You would need an FCD. The stock computer shuts off fuel to the rear rotor at 8.6 lbs of boost, and that's bad. An FCD tricks the computer into keeping the fuel going. That's good.

I personally have the RB turbo back system, and it is incredible.

The 2.5" downpipe will not fit the rest of the system, because the 3.15" downpipe and the presilencer are the same size. It's the first part of the Y-pipe is also 3.15", before it splits into the two 2.5" mufflers. The system is worth every penny. Trust me. And it was much quieter than my stock rusted out exhaust/straight pipe I was using before it. The power is just awesome.

 

so upgrading from the 2.5" to the 3" IS worth the money?

 

does the RB turbo back fit the stock turbo??

 

yes

 

thank you

 

without any exhaust. the dyno is only accurate to +/-5hp too, so i say the rb exhaust is good

mike

 

How many PSI?

And what other mods did you have?

 

i think it was at about .6bar, haltech e6k

mike

 

just the e6k? No fuel mods? Or anything removed. I wanna know your whole set up if you failed to mention other stuff.

 

Back from the dead

 

Im running a Full Racing Beat Exhaust system in my Turbo 2, as far as the exhaust is concerned its "Great" quality, and it sounds sweet. For the money your really getting a "Great" exhaust system thats is strictly designed for the Rotary Engine. In other word its been tested, and dynoed, and proven by R.B. themselves.
Im running the following fuel setup with a motor that has Low Compression at the moment, with 200,000 miles on the clock. Intake, Full R.B. Exhaust System, 550's primaries injectors, Greedy 720's in the secondaries ("Running Way to rich, needs to be tuned down with a S-AFC, on the dyno".) As far as the injectors are concerned you can go with GSL-SE, injectors from a FB (First Gen) RX7, and install those in the secondaries. Those are 680"ccs if im not mistaken. That setup is perfect !!! When your going to do the upgrade, and swap out the injectors wheter it be the primaries, or secondaries, take the time out to have the injectors profesionaly serviced, and cleaned, so you can be assure your injectors are working at there best. Also you must use the R.B. Fuel Cut defense Computer, or you can make a home made Fuel Cut Defense, from radio shack, using there transisters. The transisters will cost you about $5.00/$8.00 bucks, and its the same damn thing R.B. sells the only thing is that they install it in there infamous "Little Black Box", and charge you $90.00 bucks for it. Use the search option on the forum to find information on this matter. Also make sure your Fuel Pump is up to par if not you will be needing a new engine sooner than you think buddy. Check the voltage on your stock pump to make sure its getting the proper voltage necessary so it can do its job, at the same time re-wire the pump to make sure its getting enough electrical current. Even though "I dont practice what I preach" because I have never checked the voltage on my pump in my Turbo 2. Oh well the motor is Low on Comression right now as we speak so it really doesent matter at the moment cause im not boosting the car at the moment just crusing it, saving up money for a rebuild. Also I strongly recomend you use "Bean Oil every time you fill up your car, to keep the Apex Seals, and the housings, and everything well lubricated. I truly believe this is why my engine has lasted as long as it has, because of regular oil changes, and maintenance. Also last thing, control your "Boost", dont let your turbo hit more than 10-11 PSI on the stock turbo, not only are you not making, anymore power "due to the fact that it is way out if its efficiency range", but also you are stressing the oil seals as well.

 

Knightsports FC605 is quiet.

That is my friggen dream exhaust!!! I even bought it once, but had to settle for the Spec 90 3 1/2" turbo back single LOUD

For those who don't know, the FC605 is full stainless turbo back that splits right off the turbo into dual 3"?downpipes w/ dual presilencers and then where the exhaust pipes "Y" off it has 2 more presilencers and then the nice dual *** cannon mufflers.

Very quiet and very free flowing!

The only limit on exhaust size on turbo cars is boost creep- you know HKS makes a 4" turbo back for our cars!

The larger the exhaust the faster the spool- and a little more power as well.

 

I heard the RB 59HP claim is based on boost creep as well. So if boost creep is bad, how far can you go?

Just curious. I'm mainly worried on colder nights and seeing boost rise in each higher gear. I've yet to install my RB exhaust but will be porting the wastegate on my S4 turbo.

 

Be worried!

My S4 w/ large ported WG, larger WG flapper welded on had uncontrollable boost creep w/ just a RB 2.5" downpipe/presilencer and TID mod....

 

I'm sure the 58HP gain is compared to a completely stock diameter exhaust with all ancient, clogged cats.

Removing all that ****, and then adding a larger diameter free flowing exhaust, with its added performance benefits may give you 58 bhp.....

 

no its prolly based on new cats on a new car, that exhaust had been around since the t2

mike

 

Doh!

Think its time to look for an S5 turbo/manifold.