20b n/a exhaust for rx8
03-17-09, 08:20 AM
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20b n/a exhaust for rx8
Hey all i would to hear from anyone running a naturally-aspirated 20b PP in there car. I have fitted one into an RX8 And was wondering wat size of headers and exhaust system to make for max power? Any help on this would be great.
03-17-09, 05:46 PM
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sweet! that should be a really fun car, i like the rx8 chassis a lot (even the motor)
um id think the stock exhaust would work fine, especially in the setup/initial tuning phase.
um id think the stock exhaust would work fine, especially in the setup/initial tuning phase.
03-17-09, 07:31 PM
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Yeah so far the car made 413bhp on a dynapak dyno and yeah the handling is quite good/ Neutral. A fantastic english company called W.G.T built the motor and fitted it. When we get the handling perfected i'd like a few more horse power and feel the current system is restricting the top end power so would just like to hear wat every one else is running.
03-18-09, 05:46 PM
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If SpeedSource is capable of putting out 415HP, then 413HP is not far off...
http://www.speedsourceinc.com/index....§ion=mazda
I'd say your setup is pretty darn good. A 4 inch exhaust should flow nicely out of the passenger side behind the front wheel.
http://www.speedsourceinc.com/index....§ion=mazda
I'd say your setup is pretty darn good. A 4 inch exhaust should flow nicely out of the passenger side behind the front wheel.
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03-18-09, 07:55 PM
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If SpeedSource is capable of putting out 415HP, then 413HP is not far off...
http://www.speedsourceinc.com/index....§ion=mazda
I'd say your setup is pretty darn good. A 4 inch exhaust should flow nicely out of the passenger side behind the front wheel.
http://www.speedsourceinc.com/index....§ion=mazda
I'd say your setup is pretty darn good. A 4 inch exhaust should flow nicely out of the passenger side behind the front wheel.
! That set up is very lik our own car!! The current problem with the exhaust fitted at mo is room around the gearbox area. The gearbox we choose is a Saenz 910 sequential 6 speed box and its a tight fit so had to use a 2 1/2 inch mid pipe to fit in and can't help but think thats its killing our power from 7500-8500rpm range. Even if i change this to 3'' mid pipe is it going to make a big difference? Are there many PP 20B's in the states? It does not matter what car it is in really.
Last edited by Charolais bull; 03-18-09 at 07:58 PM.
03-19-09, 12:25 AM
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Don't know if this helps you Charolais bull. I shot this at 7Stock last year.
http://www.megavideo.com/?v=ABHNP44J
Go to 8:28 and you can see the whole RX8.
http://www.megavideo.com/?v=ABHNP44J
Go to 8:28 and you can see the whole RX8.
03-20-09, 01:17 PM
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Could you post a few more pictures of the engine where we can really see it? I am close to dynoing my 20b na. Not PP, but big street port. What rotors are you using? I cannot tell if you are using the stock throttle body, but it sort of looks like it. What about headers?
Gordon
Gordon
No we're using custom powder coated intake runners with Jenvey 50mm throttle bodies mounted before a custom carbon airbox. The rotors we're running are modified S5 6 port rotors. What size are the headers and system on your 20b?
03-22-09, 07:46 AM
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Na Gordon thats just my nick name believe it or not. My real name is Jonny.
Yeah im really liking your setup there gordon!. We did think about using the Rx8 rotors but were scared off by a local race school telling us there track rx8's have all suffered from rotor failure. So because we built our car for Comepetion use only (hill climbs/spirints) we opted to use wat we know to work saftly at this level.
Yes i also would of thought the standard 20B throttle body would still work well with a big street port. Are you planning to rev the motor to 9500rpm's on a daily basis gordon? Is it a standard 2 peice shaft your running in this motor?
P.s Im liking them pic's of your manifold!
Yeah im really liking your setup there gordon!
. We did think about using the Rx8 rotors but were scared off by a local race school telling us there track rx8's have all suffered from rotor failure. So because we built our car for Comepetion use only (hill climbs/spirints) we opted to use wat we know to work saftly at this level.Yes i also would of thought the standard 20B throttle body would still work well with a big street port. Are you planning to rev the motor to 9500rpm's on a daily basis gordon? Is it a standard 2 peice shaft your running in this motor?
P.s Im liking them pic's of your manifold!
03-22-09, 04:35 PM
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Your setup sounds very interesting
Where in Ireland is the car CB? Would be great to see (hear it ) it sometime
There are more and more interesting rotor motors popping up around this country, great to see it
Where in Ireland is the car CB? Would be great to see (hear it
) it sometimeThere are more and more interesting rotor motors popping up around this country, great to see it
03-24-09, 03:44 PM
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. We're in co, Down Northen Ireland. The car is currently away getting a new roof skin as the base car we bought came with a sunroof. lol! So its hard to get more pic's at moment but i do have sum off my phone here.[ATTACH][ATTACH]
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03-27-09, 04:04 PM
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The 20B really seems like its positioned as far back as possible, should help with handling.
How is the idle? What ecu are you using?
03-29-09, 07:23 AM
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Yeah cause we went for the sequential gearbox we didn't have to worry about the gearstick position so it made much easlier to position the engine further back.
It all worked out very well as the corner weights are within a few kilo's of each other. But then again the position of the dry sump tank and the race fuel cell has aided the corner weights too.
Like i mentioned earlier the car is not quite finished yet and really we only have the motor run in there. We have had the car at a track day at Oulton back in january there and where very happy with handling etc. She was hunting down Porsche GT3's and we where only revin the motor to 7200rpm!
Yes we will have the car at track days and sprints here in northen Ireland this year. No i would not think she will be entered in time attacks as we have other rotary powered cars that we're hopin to prepare more for that.
The ECU we're using is a DTA S80 pro with X dash and i must say the motor runs well and idles sweet too!
This is a wee pic of the exhaust manifold under construction on the dummy motor.
It all worked out very well as the corner weights are within a few kilo's of each other. But then again the position of the dry sump tank and the race fuel cell has aided the corner weights too.
Like i mentioned earlier the car is not quite finished yet and really we only have the motor run in there. We have had the car at a track day at Oulton back in january there and where very happy with handling etc. She was hunting down Porsche GT3's and we where only revin the motor to 7200rpm!
Yes we will have the car at track days and sprints here in northen Ireland this year. No i would not think she will be entered in time attacks as we have other rotary powered cars that we're hopin to prepare more for that.
The ECU we're using is a DTA S80 pro with X dash and i must say the motor runs well and idles sweet too!
This is a wee pic of the exhaust manifold under construction on the dummy motor.
04-21-09, 02:05 AM
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The ECU we're using is a DTA S80 pro with X dash and i must say the motor runs well and idles sweet too!
This is a wee pic of the exhaust manifold under construction on the dummy motor.
Attachment 337202
This is a wee pic of the exhaust manifold under construction on the dummy motor.
Attachment 337202
05-12-09, 08:19 PM
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Here's A small Teaser for you's. Also any one in the UK and wants to see more check out this months Banzai Mag for feature.
http://www.youtube.com/watch?v=S84sXX3zhq4
http://www.youtube.com/watch?v=S84sXX3zhq4
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