GReddy or Speed of racing turbo kit
 

basically i want to boost the power of my rx8

i have found 2 turbo kits i'm thinking of

1st is this SPEED OF RACING
This turbo will boost the HP of the motor over 100hp
i contacted the makers and they said i'd have to buy all teh ad ons to get the full 100 hp
the cost would be over $9000


2nd is GReddy's GReddy
this only does around 50Hp much less hp but only at $3,000

what would be the better choice? is the SOR worth it?

There's thousands of threads on this subject. You're very likely going to get flamed for posting on it again.

But I'll break it down to what it really boils down too:

Want a cheap kit that gets good power for a street car get GReddy
Want an expensive kit qith high-quality components that has more potential get SFR

The GReddy kit caps out at an absolute maximum of ~300whp. You can't do any more than that, the turbo is maxed out and you won't see more than 250whp without spending more money.

The SFR kit maxes out much much higher. Can't recall off the top of my head where, but it's way up there. So you can add the options as time goes on and keep bumping up the power as your budget allows.

By the way, it's Speed FORCE Racing.

Also, PTP Motorsports will be coming out with their turbo kit somewhat soon. Will be priced about the middle ($5K for the kit, when all is said & done probably around $7K).

Like Sigma said, it depends what you want to do with it, & how much you are willing to spend.

I got a question for you? How much do you like your RX-8? Why do I ask? Two reason here:

1. If you like your car, and more importantly, your warranty, I would do neither. If more power is a must for you, then you have to balance the equities. Speed Force Racing will add a lot more power, but it also going to cost you a ton of cash, and be much more likely to ruin you engine/drive train. I know it would be fun to put down 350+ at the crank, but I can’t imagine the 8 would be drivable with that much power. The bottom line is that the kit is a bit excessive for the RX-8.
   
   On the other hand Greddy’s kit is substantially cheaper, will require less tuning, and is far less likely to blow your engine. Furthermore it gives the 8 the additional pop the car desperately needs.
   
   In any case, there is a good chance that both kits will substantially lessen the life of your car. This leads into question number 2!
   
   
2. If Speed Force Racing is your ultimate decision I would really reflect on whether the 8 is for you. For the 10 g asking price, you could probably get yourself something of comparable power, without going into the aftermarket, which ultimately means you get to keep your warranty.

In any case good luck with your decision, and let us know how it goes.

What part of Texas you in? I'm in Austin and have the Greddy kit, if your interested for a ride contact me. Also, PTP is in Austin, so you could easily stop by and see where they're at on releasing the higher hp turbo kit.

thank you all for your imput. i've heard rumors that mazda might release a version of the RX8 with a turbo, have you heard anything about this?


also has anyone found any other alternatives to a turbo kit?

I think that concensus on this forum is actually leaning towards the Greddy kit. Espeacilly since the Interceptor-X EMS has come out. They are actually making more horsepower and torque than SFR does with a larger turbo. Plus the fact that since it is a smaller turbo it will spool faster.

The latest news is that they are working on an upgrade to the Greddy kit to supply more air at higher RPM's to sustain the boost.

They are also using other aftermarket turbo pieces (boost controller, bov, etc) so you would have to factor those in as well... All in all though the price would still come in lower than SFR and you would be making more hp/tq.. Sounds like a great option to me.

1. That ain't going to happen. Not anytime in the near future

2. Not yet. A few places are working on Superchargers. Some went by the wayside, some are still in long gestation periods. You have a few people that do nitrous (about a 55 shot), if you want to go that route. The most people are looking at from normally aspirated engines is around 25 hp.

[QUOTE=davefzr]I think that concensus on this forum is actually leaning towards the Greddy kit. Espeacilly since the Interceptor-X EMS has come out. They are actually making more horsepower and torque than SFR does with a larger turbo. Plus the fact that since it is a smaller turbo it will spool faster.


Lets see the dyno chart. PSI for PSI of boost this is impossible! We can add as much fuel and timing as we want and it doesnt matter if the Greddy Super Delux Interceptor-X-Y-Z EMS comes out, it wont change our ability to tune the 8 to the highest level :D With that being said, we are finishing up a few things here and we will have the big HP numbers that will be unattainable with the current Greddy kit or even the one with the Inerceptor-X EMS :p Dont get me wrong the Greddy is a great kit but people are realizing that they want more.That is where companies like us come into play.It might cost more but the rewards are worth it :)

more boost = more lag... if you want top end power, go for it, but if you want to be able to pull earlier, then it won't be great.

Like everyone else has said, it really just depends what you want.

[QUOTE=Pkskull77]I got a question for you? How much do you like your RX-8? Why do I ask? Two reason here:

[*]If you like your car, and more importantly, your warranty, I would do neither. If more power is a must for you, then you have to balance the equities. Speed Force Racing will add a lot more power, but it also going to cost you a ton of cash, and be much more likely to ruin you engine/drive train. I know it would be fun to put down 350+ at the crank, but I can’t imagine the 8 would be drivable with that much power. The bottom line is that the kit is a bit excessive for the RX-8.



If you pump up the car there are always possibilities of catastrophe.We have not had any as of yet, even with our higher power output. As far as I know maybe only one Greddy kit in hundreds has blown. The Renesis is pretty stout. An 8 not being drivable with 350? Well then my friend you havent expereinced what an 8 should feel like :eek: It is so much better to have real passing power at 4000 rpms then at 8500.Lugging around town can be done in higher gears without having to downshift while still having power to spare.There are so many advantages that I cant think of them all.



On the other hand Greddy’s kit is substantially cheaper, will require less tuning, and is far less likely to blow your engine. Furthermore it gives the 8 the additional pop the car desperately needs.



Less tuning? I think you might not understand what you are saying. If any turbo kit is less tuned then you have a time bomb on your hands.Tuning is tuning and I would bet that our tuning might be quite a bit closer out of the Box then the Greddy system.Boost is more likely to blow your engine then anything with a turbo kit. With the Greddy kit making modest power, people get the urge to trun up the boost.You turn up the boost too high and there goes your motor.With our kit, you dont need insane amounts of boost to make excellent power. I mean 8psi and over 300 at the wheels is pretty damn good. You would have to run about 13 psi with the greddy kit to make that type of power unless you are running so much ignition advance that you are on the ragged edge. At that point, it is only a matter of time before she blows :cool:



In any case, there is a good chance that both kits will substantially lessen the life of your car. This leads into question number 2![*]If Speed Force Racing is your ultimate decision I would really reflect on whether the 8 is for you. For the 10 g asking price, you could probably get yourself something of comparable power, without going into the aftermarket, which ultimately means you get to keep your warranty. [/list]


Actually, you can get everything required for 300 WHP for about $7500.

what happen to the guy with the bad o2 sensor???? and all the threads???

do over???

dvno???

beers

[QUOTE=SpeedForceRacing]

ummmm something tells me the car either never ran right or blown motor

That thread got closed due to all of the negative remarks directed at the owner of the RX8 in SFR's hands.. DG1T-8??.. something like that....

isn't that the guy with the blue 8 and veliside kit who keeps posting his trophies from local car shows that nobody cares about?
I might have him confused with somebody else.

Actually that is not the case my friend.We will be finishing it up soon enough.DiGI had some other things to take care of which prevented us from doing what we need to do.I was also in the process of putting the SFR twin-turbo system on my Z. The time thing worked out for both of us but now we are ready to finish.Hopefully we will be dynoing it next week.

The thread got closed which is why I havent been on here as much. I didnt feel like starting a post without some dyno charts,videos,etc.....to back it up. This will happen very soon so the guys that are still interested, I think you will be suprised :D

^^^^^^

great to hear!!!

beers

thanks speedforce

the thing i'm also looking at is at what speeds does a turbo greddy/or SFR kick in, in other words what speeds does a turbo matter???

Turbos don't kick in at speeds they kick in at RPMs.

so basically it works all the time?

[QUOTE=SpeedForceRacing] Sorry SFR, Dave is right.

Watch the video. It's in there:
Video Right Click, Save as

Well now we have the complete turbo system, with injectors, engine management and a fuel pump for 6795$ :) 350whp is definitely achievable now.

No. Turbos spin/spool using exhaust pressure. The layman's explanation is the bigger the turbo the more exhaust it takes to spin it, the smaller the turbo is the less exhaust it takes. Problem with small turbos is though that that limits the amount of compressed air that you can push into the engine, so at high revs in runs out of steam. The disadvantage of a large turbo is that it takes more exhaust to push the turbine blades, hence a term called "lag," where you step on the accelerator & it takes a bit of time before you get more power, or you have to wait until you get to 4000-4500 RPM before the turbo is giving you power/coming on. The advantage of the Greddy is it is a small turbo so in low/mid revs you are getting power, disadvantage is that at high revs you lose steam. The advantage of the other turbo kits being mentioned are they will be using larger turbos, for more peak hp, but that will come on in the mid/high rev range. There are different designs to turbos nowadays to alleviate some of these disadvantages, but this is a very general explanation.

Is it possible to have a pseudo-valve that can be closed and therefore limit the size of the turbo for low-mid rpms and act as a smaller turbo and then at high rpms open completely to get the benefits of a larger turbo?