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-   Rotary Engine Building, Porting & Swaps (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/)
-   -   Bridge Port Question (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/bridge-port-question-67335/)

RX7 13B 4 UR AZZ 09-13-2007 11:26 PM

As far as bridge ports go would this bridge be considered a safe bridge? I want to bridge my 13B-re when i get it but want some longevity out of the motor so what i was thinking to do is a nice street port primaries and this type of bridge the secondarys. What would you guys opinion be on porting for my motor? I want nice power 350-400 on a gt-40 on the conservative side mabey 450-500 on c16 would this type of porting allow my goal.

http://bdc.cyberosity.com/d/10525-2/IMG_5343.jpg

hsmidy 09-14-2007 07:11 AM


Originally Posted by RX7 13B 4 UR AZZ' post='882687' date='Sep 14 2007, 04:26 PM
As far as bridge ports go would this bridge be considered a safe bridge? I want to bridge my 13B-re when i get it but want some longevity out of the motor so what i was thinking to do is a nice street port primaries and this type of bridge the secondarys. What would you guys opinion be on porting for my motor? I want nice power 350-400 on a gt-40 on the conservative side mabey 450-500 on c16 would this type of porting allow my goal.

http://bdc.cyberosity.com/d/10525-2/IMG_5343.jpg



aslong as port doesnt comparamise the water seal you should be fine as for longevity goes , its only once you brake the water seal that longevity realy becomes a probelm, in saying that i know alot of guys have been saying you can get the same or very simlailar performance figures outa a good sized street(extended) port as you can out of extended primarys and bridged secondarys, but as for me im still waiting to speak to my engine builder bout waht track to go down(cant afford to **** a d series 20b) but i like the idea of a big extended primary with a nice secondary bridgy to go with my turbo

j9fd3s 09-14-2007 10:47 AM

i think for your power goals, a street port would work better. 350-400 and a gt40, should be really easy

treceb 09-14-2007 01:39 PM


Originally Posted by j9fd3s' post='882709' date='Sep 14 2007, 11:47 AM
i think for your power goals, a street port would work better. 350-400 and a gt40, should be really easy

yup. 320 with a t78 on stock ports at only 10psi.

RX7 13B 4 UR AZZ 09-14-2007 11:46 PM

T78 that is pertty big but really nice 320 on stock ports 10 psikick ass! ! ! I want my engine to be modestly tuned, I am going to run water/meth kit but im not going to tune with it im going to set my base tune then add the water/meth injection for additional saftey. I would like to have the car set up for a low and high mode, 350-400 low 400-450 high on pump gas being realistic mabey something like 500+ potential on race fuel if these ports will get me there then that is how i will go. What do you guys think idel will be at 1500rpm mabey a little braping https://www.nopistons.com/forums/pub...#>/biggrin.gif https://www.nopistons.com/forums/pub...DIR#>/wink.gif all this is going into my 86 Sport RX-7 should make for a fun car right!



Things I currently have

Microtech LT10s

Greddy Profec B

Greddy FMIC

Centerforce DF Clucth



Things Im wating on

13b-RE

HKS cast Manifold(Looking into investing into one of thoes sweet Turboblown mainfolds)

Garrett GT-40

84stock 10-28-2007 11:18 PM


Originally Posted by RX7 13B 4 UR AZZ' post='882748' date='Sep 14 2007, 09:46 PM
T78 that is pertty big but really nice 320 on stock ports 10 psikick ass! ! ! I want my engine to be modestly tuned, I am going to run water/meth kit but im not going to tune with it im going to set my base tune then add the water/meth injection for additional saftey. I would like to have the car set up for a low and high mode, 350-400 low 400-450 high on pump gas being realistic mabey something like 500+ potential on race fuel if these ports will get me there then that is how i will go. What do you guys think idel will be at 1500rpm mabey a little braping https://www.nopistons.com/forums/pub...#>/biggrin.gif https://www.nopistons.com/forums/pub...DIR#>/wink.gif all this is going into my 86 Sport RX-7 should make for a fun car right!



Things I currently have

Microtech LT10s

Greddy Profec B

Greddy FMIC

Centerforce DF Clucth



Things Im wating on

13b-RE

HKS cast Manifold(Looking into investing into one of thoes sweet Turboblown mainfolds)

Garrett GT-40







I have that same exact port on my s/c 13b http://media.putfile.com/BRIDGPORTED-13B-COMPILATION http://media.putfile.com/bridgeported-supercharged-13b

RX7 13B 4 UR AZZ 12-01-2007 05:44 PM

any more opinions?

RX7 13B 4 UR AZZ 01-07-2008 09:30 PM

already decided to go with BDC to do my port job if anyone has seen his porting pics they should take a look GENIUS ! ! ! ! !

C. Ludwig 01-08-2008 11:06 PM

We did a test this past summer that was pretty apples to apples. One engine was street ported and used a 62-1 compressor, p-trim .84 hotside sitting on an A-Spec manifold. It made 411 whp at 16 psi on pump fuel. Full boost hit hard at 4500 and was soft below that. Also, tuned a car which was built by another shop with the exact same turbo. The results mirrored the car we assembled identically for all intents and purposes.



We then did a half-bridge. Turbo was a 62-1 compressor, p-trim wheel in a 1.00 hotside. Manifold was the HKS FD style cast manifold. We got 436 whp at 14 psi and hit full boost at 3400 and was more linear in the boost rise. It "felt" much more responsive off boost.



The half-bridge car was using an Ebay intercooler that we determined to be very inefficient and showed a pressure drop of almost 4 psi across the core! So there was more power to be had by simply replacing that core with something that flowed and cooled worth a damn. The street port car used a large Precision Turbo IC which showed only about a 1/2 psi drop and much cooler intake temps. Short answer is there is a proven 25 more horse at 2 psi less manifold pressure with the bridge port and most likely a generous amount more with a good IC.



The only downside was the idle. It's just more time consuming to get a steady idle at a reasonable rpm.



I was a big skeptic of the half bridge until I did one. Always said that guys were making 600 hp on street ports so why go bigger. I also doubted that a bridge would spool a turbo quicker. But I confirmed it for myself and am now excited about doing more. That said when I get around to doing the engine for my FD (which I only plan to build to a 350 whp level) I will use a street port because I want a smooth, quiet, 800 rpm idle.

RX7 13B 4 UR AZZ 01-09-2008 09:09 PM

i thought so i always liked a little brap in a rotary idle


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