HardHitter

Alright guys, well, I've finally got hooked on the turbos and I'm pretty much set on buying the Greddy turbo, however, I want to be able to push atleast 300HP to the wheels with it, and from those who have it, are only getting around 230-250HP.

I was talking to Chuck at Rotary Extreme and I am going to purchase and have them install my turbo on my 8, but I was saying what would I need to do in order to push around 300HP. He told me I'd need to use more boost. He told me that I'd need a boost controller, which would allow me to alter my boost and buy larger injectors, he said atleast 2. He told me the stock engine should be able to produce up to 350HP without "prepping" the engine.

So my question is, what will I need and how much will everything cost? This is my list so far...

Greddy Turbo - $3000
Greddy Type-S BOV - How much are these usually?
Boost Controller - Which one and what is the price on this?
Larger Injectors - Chuck said they are ~$100 each also, how many do I need?
Guages - Do I really need the guages?

So far, I'm guessing $4k for turbo+install and then about another $1k for the BOV, Boost Controller, Injectors, Guages, etc etc.

All in all I would love to be running ~300-350HP for $5k, is this possible?

Aseras

greddy isn't gonna have the boost to do it stock. You are probably gonna have to lower the compression ratio and go with a diffrent turbo. You are going to need about 9-10 psi min to get that much HP.

even then you are gonna start choking on the ports. Intake is good but exhaust will probably need to be opened up a little more to flow better.

good luck

BaronVonBigmeat

You might want to read RX8PR's thread, he made 273 HP with some tuning, and managed 300 but not really streetable so he's going to a different turbo. The greddy turbo is capable of 450 HP..."in theory"...which on a rotary is more like 300 HP.

IIRC.

https://www.rx8club.com/series-i-major-horsepower-upgrades-93/first-rx8-puerto-rico-greddy-273hp-53002/

Fanman

Greddy Type S/Type RS = $200
Boost Controller = $200-$500 (depending on how fancy you want to get. From companies like Greddy, HKS, Apexi, etc.)
Larger Injectors = $200 ($100 a piece from Greddy or RC Engineering, probably 440cc's or 550cc's).
Gauges = $400 (You definitely need a boost gauge, and it is probably good to get either an EGT or AFR gauge as well. Companies like Greddy, Defi, HKS, VDO, Autometer, etc. make them).

I have all this stuff (except the larger injectors) & was going to go to 10 psi. No, you are not going to have to get lower compression rotors or go with a different turbo. You will have to go to about 10 psi-12 psi. This really is the high end on what people have tried (except for those crazy Puerto Ricans had theirs at like 18 psi ! But they are the best with Rotary tuning). This will get you to AROUND 300 whp. Be sure to add the proper fuel support. Injectors will be a must, maybe even a secondary fuel pump, although Mazdamaniac says we have like a 255 lph fuel pump good for way past 300 hp. I'm running 7.5 psi in the rev range (6 psi on the top) right now without the boost controller. Going to go for 8 psi next time around.

rotarygod

The Greddy turbo is not capable of 350 hp on a rotary. It won't happen. It's way too small.

IZoomZoomI

I don't know it migt be just me but I would take a conservatively tune FI'ed 8 or a properly prepped turbo 8 that would last me a while vs. an aggressively tuned one just so I can get to 350hp.

Don't get me wrong, Chuck seems to know his stuff but he said a stock engine "should" be able to handle that amount, I be a little more careful trying to go that aggressive. Just saying your folks bought you a 30k car, you should be more careful with it being that your warranty would be completely voided. Then again if I had money to replace the engine I wouldn't mind maxing it out and seeing what I can get. I would suggest you go over this thread.... https://www.rx8club.com/series-i-major-horsepower-upgrades-93/what-parts-needed-reach-350bhp-use-everyday-61225/

IZoomZoomI

Is there any other turbos that spools up as quick but is capable of 350hp? The only thing I see good about the greddy turbo IS b/c of the size, which cures much of our lackluster low-mid range power but are their alternatives with this same benefit but more power?

Fanman

We are already seeing around 250-260 whp at 8 psi. With another 2-4 psi we should be able to see about another 20-30 whp. He is saying 300 whp/350 hp at the flywheel. 350 whp is definitely not doable from the Greddy unit. I know you had a long explanation about this in another thread but it definitely seems doable, or at least pretty close before you have to buy another $ turbo.

IZoomZoomI,
270-280 whp from the PTP & SSR's is what I have seen so far. They are claiming 300+ whp is possible. Don't know if anybody has the guts to go for it. That is why I am thinking about staying at around 7.5-8.0 psi.

IZoomZoomI

Yea I've seen that, PTP looks promising. But again I doubt it spools up as quickly as the t6. The only way I would even think about maxing that turbo out is if I know have enough money to put in a new engine. And some people are ignorant of this fact, power w/o reliability is really nothing to boast about.

rotarygod

The big problem with turbos is that you sacrifice in one area to get something in another. If super fast spool is your goal, big power isn't. If you don't mind a little lag, bigger power can be had. If you want real big power, you also get real big lag. No miracles there.

Fanman

Both the PTP & SSR/SFR kits are running T4 turbos. I think SSR or PTP have already commented that their power is more top end (and SSR even had a little bit of detonation problem on the top end). I really wanted my power on the low/mid range so the Greddy is perfect for me. As long as I get about 260 whp everyday driver (nice pull from 2000 rpm up) I'm happy. Not really looking for 300+ whp.

Also in doing some calculations & also seeing some examples (BMW M3's, Porsche 996's seem to be dynoing in the high 260's/270 whp) extrapolating that would bring 350 hp at the crank to about 285-290 whp (roughly 18% driveline loss).

HardHitter

So do you think it is worth the extra money in order to push the turbo just a little further? In short, should I buy the injectors, should I buy the boost controller and try to add a little more boost? Or just leave it at stock boost.

Fanman

That's the exact dilemma I am facing right now. I have everything except the injectors. I'm just wondering if I should try to push it to 10 psi (on maybe even a race mode on the boost controller, as you can set 2 different settings), or just be happy with a 7.5/8 psi daily driven car & not spend more money on putting the boost controller in, upgrading the injectors, etc. Not to mention you will probably have to get the Greddy support tool software so that you can fine tune the A/F mapping (that is about another $100 right there). If you ever make it down here (maybe Sevenstock), I would be more than happy to let you drive my car to see if you need more than 7.5 lbs. of boost.

evilbada1

dude you won't get 300whp out of Greddy without alot of work
like RG mentioned , T618Z turbo is pathetic..
just wait and get PTP or SFR already
of course if you're happy with 260-280whp, then get Greddy

Longhornxtreme

OR sell the Greddy turbo (the turbo itself, not the kit) and buy a new turbo with the same flange, buy the injectors, and then tune your emanage out to a higher boost level...

the problem is that PSI is NOT what determines power... its total amount of air....

One of these days I'm going to either go scan or type up the pages on the Ideal Gas Law as well as Charles, Boyle and whatever other basic gas laws are in my General Chemistry text book... Come on people! PSI is NOT the answer....

RX8PR

Hardhitter,

Sorry but you would not see 350 HP at the wheel from the greddy turbo.......................

I have all that you mention: 850 cc injectors, boost controller, etc etc stand alone ECU and

more..................

I'm running 11 psi low boost and 14 psi high boost , I can't make more than 308

HP at the wheel. My problem? my greddy turbo!

You would need a bigger turbo for 350 HP and more than $5K !


Fanman,

I'm curious, How much HP you're making with you're setting?


Manuel

rkostolni

I think you will be surprised what 240hp feels like on this car. Its a huge improvement. You should easily be able to bump it up to 280hp or so with an exhaust boost controller and tuning. I can only imagine what that would feel like!

BigOLundh

iTrader: (1)

Mazmart is currently selling Renesis motors for $2400. Make sure to pick up one of those soon after you blow this one.

Moostafa29

HAHA...I don't think mom and dad will be happy when they hear you need a new engine

BigOLundh

iTrader: (1)

What is your goal? Why do you want more power? I am not going to assume anything so i'll just ask. Do you plan Auto-X, Road Racing, Drifting, or Drag Race with this? Are you just wanting a faster daily driver?
A standard greddy turbo will make your car fast, but you will always run into another car that is faster. No matter how much HP you have, you won't have the fastest car in town.

Anyways, before i go on, and before we offer more pointless suggestions... can you tell us what your goals are with this car and the boost upgrade?

-HS

HardHitter

What I'm looking for is just a faster daily driver. Every now and then I might go to the drag strip and have some fun, but it's basically for a daily driver and just to have the power if I'd ever need it to have a little fun.

There is another guy on the forums in the Bay Area who has the Greddy kit and is doing all custom piping and is going to be pushing around 500HP to the wheels, but he is also spending about 15-20k on everything.

So what really is holding the Greddy turbo back from pushing more HP? Is it the piping or what is it? I'll probably talk to Chuck at Rotary Extreme and see what he can do with my wants and needs.

Anywhere around 300-350WHP for a daily driver is enough for me, I don't need it right away though, I could just install the Greddy turbo, run around 230-240WHP and then later down the road, upgrade things to push for more or will there be a limit?

Aseras

This car is begging for a decent supercharger. revs + supercharger = big gains, instant boost that keeps on building.

ranger4277

Pretty sure it is the turbo itself. Inefficient once you get around 300. Need a bigger one.

Aseras

that's not bad at all.

Aseras

if you are gonna do it do it right and do it once.

the greddy turbo is TINY. It's not big enough to move enough air. you need a bigger turbo. You spin the little turbo like 15,000 rpms and it COOKS. the air gets super hot and intercooler is only so much. Since there is no overlap like there was in rx7/fd engines you cannot scavenge and you must SHOVE the air in now. Fisher price turbo aint gonna cut it. With a bigger turbo and more air you are gonna need more fuel too. to get 300+ hp out of this motor is gonna take some work until the aftermarket ( which is finally starting to get going ) catches up.