How to get 300hp on the flywheel?
 

Hello guys!

I have a Mazda RX-7 FC3C (cabrio) turbo II 1991 model. Everything in the car is stock except the "sportier", "Y", mufflers that are more wide (open) than the originals. The car has 17inch wheel, a lighter flywheel and thats it. The intake, the turbo, IC, everything is STOCK.


I would like to ask you rotormasters witch is the safest way to get 300hp at the flywheel. I am concidering a PowerFC, new bigger injectors, a more free intake, downpipe. I would like to keep the "Y" mufflers that I have. I would also like to keep the "stock look" so I don't want to use a FMIC. I would like to keep the SMIC. I want to use a "sportier" catalytic converter. I want to use a catalyt... ;)

-Does anyone has this kind of setup?
-If I wont be able to get 300hp at the flywheel, how much will it be?
-How many HP can give the stock turbo at safe circumstances?
-At what pressure? (psi or bar :) )
-What injectors should I use?
-Can RB downpipe (2,5in) can "do the job" or I need 3inc downpipe?
-Any suggestions? :) Infromation please...

help!
Thank you!

any larger fuel pump (walbro or fd)
2.5" dp
s-afc or similar fuel controller
fuel cut defensor/defender
14psi
high-flow cat
better TID and filter
720cc secondary injectors

That should do the trick for 300bhp

Thanks mate!

Do you have this set up?
I am thinking of using PowerFC in order to skip the FCD and control better the pressure. Won't be the PFC a better overall solution?

Thanks again! :)

Hard to do with the stock turbo, especially with the stock IC.
A compressor upgrade or hybrid will easily do 300bhp at the flywheel.


-Ted

RETed,

thank you for your reply. I am wondering, with the stock turbo how high can I go at hp flywheel?

And what injectors should I use? Primary - secondary? (for about 280+ hp on flywheel).

Help me... please... Here in Greece things are a bit... chaotic about the wankel modification. I have no other sourse. :(

Well, I typically see numbers of ~230-240rwhp, and I usually figure about a 15% drivetrain loss, so I figured it was close enough. I'd suspect the stock turbo is good for say ~275bhp on the stock IC?

For injectors, and only ~300bhp, you should be fine with 550's & 720's, or possibly even 1000's in the secondary spot.

Thank you guys.

Eh, someone here said to me that an FCD must be used even if I use PowerFC. I know that FCD is used with the stock ECU. I know that with the use of PowerFC I won't need FCD. Am I correct?

In my experience, I have never seen an FC with stock IC, stock turbo, and stock ECU go over 230hp on a DynoJet.
With 15% drivetrain friction, that makes it just about 270bhp at the flywheels.
Boost is limited to 14psi.

Standalone EMS replacing the stock ECU should break 300bhp.

Big front-mount IC should also help get close to 300bhp even with the stock ECU.


Get in touch with higgi on here - he's in CZ.


-Ted

I hear Greek RX-7 club is much bigger than ours and you guys do a lot more stuff (including 20B swaps) that what we do here in CZ :D

Since I am a founding member of the Greek RX-7 Club I can say without fear that modification of a wankel is somewhat in early stages here at Greece. Most users go for PowerFC etc. Most mechanics don't know exactly the right path to grabb horsepower from a 13B. Mechanics that told me that with the PowerFC I still need a FCD... Dunno anymore. :(
About the 20B swaps. Witch car? Cause I only have seen one (that doesn't work properly BTW). I only know rumors for other 2. Thats all. :(

Thank you for your interest,
Kostas Bevoudas
Mazda RX-7 turbo II Convertible FC3C

well is the power fc a standalone or piggyback stock ecu setup?? If its stand alone then you dont need one if it is piggy back then most likely you will need one.

And on another note Ill let you know what my setup makes soon. im running these mods on an 87 t2
removed emissions, a/c, and ps
Dual alt pulley
FCD
SAFC2
fd fuel pump
ported and butterflies removed from tb
3 inch turbo back exhaust
720 sec injectors
10 mm plug wires
3 inch TID pipe and cone filter
Turbo xs BOV
Thats what I have right now and plan to dyno it soon hopefully and then ad

Hybrid stock turbo with bigger compressor housing and wheel and ported
ported exhaust manifold
FMIC
Maybe light weight flywheel and clutch
dyno and wideband tune

Im hoping for 240 or so off the first set and close to 300 with the other stuff added
Ill keep my fingers crossed

Maybe u should not let mechanics work on your car and do it yourself ;)
PowerFC as any other electronics is something u could download manual for and just reading it should get you better answer than what you hear from mechanics.
Getting power from 13B is about same like any other engines, in turbo applications you need correctly sized turbo, good intercooling, proper ignition and enought fuel. Same basic rules would apply to any other engine. Of course in details it would vary, but basics are same and you are talking about basic upgrades in your case.

HiGGI,

As we say here at Greece:

"Bless your mouth"

hihihi ---> Your are absolutely right. :D :D :D

siko se to!!!

yes im greek.

Ok.
So far I have this stuff planed:
-Removal of the air pump.
-Removal of the pre catalyt- use of 2.5in downpipe from RB.
-Removal of the stock catalyt- use of hi flow "racing" catalyt.
-Removal of the stock air intake- use of TID and cone filter.
-Construction of an cold air intake box.
-Removal of the stock ECU- use the Apexi PowerFC ECU
-Removal of the stock secondary injectors- use of 720cc secontaries
-Removal of the stock spec spark plugs- use of "colder" better spark plugs.


I have:
-"Wide" dual "stock look" mufflers. ;)
-Lighter flywheel :D
-Upgraded clutch :)
-17in BBS wheels :P

What should I expect (estimate) from the dyno?
Any suggestions? Directions? Am I missing anything? :)
I am also gonna need some gauges. What do you suggest? I am wondering: Can I remove the stock boost gauge and install an aftermaket? Do the same thing at the water temperature gauge?

Guys, thanks alot in advance, I hope I am not breaking your b@lls! :D :D
Kostas Bevoudas
A "wannabe" quick RX-7 FC3C

heeeelloooo! :) :) :D

Here I am again...

Ok. Progress so far:

-Removed the air pump
-Removed the pro-catalyt and installed a RB 2,5in DP
-Use of a cone filter
-Lighter flywheel, upgraded clutch
-Wider "sportier" dual mufflers (near stock diameter)

The car right now is great. Pulls good, has a sportier sound and the stock boost meter reads above x10 at 4th, 5th but not all the way up. I am pleased so far.

Next step:
-CAI
-TID
-Hi flow catalyt

Any suggestions? Any problems with this setup? BTW, any estimate of power at the flywheel right now? I think I am about ~220hp. Engine is good ~8,6 compression and my (stock) turbo is good. :) I have a '91 S5 model...

Please share your thoughts and opinions.
Thanks! :)

No upgrade fuel pump?
No aftermarket boost gauge?


-Ted

for fuel pump you can find a used FD (92+ RX-7) fuel pump and those are good for just over 300bhp. I got mine for free ;) They flow about 20% more fuel.

walbros are even better pumps, but they are thought of as somewhat noisey.


And before you do anything else more to change your boost level (intake or exhaust) you should look into fuel pump and FCD if you do not have one already.

Personally I would go with the full Racing Beat Turbo Back. It's 3" and stainless steel. Very good sounding and not loud. Definately worth the money
Then a used HKS F-Con. This includes the FCD. You can pick one off of ebay used for $220-260 for your specific model of RX-7. Not sure if theres any reason it shouldnt work on a eurospec ECU.

Power FC is a very good piece but for 300 flywheel, you really don't need it yet. Do you plan on any more power?

not to steal this thread but isnt the powerfc only available for the fd?

Thank you guys! You are right, PowerFC is not needed for 300bhp. But I guess its a good overall solution and I want to keep my mind off of trouble. Its a good solution. :)

Ridah, the PowerFC comes for FC too, but you need some kinda adaptor. Not too hard to find. :)

Ted, thanks for the reply. About the pump... you think I need one right now? Or you mean that I will need one since I am going for 300bhp? About the boost gauge, I am working on it. It is needed. I have found from a Japanese FC that a friend has imported for spare parts a boost, oil temp and water temp gauges. Plugged into my car and working for 150e (~180$).

Guys thanks, you are so helpful! :D :D

People often recommend that you upgrade your fuel pump (I run a Walbro 255) for anything above stock boost. I also recommend that you search on this forum for how to rewire your fuel pump for full voltage. If you're running more than 10 or so psi I would also recommend you upgrade your secondary injectors to AT LEAST 720cc and get a fuel controller (S-AFC, etc.).

Thank you sir! :D :D

I think I probably have close to 300 bhp. Here´s my setup:

Atkins s4 rebuild
Stock s5 turbo and manifold (Wont really affect peak power)
Racing Beat turbo back
Greddy FMIC
RB 12lb flywheel (Again, wont affect peak power)
Microtech LT8
3 inch TID
760 primary injectors, 850 secondary
Walboro 255 fuel pump
MBC set to 12 psi
All emissions removed

My ride spanked e46 M3s on the freeway (SMG and manual) up to about 130, I would let off after that.