In seeing that the SFR Turbo kit is pushing around 280HP @ 7PSI, I began to think about something. The SFR kit is ~7.5K + install, the Greddy is 4K installed. Greddy puts out 220-240@5PSI while SFR puts out 281@7PSI right?

Now the question is, with the extra $3.5k I save by getting the Greddy, if I push my Greddy kit to 7PSI, won't I be making about the same amount of power the SFR kit is making? It doesn't cost $3.5k to buy a boost controller, injectors, and tuning time.

The only downfall I see with getting the Greddy is that if I do make that 280HP with the Greddy, that is where the power potential stops, and where the potential stops with the Greddy, the SFR kit begins. If I would push more boost with the SFR kit, who knows what kind of power it'll make, and then again, who knows what kind of problems with the engine.

 

Took me a while to find a question in that paragraph. You would be making the max amount of power with the greddy kit. But it depends what type of turbo you want. Ones smaller with quicker response the other has more boost potential for overall peak hp. Overall do you just want hp for bragging rights, or quicker boost for everyday stoplight to stoplight driving. Don't even think about over greddy's 280whp if you can barely afford guages for the ride, b/c it would probably cost more to do some engine reinforcement.

 

Pretty close, except that the Greddy kit is making 240 whp@around 6.5-7 psi. To get to the 260-280 whp range you are talking about the boost controller, larger injectors,etc (probably 10 psi). You are right it won't be $3.5K for this other stuff, but you are pretty much maxed out. The question is if you are looking for 300+ whp, is it worth an extra $3K (Assume $2.5K difference (after boost controller, injectors, additional tuning for the Greddy)+ $500 for upping the boost/tuning, etc past 287 whp on the SFR kit) for you to get there.

Also, PTP Motorsports is supposed to be coming out with their Turbo kit. Looks pretty slick & is based on a T3/T4 turbo design, with supposed numbers in the 270 whp range. Might get you 300+ whp. No firm #'s on pricing though. Maybe Jon might have more information. IzoomZoomI is right though that the power band may be quite different on these larger turbo kits than the Greddy. I think the other companies already commented that a lot of the power will hit in the upper rev range (like a bit more standard turbo kits for other cars).

 

Fanman, I have the EVC (electronic valve controller) or boost controller. If i buy the injectors what else do i need to go with higher psi? I am running at 7.25 right now...

 

From what I have seen that is about it. According to Jeff (MM) fuel system is good past 300+ hp. He might want to chime in on this. Manuel changed out his whole fuel system, & put in external wastegate but he is pushing past 300+ whp (309 I believe).

 

That is the thing Rick from Ricks Rotary Shop was telling me that was great about the Greddy was that the turbo kicks in at around 3,000rpm. Basically, I am using this for every day driving, I always shift around 3k for driving around the city in keeping my MPG high, but every now and then when I want to have some fun I rev it up. On the freeway, I cruise a little below 4k @ about 76-80MPH.

With the turbo, what are the rpm's you usually cruise at? For example, with the turbo, if I cruise at the 4k I usually do on the freeway, will my speed be higher? Meaning, if I have the turbo and I am going 76-80MPH, my rpm's will be lower right, with lower rpm's won't I save gas? Sounds strange...

Rick was also talking about how the Greddy adds about 40% more torque to the car. He says that the torque alone makes the Greddy kit worth it. He was saying he was a torque guy saying that he loves the feeling of sort of whiplash when he really steps on the gas, it pushes him against the seat, the kind of power that should of came with the stock 8.

 

SO it means that if you install the injectors only you can put it up to at least 9psi without doing anything to the engine?? (stronger apex seals or something?) Do i need anything else to tell the fuel system to inject more fuel or the injectors do it themselves automatically?? Maybe change the emanage map to get more fuel in there eh?
Thanks . I want to go at least 9 psi.

PD. Where can I buy the larger injectors?

 

[QUOTE=HardHitter]T

With the turbo, what are the rpm's you usually cruise at? For example, with the turbo, if I cruise at the 4k I usually do on the freeway, will my speed be higher? Meaning, if I have the turbo and I am going 76-80MPH, my rpm's will be lower right, with lower rpm's won't I save gas? Sounds strange...

QUOTE]
no you rpms will not change with a turbo or anything else. gearing is mechanical. it is what it is. at 74 mph your are going to turning~ 3750 rpm. i dont care if you have a turbo supercharger on conair hairdryer hooked up to your motor.

beers

 

Pretty much the way I drive. I love it for the fact that I usually on pretty mellow, ut when I lay into it I picks up fast. Love that the tq. rush comes in at 2500 rpm. Cruise the freeways at about 75-80 mph.

One down side is that a bit of boost at 4000 rpm, so you have to accelerate & de-accel. a bit so that the heat from the turbo/boost isn't constant. Gas mileage went from about 200 miles about town (mix city/highway) to about 185 miles. 250 miles on a tank of just freeway to about 230 miles.

 

I don't think an extra pound or two (9) will hurt too bad. It is when you are going to 10+ that you will have the issues of needing the other equipment.

Greddy makes injectors. Check RC Engineering as well. They specialize in injectors.

 

You guys have to stop thinking in terms of PSI as far as power goes... Increased PSI is nothing if the charge air is REALLY hot and contains less molecules of oxygen... You need to be concerned with CFM of oxygen not psi...

I don't see the appeal of full boost by 3000rpm....

That just means that you'll have less efficiency at higher RPMS... If you're going to turbocharge you really ought to by Corky Bell's book... even if you only want to do the Greddy setup. While some of it is really outdated... the theory of turbocharging is explained...

 

I don't really mind less efficiency on the high end. I don't really care about high end/peak power. If they had rolled out multiple roots/screw type SC's for this car I would have looked at them extensively. My main goal for my car was increased midrange/daily drivability. For that getting boost at 3000 rpm is perfect.

I understand what you are saying about CFM & turbo efficiency. The IC on this kit is rated for higher than the stock levels though. Not to mention I will be using a C02 system to further cool the incoming charge air. I will let people know a before/after dyno somewhat soon (once the dyno shop near my mechanic fixes their dyno).

 

But manuel has shown power, hence cfm/mass continues to increase up to about 14psi with the Greddy kit. For a given turbo turning up the boost is the only way to increase CFM, unless you go injecting something to cool the charge.

 

To get more than 300 HP we need to increase the CFM,
with a bigger Turbo you can have more CFM at lower boost.............
With the greddy turbo on my car at 14 psi boost you need to touch the intercooler, the air is too hot at that boost.
To supply more CFM to my RX8 on August 1 I'm goin to begin the process to install a Garrett GT35/40R I have plans to run it between 12-14 psi. I really don't know how much HP we're goin to get.


Manuel

 

Are you guys going to try to fit the Garrett in the same location as the greddy compressor or are you pretty much redoing everything custom?

 

We need to make a custom manifold,
I'm thinking on use the battery place to put
the Turbo.
The other option is cut the transversal of the compact and fit over there
I friend of mine all ready do it this option on his car.

Manuel

 

gt35r

 

Why did you decide on this option instead of trying to replace the Greddy turbo internals? Is the housing just that small that the turbine wheel can't be clipped and the compressor wheel replaced?

 

I can replace the greddy internals is not expensive but I really prefer the ball bearing option. Remember, I already changed all the fuel system thinking on a bigger turbine in
the future. I'm goin also to change to a cable throttle........................

Manuel

 

Speaking of bigger turbo's... what's everyone's opinion on what the 8 needs for top end power? I want at least 310-320 at the wheels... low RPM boost is not an issue to me...

I don't know where to start researching the larger turbos... anyone got good companies to buy from?

 

garrett :D

they also make all there compressor maps avaliable to the public :D

jsut match up your cars engines specs (cmf etc...) and run with it :D

 

Maybe a T3/T4 or T4 turbo. Turbonetics seems pretty good place to get a turbo. I wouldn't mind spending money on an upgraded turbo, but wonder are there any with the small housing size of the current Greddy Turbo, but better internals, that will flow more CFM. Also, how much tweaking would we have to do for the fuel. I am going into my mechanic this week. i'll talk to him. He knows the guys over at Turbonetics pretty well. Maybe they can work with him on this.

 

For turbo maps for rotaries, assume you have a 3.6 liter engine in terms of flow. That's what works out best. Trust me on that one.

 

the gt35r is just really nicely matched to the 13b. i'd go for the smaller hotside on the renesis, and the larger on the earlier 13b's.

 

Rotary God, I remember reading your post on what size our engine actually is. I remember you mentioned it was 1.3L X 3 = 3.9L because of 3 rotor faces, and then you have to account for the fact that it is a 6 stroke, making it a 2.6L. Why are you saying 3.6L now?