Exhaust System ?'s

bbade · 06-22-2008, 09:31 PM

I am currently running a 3" downpipe and Racing Beat single tip catback exhaust. I am thinking about replacing the stock main cat with either a resonated midpipe or high-flow cat.

Has anyone had experience using either, I'd like to know about differences in sound and performance. I'd rather not have a super loud car, but I would like the improved performance. Thanks!

7_rocket · 06-22-2008, 09:58 PM

If you don't a loud car just get a hi flow cat.

dregg100 · 06-23-2008, 08:20 AM

with the racing beat cat-back it wont be unbearable. if you are after performance go with the resonated midpipe, if you need to pass emissions (we dont have emissions testing) then go with the cat.

Brent · 06-23-2008, 09:00 AM

On my VR FD, I have a high flow cat and a racing beat dual tip. It has a very very nice tone to it. At idle you don't even know it has an exhaust, it really comes alive when you open up the throttle though. I drive on the interstate alot and I prefer this set up. Many years ago I ran a straight through exhaust, and while perfomance is better, I'm not trying to make my VR FD the fastest car in the world... it's a nice comprimise. My T78 FD is loud enough for the both of them. I have a resonated midpipe on the T78 and it does make it a little more quite.

SPICcnmFD · 06-23-2008, 12:48 PM

I have a single tip with open exhaust and it's not to loud, I was actually surprised how quiet it really was. It does start to make some noise once you open up the secondary turbo though, but for driving around it's not bad.

As for performance their is a big difference in the stock cat and a midpipe. You do need to make sure your wastegate is ported if you change it though.

bbade · 06-24-2008, 06:19 AM

Ah i completely forgot about having to port the wastegate. Would this be necessary with a hi-flow cat?

David Jerome · 06-24-2008, 07:37 PM

If you are still running sequential switching to a midpipe will not make the car extremely loud. The sequential cars are much quieter than non-seq and you really wont notice a lot of exhaust note change at idle or partial throttle with the RB exhaust.

bbade · 06-24-2008, 08:43 PM

Yeah I am running sequential and don't intend to change it anytime soon. Does anyone have any info on porting the wastegate (cost, difficulty, etc...)?

Phoenix7 · 06-24-2008, 09:03 PM

Quote:

Originally Posted by bbade

Ah i completely forgot about having to port the wastegate. Would this be necessary with a hi-flow cat?

Necessary? Not if you get this:
http://www.rotarycarclub.com/showthread.php?p=19652

Little-to-No downtime is always a plus.

SPICcnmFD · 06-25-2008, 07:13 AM

But then you don't get the hp advantage of an open exhaust.

To port the wastegate you are going to have to take the turbos off then take it to a good machine shop.

In single mode the exhaust is really quite its only after the transition is it loud and it's not super loud. It's actually pretty neat to be cruising down the interstate and know what mode you are in by the sound.

bbade · 06-25-2008, 08:00 PM

What kind of job is pulling the turbos, am I looking at pulling the entire engine?

Phoenix7 · 06-25-2008, 09:04 PM

^^hopefully not but I don't know what the removal calls for.

bbade · 06-25-2008, 11:03 PM

Yeah i'm pretty sure I can take the turbos to KDR for the porting so that is covered (I like to give Dave my business anyway, great guy). I'm just wondering what kind of a job I am looking at here. I have the tools and mechanical knowledge to take apart the car, I'm just concerned from a time standpoint. I also don't want to shell out the cash for someone else to do the grunt work.

SPICcnmFD · 06-26-2008, 07:14 AM

You don't have to pull the engine. It's pretty much just take-off/unhook everything over there off, Intake, IC piping, DP, vac lines, oil lines, coolant lines, etc. If you've never done it, it will probably take 2-4hrs to get them off and a little longer to get them back on. It's not very hard, just a PIA to reach the front oil return line and the 7 or so bolts that hold them to the engine is probably going to be a pain to get off. You may want to spray them wiht some penetrating fluid and let it set over night once you get to that point.

cewrx7r1 · 06-26-2008, 09:21 AM

A restrictor plate still makes good power with minimal loss as it is a small restriction less that 1/8" in length as compared to a cat. When I went non-seq and before porting my WG, I reached 170 mph at 12psi boost while testing it out with stock ports. I tested both a 2.75" and 2.5" which were made by me out of SS sheet. Had to use the 2.5" one.

You can port your own WG with a Dremel tool and save money.

06-22-2008, 09:31 PM	#1
bbade Rotary Fanatic Join Date: Mar 2008 Location: Macungie, PA Posts: 163 Rep Power: 18	Exhaust System ?'s I am currently running a 3" downpipe and Racing Beat single tip catback exhaust. I am thinking about replacing the stock main cat with either a resonated midpipe or high-flow cat. Has anyone had experience using either, I'd like to know about differences in sound and performance. I'd rather not have a super loud car, but I would like the improved performance. Thanks! __________________ Proud owner of a base 1993 Montego Blue FD. PFC, RB single tip, Koyo Radiator, KDR rebuilt motor, polished OEM front strut bar, FEED replica sideskirts, OEM 99 spec rear spoiler, SuperPro Bushings Many thanks to Dave at KDR for sparking my rotor addiction.

06-22-2008, 09:58 PM	#2
7_rocket Rotary Fanatic Join Date: Mar 2008 Location: Toronto Posts: 117 Rep Power: 18	If you don't a loud car just get a hi flow cat. __________________ http://www.rotarydynamics.ca

06-23-2008, 08:20 AM	#3
dregg100 Rotary Fanatic Join Date: Feb 2008 Posts: 432 Rep Power: 18	with the racing beat cat-back it wont be unbearable. if you are after performance go with the resonated midpipe, if you need to pass emissions (we dont have emissions testing) then go with the cat. __________________ '93 SSM Touring-S475... '87 Tii-LS1/T56

06-23-2008, 09:00 AM	#4
Brent Sua Sponte Join Date: Feb 2008 Location: Killeen, TX Posts: 839 Rep Power: 18	On my VR FD, I have a high flow cat and a racing beat dual tip. It has a very very nice tone to it. At idle you don't even know it has an exhaust, it really comes alive when you open up the throttle though. I drive on the interstate alot and I prefer this set up. Many years ago I ran a straight through exhaust, and while perfomance is better, I'm not trying to make my VR FD the fastest car in the world... it's a nice comprimise. My T78 FD is loud enough for the both of them. I have a resonated midpipe on the T78 and it does make it a little more quite. __________________ Road Atlanta August 2011 NASA TT 1:33 http://www.youtube.com/watch?v=IFY00PAK_Ps Traqmate's video of my car from the 2011 UTCC at VIR http://www.youtube.com/watch?v=2Zcn6...layer_embedded Video of Yellow LS1 FD at NASA TT at VIR http://www.youtube.com/watch?v=e6k0lJkcwrM

06-23-2008, 12:48 PM	#5
SPICcnmFD Rotary Fanatic Join Date: Feb 2008 Location: B'ham, AL Posts: 329 Rep Power: 18	I have a single tip with open exhaust and it's not to loud, I was actually surprised how quiet it really was. It does start to make some noise once you open up the secondary turbo though, but for driving around it's not bad. As for performance their is a big difference in the stock cat and a midpipe. You do need to make sure your wastegate is ported if you change it though. __________________ 1993 Rx-7 SM2 #11 At the local AutoX: http://www.youtube.com/watch?v=9VOSQkkSLQs Speed for Sale shootout 2007: http://www.youtube.com/watch?v=JiqlyAkGmpg A few laps at Barbers: http://www.youtube.com/watch?v=6_h5q...x=0&playnext=1

06-24-2008, 06:19 AM	#6
bbade Rotary Fanatic Join Date: Mar 2008 Location: Macungie, PA Posts: 163 Rep Power: 18	Ah i completely forgot about having to port the wastegate. Would this be necessary with a hi-flow cat? __________________ Proud owner of a base 1993 Montego Blue FD. PFC, RB single tip, Koyo Radiator, KDR rebuilt motor, polished OEM front strut bar, FEED replica sideskirts, OEM 99 spec rear spoiler, SuperPro Bushings Many thanks to Dave at KDR for sparking my rotor addiction.

06-24-2008, 07:37 PM	#7
David Jerome RCC Contributor Join Date: Jan 2008 Posts: 713 Rep Power: 18	If you are still running sequential switching to a midpipe will not make the car extremely loud. The sequential cars are much quieter than non-seq and you really wont notice a lot of exhaust note change at idle or partial throttle with the RB exhaust. __________________ David Jerome Broker for Speed For Sale LLC (David@SpeedForSale.com) (Pre-owned RX7/sports car sales & new parts sales/installs/tuning) PM me about low priced, high quality port work

06-24-2008, 08:43 PM	#8
bbade Rotary Fanatic Join Date: Mar 2008 Location: Macungie, PA Posts: 163 Rep Power: 18	Yeah I am running sequential and don't intend to change it anytime soon. Does anyone have any info on porting the wastegate (cost, difficulty, etc...)? __________________ Proud owner of a base 1993 Montego Blue FD. PFC, RB single tip, Koyo Radiator, KDR rebuilt motor, polished OEM front strut bar, FEED replica sideskirts, OEM 99 spec rear spoiler, SuperPro Bushings Many thanks to Dave at KDR for sparking my rotor addiction.

06-25-2008, 07:13 AM	#10
SPICcnmFD Rotary Fanatic Join Date: Feb 2008 Location: B'ham, AL Posts: 329 Rep Power: 18	But then you don't get the hp advantage of an open exhaust. To port the wastegate you are going to have to take the turbos off then take it to a good machine shop. In single mode the exhaust is really quite its only after the transition is it loud and it's not super loud. It's actually pretty neat to be cruising down the interstate and know what mode you are in by the sound. __________________ 1993 Rx-7 SM2 #11 At the local AutoX: http://www.youtube.com/watch?v=9VOSQkkSLQs Speed for Sale shootout 2007: http://www.youtube.com/watch?v=JiqlyAkGmpg A few laps at Barbers: http://www.youtube.com/watch?v=6_h5q...x=0&playnext=1

06-25-2008, 08:00 PM	#11
bbade Rotary Fanatic Join Date: Mar 2008 Location: Macungie, PA Posts: 163 Rep Power: 18	What kind of job is pulling the turbos, am I looking at pulling the entire engine? __________________ Proud owner of a base 1993 Montego Blue FD. PFC, RB single tip, Koyo Radiator, KDR rebuilt motor, polished OEM front strut bar, FEED replica sideskirts, OEM 99 spec rear spoiler, SuperPro Bushings Many thanks to Dave at KDR for sparking my rotor addiction.

06-25-2008, 11:03 PM	#13
bbade Rotary Fanatic Join Date: Mar 2008 Location: Macungie, PA Posts: 163 Rep Power: 18	Yeah i'm pretty sure I can take the turbos to KDR for the porting so that is covered (I like to give Dave my business anyway, great guy). I'm just wondering what kind of a job I am looking at here. I have the tools and mechanical knowledge to take apart the car, I'm just concerned from a time standpoint. I also don't want to shell out the cash for someone else to do the grunt work. __________________ Proud owner of a base 1993 Montego Blue FD. PFC, RB single tip, Koyo Radiator, KDR rebuilt motor, polished OEM front strut bar, FEED replica sideskirts, OEM 99 spec rear spoiler, SuperPro Bushings Many thanks to Dave at KDR for sparking my rotor addiction.

06-26-2008, 07:14 AM	#14
SPICcnmFD Rotary Fanatic Join Date: Feb 2008 Location: B'ham, AL Posts: 329 Rep Power: 18	You don't have to pull the engine. It's pretty much just take-off/unhook everything over there off, Intake, IC piping, DP, vac lines, oil lines, coolant lines, etc. If you've never done it, it will probably take 2-4hrs to get them off and a little longer to get them back on. It's not very hard, just a PIA to reach the front oil return line and the 7 or so bolts that hold them to the engine is probably going to be a pain to get off. You may want to spray them wiht some penetrating fluid and let it set over night once you get to that point. __________________ 1993 Rx-7 SM2 #11 At the local AutoX: http://www.youtube.com/watch?v=9VOSQkkSLQs Speed for Sale shootout 2007: http://www.youtube.com/watch?v=JiqlyAkGmpg A few laps at Barbers: http://www.youtube.com/watch?v=6_h5q...x=0&playnext=1

06-26-2008, 09:21 AM	#15
cewrx7r1 The Judge Join Date: Feb 2008 Posts: 196 Rep Power: 18	A restrictor plate still makes good power with minimal loss as it is a small restriction less that 1/8" in length as compared to a cat. When I went non-seq and before porting my WG, I reached 170 mph at 12psi boost while testing it out with stock ports. I tested both a 2.75" and 2.5" which were made by me out of SS sheet. Had to use the 2.5" one. You can port your own WG with a Dremel tool and save money.

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