Hey guys I'm kind of new to all of this and I've been reading a lot and can't quite seem to find an answer to my question. I have a 93 rx7 and was wanting to know, do you go to a 3 rotor to get more engine power? Or is there anything you can do to get more power out of a 2 rotor engine without turbos and what not, I don't want the car relying solely off of the turbo or turbos. I actually want some decent power coming from the engine alone. Is that possible or is the 2 rotor already at it's max that being a reason you would go to a 20b? Sorry for the newbie question just curious.

 

There is plenty that can be done with a FD for more power, but all of it is directly or indirectly tied to induction. Stock for stock, a 20B-REW without its turbos will generate roughly the same amount of power as a 13B-REW.

I'd highly suggest sticking with your 13B-REW while correcting the FD's stock faults such as getting an all-aluminum radiator and silicone vacuum lines.

As far as going 20B, you've got a LOT of reading to do. EVERYTHING is a custom job, and there is no "one size fits all" standard as of yet. My build thread, Project OldTree, is a good starting point for what a 20B conversion realistically takes in a FC, and aims to be the one starting point that all others are judged from. While a 20B FD presents its own challenges, I'm sure you can take a few lessons from my build with regard to issues like packaging all of the cooling systems in the nose, dealing with the turbos and so on.

With regard to N/A performance, there is no replacement for displacement. Defined Autoworks (GTORX7.) would be able to better answer this question based on their tried-and-true experiences with N/A 13B and 20B builds.

 

you have an FD , looking at it the wrong way makes it make more power , But there are certain rules , like the 3 mod rule , 3 flow mods and then you Need an ECU . that means , exhaust , intake , downpipe . and you need an ecu of some sort that adds more fuel in order to remove the cat (cat delete being the 4th mod ) or engine will be running in the grey area and may go boom .

check out the third gen section .

you can make alot more power out of the stock 13b , 20 b is a whole notherb all game in money investment and power as well . But they are so far from cheap LOL .


BUUUT thats power , likestated above you also need to concentrate on reliability . making sure the car keeps cool since you are adding more power , that also means more heat.

first what mods if any have you done to the car ? , a couple mods you should invest in is a wideband , water temp gauge , boost gauge I personally find those 3 being indispensable .

 

Thanks. And yeah I agree I just though I would have to rebuild the engine to then go single turbo. And I have a down pipe an mid pipe, and yeah I was told to get an ecu but not sure which one? (I'm planning on getting roughly 4-500 hp) and as far as the intake are they all the port and polish on them? Because I'm not sure which to go with either. I thought the pettit racing one might be nice but not sure?

 

It has been my experience that most anything from Racing Beat is awesome. I would immediately pull your pre-cat in favor of a downpipe. It will give you a small power bump, but also prevent the pre-cat of packing up and spewing itself through the rest of the exhaust, trashing all of it in the process. Do keep the Pre-cat for emissions testing though.

With regard to other modifications, I would wager that your car needs a few already to correct the factory weaknesses. The ones I'd recommend are silicone vacuum hose (see Dale Clark's posts for details), doing the simplified sequential mod, an aluminum radiator, swapping to the R1/R2 twin oil coolers (if not already equipped) and either eliminating or replacing the AST with an aluminum version. These are what I consider to be the core reliability mods.

As far as a Standalone EMS is considered there are many fine choices out there, though my personal selection would be either the MegaSquirt MS3-Pro or the Haltech Platinum Sport 1000 or 2000. The MS3-Pro is less expensive, but you'd be starting without a base map AFAIK. OTOH, the Haltech PS1K/2K have plenty of base maps available and a plug & play adapter harness for the FD is readily available as well. Aaron Cake would be the one to ask for more information about this.

 

Oh ok cool thank you. I already have silicone hoses but what an AST? You said to get replace it but not sure what that is?

 

That 3 mod rule was debunked years ago. Its been proven that you can add as many boltons to a stock fd as you want as long as you keep the boost at 10psi.

 

So if I had a down pipe, mid pipe, and intake my car would be fine? It won't run lean? (Serious question lol)

 

aslong as you keep the boost at 10 psi it will be fine. , But keeping it at 10 psi with those mods makes things a bit difficult atleast it was for me I couldnt keep my boost down even with a ported wastegate . PFC later , and some tunning and the car boosted and ran perfectly .

 

the point of the 3 mod rule was that the flow was more then the stock duty cycle on the stock ecu could handle with the OEM wastegate , so you'd need to invest in some boost control . weather it be a manual boost control or some other brand .

and in reality its just a bandaid fix .. if you want more power you need an ecu to give it more fuel .. and up the PSI a bit .

 

Just keep the boost at 10psi and you will be fine.

 

Your forgetting that the original tester made more power with those mods at 10psi. That testing page doesn't exist anymore but I remember with all the mods he was testing, the A/F went up to the low 11's and I think he made pretty close to 300whp. Now with less intake restrictions and back pressures within the system, the turbo obviously had to work a little harder to build pressure back up to the 10psi boost level. So since the turbos were spoiling faster to build the same pressure, their cfm jumped up and so did the power output.

 

If you have to ask this question, you are in no shape or form ready for a 20B.
A 20B swap will run you about 20K on a good day, go invest in a $200 AFR gauge to see if you're running lean.

 

+1 here. I've currently got the honor of the least expensive 20B swap, just shy of $10k including the car (excluding replacing worn out parts like my original water pump), and with the way things are going with finding a good 20B engine, it'll probably be a record that stands for all time.

A wideband is a necessity to tune the engine properly with, though they don't have to be $200+. An Innovate LC-1 can be found for under $200 if you shop around as I did. Mine was $130 shipped, brand new and complete with sensor, controller & gauge, found in our awesome Classifieds section.

A word of advice: If you're intending to use a Haltech PS2K and one of Claudio's basemaps, you can do the first startup with a narrowband sensor. His basemaps are a bit rich to not blow the engine, but trying to drive the car with a narrowband on a basemap is just plain stupid and asking for a blown engine

With regard to a stock FD, an Innovate LC-1 would be a good choice for it as it can simulate the stock narrowband's output on the controller's second channel. If you're good with wiring, you can make it look nearly stock to the untrained eye too.