Bridge port is over rated?
03-13-07, 02:50 PM
#151
BDC Motorsports
Originally Posted by fdracer
that's exactly the point of the sp side of the argument. a sp has been proven to give everything you'll ever want out of your rotary. from daily drivable twins and singles to big hp street/strip cars to all out drag cars, a sp has been a proven to support anything you can throw at it. a bp may or may not provide the benefits that it's supporters tout, but in the end it's a moot point, because a good sp can get you there as well without having to endure the cons of a more extreme port. like blake said, there are many ways to skin a cat. all us sp arguer's are saying, is that why bother with the other options when sp's have been known to make good power w/o the negatives of the more extreme ports.
B
03-13-07, 05:54 PM
#154
+1 for Blake (post #146)
not that my opinion counts for anything. i realize that i'm not known here - and that's fine with me. however, i've been following this since it's inception. i think too many people are missing what i thought was the crux of the original question. are bridgeys overrated? - which i took to mean, do you need them to make power? i guess i also inferred a street-use implication, too, but - whatever ...
i certainly have nothing against bridgeys. hell, after i finish my next 2 streetport projects, i WILL be building a half-bridge ... for boost! i just think a bridge is not NEEDED over a streetport until you start to approach stratospheric power levels. no one needs to be an expert or even an amateur engine builder to see that. both sides of this argument have said it enough times, but it seems no one has actually listened to what they, themselves, have said - there are more than enough dyno sheets out there to show that the streetports can hang with bridgeys on the street and in all but the most extreme applications on the track. this is why i would answer yes to the original question - unless i totally misunderstood it.
not that my opinion counts for anything. i realize that i'm not known here - and that's fine with me. however, i've been following this since it's inception. i think too many people are missing what i thought was the crux of the original question. are bridgeys overrated? - which i took to mean, do you need them to make power? i guess i also inferred a street-use implication, too, but - whatever ...
i certainly have nothing against bridgeys. hell, after i finish my next 2 streetport projects, i WILL be building a half-bridge ... for boost! i just think a bridge is not NEEDED over a streetport until you start to approach stratospheric power levels. no one needs to be an expert or even an amateur engine builder to see that. both sides of this argument have said it enough times, but it seems no one has actually listened to what they, themselves, have said - there are more than enough dyno sheets out there to show that the streetports can hang with bridgeys on the street and in all but the most extreme applications on the track. this is why i would answer yes to the original question - unless i totally misunderstood it.
03-13-07, 06:20 PM
#155
Originally Posted by Directfreak
Street Port Vs Bridgeport dyno sheet.
I will let Crispeed give the details.
I will let Crispeed give the details.
Both runs were done on the exact same setup meaning turbo, boost etc. the only difference being the motor was pulled and the bridges added after.
The turbo in question was a turbonetics 60-1 at 19-20psi on 93 octane. The motor is an 87-88 Turbo II motor.
One of the main reasons for posting this was to demonstrate the differences between both port types on the very same combination.
Last edited by crispeed; 03-13-07 at 06:26 PM.
03-13-07, 07:58 PM
#158
Old [Sch|F]ool
Originally Posted by fdracer
that's exactly the point of the sp side of the argument. a sp has been proven to give everything you'll ever want out of your rotary.
The PP made *much* more torque (power at a given RPM) than my stockports, or my streetport. Streetport was awfully peaky, which was acceptable for drag use but not so much for tight course work.
The PP was also almost undrivable on the street without EFI, so I pulled it back out and resigned myself to being slow.
Of course, I could have been just imagining that the thing had tremendous pull as low as 2k compared to a stock port, and when I was sorely disappointed when I drove it around the block after swapping a stocker back in, it was also my imagination...
03-13-07, 08:40 PM
#159
Originally Posted by T04Eneedy
mmm hmm,now thats a good example! jeez,thats all it took for crispeed to crush this thread!!!
If you look on the dyno sheet the plot with the 'X' is another motor I did but it was a SP with a different combination. Not much difference to the dyno run with the BP but again it was an entire different combination and that's why you can't really compare the both unless it's actually on the same setup etc.
Also if you look closer there's a third run in there the one with the 'dot' which was the BP motor with a larger turbo. See the difference the larger turbo made at the same boost. It was around 520rwhp with the larger turbo.
03-13-07, 09:43 PM
#160
Lives on the Forum
Originally Posted by rotarygod
It's extremely simple math (as in freshman level high school or lower!) to determine rpm based on vehicle speed. All you need to know is the total drivetrain gear reduction and these numbers have been public information from day 1 of the car. If you do the math for 1st gear and find that he was at a 26000 rpm redline, you're probably using the wrong gear as a reference! 3rd or 4th are the best guesses to start with. I've never seen anyone dyno in 1st, 2nd, or 5th for the sake of getting full throttle numbers. Common sense apparently isn't so common.
doh
BP's make power, period.
I didn't deny this fact.
If we're talking about race rules that allow it, then why not do it?
The better VE (on the top end) for BP's is a moot point.
I'm talking about STREETING the motors for each application.
Idiots are arguing that the BP is "superior" at low RPM's.
Sorry, I drive my daily-driven FC under 4k RPM's 99% of the time on the street.
To me, performance / efficiency is IMPORTANT at this low range.
For my customers who STREET their cars, this IS important.
And I'm sorry for being a ***** for not being able to rev the **** out of my engine above 4kRPM more - I'll end up in jail, and it's a waste of gas (prices are edging over $3 / gallon now).
I haven't seen a BP (not dedicated race cars) dyno sheet that had this "superior" power at lower RPM's.
It's just not there.
That's physics.
People are arguing I'm bullshitting - I ask for proof.
They just tell me to believe it - what kinda crap is that?
So I'd like to see dyno graphs of all these superior BP's that have better low end power?
Would be nice to see RPM-dependent graphs...or get a competent dyno operator to be able to do this for you...
All BDC does is try to railroad me with his eloquent command of the English dictionary...
All it is is smoke and mirrors to try and avoid the point.
All is ask is a BP dyno sheet that's RPM-dependent - why all the excuses?
-Ted
03-13-07, 09:48 PM
#161
Lives on the Forum
One example from Wagasm's old dyno database...
Another example...
And this is the graph which BDC is bitching about which isn't a fair comparison...my T5/T6 compressor upgrade versus his T66 build-up...
You can interpret the data yourself...
Another example...
And this is the graph which BDC is bitching about which isn't a fair comparison...my T5/T6 compressor upgrade versus his T66 build-up...
You can interpret the data yourself...
03-13-07, 10:08 PM
#162
Old [Sch|F]ool
Originally Posted by RETed
I'm talking about STREETING the motors for each application.
Idiots are arguing that the BP is "superior" at low RPM's.
Idiots are arguing that the BP is "superior" at low RPM's.
You don't dyno a car like you drive it on the street. On the street you idle a bunch and drive at 10-20% throttle most of the time. In situations like this, yes, they're not so hot, since part throttle power (different from low RPM full throttle power) is poor.
Cruising around last weekend was fun... I was in 4th gear before the BP'd car in front of me was out of Second. Then again, I'm in 5th before 25mph when driving around town.
03-13-07, 11:24 PM
#163
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Now that is what i called a properly done Bridge engine. 
impressive #'s on such a small turbo.
who says the 60-1 was out of the efficiency?
impressive #'s on such a small turbo.who says the 60-1 was out of the efficiency?
Originally Posted by crispeed
Ok this is a dyno run of my first bridge port turbo motor done way back in 1998 I believe.
Both runs were done on the exact same setup meaning turbo, boost etc. the only difference being the motor was pulled and the bridges added after.
The turbo in question was a turbonetics 60-1 at 19-20psi on 93 octane. The motor is an 87-88 Turbo II motor.
One of the main reasons for posting this was to demonstrate the differences between both port types on the very same combination.
Both runs were done on the exact same setup meaning turbo, boost etc. the only difference being the motor was pulled and the bridges added after.
The turbo in question was a turbonetics 60-1 at 19-20psi on 93 octane. The motor is an 87-88 Turbo II motor.
One of the main reasons for posting this was to demonstrate the differences between both port types on the very same combination.
03-13-07, 11:29 PM
#164
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Originally Posted by crispeed
Ok this is a dyno run of my first bridge port turbo motor done way back in 1998 I believe.
Both runs were done on the exact same setup meaning turbo, boost etc. the only difference being the motor was pulled and the bridges added after.
The turbo in question was a turbonetics 60-1 at 19-20psi on 93 octane. The motor is an 87-88 Turbo II motor.
One of the main reasons for posting this was to demonstrate the differences between both port types on the very same combination.
Both runs were done on the exact same setup meaning turbo, boost etc. the only difference being the motor was pulled and the bridges added after.
The turbo in question was a turbonetics 60-1 at 19-20psi on 93 octane. The motor is an 87-88 Turbo II motor.
One of the main reasons for posting this was to demonstrate the differences between both port types on the very same combination.
I wish both of your runs were done on same gear and exact same conditions.
BP run was done in 4th with no exhaust as noted and SP was obvious done in 3rd gear where load alone will make a difference.
I'm
JD
03-14-07, 12:19 AM
#166
Originally Posted by Boostn7
Chris, obviously your BP run is impressive but your SP run seems low for that amount of boost making BDC's SP dyno(424rwh) even more impressive at much lower boost and 5-10% less flow 60-1.
I wish both of your runs were done on same gear and exact same conditions.
BP run was done in 4th with no exhaust as noted and SP was obvious done in 3rd gear where load alone will make a difference.
I'm
JD
I wish both of your runs were done on same gear and exact same conditions.
BP run was done in 4th with no exhaust as noted and SP was obvious done in 3rd gear where load alone will make a difference.
I'm
JD
That was the closest I had on one dyno sheet from way back then using the same setup. The street port was conservative by today's standards.
I would not use a SP dyno I've done today as a comparison to a BP I've done many years ago especially when the combination is completly different. Actually that SP only made like 15hp more in 4th. If you look at the dyno plot with the 'X's' that's a different SP with the same turbo showing how close it came to the BP. Back then I mainly used the dyno to figure out porting differences because what I believed or thought the 'butt' dyno felt was proven wrong many times by the real dyno.
Again it's not about comparing one dyno to the other. There are too many variables that would have an influence on the power. What's most important are the differences between both porting styles on the exact same setup. For me with everything being the same the BP always made more power and torque once on boost. I have street ports that have narrower and peaky power bands than bridgeports that I have done but will never use that as a comparison unless the bridge port was added to those same street ports and even then there was always an increase in power. One thing I always experienced was once the bridges were added to the same street port and the rest of the combiantion remained the same the power band never changed but only increased. It's only when intake/exhaust manifold and turbo sizing came into the picture that the power band changed.
Off boost the bridge port had all the down falls that they exibit for a daily driver. But then again that depends on everyone's opinion of a daily driver.
03-14-07, 12:46 AM
#168
BDC Motorsports
Originally Posted by Boostn7
BDC did :-)
60-1 vs. 60-1 HIFI. Substantial difference. You and I both know not only that but also what I said. Nice try, pal.
B
03-14-07, 09:32 AM
#169
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What other differences are there between the two turbos other than the shaft and the housing? a 2.75" diameter can flow a max of 1100cfm at mach 0.4. I'm not exactly sure what the air velociity would be at the boost level but it doesn't sound like the housing would be the restriction....
Originally Posted by BDC
I did? Oh, you're mincing my words again and changing what I've said to suit your lousy arguments against me. You know dude, if you've got a personal problem with me, just say so.
60-1 vs. 60-1 HIFI. Substantial difference. You and I both know not only that but also what I said. Nice try, pal.
B
60-1 vs. 60-1 HIFI. Substantial difference. You and I both know not only that but also what I said. Nice try, pal.
B
03-14-07, 10:29 AM
#170
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Originally Posted by crispeed
John
That was the closest I had on one dyno sheet from way back then using the same setup. The street port was conservative by today's standards.
That was the closest I had on one dyno sheet from way back then using the same setup. The street port was conservative by today's standards.
Originally Posted by crispeed
I would not use a SP dyno I've done today as a comparison to a BP I've done many years ago especially when the combination is completly different. Actually that SP only made like 15hp more in 4th. If you look at the dyno plot with the 'X's' that's a different SP with the same turbo showing how close it came to the BP.
You mentioned earlier that "X's" dyno plot was a SP with different combination.
Originally Posted by crispeed
Back then I mainly used the dyno to figure out porting differences because what I believed or thought the 'butt' dyno felt was proven wrong many times by the real dyno.
Again it's not about comparing one dyno to the other. There are too many variables that would have an influence on the power. What's most important are the differences between both porting styles on the exact same setup. For me with everything being the same the BP always made more power and torque once on boost. I have street ports that have narrower and peaky power bands than bridgeports that I have done but will never use that as a comparison unless the bridge port was added to those same street ports and even then there was always an increase in power. One thing I always experienced was once the bridges were added to the same street port and the rest of the combiantion remained the same the power band never changed but only increased. It's only when intake/exhaust manifold and turbo sizing came into the picture that the power band changed.
Off boost the bridge port had all the down falls that they exibit for a daily driver. But then again that depends on everyone's opinion of a daily driver.
Again it's not about comparing one dyno to the other. There are too many variables that would have an influence on the power. What's most important are the differences between both porting styles on the exact same setup. For me with everything being the same the BP always made more power and torque once on boost. I have street ports that have narrower and peaky power bands than bridgeports that I have done but will never use that as a comparison unless the bridge port was added to those same street ports and even then there was always an increase in power. One thing I always experienced was once the bridges were added to the same street port and the rest of the combiantion remained the same the power band never changed but only increased. It's only when intake/exhaust manifold and turbo sizing came into the picture that the power band changed.
Off boost the bridge port had all the down falls that they exibit for a daily driver. But then again that depends on everyone's opinion of a daily driver.
We have enough proven combinations making more hp then needed for the street and hopefully people will make the right decision based on their needs.
JD
03-14-07, 11:08 AM
#172
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Originally Posted by BDC
I did? Oh, you're mincing my words again and changing what I've said to suit your lousy arguments against me. You know dude, if you've got a personal problem with me, just say so.
Originally Posted by Boostn7
Sorry, but I will disagree with the turbo being out of it's efficiency range.
Originally Posted by BDC
Disagree all you'd like, but it most definitely was. Fred is right on the money.
I do not have any personal issues with you or anyone on this forum.
I just hate when people are mis-informed and then make bad decisions based on someones "butt-dyno" results.
JD
60-1 vs. 60-1 HIFI. Substantial difference. You and I both know not only that but also what I said. Nice try, pal.
B[/QUOTE]
03-14-07, 11:50 AM
#173
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Just to clarify why I don't believed the compressor housing was the restriction.
the inlet (2.75") will flow 1100cfm or 145.5lbs/min while the outlet (2") will flow 585cfm or 77.4lbs/min (both at mach 0.4) the compressor wheel will flow approx 60lbs/min. This leads me to believe that the only restriction will be on the compressor wheel.
the inlet (2.75") will flow 1100cfm or 145.5lbs/min while the outlet (2") will flow 585cfm or 77.4lbs/min (both at mach 0.4) the compressor wheel will flow approx 60lbs/min. This leads me to believe that the only restriction will be on the compressor wheel.
Originally Posted by pluto
What other differences are there between the two turbos other than the shaft and the housing? a 2.75" diameter can flow a max of 1100cfm at mach 0.4. I'm not exactly sure what the air velociity would be at the boost level but it doesn't sound like the housing would be the restriction....
Last edited by pluto; 03-14-07 at 12:12 PM.
03-14-07, 04:10 PM
#174
Originally Posted by pluto
Now that is what i called a properly done Bridge engine. impressive #'s on such a small turbo.
who says the 60-1 was out of the efficiency?
impressive #'s on such a small turbo.who says the 60-1 was out of the efficiency?
Same car last year ran 10.0 with only 540rwhp with a street port and a slipping clutch in 4th gear.
03-14-07, 06:39 PM
#175
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Wow, I had no idea this thread would ever start this long of a conversation. I apologize for not getting back to you all sooner but I was layed up in bed with the flu that was then followed by bronchitis.
To answer some of the questions, this was based on a streetable car that will see track time. To even remotely bring in professional drag cars and the porting they use is rediculous and even remotely using a comparison between their motor and a motor that would go into a car I own is rediculous as well. The amount of money they have put into their cars is most likely more than I make in year, and with that much cash and development time, they could probably make similar power figures using stock ports. They use whatever port they want and build an engine around it with one goal in mind.
But I digress...
To everyone that included first hand experience, dyno results, and hard facts like Crispeed, BDC, and ReTed, and anyone else that I can't remember right now (you know who you are) I thank you for being generous enough to provide information for a great read on porting.
To everyone else who was making insubstantiated claims based on speculation, guesses, 2nd hand info, magic, moondust, and voodoo, please refrain from posting here.
For the people who have actually done/driven bridgeported cars, are the idle and off boost light throttle issues tuning related or porting related? If they are porting related, is there a particular style of bridgeport that is more streetable than another? For example a longer eybrow cut or the eybrow located further up or further down.
From what I have read, I am more compelled to go bridgeport than before. Having better transient boost response is what I was looking for and would be perfect for a track application. I don't have smog where I am so I'm not worried about emissions and my current gas mileage is 11 mpg so I doubt it could get worse than that. The only thing that I wouldn't like is light throttle hesitation and a great loss of power down low but I strongly suspect good tuning would remedy this.
So in short, the guys that provided facts, thanks. The guys that are defending streetports simply because they have them and have provided 0 relative information on the various methods of bridgeporting and how they are beneficial, please troll another thread.
Also please expand the scope of thought to include track racing and not just drag racing. I enjoy drag racing and completely respect those of you that do it to the extreme, but the turns are where it is for me. I enjoy auto-x and I am also looking into possibly attending some NASA events this year.
Thanks again guys for so much information and now that I'm not so sick anymore, I'll be a little more involved in this thread.
-Maniac
To answer some of the questions, this was based on a streetable car that will see track time. To even remotely bring in professional drag cars and the porting they use is rediculous and even remotely using a comparison between their motor and a motor that would go into a car I own is rediculous as well. The amount of money they have put into their cars is most likely more than I make in year, and with that much cash and development time, they could probably make similar power figures using stock ports. They use whatever port they want and build an engine around it with one goal in mind.
But I digress...
To everyone that included first hand experience, dyno results, and hard facts like Crispeed, BDC, and ReTed, and anyone else that I can't remember right now (you know who you are) I thank you for being generous enough to provide information for a great read on porting.
To everyone else who was making insubstantiated claims based on speculation, guesses, 2nd hand info, magic, moondust, and voodoo, please refrain from posting here.
For the people who have actually done/driven bridgeported cars, are the idle and off boost light throttle issues tuning related or porting related? If they are porting related, is there a particular style of bridgeport that is more streetable than another? For example a longer eybrow cut or the eybrow located further up or further down.
From what I have read, I am more compelled to go bridgeport than before. Having better transient boost response is what I was looking for and would be perfect for a track application. I don't have smog where I am so I'm not worried about emissions and my current gas mileage is 11 mpg so I doubt it could get worse than that. The only thing that I wouldn't like is light throttle hesitation and a great loss of power down low but I strongly suspect good tuning would remedy this.
So in short, the guys that provided facts, thanks. The guys that are defending streetports simply because they have them and have provided 0 relative information on the various methods of bridgeporting and how they are beneficial, please troll another thread.
Also please expand the scope of thought to include track racing and not just drag racing. I enjoy drag racing and completely respect those of you that do it to the extreme, but the turns are where it is for me. I enjoy auto-x and I am also looking into possibly attending some NASA events this year.
Thanks again guys for so much information and now that I'm not so sick anymore, I'll be a little more involved in this thread.
-Maniac