My bridgeport project
09-15-08, 02:13 AM
#28
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Yes I would recommend them but they are quite pricey so probably not worth it if your going for a street port. They are about 630USD without shipping. If your willing to do a bit of fabrication you could use some CBR600 throttle bodies, should work out quite a bit cheaper. Power wise, im not sure, 205whp - 250whp?? Will have to see once I have car on the dyno still much more tuning to be done.
10-01-08, 05:16 AM
#30
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First Dyno
Ok so I got the car on the dyno just to see where im at. I knew my setup wasnt optimal but wanted to get an idea of where im starting from. Please note the figures on the graph are in kilowatts and N/m so my peak WHP was 192whp and peak Torque was 140 Foot pounds. Im happy with the result as I know how much I can still do to squeeze more out of the engine.
Timing - Leading total advance: 20*
- Trailing total advance: 13*
Car was running quite rich. I am hitting as low as 11's at high rpm which is WAY to rich and you can see how the power stops climbing at that point. I will bring the AFR's up to 13+ and should see some good gains. I have also shortened the trumpets/ram tubes on my throttle bodies as I want to see if I can get some more high rpm power from that. Im also going to better match my intake manifold to my throttle bodies. I think the most important thing however is my header. The primaries are far from equal length and are crush bent, im pretty sure the header is choking the engine at high rpm. I also think my middle muffler may have disintegrated
. So my next project is to fabricate a decent, short header system and at the same time open up that muffler and see whats what. I want to try and take advantage of being able to rev to 9500rpm which is why I have shortened my trumpets and why i'm going to shorten my primaries, i'm hoping it will help give me more power at high rpms.
I also feel the engine prefers a bit more advance than 20* but was being conservative for now. Once I have the tune perfect and the exhaust system done properly ill start adjusting the timing. Im fairly confident I can get quite a lot more power ( I reckon 210whp - 230whp isn't completely out of the question). Car is very quick already so im happy, just wanting to get the most out of my setup.
Timing - Leading total advance: 20*
- Trailing total advance: 13*
Car was running quite rich. I am hitting as low as 11's at high rpm which is WAY to rich and you can see how the power stops climbing at that point. I will bring the AFR's up to 13+ and should see some good gains. I have also shortened the trumpets/ram tubes on my throttle bodies as I want to see if I can get some more high rpm power from that. Im also going to better match my intake manifold to my throttle bodies. I think the most important thing however is my header. The primaries are far from equal length and are crush bent, im pretty sure the header is choking the engine at high rpm. I also think my middle muffler may have disintegrated
. So my next project is to fabricate a decent, short header system and at the same time open up that muffler and see whats what. I want to try and take advantage of being able to rev to 9500rpm which is why I have shortened my trumpets and why i'm going to shorten my primaries, i'm hoping it will help give me more power at high rpms. I also feel the engine prefers a bit more advance than 20* but was being conservative for now. Once I have the tune perfect and the exhaust system done properly ill start adjusting the timing. Im fairly confident I can get quite a lot more power ( I reckon 210whp - 230whp isn't completely out of the question). Car is very quick already so im happy, just wanting to get the most out of my setup.
Last edited by EpitrochoidalPower!; 10-01-08 at 05:24 AM.
10-01-08, 04:30 PM
#31
Your graph looks awefully high for your setup. going by this you putting down 192 wheel Kw is actually saying you're putting down about 258 whp ... I really do believe that something wasn't done right on your dyno there? What kind was is ... but if it is actually true ... you might have the worlds most powerful bridgeport there. I'm really surprised about your tQ curve too ... should be quite a bit flatter than that .
10-01-08, 05:57 PM
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No no no 
. Sorry if I wasnt clear, I already did the conversion in my text. If you look on the graph the peak power is 143KW at the wheels with 191 NM of torque. So thats 192whp and 140 foot pounds of torque. You were probably confused because on a KW - NM dyno graph the torque curve is usually above the Power curve, whereas with the HP - Foot Pound dyno graphs your probably used to seeing the torque curve is usually below the power curve. Have another look at the text and graph and you will see 
.
Oh and as for the torque curve, he only have it WOT after getting it up to between 4000 - 5000 rpm which is why you see it suddenly climb. And as for it dropping off after 7000rpm, I think thats partly due to how rich its running above 7000.
Anyway, hope that clears things up for you.
. Sorry if I wasnt clear, I already did the conversion in my text. If you look on the graph the peak power is 143KW at the wheels with 191 NM of torque. So thats 192whp and 140 foot pounds of torque. You were probably confused because on a KW - NM dyno graph the torque curve is usually above the Power curve, whereas with the HP - Foot Pound dyno graphs your probably used to seeing the torque curve is usually below the power curve. Have another look at the text and graph and you will see .Oh and as for the torque curve, he only have it WOT after getting it up to between 4000 - 5000 rpm which is why you see it suddenly climb. And as for it dropping off after 7000rpm, I think thats partly due to how rich its running above 7000.
Anyway, hope that clears things up for you.
Last edited by EpitrochoidalPower!; 10-01-08 at 06:03 PM.
10-02-08, 02:06 AM
#33
props to you still if you got 192whp ... I'm still not sure how you converted it ... i just used an online calculator which gave me that number ... I actually tried 2 of them just to be sure ... Also about the torque .. i definatly didn't realive that they weren't crossing ... i'm not used to seeing this type ... I would say go to another one just to double check if there is another one.
10-02-08, 02:45 AM
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1 Kilowatt = 1.34102209 Horse Power
143 peak rear wheel kilowatts (read from the lower line on the dyno graph)
143 rwKW * 1.3410 = 191.766 rear wheel HP
1 Newton Meter = 0.737562149 Foot Pounds
191 peak rear wheel newton meters (read from upper line on dyno graph)
191 rwNM * 0.737562149 = 140.87 rear wheel Ft/Lbs
Therefore the read wheel figures in imperial units is
192 Rear wheel horsepower
140 Foot pounds
I really think this should be cleared up by now
The units of the dyno are metric, so the dyno is going to look different to what u used to
143 peak rear wheel kilowatts (read from the lower line on the dyno graph)
143 rwKW * 1.3410 = 191.766 rear wheel HP
1 Newton Meter = 0.737562149 Foot Pounds
191 peak rear wheel newton meters (read from upper line on dyno graph)
191 rwNM * 0.737562149 = 140.87 rear wheel Ft/Lbs
Therefore the read wheel figures in imperial units is
192 Rear wheel horsepower
140 Foot pounds
I really think this should be cleared up by now
The units of the dyno are metric, so the dyno is going to look different to what u used to
Last edited by EpitrochoidalPower!; 10-02-08 at 02:48 AM.
10-02-08, 03:18 AM
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The units of the dyno are metric, so the dyno is going to look different to what u used to. With my figures on a metric dyno the torque curve will not cross the power curve as the torque values always remain higher than the power values ( 191(torque) > 143 (power) ). Whereas if you plot my values onto a HP - FT/lbs dyno graph the curves would cross like you're used to as the peak power value would be more than the peak torque value (192(power) > 140 (torque)). So there is nothing wrong with the graph or dyno its just looks different to what your used to. I'm confident that the 192whp figure is accurate with the way this car hauls. 192whp is far from pushing the boundaries of what a Bridgeport can make so I don't think its hard to believe.
If you want to check whether the torque makes sense with respect to the graph use the simple relationship between torque and power.
Power = torque*angular speed
When converting this to the application of using kw, nm and rpm we get the formula
Power (kW) = { torque (Nm) * 2 * PI *rotational speed (rpm) } / 60000
So lets take the peak torque at about 7000 rpm, the power value given by the calculation is 140kw, take a look at the graph and its correct.
Try the 190Nm at about 5000 rpm we get 100kw, take a look at graph and we get 100kw.
Try 170Nm at the peak power at about 8000 rpm we get 143 Kw.
Therefore this graph is reading accurately. For those of you who didnt know power is related to torque and is actually calculated from your torque values through the rpm range using that formula, so if your dyno graph deviates from the actual physics, u know something is wrong.
Another interesting thing if u take another look at
Power = torque*angular speed you can see that
torque = power/angular speed therefore meaning the higher the rpm the more power u need to make the same torque, therefore the only way to make more torque at a specific rpm is to make more power at that rpm, maybe im stating the obvious, but in my experience ive met many people who have the misconception that torque is a separate entity to power and can be increased etc. separately to power. In fact, if u want a more torquey engine you have to increase the power, but as u can see it requires less power to make torque at lower rpms, so if u aiming for torque its easier to aim for low rev power to make it. Thats why high revving engines with power in the high rpms are considered to have low torque and put out low torque figures because they are making their power at high rpms. You can see it quite clearly in my dyno graph, from about 7000rpm onwards power stays fairly constant, and torque drops off fairly linearly, and where the torque stays fairly constant from 5000 to 7000rpm the power increases fairly linearly.
Anyways just thought id put that out there
If you want to check whether the torque makes sense with respect to the graph use the simple relationship between torque and power.
Power = torque*angular speed
When converting this to the application of using kw, nm and rpm we get the formula
Power (kW) = { torque (Nm) * 2 * PI *rotational speed (rpm) } / 60000
So lets take the peak torque at about 7000 rpm, the power value given by the calculation is 140kw, take a look at the graph and its correct.
Try the 190Nm at about 5000 rpm we get 100kw, take a look at graph and we get 100kw.
Try 170Nm at the peak power at about 8000 rpm we get 143 Kw.
Therefore this graph is reading accurately. For those of you who didnt know power is related to torque and is actually calculated from your torque values through the rpm range using that formula, so if your dyno graph deviates from the actual physics, u know something is wrong.
Another interesting thing if u take another look at
Power = torque*angular speed you can see that
torque = power/angular speed therefore meaning the higher the rpm the more power u need to make the same torque, therefore the only way to make more torque at a specific rpm is to make more power at that rpm, maybe im stating the obvious, but in my experience ive met many people who have the misconception that torque is a separate entity to power and can be increased etc. separately to power. In fact, if u want a more torquey engine you have to increase the power, but as u can see it requires less power to make torque at lower rpms, so if u aiming for torque its easier to aim for low rev power to make it. Thats why high revving engines with power in the high rpms are considered to have low torque and put out low torque figures because they are making their power at high rpms. You can see it quite clearly in my dyno graph, from about 7000rpm onwards power stays fairly constant, and torque drops off fairly linearly, and where the torque stays fairly constant from 5000 to 7000rpm the power increases fairly linearly.
Anyways just thought id put that out there
Last edited by EpitrochoidalPower!; 10-02-08 at 03:39 AM.
10-02-08, 04:04 PM
#36
With full bridge and those itbs still not 200hp, my street with those same itbs will never have a chance. Really hope you get well over, for both of our sake. ha ha jk. When final tuning is done im sure you'll get a lil over. cool
I'm still going to do those itb's it's easier to get manifold then to have somebody make one for me. give or take
I'm still going to do those itb's it's easier to get manifold then to have somebody make one for me. give or take
10-02-08, 07:01 PM
#37
FWIW, I'm getting 198hp to the wheels on my 12a bridgeport. YOu really need a non restrictive exhaust. 3" all the way back with no resonator and a RB high flow 3" muffler is what I run. If you choke it down on a bridge or pport you will not gain the power.
10-04-08, 02:24 AM
#38
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Yes your right, bridgeports need to breathe. My current exhaust is quite good actually. Its a mandrel bent 3" exhaust with a big, free flowing muffler at the back. However the resonator i'm not so sure about. I heard it making some strange noises recently so my plans are to remove it and just replace it with some 3" tube or a megaphone. My header is not very good though. Im sure its causing restriction and I think the primaries are too long so i'm going to cut off my current one and make up a rig so that I can make a mandrel bent header with short primaries with slightly larger diameters.
What i've done so far is shorten my ITB's ram tubes by about and inch. I have also done some nice work on my intake manifold. It was designed for a 48IDA so the inlets were 47mm while my ITB's are 50mm. My thoughts are that 3mm could make quite a difference to flow. So I have ground out the inlets to match the ITB's now and ive done work throughout the whole manifold. Smoothed it all out well and ground down all the seams. Don't worry I didn't polish up the ports they still have a well scratched surface. I'm going to put the intake back on the car today and once the RTV has dried i'll go tune the car properly. I'm sure tuning is all I need to break 200whp. And the work on the intake system should help a little. The key however is the exhaust system. Once I get around to sorting that out i'm sure I can unlock a decent amount more power. Once all thats sorted I'll get a bit more agressive on the timing and see how that works out.
What i've done so far is shorten my ITB's ram tubes by about and inch. I have also done some nice work on my intake manifold. It was designed for a 48IDA so the inlets were 47mm while my ITB's are 50mm. My thoughts are that 3mm could make quite a difference to flow. So I have ground out the inlets to match the ITB's now and ive done work throughout the whole manifold. Smoothed it all out well and ground down all the seams. Don't worry I didn't polish up the ports they still have a well scratched surface. I'm going to put the intake back on the car today and once the RTV has dried i'll go tune the car properly. I'm sure tuning is all I need to break 200whp. And the work on the intake system should help a little. The key however is the exhaust system. Once I get around to sorting that out i'm sure I can unlock a decent amount more power. Once all thats sorted I'll get a bit more agressive on the timing and see how that works out.
10-04-08, 07:37 PM
#39
Yes your right, bridgeports need to breathe. My current exhaust is quite good actually. Its a mandrel bent 3" exhaust with a big, free flowing muffler at the back. However the resonator i'm not so sure about. I heard it making some strange noises recently so my plans are to remove it and just replace it with some 3" tube or a megaphone. My header is not very good though. Im sure its causing restriction and I think the primaries are too long so i'm going to cut off my current one and make up a rig so that I can make a mandrel bent header with short primaries with slightly larger diameters.
What i've done so far is shorten my ITB's ram tubes by about and inch. I have also done some nice work on my intake manifold. It was designed for a 48IDA so the inlets were 47mm while my ITB's are 50mm. My thoughts are that 3mm could make quite a difference to flow. So I have ground out the inlets to match the ITB's now and ive done work throughout the whole manifold. Smoothed it all out well and ground down all the seams. Don't worry I didn't polish up the ports they still have a well scratched surface. I'm going to put the intake back on the car today and once the RTV has dried i'll go tune the car properly. I'm sure tuning is all I need to break 200whp. And the work on the intake system should help a little. The key however is the exhaust system. Once I get around to sorting that out i'm sure I can unlock a decent amount more power. Once all thats sorted I'll get a bit more agressive on the timing and see how that works out.
What i've done so far is shorten my ITB's ram tubes by about and inch. I have also done some nice work on my intake manifold. It was designed for a 48IDA so the inlets were 47mm while my ITB's are 50mm. My thoughts are that 3mm could make quite a difference to flow. So I have ground out the inlets to match the ITB's now and ive done work throughout the whole manifold. Smoothed it all out well and ground down all the seams. Don't worry I didn't polish up the ports they still have a well scratched surface. I'm going to put the intake back on the car today and once the RTV has dried i'll go tune the car properly. I'm sure tuning is all I need to break 200whp. And the work on the intake system should help a little. The key however is the exhaust system. Once I get around to sorting that out i'm sure I can unlock a decent amount more power. Once all thats sorted I'll get a bit more agressive on the timing and see how that works out.
10-05-08, 04:18 PM
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will do. Something interesting happened today. Got the intake back on and went for a drive. I gave it a WOT run and as I got to around 9000rpm the engine bogged and made strange noise but wouldnt drop revs. I immediately killed the engine and assumed the throttle had somehow got stuck. Opened the hood to find that the front rotor had sucked its air filter into its throttle body 
. It had got wedged in at the butterfly and was holding it open. Pulled it out and took other filter off and drove home. These filters are basically tubes of foam with a tubular spring inside them to stop them collapsing. I couldnt see the spring anywhere and I knew there was no way the engine sucked it in so I assumed I had forgotten the spring and that it was the reason the filter had got sucked in. Turns out I was wrong, went for a drive down the street where it happened and found the spring on the side of the road. That means the suction was so much that it compressed the spring down and then pulled it through the top of the spring 
. I tried removing the springs and used cable ties to hold the filters onto the ram tubes. I soon scrapped that idea because I lost ALOT of power, I guess that without the springs to hold the tubes a bit above the top of the ram tubes and with the cable ties it blocks off a lot of flow. So now that I have both of my springs back i'm going to go with them again. I must now figure out a way to modify them so that this doesnt happen again though. First idea is to weld some rods horizontally across the top to make it impossible for the filter to squeeze its way through and some rods vertically to stop the spring from compressing as I think at high revs it may be killing power. It may also be why i'm running rich on the top end because the air flow is being restricted as the filter's springs get squashed. This approach worries me because if those welds break the rods are going straight into my engine 
. The other idea would be to make my own sort of basket from scratch to support the filters. And my final idea which I think may just work is to throw the springs into a hot fire and get them very hot and then quench them in some water to stiffen them up. Any ideas? Ive attached a diagram to give you an idea of what the filters are like now. I want to avoid having to use/make up an airbox as I think it defeats the purpose of ITB's and I quite like these foam filter's as they shouldnt restrict flow much if I get those springs supporting them properly.
. It had got wedged in at the butterfly and was holding it open. Pulled it out and took other filter off and drove home. These filters are basically tubes of foam with a tubular spring inside them to stop them collapsing. I couldnt see the spring anywhere and I knew there was no way the engine sucked it in so I assumed I had forgotten the spring and that it was the reason the filter had got sucked in. Turns out I was wrong, went for a drive down the street where it happened and found the spring on the side of the road. That means the suction was so much that it compressed the spring down and then pulled it through the top of the spring . I tried removing the springs and used cable ties to hold the filters onto the ram tubes. I soon scrapped that idea because I lost ALOT of power, I guess that without the springs to hold the tubes a bit above the top of the ram tubes and with the cable ties it blocks off a lot of flow. So now that I have both of my springs back i'm going to go with them again. I must now figure out a way to modify them so that this doesnt happen again though. First idea is to weld some rods horizontally across the top to make it impossible for the filter to squeeze its way through and some rods vertically to stop the spring from compressing as I think at high revs it may be killing power. It may also be why i'm running rich on the top end because the air flow is being restricted as the filter's springs get squashed. This approach worries me because if those welds break the rods are going straight into my engine . The other idea would be to make my own sort of basket from scratch to support the filters. And my final idea which I think may just work is to throw the springs into a hot fire and get them very hot and then quench them in some water to stiffen them up. Any ideas? Ive attached a diagram to give you an idea of what the filters are like now. I want to avoid having to use/make up an airbox as I think it defeats the purpose of ITB's and I quite like these foam filter's as they shouldnt restrict flow much if I get those springs supporting them properly.
10-05-08, 07:25 PM
#41
If you're not driving on dirt just run without filters. You will get more horsepower and with the hood closed nothings going to get inside. It would take a miracle for a rock or something to fly under your hood and inside your engine. I run without filters in my car all the time. If you're really worried about something big getting inside than an old trick we use to use is panyhose- they flow really well and will keep large materials from getting inside.
10-05-08, 10:55 PM
#43
Yes, at a dirt track, but not a drag stip. I don't know of any serious drag racers using filters. It all depends on what you want. If you want a daily poker and dont' race then use filters. If you are racing or running in dirt= filters. If you drive on the street and are a weekend drag racer then use the filters on the street and then take them off when you race. Basically filters = less power and more longevity. It all depends on what you want to do.
10-06-08, 03:55 AM
#44
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This is a mostly a street car so I want to keep the filters. When I go to drag strip I will probably remove them like you said. Another problem is I have a hood scoop fitted right above the throttle bodies. So there is a much larger chance of crap getting sucked into them, I don't think rotaries like the taste of bugs, they prefer to eat large quantaties of petroleum . So in short, filters are a must for me.
. So in short, filters are a must for me.
10-06-08, 09:48 AM
#45
This is a mostly a street car so I want to keep the filters. When I go to drag strip I will probably remove them like you said. Another problem is I have a hood scoop fitted right above the throttle bodies. So there is a much larger chance of crap getting sucked into them, I don't think rotaries like the taste of bugs, they prefer to eat large quantaties of petroleum . So in short, filters are a must for me.
. So in short, filters are a must for me.
10-09-08, 12:42 PM
#48
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Yes, at a dirt track, but not a drag stip. I don't know of any serious drag racers using filters. It all depends on what you want. If you want a daily poker and dont' race then use filters. If you are racing or running in dirt= filters. If you drive on the street and are a weekend drag racer then use the filters on the street and then take them off when you race. Basically filters = less power and more longevity. It all depends on what you want to do.
and they rebuild the engine at least once. if you're only running the thing for 7 minutes you dont need an air filter.
in road racing we double the track time by lunch on the first weekend.
10-13-08, 07:48 AM
#49
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My Air Filter Solution
Ok so i've sorted out my air filters. I bought two cone filters and modified them to fit my ram tubes. I made up some adapters by using some rubber reducers and a bit of initiative. The ram tubes protude into the filters but do not touch the side.. These should easily flow plenty of clean air and they definitely wont get sucked into the ITB's . Here are some pics:
. Here are some pics:
