KRMRX8

iTrader: (1)

As a Noob to rotary but 56 year old experienced for way too many years with the AEM ems on Mitsu twin turbos I am really in need of good advice from those well experienced tuners/builders with the RX8.

History: I bought a 40th last month. It is still bone stock because I have the dealer's lifetime warranty on the drive train ($100.00 deducible) so I need to keep her warranty safe but sure need some extra power from this car. I was told that only Mazda speed parts are ok to keep the warranty intact. Mazda engineers seemed to have done an excellent job with basic tuning but there needs that bump in power.

Options:
The Access PORT stage 1 looks ideal for my needs ( a DD with a few Auto X days a year)
The AEM EMS would require closer to $2,000.00 with all sensors and upgraded fuel pump and then of course a single turbo_ or SS. So the AEM doesn't offer what I need for a modest increase.
The question is if the AP stage 1 will equal or exceed just the mild gains/advantage of doing a test midpipe and a drop in K&N air filter?

I am looking for a noticeable bump in torque as the primary reason.

Also, can the AP stay connected an mounted to monitor water temp and oil PSI and AFR's or is aftermarket gauge the way to go?

Thanks in advance for anyone knowledged to help me out.
Kim in MN

myriadshalaks

iTrader: (1)

the AP is good, but the stage 1 map is pretty weak. You'll want a better tune. you won't need any other engine management if you have the ap.

you'll get more from a midpipe than you will from the stage 1. but with a good tune, i think you'll see about the same gains from either, +10 whp. or +20 with both.

the ap can be mounted, but you'll be scrolling through 3 different screens to see the oil, water and equivalence ratios. you don't really need to see that stuff while you're driving anyway. it's almost always going to stay in acceptable levels unless something is wrong. and if i is, you'll know it, IMO.

i think for your usage, you would want the following:
AP tuned by someone other than Cobb -- MM and Kane come to mind
MIdpipe or Supercat
VFAD removal
lightweight flywheel
underdriven pulleys
afe shortshifter


That should get you about 20 more whp and some much needed kick in the seat.


Also, search around in the tuning forum. i've done some reviews of the cobb stage 1 map. I've also got a thread that has a free map(s).

J8635621

iTrader: (10)

Good buy on the lifetime drivetrain warranty.

KRMRX8

iTrader: (1)

Thanks so much for the reply!
Cost wise, you are saying that a decent mid-pipe ( "mid-pipe" then is the same as what we used to call a Test pipe that on other cars was a straight pipe that replaced the main cat?) and that mid-pipe will be less than doing an AP with a Stage 1 tune. ..but then the lifetime warranty I got for free will be killed
I assume the stage 1 has a bit more timing at the higher rpms and has the fuel trimmed a bit to get her a little less factory rich ( maybe closer to the 11.7 to 12.00 AFRs?)
Since I do a fair amout of long trips in the car I need the cruising decibles at 75 mph range to be near factory level so the Cobb AP seems the best and leave the cat as is for warranty.

Thanks for the help! BTW, why the heck does Mazda not include a spare for a sports car or do the run flats?? dumb marketing on their part...or Japan doesn't have their cars out from town by more than few miles? MN through MT has some desolate roads!

KRMRX8

iTrader: (1)

Thanks...the Lifetime warranty on drivetrain for free was the deciding factor to buy the car with taking my other vehicle in trade. I have replaced transfer cases and trannys and engines on my older Mitsu VR4 and that was pricey!
BTW, Morries Mazda in Minneapolis has a 2006 white Shinka with about 40K miles..nice car for anyone who is looking. My understanding is that the 40th is actually a Shinka with every option they could find.

J8635621

iTrader: (10)

Are you sure they would void the warranty because of the cat? Definitely get the AP from mazdamaniac. It has numerous VERY important benefits (cooling fans come on faster, more oil injected, etc.) and will also get you better MPG (from low 18s to upper mid 19s mpg for me) since you go on long trips. There is no spare to save cost/weight, no runflats because they ride rougher/less grip usually/cost more. Mazda makes a spare but it takes up most of the trunk.

myriadshalaks

iTrader: (1)

they give a tire fix kit. less weight.

KRMRX8

iTrader: (1)

Thanks..will def do the AP from mazdamaniac.
re: advice for VFAD removal. I assumed by the design this was to control sound and increase flow at the higher rpms with a shorter tunnel and a longer one for low end torque. Can someone comment on how this VFAD removal will benefit?


It is relief to know there are some experienced here on this forum that actually know what they are talking of instead of hearing, " well, I heard___this is the best ( but no facts to support). Too may other car platform forums have too many kids blowing steam to feed their ego and some end up causing other kids a lot of regret for their advice.

re: cat removal..I assumed it would void the warranty because Mazda would say the less back pressure affected the tuning_ bleh.
AccessPort looks to be much easier and less costlier than the AEM ems even though I know the AEM system, it was laborious to set up and fine tune plus you needed to splice a few ECU wires to connect the ems and needed a laptop for tuning changes..fun but costly.

Once I buy another FJO Wideband, I will get the AP from mazdamaniac for any future tuning needs. Thanks again for the advice.

myriadshalaks

iTrader: (1)

skips the opening and closing part. maybe helps a little with acceleration. sounds more aggressive.

opinions are mixed. i probably shouldn't have recommended it.

btw, welcome. addictions ... who do they hurt?

Jon316G

iTrader: (1)

The nice thing about doing the "VFAD Delete" is that you can try it and revert back easily if you don't care for it.
There is a hose for the VFAD behind the throttle body.
Remove the hose and cap the nipple (might want to zip-tie the hose so its not just dangling).
Once you start driving and go above 5500rpm, the VFAD solenoid will open and "bleed off" the remaining vacuum that kept the valve closed.
And by having the hose disconnected from the upper intake manifold, you eliminated the chance of vacuum being introduced and closing the valve.
So now its kept open at all times.

fastlaneracing

You can always install your stock cat when you bring your car to the dealer. it isnt that mutch work to do.

carbonRX8

iTrader: (1)

I would second that the two easiest and most reversable modifications are the AP and the midpipe. But I wonder...

First, what are your objectives? From your first post, you are interested in auto-x but you also want more torque. You also want a quiet daily driver. You dont want to void your warrenty, but brought up adding forced induction.

I would start with picking out exactly what you want and how much your warrenty means to you.

For auto-x, I do not believe that anything would decrease your times more than a set of tires and some suspension mods. Depends on what class you are interested in, of course.

Risking rambling, I will say that I had an interesting experience this weekend. Even with around 50 extra horses, I had my hands full following a NA on backroads. There is MUCH more to this difficulty than just power, but the point is that what you are trying to do should precisely dictate your plan.

fastlaneracing

Good post carbonRX8

A nice chassie setup and good tires will make more impact on your autox times then any other engine tuning and it shouldnt void your warrenty.

From experince I would recommend KW V3 Coilovers, AP Sways, AP Endlinks, some strut braces and Toyo R888 tires and a Accessport for lite more umph and call it a day.

Flashwing

Using the Mazdaspeed parts is a pretty good move if you're trying to keep your warranty intact. Be careful with some of the Mazdaspeed purchases as some of them carry different warranty levels. I believe there are 3 levels associated with MS parts.

I might be going against the grain on a few things but I'll happily explain my reasons.

Assuming warranty is your primary concern:

-The accessport is a great buy for many reasons. The best being, unlike the AEM, it's very easy to uninstall for trips to the dealership. Even though the dealer doesn't flash the PCM (read: ECU) every time you go to the dealer, they do use the OBDII port for diagnostic purposes. While I've not been told one way or another if the AP prevents this process from being used, if they attempt to flash the PCM it will error out and they might suspect the car has been messed with.

The AP can be uninstalled in under 5 minutes, does not need to remain hooked up to work and stores the tunes on the device.

As for the intake...

There's no proof as of yet that the stock intake is restrictive in airflow compared to the AEM, Racing Beat or any other intake out there. Intakes work by fooling the Mass Airflow sensor into running leaner air/fuel mixtures. The PCM on the RX8 is capable of "trimming" your fuel delivery if it sees values on the o2 sensor that are different than what the fuel table is calling for. This lean effect created by the intake will simply be negated in about 1 to 2 drive cycles.

The MazdaSpeed intake retains the stock diameter tubing which means your MAF calibration won't be seriously off from stock. The stock intake, however, does draw air from outside the motor so in effect is it already a cold air intake.

$300ish is a lot to spend and even if it does provide a HP increase it's going to be 2 to 3 WHP max. That's within the margin of error on most dynos.

Don't do underdrive pulleys. I just got done messing with that nonsense. IIRC, the unorthodox kit seems to be lighter than stock and only 10% underdriven but it's rather expensive and it would void your warranty.

A mid-pipe is something that has been shown to help a bit in the power department but not having the cat means not having to deal with it possibly failing. Also the cat can be put back on for warranty/emissions purposes.

Aftermarket gauges might be a good option. There is no way to monitor oil pressure via the OBDII interface nor can you get oil temperature information. You can read a lot of other stuff however.

Water temp, oil temp and oil pressure are good gauges to get. Air/fuel can be read through the AP via the front o2 sensor. The rear sensor is a dummy narrow band.

Finally, check out posts regarding the BHR ignition system. The RX8 ignition coils are known to be weak and fail within 25,000 to 30,000 miles on some vehicles. Paired with the AP and using longer dwell times you will see some performance gains across the whole RPM band as well as perhaps a couple MPG.

The ignition upgrade is plug and play as well so you can throw your stock coils back on the car for warranty purposes without splicing into the wiring harness.

The AP is much much cheaper than the AEM and in some respects just as powerful but perhaps not as robust.

oh yeah! Tires!

KRMRX8

iTrader: (1)

Thank you to all for the ideas. Flashwing's comments helped as well.
Keeping a lifetime warranty with a lousy $100 deductible for the drive train is paramount. In that regard the AP seems the way to go for that little extra torque.

Am I to understand that the front O2 sensor is indeed a wide band sensor while the cat's o2 sensor is a narrow band? If so, then the AP seems an even better bet as it can use open loop fuel/AFR control map and timing map control, just as I had on the AEM ems on a Stealth TT.

Re: midpipe straight =too loud for a daily driver for an hr commute at times?
resonated midpipe from RB solves that problem?

I once ran a 3" Borla on a twin turbo car and the drone was terrible unless kept in the higher rpms. But the Borla freed up a lot of power but at a noise consequence.

Q: Would the midpipe alone, by RB equal the gains that could be achieved with the stage 1 AP since it is tweaking the fuel map or AFR feedback map, the increased dwell and ignition timing on a stock car with stock injectors?
Thanks for the feedback!

fastlaneracing

Well it will be loud but too loud? it depends on you

Stick with Racing Beats exhaust components, they are quiet ones with good quality.

You are right about the O2 Sensors.

epikeddie

To the OP,

I think if you can mod a VR4 Stealth TT.....you should have NO PROBLEM removing midpipes, flashing with the AP, and other lights mods like the VFAD removal.

I was helping a buddy at a shop rebuild the motor on those things. My god......why are the gasket sets like 800-900 dollars on those things? The engine shop manual is about as thick as a bible!

Those are some REALLY temperamental cars, but when those things run well.....they're just plain awesome.

Go with a midpipe, AP, K&N drop-in, RB duct - stock intake box mod, suspension, and lightweight wheels and tires.

KRMRX8

iTrader: (1)

Thanks. The Rx8 midpipe is amazingly expensive! The Stealth's Test pipe as we call it ( no cat, 3" with 2-3 bolt flanged and about 20" long) was maybe only $40.00
Your are correct on the hassles. The old Stealth was a bear to swap in bigger twin turbos from DSM 14B's and then the bigger Evo 16G's because there is no room for hands by the firewall. Tuning her with the AEM was OK as I spent years with each of AEM's next revision for that platform as they worked out the bugs. Going from a stock V6 300 HP at the crank to a 428-434 HP at the wheels was a pure delight but handling was barely good with AWD but so damn nose heavy even with a CF hood and deleted OEM useless stuff under the hood.
Now that I have the RX8 40th Edition, I am spoiled by the excellent handling on dry roads that the 50/50 weight ratio and Dunlop tires provide.
Since we have a Wideband ( Yea!!!) in the #1 O2 location, tuning her with the AP should be a breeze since the O2 sensor is factory calibrated for the ecu and the potential to tune under WOT with a wide-band using AP's O2 feedback map ( they do use one right?), should be great.. My prior dual FJO widebands needed tweaking to get them spot on with no drift at FT.
Do I need a better strut tower brace/bar? The 40th has a front strut tower bar but it is not the trapezoidal type as the '09 R3 has..it feels solid though except for the sway bar action which seems to lose it's linear feel as loads increase. I had to make custom sway bar links on the Stealth TT to get corner weighting and lose the slight flex that the OEM end links had. Road racing the Stealth was a chore, autoX her was a surprise when I finally "accidentally" got her to drift through 2 simultaneous corners. Yes, it was 1/4 mile fast ( high 11's) but handled poorly compared to the RX8. Then again the Stealth is a GT car and the RX8 is a sports car, yet they feel the same at straight line triple digit speeds.

Thanks again for the advice from everyone on what and what not is needed to improve an already excellent design from Mazda engineers!
BTW_ my second son is an Acura/Honda engineer for the engine dept. and even he agrees the RX8 is an excellent design ( minus the mpg) but 23 mpg on the freeway is fine with me

Hesselrode

iTrader: (3)

23 mpg??? I wish

elysium19

iTrader: (1)

I understand that keeping your warranty is your primary concern, and that's fine. Just be aware that a lot of bolt ons could cost you $2k easily, and get you no more than 10-12 HP, and the accessport with a good tune, even with a midpipe, is good for possibly 10HP, so even for a lot of money you're still only up 20 horsepower or so. If you want more power, consider the costs and think about a turbo system, it's really the only way to do it.

KRMRX8

iTrader: (1)

Well, considering the costs for HP factor, the AP and/or midpipe just doesn't seem to justify the cost unless using the AP with F.I. I should start the research on turbo vs. supercharger. I just would like to see about an extra 40 ft/lb of torque or even an extra 20 starting at 3K rpms.

I have to admit that I was spoiled with the Stealth/VR4's electronic control suspension. The Tour setting made the Eibachs feel like OEM ride, 8 hr tours was noting to handle. In comparison, the new RX8 feels still a little too choppy on the freeways at speed unless they are new pavements. The car just turned 5,000 miles and the Sport Bilsteins have softened up a tad. Starting to think that maybe? the Tein Mono Flex with controller would equal the Stealth's Tour setting for smoother trips? I can't find their specs on the RX8 setup for damping/rebound to be sure it could soften the ride up to justify the cost while also getting the track settings an lowering capability.
Do all 2008 RX8's use the same OEM springs?
Make no mistake, I love the new RX8..just would like to see them come out with an adjustable suspension such as the reo-magnetic type shocks that the Vette uses

DAC17

Very nooby question, but I'm having a hard time finidng a direct answer to this. If I get the MazdaManiac tune on the AP, is it just an "install and forget it" tune? I know that many others will do more precise tunes, but I assume I can use the MM tune without any other upgrades, and still get a decent power increase (10-15 HP, 10-15 TQ.)

Thanks. Sorry if this has been answered, but damned if I could find it.

stinksause

iTrader: (5)

Installing a midpipe will throw a CEL from the 2nd o2 sensor (narrowband) right? Doesn't that drop the car out of closed loop and into open loop? Is this still true with AP?
Subscribed to thread....

fastlaneracing

No i don't think so, when in closed loop it uses the front O2 sensor anyway.

The rear is only for checking catalysator status.

Huey52

iTrader: (2)

I can't give a precise Hp increase range (awaiting a fairly stock MazdaManiac AP tune myself), but yes it could be thought of as an "install and forget it tune." It's quite precise actually given that you provide idle and at speed data logs of key parameters as a baseline and then can re-tune upon additional modifications.

btw: it's pretty amazing all of the sensors that exist in the '8 and are being tracked by the ECU, and you can therefore use the AP, but I would still recommend gauges for the critical readouts. The Racing Beat gauge pod is a recommended addition (oil temp/pressure and coolant temp) and nicely takes the place of the useless cigar lighter recess.