| JDC™ |
for the FD's, its the rotary in the TT, the same one in the n/a. like same engine, just no turbos?
thanks |
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| REFLUX |
pardon my ignorance (seeing as how i OWN an rx-7...)
but i never knew FD's came in N/A!!! |
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| PraxRX7 |
The FD comes only with a 13B-REW with Twin Turbo.
The Other RX-7's (1986-1991) came with the 13B engiine and the 1979-85 RX-7s had the 12A (the 1985 1st gen GSL-SE came with a fuel injected 13B, all the others were carburated).
The difference between the 13B and 13B-REW are not huge, but the rotors on the 13B-REW are lighter, as well as set for different compression. I do not know for sure but I also think there are some porting differences. (heck I am not even sure if the rotors are lighter or heavier). I believe there are also some other differences in the housings and seals.
I own a 1989 Turbo II RX-7 so I really don't know a whole lot about either the 1st gens or 3rd gens...just a little.
<!--EDIT|PraxRX7|Dec 14 2002, 02:50 PM--> |
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| WookeysRX7 |
| Hey Prax, what kinda mods do you hvae done to your engine? And i was wondering, what does the termonolgy streetport mean? Does that just mean you have a ported and polished intake? |
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| redbaron303 |
| If i'm not mistaken, street porting is enlarging the ports in the engine allowing for more flow.... |
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| WookeysRX7 |
| so its pretty much port and polishing then. k thats what i though :bigthumbup: |
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| Al36rx7 |
| Check out the MAZDATRIX website. There is a section under racing that shows the difference in porting for a rotary. |
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| PraxRX7 |
Currently I have not done much as far as actual engine modification goes.
My car has nearly 300,000 kms (re-build engine and turbo) on it so I am spending most of my money right now into restoring the look (stock) and older engine components.
I replaced the Stock Blow-Off Valve with an APEXi unit because I was not happy with its response times or its psi leaking nature, I also re-wired the fuel pump to help avoid lean conditions, installed an A/F gauge (not wideband) and an aftermarket boost gauge. I also replaced my rusted out exhaust with a custom exhaust (stock diameter for now to reduce boost creep) but I kept the old mufflers because they were still good.
I currently run my car at 8 PSI at right around stock HP/Tourque levels.
Right now I am in the middle of replacing all of my brittle rubber vacuum hose with silicone hoses from hose techniques.
I will be doing some actual modifications as soon as I take care of a few other things (radiator, air-pump removal, AVC blockoff plates, duel alternator pully, then I will upgrade my injectors and install an APEXi S-AFC and go to an open intake and exhaust with the racing beat FCD, and eventually a full suspension (struts, springs, anti-sway bars, strut tower bars rear + front) running at ~12 PSI eventually leading to the requirement of a bigger turbo TO4/3 Highbrid ball bearing Turbo, or maybe the APEXi RX-6 Turbo leading to an external wastegate and then an upgrade to a new ABS hydralyic unit for safety along side a full roll cage, complete brake/fuel line replacement, racing seats and harnesses). I will probably only move on to the ~12 PSI mark for this car though. But if I bought another car those are the order of modifications I would do.
These have been my modification plans since I purchased the car, but I have not really gotten to them yet (I spent most of last winter just grinding the under-body of my car and re-coating it to fight off any rust that might try killing my car). I don't like working on my car in the summer because it takes away from my actual summer drive time. :crying: |
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| PraxRX7 |
Also yes, a streetport is basically port and polish
The intake and/or exhaust ports are widened a small amount to allow better air flow resulting in a modified power/tourque curve. If the porting job is done crappy and the sides of the ports are not smooth, you will not see major benefits.
A perfect porting on an RX-7 is very smooth.
Street Port is the highest I personally recommend a rotary to be ported. The Bridge or Peripheral ports are just insane! |
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| 4kruzn |
| aslo keep in mind that not all street ports are created equally.... racing beat and mazda trix say that not much power is to be had but they also have to worry about emissions and the likes cause they are in california. the one of the street port 12a first gens we built ran 15.0 in the quarter , and we had a 13b first gen that broke into the 13's 13.89 @ 98mph both theses cars were street ports. but you are correct about the finish of the ports, detail and finish is very important. the car we will bring out this summer will be a SP 13b with a 7" camden supercharger and NOS also 12"s or go home crying... see ya at the track. :tear: |
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| WookeysRX7 |
| so you had a 13B run a 13? is that just with the streetport? and what year of 13B is that? How much did that set up cost for the whole engine? |
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| IH8V8S |
quote:
Originally posted by PraxRX7@Jan 13 2003, 01:49 PM
Also yes, a streetport is basically port and polish
The intake and/or exhaust ports are widened a small amount to allow better air flow resulting in a modified power/tourque curve. If the porting job is done crappy and the sides of the ports are not smooth, you will not see major benefits.
A perfect porting on an RX-7 is very smooth.
Street Port is the highest I personally recommend a rotary to be ported. The Bridge or Peripheral ports are just insane!
Trevor! :angry: Don't talk about stuff unless you have some idea of what you're talking about!!!!! :wtf: A street port isn't just porting and polishing the intake. It involves changing the shape and volume of the port to allow longer duration of the intake and exhaust "strokes". This allows you're engine to make more power but often you're low rpm power suffers a little to compensate. It's like changing to a bigger cam in a "BOINGER" engine.
There you go. If you wanna see the differences go to Mazdatrix or Racing Beat. I think Pinapple Racing has some good pics too. Howstuffworks.com has a really good page about rotarys that all you guys should check out. Goes through the parts and how they work! B)
:gay: Karl |
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| IH8V8S |
quote:
Originally posted by WookeysRX7@Jan 14 2003, 03:44 PM
so you had a 13B run a 13? is that just with the streetport? and what year of 13B is that? How much did that set up cost for the whole engine?
It wasn't just the engine. You have to keep in mind that exhaust, intake, and carburation play huge roles in overall performance! :bigthumbup:
:gay: Karl |
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| 4kruzn |
| thats right one must always remember that performance is a total package not just one or two pieces..... :blink: |
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| PraxRX7 |
quote:
It involves changing the shape and volume of the port
Yea....widening...how you go about it (shape and volume as you pointed out) are what give you the results, but basically it widens them to allow more air flow (volume of air). I gave a basic description so don't say I have no idea what I am talking about. :angry:
I assumed from his previous question of a street porting being similar to a "porting and polishing" that he knew the fundamentals of porting.
He asked a simple question, so I gave a simple answer. If he wanted to know the entire thermodynamics and physics behind it I would surely of pointed him to you. :P lol
My favorite porting is the swiss cheese experimental port that you guys rigged up, amazing that thing even runs! :bigthumbup: |
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