Another exhaust thread, RB road race exhaust questions
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Another exhaust thread, RB road race exhaust questions
I'm trying to find the best exhaust for my NA S4 but unfortunately most of the threads on this topic are old and discuss discontinued products. I wanted to buy a true dual HKS system because I don't care too much for sound dampening but it doesn't seem like that's available anywhere. I went ahead and ordered most of the RB road race system, minus the mufflers, but now I'm getting some buyers remorse because I hear people talking about how this system is restrictive and only really meant for people who care about having a quiet car. Or are they not talking about the "road race" exhaust? Is it the presilencer or the mufflers that are the most restrictive? How loud do you think it'll be with just the presilencer? Sorry for the mess of a thread but I just have a lot of concerns.
#2
REINCARNATED
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Racing beat makes a great product. I am running the road race true dual system on my s5 N/A car and had fantastic results when I went from stock OEM to full SS header/pre silence/twin mufflers. I did not dyno the car but there was certainly an increase in performance. The system is designed to work for a stock port engine. Some restriction is a good thing and for your situation you'll need back=pressure to operate your aux ports at higher RPM. On a previous N/A car I ran Racing beats header assembly and no center section silencer which split into a Y pipe to Borla mufflers. It was really way too loud for street use.. I'll gladly stick to the RB roadrace true dual setup until I make major internal changes to my engine which may be a long time from now since I drive it 2 days a week.
Good luck!
-M
Good luck!
-M
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Thanks for the reply. Just to clarify I meant restrictive in terms of power and not exhaust flow, but I believe most people who claim the RB setup is restrictive are referring to the catback system, though I could be wrong. I'm sure I'll be happy with the system, I hear I can expect gains of 15-20 hp from it.
#4
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We stopped using 'true dual' and the awful 6 bolt flanges in our E-prod cars years ago. We realized zero benefit in both weight and flow compared to a properly collected header to a single passenger side outlet. Also don't try to play with ovular piping if you're trying to get froggy. Exhaust resonance tends to blow it up over time.
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We stopped using 'true dual' and the awful 6 bolt flanges in our E-prod cars years ago. We realized zero benefit in both weight and flow compared to a properly collected header to a single passenger side outlet. Also don't try to play with ovular piping if you're trying to get froggy. Exhaust resonance tends to blow it up over time.
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Rotary engines require back pressure to operate seeing as how they don't have the "plunger" effect of a piston engine, unless you have a peripheral port engine. A straight through exhaust will only only hurt your performance. On a N/A rotary engine, the factory spec for exhaust is ideal if you plan on keeping the factory fuel injection system. Unfortunately, the N/A rotary is pretty much maxed out in its current design.
#9
I wish I was driving!
Rotary engines require back pressure to operate seeing as how they don't have the "plunger" effect of a piston engine, unless you have a peripheral port engine. A straight through exhaust will only only hurt your performance. On a N/A rotary engine, the factory spec for exhaust is ideal if you plan on keeping the factory fuel injection system. Unfortunately, the N/A rotary is pretty much maxed out in its current design.
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#10
Information Regurgitator
Rotary engines require back pressure to operate seeing as how they don't have the "plunger" effect of a piston engine, unless you have a peripheral port engine. A straight through exhaust will only only hurt your performance. On a N/A rotary engine, the factory spec for exhaust is ideal if you plan on keeping the factory fuel injection system. Unfortunately, the N/A rotary is pretty much maxed out in its current design.
https://www.rx7club.com/naturally-as...1/#post8663850
https://www.rx7club.com/naturally-as...0/#post8426237
Last edited by Dak; 02-08-19 at 11:33 PM.
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#11
xXxFC3SxXx
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Here is a link for the S4 RB Road Race Exhaust
I'm running a complete S5 Racing Beat Road Race Exhaust. Great throttle response and the car is not loud what so ever. No nonsense with mounting, it bolts up correctly because it's made for our vehicles. Combined with my street port engine, vdi mod, and pineapple 6 port inserts i'm putting down 165whp. I'm still using the stock ECU and injectors.
S5 NA Streetport Build
I'm running a complete S5 Racing Beat Road Race Exhaust. Great throttle response and the car is not loud what so ever. No nonsense with mounting, it bolts up correctly because it's made for our vehicles. Combined with my street port engine, vdi mod, and pineapple 6 port inserts i'm putting down 165whp. I'm still using the stock ECU and injectors.
S5 NA Streetport Build
#12
RB makes the best exhaust for rotaries IMO. Ive had different mufflers and tried all kinda stuff thru the years and RB if anything sounds a ton better and had the best throttle response from cruising to WOT.
Ive done...
Full dual using 6 glass packs sounded really nice but burnt thru the packing in less than a month
Single to Y into Borla XR1 2.25 in/out felt good but freaking loud as all hell
Single 2.5 to Dynomax. Piping felt too big on this as RPM’s seem to take for ever to get up at WOT
RB full exhaust single to Y
Ive had all 13B na motors from 4 port carbed to 6 port injected
Ive done...
Full dual using 6 glass packs sounded really nice but burnt thru the packing in less than a month
Single to Y into Borla XR1 2.25 in/out felt good but freaking loud as all hell
Single 2.5 to Dynomax. Piping felt too big on this as RPM’s seem to take for ever to get up at WOT
RB full exhaust single to Y
Ive had all 13B na motors from 4 port carbed to 6 port injected
#14
Smells like 2 stroke.
I've had the Racing Beat "Road Race" true duals on my car for a few years, and this is one of the best systems money can buy. The car makes more torque across the usable range, and more horsepower on the top end. Mine has a really agressive exhaust note because I used 2 1/2" magnaflows behind the RB presilencer. Compared to stock, the engine wakes up very noticeably around 1,700 RPM and pulls hard to redline.
I've raced guys who have a Racing Beat single exhaust and they just don't pull as hard. Long primary systems are perfect for these engines in most applications, and Racing Beat knows that- that's why they made this system, and that's why it's not cheap.
I've raced guys who have a Racing Beat single exhaust and they just don't pull as hard. Long primary systems are perfect for these engines in most applications, and Racing Beat knows that- that's why they made this system, and that's why it's not cheap.
#15
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With Stockports, 89+ engine and intake, I've made 173+ on 4th gear pulls with a 5.12 diff. peak power was near 7000-7200 rpm IIRC. That was with RTek ECU. I don't think anybody builds that exhaust anymore, except maybe Steve Eckerich. With ceramic seals and more computer control, I bet you could see over 180 with stock ports. There is a LOT to properly designing an exhaust for an NA rotary car.
#16
djessence
Racing beat makes a great product. I am running the road race true dual system on my s5 N/A car and had fantastic results when I went from stock OEM to full SS header/pre silence/twin mufflers. I did not dyno the car but there was certainly an increase in performance. The system is designed to work for a stock port engine. Some restriction is a good thing and for your situation you'll need back=pressure to operate your aux ports at higher RPM. On a previous N/A car I ran Racing beats header assembly and no center section silencer which split into a Y pipe to Borla mufflers. It was really way too loud for street use.. I'll gladly stick to the RB roadrace true dual setup until I make major internal changes to my engine which may be a long time from now since I drive it 2 days a week.
Good luck!
-M
Good luck!
-M
#17
Information Regurgitator
Yes. On the uncollected it is on the rear rotor. I can only go by pictures but doesn't look to be too far back. On the collected it is just after the collector.
#18
Information Regurgitator
From what I understand the RB collected system though good is somewhat of a compromise as it's better than stock but not as good as a properly tuned system. The primaries are too long for a "short" primary system and too short for a "long" primary system. Hence why yours pulls better than their off the shelf single/collected system. I'd really like to build a system that collects as close to the diff as possible to still be able to split to keep the dual muffler setup. Something like the Defined Autoworks header but with a pre-silencer in it.
#20
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#21
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FWIW, I've actually dyno'd my s4 NA with two separate exhausts on the same day with no changes in between. While I was stock port (albeit, with itb's) at the time, the true dual made less power and torque than a collected exhaust that I borrowed for testing. Now that I'm peripheral port, the true dual is really holding me back in terms of the power I could have (currently at 253whp, can be higher).
Overall, the road race system is good but not ideal, especially considering you can have a custom stainless exhaust built to your specs for 300-700. In addition, I'm not a fan of the added weight you gain for less power.
If you'd like more info on my dyno tests, I have a thread in the dyno graph/time slip area of the naturally aspirated section. Cheers.
Overall, the road race system is good but not ideal, especially considering you can have a custom stainless exhaust built to your specs for 300-700. In addition, I'm not a fan of the added weight you gain for less power.
If you'd like more info on my dyno tests, I have a thread in the dyno graph/time slip area of the naturally aspirated section. Cheers.
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