Hi all,

Specific setup question. 92 RHD FD3S, stock twins.

My car is currently bone stock engine-wise, minus an ARC intake box and HKS Hi-Power Silent axle back.

I have the following, ready to install:

• Power FC w/commander
• FC Tweak
• Catless midpipe
• AEM Wideband AFR
• Datalogit (probably redundant with FC Tweak?)

I have heard mixed reviews about whether or not I'll run into boost creep issues with catless midpipe + stock twins + FC Tweak. However those opinions came from Facebook groups and I generally trust RX7club/forum people WAY more because the info is typically more rooted in actual experience.

So, anyone with a similar setup?

I'm wondering if I should hold off on installing the catless midpipe, and just start with the FC Tweak stuff, or if I should go all-in right away and do the mid pipe.

Also, assuming not, but does the stock downpipe have a spot to bolt in the sensor for the AEM wideband? Or are there any stock O2 sensors that can be removed/tuned out and I can put the AEM in its bung?

Thanks a lot for all the help. New to rotary power mods but not new to modified cars in general so feel free to share knowledge you may have. Cheers

Edit: I've also been reading some Banzai threads (older) where they were testing various parts as they installed them, and I noticed they had done a Walbro 255 before doing really any other mods. Is that a necessary precaution for these mods? Thanks.

 

You can setup the Power FC to manage your boost control. I would suggest that.

I would also suggest getting an aftermarket downpipe before a mid pipe personally. Downpipe holds a lot of heat and chokes the turbos. This might be good in your case if you don't have a boost controller.

If you look at your wideband instructions, it will tell you to place the sensor at least 18" away from the turbo manifold so it doesn't burn out quickly. I had a bunch welded at the beginning of my mid pipe.

Is your fuel system completely stock? What boost do you plan on running? As our cars have aged the wiring to the fuel pump delivers lower voltage, which means the pumps output is less. Sakebomb and other make a relay kit that you can purchase to ensure the correct voltage goes to the pump. You don't want your pump to be running less than under full load

If this car is newer to you, I would suggest a handful of maintenance things to start. Replace fuel filter, have injectors cleaned and flowed or at very minimum run a few bottles of techron fuel system cleaner through the car.
You will need a datalogit if you are running just the FCtweak software. The datalogit allows you to log your air fuel ratios. Get the USB version and the highest bit rate adaptor. There is one suggested in the FCtweak manuals that works well.

Eric

 

to answer your question, software will not stop boost creep. boost creep comes from the inability to divert exhaust energy. even with the wastegate completely open, if the orifice is not large enough no computer will prevent that.

 

Great info Eric, thank you. I do already have the midpipe and it's a much easier install, so I think I'll be installing that, but good to know about heat buildup. Is it true that the Efini downpipe doesn't have the pre-cat? I was under the impression that the RHD models are less prone to the excessive heat issue because they don't have that additional restriction.

Fuel system is completely stock, yes — boost levels I just want to keep safe-ish for a stock motor. My compression numbers are healthy, so I'm trying to safely gain some power without blowing everything up immediately.

Good to know about the fuel pump/output/voltage as well. I'll look into that relay kit, that's something I certainly would not have thought of.

The car is new-ish to me. I've had it for four years, but only drive it ~500-1000 mi/year, and I haven't had a garage at home until this year, so I'm FINALLY digging into some long overdue maintenance. Fuel filter and spark plugs were top of my list, but I'll look into injectors as well over winter.

I was planning on taking things apart a bit to port the wastegate anyway, so I guess while the car is under the knife I'll take that route too. Though if I know myself, I'll just end up upgrading the injectors while I'm there. For now, I'll hit the Techron!

10-4 on the datalogit as well. I do already have one which is cool. Haven't looked into what adapter I have, hopefully I have the high-bit USB option but unknown at this point. I'll definitely check out the manual there for more info. Thanks again for your responses!

That was my fear! I figured that would probably be the case, but didn't know if the FC Tweak could work some voodoo magic electronic control to keep things tame. Ported gate it is, I suppose. I was planning on doing that over winter anyhow. Until then, if I put it on, I'll just steer clear of WOT.