difference in performance between stock exhaust and racing beat dual tip?
 

I have a nice amount of bolt on mods, as you can see below. I'm wondering if I put the stock exhaust back on (just the cat back) how the car might sound and perform compared to the RB dual tip I have on it right now. I like the RB, but sometimes, I feel like a bit quieter exhaust might be more preferable & a bit more mature when showing up to certain places.

I know there's a toss up regarding sound, but the real question is how much performance would I lose?

Thanks for your opinions,

Ian

PM'ed you

I would say that the difference in HP from RB Dual Tip to OEM could not exceed more than 5hp if even that.

Do you still have your cat / downpipe? <-- These two components contribute more so to the loudness than the muffler. But swapping them out would certainly help.

from racing beats site:

Cat-Back Exhaust
93-95 RX-7 - Dual Tips

Part Number: 16427
Retail Price: $580.00
Qty:
Racing Beat Stainless Steel RX-7 Muffler – Dual Tips

Every Racing Beat 304-Series Stainless Steel RX-7 Exhaust System benefits from high-quality materials and cutting-edge construction techniques to provide superior performance and sound. Each system is designed by Racing Beat to maximize performance while maintaining a deep and mellow exhaust note. Normal driving produces a mellow deep tone, but jump on the throttle and these systems come alive with an even deeper, throaty sound.

Over the years we have been amazed at just how many of these systems we have sold! Considering the rather small number of 1993-95 RX-7’s that were sold, we though that certainly the sales of these mufflers would have been rather modest. However this has not been the case at all! This left us thinking as to why our system has proven to be so popular for such a long period. Comparison with other available systems showed that most of the other systems featured large exaggerated muffler tips and a loud exhaust tone. The Racing Beat systems have featured either an OEM style Dual Tip or a modest Single Tip configuration. (The Dual Tip has been far more popular!) If you in the need of a replacement system for your RX-7, take the recommendation of those before you and give the Racing Beat system a try!

Racing Beat exhaust systems are designed as a bolt-on system and utilize all existing mounting brackets and hangers. Beautifully manufactured from pre-polished 304 series stainless steel, the internal-Y, straight-thru design of this exhaust muffler has been designed to offer your RX-7 maximum turbo performance with a 12-13 horsepower gain!

To view a detailed photo of the complete exhaust system, visit this link.

To view the exhaust system on a 1993 RX-7, visit this link.

The heart of every Racing Beat exhaust system starts with the muffler canister. High temperature, compressed sound insulation is wrapped around the core of every muffler canister to provide noise suppression. This 3-inch OD system is offered for the 1993-95 RX-7, and is designed with polished, dual 3-inch tips. These tips feature a 70-degree angle cut with a rolled edge and a unique internal core pipe. These beautiful tips are finished with the RB logo embossed on each tip. Every system comes complete with all required mounting hardware and gaskets.

This is my only mod (have dp need time for install). I like the sound and it does feel a better up top. I have no way to prove if it make more or less than advertised.

I have a basically stock car. I'm still runnig the stock cat, with a downpipe. I went to an RB single tip, then back to the stock catback. I prefer the quieter sound and the complete absence of backfires - not bad with the RB, but it did backfire occasionally. In terms of performance, in street driving I can't tell any difference at all. -Randy

Can't answer directly but the higher the boost level the more power loss due to backpressure. I wonder if that 12-13 hp is with no other mods if so, the loss would be more with other mods.

Jack

The RB is about the quietest aftermarket exhaust you can get. The stock one is a huge bottleneck and you can easily pick up 15-20 hp by replacing it. However, if you are sensitive to noise, at least ditch the precat. Anyone that leaves that thing there will prematurely be replacing turbos as well as other underhood components due to the heat it traps. I recently pulled one off an older gentleman's car that was 100% stock with only 45k miles on the clock. The precat was so clogged that the car had about 100 hp when it came in.

that bad eh Ihor? suckish...

i love my RB dual tip

That's what the STR8 Cherokee is for Ian, you have the perfect exhaust on the seven in my opinion :) I've been thinking about going with the Greddy Ti just to take the car out and annoy people once in a while.

Pretty bad... The funny thing is the owner thought it was still relatively fast compared to his other car. If anything ditch the precat and keep the stock catback. The only sound difference is you will be able to hear the turbos slightly more. The exhaust note won't really change.

The stock cat back is very restrictive. To put it in perspective, in actual flow bench tests, it is the equivalent of two catalytic converters in series, by itself!

I replaced my OE with a PFS (straight through, similar to the RB) and when I did, tuning, particularly in the mid-range 4500+ RPM region, was affected, probably due to an increase in volumetric efficiency. The performance improvement is significant, but you do have to tune for best results. In particular, I had to pull out some timing to eliminate pinging under load. The car, at the time, had a cat and a downpipe; I eventually added a couple of resonators to tone the exhaust down.

I have a DP, stock cat, PFS catback combo and i think my car is loud.

Sometimes i wish to go to a stock catback but sometimes you want some noise in your race car.

If the car is your daily driver, a stock catback would probably be a wise choice. But if its not, you're gonna want some noise after a while again anyway. I would just leave it.

The PFS exhaust is on the louder side.

When I had that combo, it droned on the freeway. Otherwise, I didn't think it was too loud. I now have the RB dual-tip CB. The droning is gone, but, if anything, at lower speeds it seems louder to me than the PFS CB was.

In my experience, the PFS combo is loud and drones unless you add resonators elsewhere. I put a resonator where the precat was (in a 3" DP) and one in front of the cat back and was able to eliminate most of the droning without any flow penalty. I eventually cut open the PFS and stuffed one of the chambers with mineral wool; in this respect it is now similar to the RB catbacks. The end result is that it is very quite in the car, you really don't hear the exhaust with the windows up. I daily drive the car and I routinely drive long trips; it has proved to be very tolerable, with no passenger complaints. Outside, it sounds good; it sounds muscular without being overly aggressive and annoying.

Yep, Speed of light's exhaust system sounds awesome.

The SMB dual tip cat back is actually quieter and less raspy than the RB. I had the opportunity to compare side by side one a similarly built car with the same DP and mufflered, metal cat SMB mid pipe. For anyone looking for the quietest, that would be it.

I had put a resonator in the pipe in front of the PFS muffler in the hope of eliminating the drone. Unfortunately, it didn't help much. That's when I decided to go to the RB Dual tip (found one used for a good price).

idk...I have a RB dual tip, high flow cat, and dp and i think my car is relatively quiet. When compared to v8s, hondas, and other 7s my you can't even hear my car.

Maybe i'm just used to it but I love going WOT because then it really comes alive but daily driving it I don't even notice

i love mine.......the old butt dyno says its works!

With my stock engine, I experienced a noticeable increase in performance when I simply switched from the stock unit to the RB dual tip. No real 'numbers' to convey, but one simply KNOWS by comparison, and yes...the old 'butt dyno' is actually a "real" phenomena.

The fisrt mod I made was a Pettit downpipe, followed by an RB dual tip. The downpipe made a very significant differance in performance, with little increase in noise - the turbos could be heard better. The RB, on the other hand, provided a very sporty sound without being obnoxious, but not all that much of a performance increase compared to the downpipe. This is based on my very well calibrated butt dyno. The catback's power gain was less than 1/4 of the gain from the downpipe.

This is based on my very well calibrated butt dyno...................lol

I suggest that if you had done this in the reverse order, you would have noticed more power gain from the CB than from the DP. The reason is that once the DP is replaced, the remaining restriction from the stock main cat reduces the gains that can be seen by subsequently replacing the CB. A similar scenario would have been noted if it had been done in the reverse order.

I went with a DP first, then the RB catback at a later date. I didn't notice much of a difference after adding the DP. Of course, unlike many of you, I have not had my butt dyno "tuned" in a while :D

The pre-cat on my car seemed to be coked up, so replacing it with a downpipe produced a bigger gain in power and let the turbos boost noticably faster. I agree that if you still have the stock cat with a downpipe, the cat is then the bottleneck in your exhaust system and what happens downstream won't have all that much effect on performance. But the RB catback sure sounds nice.