Recently bought a 1990 GTUs, but it's definitely showing signs of needing a rebuild. I can do the rebuild fine, but I'm pretty new on porting. I've done all the searching I can, but I absolutely can't find anything about doing a street port with all stock parts. I'm not looking to go with a crazy aggressive street port, but something to give a noticable power boost.

Is a mild or moderate street port possible with the stock ECU, injectors, etc? The only thing that won't be stock is a Racing Beat exhaust, with the stock Exhaust manifold into downpipe setup.

 

it been done, you won't see big gains unless you do some other mods though. back in the day people were porting the intakes and other stuff.

here are a couple of OLD threads, pics are kind of gone
https://www.rx7club.com/2nd-generati...thread-871641/
https://www.rx7club.com/2nd-generati...arison-269462/

 

I don't think there's a single, concise answer to your question, but I found these videos pretty informative and very detailed. A bit scattered and unorganized, but well worth the listen: https://www.youtube.com/@RADPotentia...?query=porting

 

I have been running a streetport on the stock ecu for around 90,000 miles now. I would say yes you can and it's fine but as already mentioned you won't get the full benefit of the porting until you go to a standalone ECU. I had planned to do this years ago but have not. I think mine might be considered mild to moderate. I used Pineapple Racing's templates for the intake and exhaust. I think I used their Ep2a exhaust template. Also to port the exhaust you have to use TII rotor housings or get rid of the exhaust diffusers in the N/A housings. On the intake I barely touched the 5th &6th ports. Just cleaned them up a little. All my porting was on the primary and secondary ports. I may have noticed a slight increase in power. The most noticeable difference I noticed is on the stock port was power fell off around 7500rpm. With my street port it pulls all the way to the factory rev limit of 8500rpm. I am using a RB header that I attempted to port match to the exhaust port.

 

my 2nd gen had a mid to large street port, exhaust ported and baffles removed, intake, RB header and a mid pipe, secondaries wired open, TII injectors, underdrive pulley........ It ran strong as hell on the facory ECU. My port work was done by a builder in Tampa who built SCCA engines.

So my experience was I threw all the bolt ons at it, rebuilt, ported and stock ECU and it ran very well.

 

yeah that is another life hack, the RB header doesn't match up to an FC/FD exhaust port very well