Bridgeport RX8
Rotor User
Joined: Nov 2007
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From: Sweden
I needed a new engine, and I had been wanting BDC to do a BP for me a while, so I put in an order. $2,500 including short block, port work, and a rebuild kit is pretty normal. I have a Mazda reman sitting on the floor for a back up in case it did puke after 5,000 miles. $2,500 is pretty average in terms of a quality rebuild, so I'm not sure where you're "thousands of dollars and hours and hours" comes from. Considering it was a necessary rebuild, so I was going to have to spend at least $2,000 for a quality job to begin with. As far as time... MAYBE an hour to stack the motor, 6 hours (tops) to pull and replace a block if you're lazy. It's honestly a weekend beer drinking, cutting up with friends job.
So we're looking at 8 hours labor, and $2,500? If you think that's a lot of money / time to spend on necessary maintenance, or a basic rebuild, then you have the wrong hobby. To me, $500~$700 was worth the risk to invest in port work, but that's all the additional money I was out.
You don't need a dyno to tune a car. Again, a dyno sheet is useless without something to compare it to. What if I posted a sheet showing 250 WHP? People would scream foul. Now take into account that under similar conditions I posted my factory engine with 230 WHP. Now you can see that the bridge was good for a 20 HP gain because you have something to compare to.
I prefer my engine to last. I rather it be tuned for reliability as opposed to max power. An engine that only lasts 5,000 miles is useless to me. I'll gladly take a 10 HP gain with 20,000+ miles over a 20 HP gain and only 5,000 miles. This is basic tuning theory, and every tuner has a different stopping point between reliability and max power.
Do I need more tuning? Yes.
Is it going to add a LOT more power? No
I trust a dyno sheet to tell me how much power I'm making about as far as I can ball it up and throw it.
fastlaneracing,
I agree. I would like to see some before and after dynos, all conditions equal, and see what it really does for the overall power band and output. I think what we'd see though is a higher power band (more power at high RPMs) and small power gain. I honestly don't think you're going to see more than a 20 HP gain (NA) from these ports, and I think 20 HP is generous.
The question becomes, is 10~20 HP (NA) worth $500~$700 plus shipping to you?
So we're looking at 8 hours labor, and $2,500? If you think that's a lot of money / time to spend on necessary maintenance, or a basic rebuild, then you have the wrong hobby. To me, $500~$700 was worth the risk to invest in port work, but that's all the additional money I was out.
You don't need a dyno to tune a car. Again, a dyno sheet is useless without something to compare it to. What if I posted a sheet showing 250 WHP? People would scream foul. Now take into account that under similar conditions I posted my factory engine with 230 WHP. Now you can see that the bridge was good for a 20 HP gain because you have something to compare to.
I prefer my engine to last. I rather it be tuned for reliability as opposed to max power. An engine that only lasts 5,000 miles is useless to me. I'll gladly take a 10 HP gain with 20,000+ miles over a 20 HP gain and only 5,000 miles. This is basic tuning theory, and every tuner has a different stopping point between reliability and max power.
Do I need more tuning? Yes.
Is it going to add a LOT more power? No
I trust a dyno sheet to tell me how much power I'm making about as far as I can ball it up and throw it.
fastlaneracing,
I agree. I would like to see some before and after dynos, all conditions equal, and see what it really does for the overall power band and output. I think what we'd see though is a higher power band (more power at high RPMs) and small power gain. I honestly don't think you're going to see more than a 20 HP gain (NA) from these ports, and I think 20 HP is generous.
The question becomes, is 10~20 HP (NA) worth $500~$700 plus shipping to you?
Sheers
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Joined: Jun 2004
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From: Brisvegas
i ran my engine in using the factory ecu. I did fit a racing beat intake set up, headers and 3in exhaust. the car ran fine and perfect. it felt like it picked up power from low end to mid range. i didnt take it past 6000rpm so i cant tell you what it was like up top. i was getting about 250-300km to a tank of fuel. it ran rich and you could smell the fuel. The car did feel like it had more power to unleash with a tune.
i ran my engine in using the factory ecu. I did fit a racing beat intake set up, headers and 3in exhaust. the car ran fine and perfect. it felt like it picked up power from low end to mid range. i didnt take it past 6000rpm so i cant tell you what it was like up top. i was getting about 250-300km to a tank of fuel. it ran rich and you could smell the fuel. The car did feel like it had more power to unleash with a tune.
Charles,
Spot on as usual. I think that we'll eventually find that it's more of an RPM range / power band extender than a power adder.
shadycrew31,
Why? I'm not into playing "big *****". What will it prove without a before and after? Nothing. I could put some tiny 14's with low profile tires on the car and pull a 260 WHP paper off the dyno, but what does it prove in comparing a stock port to a bridge port...
It's something I will do at some point, but it proves nothing being a stand alone pull, and is just a quick way to burn $100. It's not even worth doing till the car is completely tuned, and even then it's just "for fun" and means / proves nothing about having a bridge port.
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Joined: Apr 2006
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From: Cali
I was thinking about bridge poring the RX8. I just had some worry about there not being enough material to add the eyebrow..I think the bridge would be kinda small on the Renesis.. So I was wondering if not going with a full eyebrow and using like 4-5 holes ported in the eyebrow location would be a good compromise.. Still getting the extra port but not weakening the area or bridge too much? I could be way off on this but maybe you can see what im thinking..
shadycrew31,
Why? I'm not into playing "big *****". What will it prove without a before and after? Nothing. I could put some tiny 14's with low profile tires on the car and pull a 260 WHP paper off the dyno, but what does it prove in comparing a stock port to a bridge port...
It's something I will do at some point, but it proves nothing being a stand alone pull, and is just a quick way to burn $100. It's not even worth doing till the car is completely tuned, and even then it's just "for fun" and means / proves nothing about having a bridge port.
Secondly, you just dropped a good amount of money on something for the sole purpose of generating more power. Not for better fuel economy, longevity, or any other practical purpose. why wouldn't you want to know that you got what you paid for?
Thats just how I see it... Not trying to bust your ***** or anything just trying to see where you are coming from.
I was thinking about bridge poring the RX8. I just had some worry about there not being enough material to add the eyebrow..I think the bridge would be kinda small on the Renesis.. So I was wondering if not going with a full eyebrow and using like 4-5 holes ported in the eyebrow location would be a good compromise.. Still getting the extra port but not weakening the area or bridge too much? I could be way off on this but maybe you can see what im thinking..
It's been done. Doesn't make any sense to me. But then again neither does a bridgeport on a renny.
I was thinking about bridge poring the RX8. I just had some worry about there not being enough material to add the eyebrow..I think the bridge would be kinda small on the Renesis.. So I was wondering if not going with a full eyebrow and using like 4-5 holes ported in the eyebrow location would be a good compromise.. Still getting the extra port but not weakening the area or bridge too much? I could be way off on this but maybe you can see what im thinking..
Should be as reliable as a ported motor can be. A little less bottom end power, and more mid to top end power.
I also don't like when people claim that a dyno is the be all end all to a high performance car. Those pieces of paper that are printed out from a dyno essentially mean nothing other than to show a start and end point as you progress though your build. I have no start, so only an ending paper means nothing to me. You can monitor things like valves etc without a dyno through the data logs just the same as you would on the dyno.
This is a daily driven car, so I can't be bothered with a mechanically unpredictable car by focusing on performance over reliability, and when the bridge goes, it'll get an REW swap. Again, increasing the power envelope without sacrificing reliability.
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From: Cali
I have 14,000 miles on my bridge port, and the tune isn't even 100%, so I don't think that the amount of material would be a problem. I also don't think the individual holds would help you much. Porting has a lot to do with shape and volume to control the air flow, and I don't think the small holes would flow as well.
Should be as reliable as a ported motor can be. A little less bottom end power, and more mid to top end power.
Should be as reliable as a ported motor can be. A little less bottom end power, and more mid to top end power.
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Joined: Jun 2004
Posts: 66
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From: Brisvegas
I don't know about the other Bp motors in this thread but my exhaust ports have also been ported extensively. It's not just an extend port and the secondary bridge port. We are hoping to make close to 200rwhp but I think it will be closer to 180. I didn't dyno it stock but other rx8s have made 110-130rwhp on the dyno I will be using.
I don't know about the other Bp motors in this thread but my exhaust ports have also been ported extensively. It's not just an extend port and the secondary bridge port. We are hoping to make close to 200rwhp but I think it will be closer to 180. I didn't dyno it stock but other rx8s have made 110-130rwhp on the dyno I will be using.
How did you do more than extend the exhaust port? There's no room to port out the exhaust port without cutting into the water jackets, and if you cut them out and filled them in, then you run a serious risk of overheating your engine. I hope that's not what you did, but good luck if you did. We'll see what happens...
Only my secondary ports are bridged, so I have no clue how your motor will behave. When my engine was done, it was very experimental. Brian wasn't willing to go that far just yet, and I'm not sure I would have wanted that for my own set up. I'm happy with what I have.
I'm curious to see how your setup comes out.
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Joined: Jun 2004
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From: Brisvegas
.
How did you do more than extend the exhaust port? There's no room to port out the exhaust port without cutting into the water jackets, and if you cut them out and filled them in, then you run a serious risk of overheating your engine. I hope that's not what you did, but good luck if you did. We'll see what happens...
Only my secondary ports are bridged, so I have no clue how your motor will behave. When my engine was done, it was very experimental. Brian wasn't willing to go that far just yet, and I'm not sure I would have wanted that for my own set up. I'm happy with what I have.
I'm curious to see how your setup comes out.
How did you do more than extend the exhaust port? There's no room to port out the exhaust port without cutting into the water jackets, and if you cut them out and filled them in, then you run a serious risk of overheating your engine. I hope that's not what you did, but good luck if you did. We'll see what happens...
Only my secondary ports are bridged, so I have no clue how your motor will behave. When my engine was done, it was very experimental. Brian wasn't willing to go that far just yet, and I'm not sure I would have wanted that for my own set up. I'm happy with what I have.
I'm curious to see how your setup comes out.
I just landed in aus today, going to the work shop on Friday and see what's been done. I'm hoping it's all finished an tuned.
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Joined: Jun 2004
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From: Brisvegas
I spoke with Ben my engine builder earlier on. On the standard ecu it made 209rwhp. Standard they make around 130-40 rwhp on his dyno, standard ports + bolt ons see about 180rwhp. He is tuning it today/ tomorrow. I pick it up on Friday. Very happy with the figures so far!!!! We were aiming for about 190-200rwhp once tuned and completed but its already seeing more then my expectations.
