going for at least $1,000 no matter who you turn to. Then there's the gauges and boost controller you'd need, supporting mods like fuel injectors, spark plugs, ignition coils, and such. And you'll probably want/need better tires. Plus you'll go through oil twice as fast. So you're looking at closer to $10,000 than $5,000.

Mspeedpro

iTrader: (1)

Looks closer to 6k depending on turbo upgrade.

blackenedwings

Gauges, gauge pod, boost controller, plugs/coils, injectors, midpipe (stock cat melts with FI), couplers, AccessPORT, BOV, upgraded turbo, intake ...etc

Price totally depends on how thorough you are in looking for deals and knowing up front what items you need. If you buy a bunch of crap you end up being unable to use it will end up costing you a lot more.

Brettus

iTrader: (2)

The turbo I have is just an upgraded Greddy that I believe is actually inferior to what is being offered by a couple of vendors on this site . It is close to maxed out at the hp i'm currently at but in actuality I find the most fun for me is from the extra torque in the 3000-6000 range . Something equally achievable using the stock Greddy turbo .

With regard to the extra tweaks - there is probably more to this than what i alluded to . I should do a thread on all that sometime .

Bastage

iTrader: (1)

Even still, when you piece a kit together like this on your own you run a much higher risk of making a mistake or buying a faulty part and blowing up your engine. I would bank an extra 3k to pay for a rebuild in the event you blow your **** up (it happens more often than you'd think).

Or you can just buy a proven/complete kit and avoid the worries/headaches. I'm about 40 miles away from breaking 20k boosted miles.

JinDesu

iTrader: (2)

Then this should be a project I'll undertake in a few years, definitely not at this time. In consideration, the AP, intake, exhaust, tires should all be done along the way anyways.

blackenedwings

When you buy a proven/complete kit you run less of a risk, and it requires a lot less personal knowledge. For me, my whole goal in going FI was to learn everything I can about the car and do as much as I can myself. Because of that, I didn't mind doing some of the extra research to get the best setup I think is available.

I do agree, if someone wanted to just get boosted and didn't want to get really hardcore into building their own kit, I would recommend getting the Pettit kit. Superchargers aren't less dangerous for the engine, but a complete/proven kit is less dangerous than something you put together yourself unless you really take your time and have people who know wtf they are doing lol.

Bastage

iTrader: (1)

^ agreed.

Sometimes though, people think they know or actually KNOW what they're doing and the their engines blow up anyway. There are at least two people posting in this thread that have had their engines rebuilt because of something going wrong with their FI setup.

My point was, that if you're going to experiment, be prepared to pay for the lessons you learn. I enjoy the fact that when I put my foot to the floor the only worry I have is keeping traction, and not that my engine will go boom. I suppose some people get a gambling thrill out of the potential for unintended explosions.

I'm glad your kit is working well for you blackenedwings, and I may get a chance to see it this year as I'm planning a roadtrip up to Boston in the Fall and we were thinking of stopping by that area to visit Moon/Rotr8, and check out D.C.

Red Rex

iTrader: (1)

Damn you Bastage! Stop giving people reasonable and safe alternatives!

As I said before, talk to someone with a turbocharger long enough, you'll want a turbo. Same story with a supercharger.

How many lbs-ft does the Pettit get? They recently pushed it to ~326 whp with a header I think. Bastage's set-up is probably the only thing thats keeping me considering a supercharger. 20,000 miles and is currently at 13 psi? Don't try that with a GReddy kit

Pettit supercharger Stage II or GReddy kit with various cooling and reliability upgrades...

Bastage

iTrader: (1)

+~140 whp and +~80 ftlbs of torque with the 13 PSI pulley.
+~100 whp and + ~60 ftlbs of torque with the stage II pulley.

It's highly recommended to run w/m injection if you're going to 13 PSI and intend to run the car hard for extended lengths of time. I've only been at 13 PSI since January, and a couple of weeks of that I had to drive my car like a grandpa because my clutch could not take the extra power. I have since upgraded the clutch and flywheel and my wife once again hates riding in the car with me.

In a couple of weeks I will have had this kit installed in my car for 2 years. The only thing negative that has come from it is that I've gone through a few tires, and I needed a new clutch at about 36,000 miles.

mscamp02

iTrader: (3)

2 years running with a FI kit....and now running at 13 psi.....go pettit for building such a reliable kit

blackenedwings

The truth of going FI with this car is regardless of which form of forced induction you go with you will reduce engine longevity and run the risk of blowing your engine. That is just as true with a supercharger kit as a turbo kit. There are people who have run turbo kits for as long as you trouble free, and plenty who have blown motors too. Fortunately with the AccessPORT and some better turbo options than the base TD06 GReddy turbo those explosions are fewer and fewer.

Because the Pettit kit is so nicely put together it lowers the risk of one of the components failing causing catastrophic engine failure, but it does not make it impossible. People don't get a gambling thrill out of potential engine failures, but god knows there are enough naturally aspirated RX-8s with blown motors. FI just makes it more likely.

mysql is a good example of someone who ran a turbo RX-8 for a long time trouble free, and his engine problems were not the result of his FI setup, but directly related to a faulty ignition component. If he had been running a SC instead it would have still happened, boost is boost and misfires due to the crappy ignition kit caused engine damage. More interesting still is the fact that when they cracked his engine over to rebuild the interior of the engine was in fantastic shape despite having been turboed for ~20k miles.

I have never played a part in the turbo vs. supercharger "war", but the one thing that frustrates me is the misinformation being passed around as "fact" about the safety and reliability of the solutions. Pettit in particular makes a great kit, I've seen it myself on Greg's car and can vouch for that. That does not make superchargers somehow safer boost than turbo boost. The overall solution is generally less risky than a kit you put together yourself, and that is the benefit.

Let me know if/when you make it up here, I would love to see your car... I really want to feel 13 lbs of boost! Hopefully I'll have everything tuned the way I want by then and we can compare and contrast.

Red Rex

iTrader: (1)

I think some people confuse the engine's durability with the kit's duarbility. Yes, supercharging is just as dangerous as turbocharging. There's nothing that could go wrong on a turbocharger that can't go wrong on a supercharger. You can run lean and detonate on either set up.

HOWEVER, the turbochargers that are available for our cars seem to be lower quality than the superchargers available (improper sizing, journal bearing turbos, etc, etc). Do not discredit a turbocharger and call it less reliable. Blame the company for lack of R&D and cheaping out on parts. Pettit took the high-road and built their kit the right way. GReddy did not. As a result, people are blowing engines on the GReddy kit and the turbocharger design is being blamed rather than the company. As blackenedwings stated, plenty of people have installed turbochargers on their car and lasted just as long as some of the supercharger owners. A lot of people say the rotary engine is unreliable by design. It isn't. Just depends on how much time and effort you're willing to put in to make it work. Same story with the turbochargers for our cars. Its not that "oh a GReddy kit will always be unreliable", its just that you have to put in that extra work to make it reliable.

Red Rex

iTrader: (1)

I would run a water/meth kit regardless of what kit I got at any psi. Just cheap insurance on an expensive engine.

Are the stage II figures from an otherwise bone stock RX8? Stock exhaust, flywheel, tune, ignition, etc? And from what I understand the Pettit kit comes with its own tuning. Is it effective or do you/did you feel the need to switch to the AP?

blackenedwings

Water/meth is a good idea for any form of FI, especially as insurance. If you aren't tuning for it, nothing bad will happen if your meth kit stops working, but while its working you have a great degree of protection from detonation.

renesisgenesis

when i think supercharger i think of boring american v8's. Turbo makes be think more european, but also makes me think of burning rice CRX's.

Both are very foolish in my opinion, but I am extremely biased towards NA.

blackenedwings

Doubling the torque and increasing the hp of the car by 160% reliably isn't foolish. It's expensive and time consuming, but not foolish.

Brettus

iTrader: (2)

Sure I blew an engine - which I now believe was due to an ignition "upgrade" . But having gone through that I am now 100% confident that a turbocharged Renesis with a good tune can be reliable .
I was one of the people that was pro supercharger and have argued the SC argument extensively on this site . I still today believe that many of the arguments I've put forward on that subject are perfectly valid although I got quite a bashing at the time from mysql and MM .
BUT I'll tell you one thing - a well set up turbo on this engine is a beutiful thing and i believe if you ever get to drive one you may just find yourself saying "o **** - this is what iv'e been missing all this time"

renesisgenesis

Well, obviously if the only thing we know is that doing a certain something increases power by 60 percent (I don't think you meant a 160% increase, because that would be about 603 flywheel BHP.....) then yes that would be a good idea, but of course that certain something can create all kinds of unwanted side effects. You did not even mention the loss in drivability, throttle response, and of course the unwanted extra stress on your motor, transmission, etc. Bottom line is simple: I don't trust adding FI to a car which was specifically designed as NA. The rx7 is turbo, the rx8 is not.

don't get me wrong, I LOVE turbo, but only in rare cases.

F40 anyone...?

blackenedwings

A 60% increase is 160% of the base power. A properly set up turbo will not have a loss in drivability, or throttle response. The stress on the motor is definitely a factor, but that is the cost of the increased power. The rx7 was set up as a turbocharged vehicle from factory, that didn't stop many people blowing rx7 motors (or many stock turbocharged piston engines!) over the years.

With a good OEM reflash tool, proper tuning and good components the RX-8 can be reliably turbocharged or supercharged safely. Meth injection provides another layer of safety as well.

renesisgenesis

Ok, you said INCREASING the power by 160%. That is 603 flywheel bhp. Please don't pretend you didn't screw that up. I know it is not important, but come on now..

Anyway, unless you get a turbo with absolutely zero lag(impossible, even with awesome turbo setups like in the 335i BMW....Yes i have driven one and yes there is still a little lag, even in that car.) and a torque curve showing no jump in power (again, impossible, unless you have multiple turbo's hooked up to a reasonably large motor with decent low-midrange anyway) , then yes, there absolutely would be a loss in drivability and throttle response. Please don't pretend otherwise.


So, really this comes down to whether or not each person finds the added surge of power worth the extra money, stress on motor, and loss in linearity of torque delivery/throttle response.


Maybe it's worth it, maybe it's not. I am very biased towards NA, so of course i would not do it...