Ok....this sounds kinda noobish but do you REALLY need a streetported engine to put up some respectable RWHP numbers???

I have been doing a lot or research on porting. I wanted to go this way as soon as I bought my FD. HOWEVER my FD only has 6500 miles on a new 13b-REW. I am running seq. and everything works perfectly. I don't really want to take it apart until something fails. I'd hate to rip open a brand new REW to port it.

Also, have you guys done this yourselves? Like i have been saying I have been doing a lot of research on this topic and would like to learn how to port/built rotaries for myself. You just get a satisfaction from doing your own work, and I would love to start building/porting my own motors.

So please let me know what kinds of numbers you non ported guys are putting up. Also let me know if you build/port your motors. I have the tools and decent mechanical skill so i believe I could do it.

thanks so much for reading this,

Bobby

 

https://www.rx7club.com/forum/showth...hreadid=128190

Nope, you don't need a port to put down some large numbers. However, you'll have to run a large single to compensate for it like ErnieT there. 10 second FD on a stock ported reman.

 

Street port isn't needed, but it's wanted

 

you dont need a street port at all, one of my friends made 320hp on the stock engine/turbos/airbox/ic @15psi. it had a dp/mp/cat back
1fookintite made 340something @14psi on his stock motor with an apexi turbo
and erniet is running 10's on a stock port engine

mike

 

hey j9....your pal running fifteen lbs on that stock ported motor thru the stock ic will need new turbos soon.

but i agree with elmo...its wanted.

but youll lose some down low...but what you gain up top makes up for it...as long as you balance it out down low.

a streetport and non seq is pretty laggy...but it will make good power if you have the proper mods.


j

 

awsome. do any of y'all do your own engine work? If so show some pixs of the ports!

 

well its kind of a long story but batman used some "octane booster" that wasnt and it blew up both ivans motor and batmans 3rd engine, so they didnt have time to die

mike

 

Also, would it be worth it for me to take out the motor and have it ported when it is this young? Will the gains be big enough to motovate me to do this? I have never ridden in a ported motor rx-7 so i dont really kow what its like. thanks

bobby

 

That really depends on your goals for the car. What do you want to do with your car?

Me? I'll never have a street-port. Don't need one.

 

well I am going to be road racing the car more often then drag. I have been thinking very hard about what type of RWHPO goals to set for myself. I would like to see 400 RWHP. I know I will have to get a lot more upgrades but thats the fun right? I am just trying to decide If i want to take the motor out now and port it while I can. What i mean by that is its winter here and the car doesent get driven too often in the winter, s i can afford t take the motor out and take my time, do it right...ect.

thanks

bobby

 

don't port it right now. get everything else first, then port it when you need to rebuild the motor, i.e if it pops or just starts getting tired.

 

cool, that is what i think i am going to do. I may completley rebuild the motor and onvert to a single. I really need to start saving my cash

thanks bobby

 

Most people with a mild-streetport gain 15-30 rwhp trhoughout the powerband. There are larger ports but really only meant for drag racing. A streetport like others stated is not needed to make good numbers but it sure helps - it is noticed from 5K-8K rpms where before it would somewhat flatten out - with a streetport it pulls harder up top. If your goal is 400 rwhp then, like artguy said, you NEED to have a larger single turbo to make up for not having a streetport. 400+ rwhp is possible with upgraded twins and a streetport but not with the stock twins

 

you beat me to it, i was ready to post the exact same question.

new question:

HOW MUCH BOOST CAN YOU RUN ON A SINGLE TURBO (GT 35/40) ON STOCK PORTS? this is of course with all the necessary bolt ons (fuel, ecu, cooling, etc.)

luigi

 

That shouldn really matter right? It just may flow a lil worse, giving you less power. What you really need to worry about is your apex seal choices when comsidering running large boost. I cant really say from experence, but i hear that the stock 2mm (pretty sure its 2mm, right?) seal is the best sealing. 3mm hurley and atkins (sp?) are very strong and can stand more detonation then the stockers blah blah blah hats a whole differen thread. I dont think that running big boost is an issue, you just will not have the flow you wold get with a streetport bridgeport...ect

still waiting for y'all that port yourselves!!

bobby

 

^^^

 

Hey kwikrx7, what kind of numbers are you putting down? I'm planning on doing a similar setup as yours on my car. My aim is to get between 350-400rwhp without being too laggy.
Are the BNR twins just ported stock twins?
Also, I've heard that a single setup with a turbo like GT35 is not too laggy, is that right?

-Mike

 

No, the BNR twins are totally redesigned twins with modified thrust bearings, and larger, more efficient compressor wheels. Bryan at BNR now started also using dynamic seals instead of carbon seals to help with response and spooling. You can run these sequential or non-sequential. The GT35/40 is probably the best single turbo out there for the FD as far as spooling/power. 15 psi comes on at 3500 rpms and can make anywhere from 400-500 rwhp depending on boost and tuning. But it's pretty expensive. The BNRs can put down 380-400 rwhp depending on mods and boost. I'm got dynoed yesterday but don't know results yet - will post soon.

 

Nope, you just need a big single turbo, and lots of fuel.

65K miles isn't time yet for popping open your current motor. I'd wait to port when you get a new motor, which is exactly what I've done:

https://www.rx7club.com/forum/showth...80#post1369080

FWIW, I've ridden in rceron's KD Rotary ported motor, with CWR SMIC, CAI, Apex Power FC, stock sequential twins, and 10.5 psi. It was FAST at Road America. In my tired-motored car with 275/40-17 Hoosiers, my car did 125-130 mph top speed before turning the corners. Ramon was doing 145+ mph before turning the corners; with much skinnier stock wheels, and 225/50-16 Toyo RA-1s (he wasn't cornering as fast as I was--no offense, Ramon! )

Chassis dyno numbers are artificial, not very translatable to real world use. The true test of a motor's power is on a real race track, with very long straights. Road America's last turn leads onto the longest straight of any North American road racing circuit...AND it's uphill...Only monster horsepower will pull your car smartly up that big-as hill, and Ramon's motor had it in "spades".

That was really the motivator behind my getting a KDR ported motor...and the low compression, 102,550 miles on the original motor and turbos

 

Is a streetport purely for more power, or is it neccesary in some cases?

How about wastegate porting?.... I hear they are neccessary simply to control boost creep if you have a MP.

Do more people port their wastegate and not their motor?

 

Thanks Sleepr1. BTW my motor has 6,500 miles not 65k. Makes it even harder to break it open. .. .

Mavrick....
People port their wastegates to control boost creep. You do not have to have a ported motor to make it nessassary to port your wastegate. With a ported motor, you will be getting more flow, and porting your wastegate is a very good idea... hope this helps some.

bobby

P.S. should i just make a new thread intitled "Post pics of your Engine Porting?"

later

 

6500 miles? don't ******* touch that thing. a street port won't make really big power until you go really big anyway to change the port timing. but then you lose a lot of low end torque, so there's really no point unless you rarely drive on the street.

 

NO.
you should just do a search.