janrx7

i have a stock ported motor. my engine has about 70k miles on it and i don't know
when it was last rebuilt. my car feels great but i think i could have more. i managed to squeenze 290whp@ 14 psi on stock twins with power fc, v mount, walbro pump, downpipe and catback. it seems a bit low for this forum.

my question is, will a freshly rebuilt engine with a street port worked well on stock twins? could i manage 330-340whp with my mods and a street ported engine?

i know of an fd with stock turbos and ported engine that managed 281whp@ 11psi with a blitz chipped ecu. could i see such high whp with a street port?

Mahjik

iTrader: (1)

Yes, the stock twins work just fine on a street port.

silverTRD

iTrader: (37)

what do you have for a midpipe?

janrx7

custom 2.5 inch pipe

moconnor

iTrader: (14)

It depends on what dyno you used. What was the model?

Fred Villamor

While you have the motor out , PORT THE WASTEGATE too !!! ... easier with them OUT of the car , and you'll be glad you did it later

HawaiianRedMako

Yes, a street ported 13b will work on stock twins. We just installed one last week, its running non-sequential, all emissions removed, gutted out all cats. Basically a straight through stock exhaust.

The owner has a DP, but couldn't get me a flange to weld, he was rushed to get the FD on the road. Still breaking in the motor.

XxMerlinxX

iTrader: (2)

What kind of catback are you running and what sort of ducting do you have for the v-mount?

janrx7

bought the car with the catback. really don't know anything about it. the v-mount came with its own piping kit in alumium,

D3a7hX

iTrader: (1)

i did a pretty large street port with the stock twins and it was quite a kick in the butt over stock twins. 3inch down 2.75mid 3in cat back. open filters to the turbos and ported the waste gate to max of the stock flapper. non seq, no emissions.
not sure of whp but was able to max out a 15psi gauge low in the rpm band.
stock twins wont handle that to much though, but was definitely alot more air gettin to them. in all yes a streetport will work well with the twins just keep an eye on the boost and dont push them to hard.

janrx7

where can i get the rebuild kit? atkins? do these kits came with everything i need? i

Tom93R1

iTrader: (2)

Run a stock Mazda rebuild kit. Plenty of shops sell it and I am not too fond of most of the aftermarket apex seals or any of the aftermarket coolant o-rings.

Get a full rebuild kit and it will include all the rotor hard parts such as oil control rings and apex, side, and corner seals with springs. Also it will have all the soft o-rings and gaskets. It will be everything you need except of course rotors, housings, etc. for about $1600 or so.



Indeed stock twins work well on a street port motor. I have a pretty aggressive port and pulled 340 at the wheels running only 9psi. Ran into some fuel issues above that but should be able to get another 50 or so once that is all sorted out and I can raise the boost.

janrx7

right now i am at 290whp@ 14 psi. could i expect 330-340 @ 14psi with the street port?

arghx

iTrader: (3)

1. you didn't say what kind of dyno it was on and what the conditions were

2. we don't know how it was tuned (timing advance, AFR) or whether the car had any boost leaks or not, which is certainly possible.

JStrib

iTrader: (6)

Yes with descent tuning.

janrx7

don't know what type of dyno what it. afr was about 13. i don't think there was any boost leaks.

RX7 RAGE

iTrader: (22)

wow 13 afr at wot? that is lean my friend

gbomb91

iTrader: (1)

AFR 13? That is lean, I think it should be around 11 if I am not mistaken.
I have a good tune, power fc, dp, cat back, intake, high flow cat, greddy smic, and "99" twins with a street port and produced 343hp @ 13psi on a conservative tune during a humid day.
So yes it's possible but as everyone has said, it depends on a lot of things: type of dyno, how good of a tune, boost leaks.
Get someone who really knows how to tune, make sure everything is working correctly and get those AFR's in line, nothing worse than popping a motor while on a dyno.
By the way, as Mahjik has said so many times, forgot about a number that you have in your mind for hp and make sure you have a good working, reliable, fun, well tuned RX7 and enjoy the hell out of it!!

janrx7

sorry afr was 11.6. Somebody said to port the stock wastegate. how about putting an after market wastegate like a 44mm tial? will it work?

gracer7-rx7

iTrader: (16)

wastegate will only help with boost creep and spike. won't affect power output. if you are removing the motor for a rebuild, definitely port it so you can better control boost.

post your dyno sheet w/ the air/fuel ratios on there so we can review if you want further input on that. 290 HP on a tired stock port 70k mile motor ain't too bad. The stock injectors don't flow enough to safely support 14 PSI so I wonder how/if you were able to do 11.6 a/f ratio on stock injectors running that much boost.

a street ported motor with stock twins will put down good power when coupled with a good flowing intake and exhaust. What is the diameter of the cat back exhaust measured after the mid pipe? Is it 2.5" also? Don't measure the tip as the tips are often larger than the actual piping through the system. 3" will flow more and provide more power.

Why not post some engine bay and exhaust pics to give us more to work with.

janrx7

it was 290whp@14psi on a dynojet. afr was 11.6, injector duty @80%.

my friend's fd has a jdm engine,with a blitz chipped ecu @13psi. we think it is ported due to sound. it ran 12.6 on street radials. my guess that the engine is pushing around 330whp.

i wish to rebuild and street port my engine to opt from 290 to 330whp and tried to run in the 12.6-12.5.should i run my twins seq or non seq? having no problems with boost. just wondering which is better for a street ported engine.

spiritrmazda

iTrader: (3)

My old FD had the following and made 304rwhp:
-HKS downpipe
-HKS carbon TI exhaust
-HKS twin power ignition amplifier
-HKS intakes
-AEM EMS
-Street port
-Stock twins

Wo:Deep

As ARGHX said,
you heavenīt said which dyno you used.

f.e. My car was on a dyno before I bought it (canīt tell which dyno.. sorry - I can take a look when I get home again)

My setup is have:
Knight Sports V-Mount
Knight Sports Cold air intake (Air groove intake for V-Mount)
SARD fpr
SARD 280l fuel pump
850cc primary+sec injectors
series twins (sequential)
stock port
3,25" Re-Amemiya DP
3,25" Kakimoto MP
3,25" Kakimoto Catback


and my dynoplot says (@ 13psi):
350 hp (efficient power)
320,3hp (engine power)
260,8hp (wheel horsepower)

when I compare with the dynosheets I can see here I should have at least wheel horsepower what I have @ the engine.

+ My car kicks some cars *** what have dynosheets which say that the other cars have 350+ whp!!

___
Another story is:
A friend of mine was on the same dyno with its Nissan 200SX S14.
Running 315hp (engine) 262whp
When he was on an event where a "dynoday" was.
He dynoed it there and WOW... 324whp on that dyno.
So you can see...
it is very important which dyno type you use.

+ For further tuning.
Keep that in mind.
Donīt run after special numbers.
Compare it to other cars.
And try to use the same dyno every time you changed your setup. Donīt switch between different dynos!!!

Regards
Marc

janrx7

djseven

iTrader: (56)

Go with the ALS apex seals. Everyone who is running them love them. Especially if you want to run 14-16psi all the time on the stock twins I wouldnt reuse the factory seals. Everyone has their own opinions and this is just mine. Plenty of power has been made on about every type of apex seal on the marekt. Some seals are just more forgiving than others.