My FC currently has a PT61 with the racing beat turbo exhaust. The downpipe has been modified/extended to connect to the turbo with a vband connector.

The catback is a bit too restrictive and is killing my power when i turn up the boost.

What high flowing exhaust options are there that aren't too awfully loud?

Ideally I'd like to find a catback that would bolt up to the RB presilencer, I don't care if its single or dual. Anything with a 3" flange would work as I don't have a problem fabricating a connector pipe.

So, what options are out there that meet this criteria? What is everyone running?

 

the RB catback is not holding you back unless your making in excess of 500rwhp... just make a test pipe in place of the cat. any decent welding shop can pull this off

 

why not run a cutout? rx7store is making me a downpipe with cutout right now and im going to add it to my racing beat. If you know how to weld you could do it with around $40 for a decent one.

 

any aftermarket cat-back should bolt to you prescilencer as that is same location where the stock main cat ended. but as stated above, you RB exhaust probably isnt holding you back.

 

Custom, biatch!
Go 4" or go home!


-Ted

 

1: no cat
2: it is

made around 430rwhp with it on, a lot more with it off. 18psi pt61 large street ports etc.

I dynod with the catback on and off and it was quite a large difference. I had to pull a ton of fuel from my maps to get my afr's proper with the catback on.

The mufflers dont flow for ****, and the exits are tiny. I confirmed this with steve from gotham as he ran into the same issue at the same power levels.

restrictive: http://countercultured.net/pics/cars...4/114_1459.JPG

soooooooooo, original question, whats a decent exhaust thats not too loud

 

I have to agree cause thats what i ended up doing. Custom 4" will flow fine

 

The Corksport 80mm 'Power Series' should work for you. I'm not sure on how loud it will actually be though.

 

Isn't J-Rat making like 490rwhp with the RB catback? He maxed out his turbo.

 

not only is he making 490rwhp out of the rb catback... but it's the 2.5" version. the smallest they make for the TII's.

but i guess if he ran a 4" he would make 600rwhp on that tiny T61.

i'm all for the large *** exhausts... but i just don't like to see people immediately point at a good catback for their lack of power. YES you'll increase with less back pressure but if you think your missing out on 100hp from such a deal then go ahead and see what happens

 

how much boost was j-rat running to make that power?


EDIT: I searched, he was running 25+ and it was trailing off to 20. I'm having the same symptoms since there is too much backpressure from the exhaust. the torque curve just falls on its face. I hardly think a turbo that can flow 65 lbs / min is running out of breath that bad

 

wow, stubborn = the win

put a 4" exhaust on a stock turbo and tell me if the boost doesn't fall off. look, i'm not trying to say a larger exhaust won't flow more... it obviously will but it's not the reason your having power issues.

you have a PT61... how much power are you looking for? if you had a pt67 or so i'd be agreeing 100% with you.

 

we've noticed that the 3" presilencer is good enough, that just about any muffler in the cat back is fine, noise-wise.

 

^^^ uhh have you checked your wastegate spring?

 

yes. I have 3 different springs. I've tested with them all.

 

a stock turbo will hit compressor choke. a PT61 can move a Lot of air.

I wasn't looking for a debate about the racing beat catback as I've dynod the car with it on and with it off. I've blown many turbos from maxing them out and over revving, i know what it sounds like. This is not the case here.

I went through all the troubleshooting first. Wastegate springs, different turbos, etc. The simple fact was when the catback was off there weren't any boost control issues and the power didnt taper off like it was before. The turbo spooled faster and I had to add over .50ms of fuel to certain spots in the map to keep from running lean. I tried everything else before trying to point the finger at the exhaust. Believe me, I'd rather it was something thats an easier fix. I LIKE the racing beat exhaust.

 

I guess I'll be ordering some flanges and piping shortly becuase I can't seem to find any that bolt up with a 3" flange.

I'm also debating just cutting off the rb mufflers and putting on something else, but I'd rather not ruin something I can sell or may want to use on another car.

I've been hearing decent things about magnaflow. But if the 3" presilencer is really adequate chances are I'm just going to pickup a used 3" catback and adapt it and go single exit

 

Its not the mufflers, its the Y pipe. The old Racing Beat exhaust system used to be a true 80 mm system (thats 3.15" for the metrically impaired) and the "Y" pipe did NOT neck down to split into dual 60mm (2.36"). The "Y" pipes were EXCELLENTLY fabricated actually splitting the 60mm section down the middle and stretching them open to mate to the rest up stream 80mm piping. Now, Racing Beats new exhaust is nicer looking (Stainless now instead of mild steel) but its gone down in size to 3" and theres other small things that impeed flow, like some of the cheater bends (straight piece of tubing being welded at an angle were flanges meat would be a cheat). And the new "Y" pipes SUCK were the 3" section is crimped down to split off into the dual 2.25" pipes.

The mufflers flow just like a straight piece of pipe of the same diameters and bends. There a straight through perf core type muffler, so switching out to another straight through muffler (Magna Flow, Thermal, Borla XR-1 etc) will gain ZERO gain in power or turbo spool time. Your gonna have to eliminate the "Y" pipe and make something bigger be it single or dual mufflers or not.

~Mike.................

 

If that's the case maybe I'll get a new y-pipe fabbed and see if it helps. won't hurt to try that first.

 

what muffler/presilencers would be the best for a 4" exhaust anyway

 

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/review-specs-4-inch-turboback-magnaflow-exhaust-676685/

 

^If only Sean would make a 4 inch exhaust for the FC.

I'd actually love to see a 4 inch to dual 3 inch FC setup. That would be

 

a couple of the 1st gen guys who have experience w/ magnaflows say that it has significantly gotten louder after awhile of usage... and they're not even turbo.

i don't have a 1st gen[anymore], but i'm running a 3" magnaflow w/ dual presilencers on a 13b DBP and i did notice the magna has progressively become louder over time... Jeff20b discusses about the Magnaflow vs. Borla pros and cons.

i will be using a borla next.

 

We run a custom one on our 20B FC.


-Ted

 

I think one of the best flowing bolt on exhausts for the FC is the JIC Magic Spec 90 90mm (over 3 1/2") turbo back exhaust.

It is a single system with only one muffler at the end so it is LOUD, but it could be tempered with a short 3 1/2" borla XR-1 or two as a midpipe.

I have one, but it was soo loud that I am using its front section (1st 57") to the Racing Beat 3" turbo back rear section. The spool is much better than with RB 3" downpipe and presilencer (and its 4 cheated radius cut/welds).

I don't know if Spec 90 is still in production, but Rishie at Auto RnD had one in stock a while ago.