Originally Posted by RIWWP

Power Modifications: (Updated January 26th 2013)
Newbie's Guide to Modding the RX-8: https://www.rx8club.com/rx-8-discuss...rx-8-a-233937/ (I wrote that one too!)
2004-2008 Power Modifications subforum: Series I Aftermarket Performance Modifications - RX8Club.com
2009+ Power Modifications subforum: Series II Aftermarket Performance Modifications - RX8Club.com

From the factory, the 8 is VERY well tuned (mechanically). There are only 2 things you can do for easy power:
- Custom tune to remove some of the "safe" parts of the tune. The AccessPORT is available for Series1, MazdaEdit is available for Series1 and Series2
- Removing the naturally restrictive catalytic converter.

Doing the rest of the common upgrades piston cars get (intake, exhaust, pulleys, etc...) nets you MAYBE 5hp. MAYBE. Depending on the brand, alot of them are inferior to the OEM stock system, and plenty cause you to lose power.

Why?
The basic engine design/configuration of the 13b used to only put out around 110hp naturally aspirated. Mazda has adjusted and tweaked everything to get it to a razor's edge of how much power they can pull out of the same basic 1.3L engine, and they have over doubled the original hp. A lot of R+D went into squeezing this much power out of the tiny engine, and companies that just slap something together typically make it fall off that razor's edge of peak performance, and the impact is considerable. Think of the engine as already modded to nearly peak N/A HP, and you will start seeing how it's hard to get any gains, and easy to create losses.

Another way to think about it would be to think about a Civic B16 engine. It's a 1.6L engine that from the factory makes about 160bhp (plus or minus a bit depending on what car it's in). Someone can take that engine and go all out on modifying it to make as much N/A power as they can. Max power reported seems to be around 240bhp (sound familiar?). This includes more expensive engine management, higher compression, possibly some displacement increase, different cams for port timing changes, etc... So, what if Honda had released the engine from the factory with 240bhp from those changes? Well, think about how these compare to the RX-8's Renesis:

• There would probably be quite a bit of trouble getting it to pass emissions standards (like the RX-8)
• The stress on the cooling and oiling systems would be considerable (like the RX-8)
• The engine wouldn't be expected to last forever, frequent rebuilds would be standard (like the RX-8)
• It would cost THOUSANDS for tiny power increases (like the RX-8)
• It probably wouldn't take to being turbocharged very well due to the high compression (like the RX-8)

Does it make more sense now? Mazda basically already modded the engine to get near max N/A HP, detuning it only slightly to get it to pass emissions and having to add the obligatory catalytic converter. It's difficulty and costly to improve on their design as a result.

So...how DO I get more power?
If you want power, you have to go forced induction: turbocharger, supercharger, or nitrous. For turbocharging or supercharging, you need a starting amount of about $8,000 to $10,000 for a complete set up. If you find what you think is a "deal", please don't get fooled. If you spent $1,500 on your turbo system, you will still spend $8,000 to $10,000 in modifications, errors, swapping parts, getting stuff to finally work right, and probably an engine replacement along the way. There is NO complete key that is 100% perfect. Every single kit has something wrong with it that you will have to correct. If you don't have an AccessPORT or MazdaEdit, you have very little chance in making it work. Piggy backs will not work with the RX-8, the ECU is too smart. Standalones are possible, but rarely pursued for street cars.

If you don't go that route, then the most you can expect is about 200 whp without a custom engine rebuild, which can run you $5,000+. The advancements in porting work have been slow coming, but they are still moving the needle upwards.
BDC has the higher N/A power recorded for a non-race team, posted on 5/16/2011 here: BDC Street port vs. stock port dyno comparison - RX8Club.com 223whp:

Please note that "heavy" has not been defined as of this edit. The gains are from more than 1 source. Likely full 3 inch headers to tips on the exhaust, entirely unknown what the intake is. The porting work above was mostly on the intake ports rather than the exhaust ports. There was also likely significant improvement in the seal tolerances over factory specs.

Eric Meyer posted his 233hp dyno sheet here: 233 rwhp dyno sheet - RX8Club.com
But keep in mind that it's likely his team invested $100,000+ (just a guess) into the R+D of the engine and drivetrain to get it there (including special treatments of the transmission and diff to reduce drivetrain loss)

Don't get fooled by any "chips", ebay or otherwise. There is no "chip" for the RX-8 that will do anything beneficial. The best you can hope for is nothing at all...a costly metallic sticker on your ECU. You can easily fry your ECU with one though, and that is $1,600+. The only reliable method of improving the ECU is through an AccessPORT or MazdaEdit. The piggybacks such as Interceptor-X and GReddy's E-Manager are terrible for the RX-8. You can get it to run, kinda. But you won't be making more power than stock. There are a few other ECU flashing tools out there, but most are no longer supported, and had trouble to begin with.

If you think you want to go turbocharging or supercharging your engine, start here: Series I Major Horsepower Upgrades - RX8Club.com and keep reading thread after thread. Get to know the issues people have had, read their responses, their solutions, their frustrations.

Originally Posted by Charles R. Hill

Thanks for the mention, although I have yet to verify fitment or performance on any of the A/T models. I will, at some point, though.

Originally Posted by Brettus

Don't touch that Greddy Emangle with a barge pole . It has been proven over time to be a POS .
Go for either Mazdaedit or Cobb Accessport .
I would have a look at the BHR midpipe + headers + the tune . That should get you close to your goal .

Originally Posted by Charles R. Hill

Finding the time to perform the final dyno/fitment test is tough right now, but I am working on it.

Originally Posted by stigma8

Just a note the best computer for the rx8 is the adaptronic. I can put my car on it. Its by far the mosr advanced ecu ive ever used and I have used over 5 different ones on my turbo kit

Originally Posted by ShellDude

just don't let it ever get back to the wife

Originally Posted by stigma8

Just a note the best computer for the rx8 is the adaptronic. I can put my car on it. Its by far the mosr advanced ecu ive ever used and I have used over 5 different ones on my turbo kit