Greddy Turbo Kit w/ Cobb Access Port 2005 AT RX-8. Help Please, little intimidated!
 

Hey there!

I'm pretty new in the Mazda/Rotary scene. I previously was into 2nd gen eclipses' which I had a lot of fun with. I accomplished my goal of 300whp, 298ft torque. =) Unfortunately, I had to sell the car because I inherited a 2005 Mazda RX-8 AT, along with the HUMANGOUS monthly payments due to my ex-finace'. hehe =)

I also have experience swapping B-series engines into Honda CRXs and Hatchbacks as well as boosting them with OBD-1 Uberdata tuning (which was a pain in the butt, but worked VERY VERY well.. got my b18 non vtec Civic Hatch into 13.9s on 9 psi of boost. =)

I've come to a realization that I'm going to have the car for a LONG time, until it's paid off, because the value on this has dropped dramatically and cannot trade in for a Mazda Speed 3..

So, I've decided to keep it and start making it a more fun car to drive.

I NEED YOUR GUYS' and/or GALS' help because I KNOW NOTHING about this car, and for some reason, The RX-8 seems to be about the most complicated vehicle that I will ever work on. I am trying to get over my cold feet, as I almost sold my kit and I am holding off on ordering the other needed items.. =(

I bought a slightly used Greddy T618Z Turbo Kit w/ intercooler and Greddy Type S BOV. I am about to order my mazda maniac COBB Access Port.

Here are the questions prior to beginning my awesome adventure of boosting a Rotary engine!

---Does anyone on here have a OEM parts list for the misc screws and gaskets that I'll need to do the install?? i.e. exhaust manifold gasket, etc.? (I want to be prepared because I can't afford a rental car!)

--- Change Spark Plugs?? I'll be boosting the stock wastegate settings of the turbo.

--- Do I need any sensors or anything to use the COBB AP as my primary engine management route?? (Reason I'm asking is because I may have read that I need to use a different MAF???)

--- My kit didn't come with any heatshielding.. I'm ordering DEI 010113 (Universal Turbo charge heat shield kit) I've read many reviews and this should work well.

--- I'm keeping the car as STOCK as possible, but will probably install a test pipe for offroad use to free the exhaust a bit. (I heard the RX8 CAT is VERY EFFICIENT at burning un burnt fuel and oil, so it's also very RESTRICTIVE..)


IF Anyone has any other tips, pointers, or any information whatsoever, please please please let me know! I'm new to this and cannot afford to blow anything up. I'm also not trying to make a race car, just trying to have a little more fun with my RX8.. =)


Thanks again for your help and support in advance! I hope this is not too much to ask.

I've done my research, but I would love to get more specific/personalized responses regarding my install, in case anyone is trying to pursue an ECONOMICAL Turbo Charger Upgrade path for their RX-8...

Take care!!!

Mark Padilla

I am pretty sure you have already visited my blog because you posted a comment asking the same questions.

You will eventually need a turbo rebuild. Since the kit is used you will get even less miles than you normally would. You need to send the turbo to Bryan @ BNR Supercars for the GReddy turbo hybrid rebuild.

You also need to replace all the cheap couplers with silicone couplers. T-bolt clamps are also a good idea.

With the Cobb AP you will need a new intake. The GReddy intake is too short to get a clean MAF reading.

Upgrading your coils to the BHR Ignition System is also a good idea to avoid spark blowout with all that extra air you are forcing into the engine.

The spark plugs recommended are NGK BUR9EQP for leading and RE9B-T for trailing.

Do you have a blow-off valve? If not you need one.

As you can see there is allot more to buy besides the turbo kit. Good luck!

do you have a 4 port or 6 port ? If 4 port the stock Greddy will do the job without an upgrade although still not ideal .

You may find this usefull although it does relate to 6port MT
https://www.rx8club.com/series-i-major-horsepower-upgrades-93/getting-most-out-your-greddy-turbo-without-breaking-bank-172542/

I am pretty sure he has a 2004 so it would be a 4-port.

Why would he not require a rebuild? It would only be a matter of time no?

I agree he should get it rebuilt , just think the BNR upgrade is not necessary unless he has a 6 port .
He will be lucky to make 220whp at which point the stock greddy is ample ....

Wow 220whp, I was thinking more like 240. Then again, it is a 4 port. It will only benefit him to not leave the greddy kit stock, well I don't think it will hurt lol.

Space reservered for comment later tonight:.. :-)
All of us when we started didn't anything about the 8 either. All that is diffrent is the motor spins and has an PCM that is smart enough to figure something was modded.

The AccessPORT so far to date the most useful aftermarket tool we can get.

9 (colder) range plugs will help mitigate any desire for detonation. So that would be a good idea.

You shouldn't have to replace the exhaust gasket. Only if the dimples that hold the metal layers together have come apart. Stock part #N3H1-13-461B.
As for the screws/gaskets needed, what are you missing? Do you know? There are only 4 gaskets in the turbo system.
1. Between the Charge pipe and the compressor
2. Between the compressor discharge and the discharge pipe.
3. Between turbine and downpipe.
4. Between exhaust manifold and inlet to turbine.

I know somewhere around here is a bolt size/thread pitch list.

You do not need any additional sensors fo rthe AccessPORT to function correctly. It pulls all of it data from the existing sensors. Reguarding the MAF. the AP dosent' like the MAF housing size of the Greddy. Also the Greddy locations sucks in hot engine bay air therefore robbing HP. Pick up an AEM/Mazdaspeed CAI. it's MAF section is the proper ID. Also the AP isn't an enigine management. It's a map reflasher/datalogger.

Can never have too much heat shielding. The stock cat may give up the ghost soon afterward the turbo is placed in front of it. Also will cause hi back pressures and a slower responding turbo. A hi-flow cat or catless midpipe will help with backpressure issues and turbo response will improve.

The Ap will mask the Code for the inefficient cat.

Rebuild the turbo for sure, and install a .041 oil restrictor. The oil pressure unrestricted will blow out the oil control rings in the turbo and make it a mosquito fogger.

Also pick up the BHR fuel pump replacement. My pump had failed (not entirely) on my last dyno run and wasn't supplying enough fuel in boost. Nothing like lean misfires. So nip that issue in the bud.

The Greddy turbo isn't that bad of a match for a 4port. It's boost starts to fall off around 7k and the stock rev limiter is 8500k on the 4port 8. the fuel delievery of 1570 cc is maxed out at 9psi on the Greddy. Want higher boost? you need bigger injectors.

I know I could have done 220 hp with my Greddy, stupid fuel pump! Full boost comes on at 2800 rpm.

I have a 2005 AT RX8 grand touring with a 4 port engine... =( but I'm sure it'll wake it up a bit?

Thanks so much.. seriously, all the help and tips, suggestions I can get please keep em coming..

Greddy didn't recommend injector or spark plug upgrades.. I'm only boosting the stock greddy kit wastegate limit.

I'll do other upgrades later.. just trying to boost reliably for now, with minimal power gains. I'll do the exhaust system, injector, etc upgrades as I get more money. Right now, I'm tight on cash. Infact, I should not even have purchased the kit! I just won the auction and got a decent deal on it...

I hope I'll feel atleast a little difference in power.. specially in the low/midrange rpm band.. =( if not, then is it really worth the trouble?

I remember boosting 8 psi on a B18 non vtec engine and noticed a WORLD of difference.. I know rotaries are different, but I'm hopeful..

you can also use the "multi-quote" feature instead of quoting each response seperatly.

it looks like mazdamaniac is still offering GT3071R for greddy turbo upgrade . only this time the price went up from $1,800 to $1,900. maybe it is just me that noticed the price change. ^_^