Should I bridgeport?
02-10-02, 09:36 PM
#1
Persona non grata
Thread Starter
Should I bridgeport?
My engine is being built right now. I have the choice to do a mild bridgeport, or to just streetport. That's my dilema.
You can see the mods I have here - https://www.rx7club.com/members/rscott.htm
The car is going to be mainly a road course car, doing lapping days and drivers schools. So I think the main importance is to have a engine/turbo combo that isn't laggy. I can't have the turbo decide to come on right at the apex of a turn. I need something that's a smooth, linear power delivery.
430-440 rwhp is the target. So which port is going to best suit my needs? I'm leaning toward a mild bridge, mainly for the boost in the mid-high revs ... right where you need it on a road course. But I'd love some feedback.
Since I just made the 20B forum for you guys, you GOTTA give me some good advice
You can see the mods I have here - https://www.rx7club.com/members/rscott.htm
The car is going to be mainly a road course car, doing lapping days and drivers schools. So I think the main importance is to have a engine/turbo combo that isn't laggy. I can't have the turbo decide to come on right at the apex of a turn. I need something that's a smooth, linear power delivery.
430-440 rwhp is the target. So which port is going to best suit my needs? I'm leaning toward a mild bridge, mainly for the boost in the mid-high revs ... right where you need it on a road course. But I'd love some feedback.
Since I just made the 20B forum for you guys, you GOTTA give me some good advice
02-11-02, 08:23 AM
#6
Persona non grata
Thread Starter
Yea, half bridge is what I mean by mild bridgeport .. or j bridge
How much loss of life expectancy can I expect, seriously? Even a half bridge won't last as long, but if they can still last 30K miles, that's enough for me. The car isn't going to be driven on the street, just at the track.
How much loss of life expectancy can I expect, seriously? Even a half bridge won't last as long, but if they can still last 30K miles, that's enough for me. The car isn't going to be driven on the street, just at the track.
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02-11-02, 10:30 AM
#8
Rotary Freak
Re: Should I bridgeport?
Originally posted by BOOSTD 7
My engine is being built right now. I have the choice to do a mild bridgeport, or to just streetport. That's my dilema.
You can see the mods I have here - https://www.rx7club.com/members/rscott.htm
The car is going to be mainly a road course car, doing lapping days and drivers schools. So I think the main importance is to have a engine/turbo combo that isn't laggy. I can't have the turbo decide to come on right at the apex of a turn. I need something that's a smooth, linear power delivery.
430-440 rwhp is the target. So which port is going to best suit my needs? I'm leaning toward a mild bridge, mainly for the boost in the mid-high revs ... right where you need it on a road course. But I'd love some feedback.
Since I just made the 20B forum for you guys, you GOTTA give me some good advice
My engine is being built right now. I have the choice to do a mild bridgeport, or to just streetport. That's my dilema.
You can see the mods I have here - https://www.rx7club.com/members/rscott.htm
The car is going to be mainly a road course car, doing lapping days and drivers schools. So I think the main importance is to have a engine/turbo combo that isn't laggy. I can't have the turbo decide to come on right at the apex of a turn. I need something that's a smooth, linear power delivery.
430-440 rwhp is the target. So which port is going to best suit my needs? I'm leaning toward a mild bridge, mainly for the boost in the mid-high revs ... right where you need it on a road course. But I'd love some feedback.
Since I just made the 20B forum for you guys, you GOTTA give me some good advice
02-11-02, 11:27 AM
#9
standard combustion
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I love the hell out of my 12a full-bridgeport when I can afford to drive. Milage is poor and I'm not finshed upgrading her. She is only meant to last 20,000miles between engine disassemblies. I am not driving it again till I get a light flywheel, but it should really haul to 100mph then. Not to say it didn't now. Beats the hell out of my mildport. REally moves up to 60mph quick! Thats my 2cents.
02-11-02, 09:22 PM
#10
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Do IT!
Why do you want a bridgeport?
You want big HP/Torque, but not 22psi of boost, right? You want to run pump gas, save the $8/gallon stuff for special occasions, right?
Bridgeport is the ticket.
You can bridge the primaries if you want to, but you'll loose velocity in the runner (see Paul Yaw's work). Bridge the secondaries (aka partial, or secondary bridge), and you make the trade-off - acceptable (but not great) low-end, and big HP and torque from the mid range on up... If you don't care about velocity, cut into the rotor housings (didn't make sense to me), bport all four, or go with ITO's mini-p'port.
If you're a DIY'er, its plenty of work. If you're patient, have a dremel (or compressed air) with a flex shaft and a good assortment of carbide bits, and stones, you can say, "I did it myself!"
I can't speak to performance, or drivability yet.
I'm smack in the middle of the job.
- Don't let the streetporters talk you out of it.
- Bridgeporters of the world, UNITE! (and the crowd goes wild!).
Steve C.
You want big HP/Torque, but not 22psi of boost, right? You want to run pump gas, save the $8/gallon stuff for special occasions, right?
Bridgeport is the ticket.
You can bridge the primaries if you want to, but you'll loose velocity in the runner (see Paul Yaw's work). Bridge the secondaries (aka partial, or secondary bridge), and you make the trade-off - acceptable (but not great) low-end, and big HP and torque from the mid range on up... If you don't care about velocity, cut into the rotor housings (didn't make sense to me), bport all four, or go with ITO's mini-p'port.
If you're a DIY'er, its plenty of work. If you're patient, have a dremel (or compressed air) with a flex shaft and a good assortment of carbide bits, and stones, you can say, "I did it myself!"
I can't speak to performance, or drivability yet.
I'm smack in the middle of the job.
- Don't let the streetporters talk you out of it.
- Bridgeporters of the world, UNITE! (and the crowd goes wild!).
Steve C.
02-11-02, 10:17 PM
#11
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there is no reason to bridge port a street car, for the money you will spend to do this it is not worth it. I would suject getting a stage 2 street port. very driveable engine and and cost far less to have it done. If you have any major qusetions look up Hayes Rotary on the webb and call them. Don is really helpful and know his **** well
02-11-02, 10:49 PM
#12
standard combustion
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I spent no money on bridgeporting. I did the porting in the project's lab at the college I went to. I used a very nice digrinder and a assortment of carbide bits I beat the crap out of. I would say to anyone that makes a bridgeport with rotor housings match, you don't know what your missing. Lots more flow...equals more power. If your a turbo fellow, maybe you should stay mildport though. But I am convinced that my bridgport is a drivable as my mildport except much more fun to drive. The major trade off is carbon seals that have a short life, and a rough running engine in part throttle conditions. Big deal, is this your primary car? In that case, you need to re-evaluate your goals in this project. Bridgports are summer weekend cars...I think at least. Again....My 2 cents....
02-11-02, 11:09 PM
#13
inteligent extratarestril
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No you definitly shouldn't do it - cause reTed thinks its a load of crock......................................
i wont say anymore other than the motor which i will be putting together shortly DOES HAVE small/medium sized bridge ports in the secondary ports
i wont say anymore other than the motor which i will be putting together shortly DOES HAVE small/medium sized bridge ports in the secondary ports
02-12-02, 04:10 AM
#14
Pew Pew Pew
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go the bridge port all the way. I just got my rx7 done its heps af fun to drive and just as streetable as my street port was and lots more power and torque
02-12-02, 09:34 AM
#15
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Originally posted by BOOSTD 7
Yea, half bridge is what I mean by mild bridgeport .. or j bridge
How much loss of life expectancy can I expect, seriously? Even a half bridge won't last as long, but if they can still last 30K miles, that's enough for me. The car isn't going to be driven on the street, just at the track.
Yea, half bridge is what I mean by mild bridgeport .. or j bridge
How much loss of life expectancy can I expect, seriously? Even a half bridge won't last as long, but if they can still last 30K miles, that's enough for me. The car isn't going to be driven on the street, just at the track.
02-12-02, 10:25 AM
#16
This is the first BP turbo I did. It's from an 88 turbo II motor.
We kind of step on it late at around 4500 rpm so the figures are from there upwards.
It was running a 66-1 at 24psi
RPM... 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5
RWHP. 150 250 400 475 500 530 550 550 525
RWTQ 150 270 380 420 419 400 380 350 325
What I like most about Bp Turbo motors on the street are that they always produce 500 RWHP and 380 plus RWTQ at 18 to 20 psi on 93 octane!
crispeed
87TII
9.20@150mph
We kind of step on it late at around 4500 rpm so the figures are from there upwards.
It was running a 66-1 at 24psi
RPM... 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5
RWHP. 150 250 400 475 500 530 550 550 525
RWTQ 150 270 380 420 419 400 380 350 325
What I like most about Bp Turbo motors on the street are that they always produce 500 RWHP and 380 plus RWTQ at 18 to 20 psi on 93 octane!
crispeed
87TII
9.20@150mph
Last edited by crispeed; 02-12-02 at 10:30 AM.
02-12-02, 10:39 AM
#18
Originally posted by BOOSTD 7
Ok, I wanted a bridge before ... but now I'm convinced
I'm not going to overspin my relatively small T04B Hi-Fi am I?
Ok, I wanted a bridge before ... but now I'm convinced
I'm not going to overspin my relatively small T04B Hi-Fi am I?
The last time I used a 60-1 HI-FI the Dynojet was not even invented!
It should support 450 RWHP. My friend made 500 RWHP but with a full size 60-1!
crispeed
87TII
9.20@!50mph
02-12-02, 10:54 AM
#19
so chris, you are saying that the turbo bridge is a better option for the street than a turbo secondary pp? are those hp #'s you posted for a full bridge or a secondary bridge?
what would be the advantages/disadvantages of using a small secondary pp on a turbo street car? i was all set to build a pp motor, now you guys got me thinking again.....
what would be the advantages/disadvantages of using a small secondary pp on a turbo street car? i was all set to build a pp motor, now you guys got me thinking again.....
02-12-02, 11:13 AM
#20
Gaijin Racing
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Originally posted by BOOSTD 7
Ok, I wanted a bridge before ... but now I'm convinced
I'm not going to overspin my relatively small T04B Hi-Fi am I?
Ok, I wanted a bridge before ... but now I'm convinced
I'm not going to overspin my relatively small T04B Hi-Fi am I?
02-12-02, 01:31 PM
#21
Persona non grata
Thread Starter
I don't see any reason to get a new turbo or manifold right now. If I can do 420-440 at the wheels with my current setup, than I'm happy. Brian Cain has the exact same turbo as I do and did 422, so I should be fine. I've done a lot more 'other' stuff than he did - like my FD upper/lower intake and throttle body.
