MrMinerMan50

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.

j9fd3s

iTrader: (3)

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/

ruddyrid

iTrader: (8)

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

Dak

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.

ATC529R

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.

j9fd3s

iTrader: (3)

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