Hey guys, Just want to get your views on my modifications. I've searched and still confused if there is a three or two modification limit before you need to upgrade the ECU before I hit fuel cut. My goal is to keep it very minimal as far as mods and have no further plans of upgrading that's why I'm not considering the Power FC for now.

My mods are:

1. HKS downpipe
2. Apexi N1 dual exhaust
3. Apexi power intake w/ hard pipes

Everything else is stock except for the AST and the 51R battery. Any advice will be helpful. No flames about searching please...

-Jay-

 

stay strictly at 10 psi and you'll have no problems

 

Thanks for the advice, I am going to get a boost guage ASAP.

 

Anybody has the same mods with an ECU upgrade?

 

All you need to do is watch your boost. I would get a boost controller just to be safe, the stock map runs really rich so you are fine for now.

 

Really...
That's all you need to know.

 

Hey Jason stop giving me a hard time...

What I'm confused with is a two or a three limit mod. I've read post and websites covering the topic.

 

The only way you could be confused about how many mods are allowed with the stock ecu is you are listening to people who don't know what they are talking about....

Stay at 10 psi and your setup is perfectly safe on the stock ecu. Period.

 

Thanks again for the clarification. Too bad the forum is filled with post with misinformation and you really have to be extra careful as to who you get your information from.

 

The problem is that people read the old Robinette site or old posts from www.fd3s.net and don't realize that new info has come to light in the past 6 years....the worst part is when those people argue with people who know better!

There is a lot of wideband info out there on stock ecu cars showing them to be very safely rich, even with several bolt-ons. My own car was below 10:1 AFR for most of the rpm range, with a downpipe and cat-back.

 

Yeah, get a boost controller and the boost gauge ASAP. From what I've seen on this board and experienced myself, is that with a dp and cat back you'll get boost spikes. Limit your boost to 10psi and you should be fine.

 

Hehe, just kidding Alfred. I forgot to add a smiley on to the end of that post.

 

that is interesting. how did you verify those AFR's?

i am planning to dyno on the 18th with the only mod being a downpipe and the full-nonsequential mod, with the wideband o2 sniffer in the tailpipe, but i am worried about how accurate it is going to be with the stock cat being in there...

 

https://www.rx7club.com/3rd-gen-archives-73/stock-ecu-10-psi-myth-308996/

 

people need to forget about the three-mod theory and stick with the one reality: first mod should be a boost gauge. After that, common sense and your eyes will tell you what needs to be done.

 

My car DP, Catback, Modified stock airbox, at 10 psi

 

Thanks for posting your log, Gadd, even if it does read significantly leaner than most other stock cars I've seen...

 

Gadd, no boost controller ?

How do you make sure you don't spike ?

:-) neil

 

Every car is different, that is why everyone says you need the boost guage. For instance mine is fully stock minus silicon IC pipes and I am currently getting 12-13psi. I am investing in the home depot MBC as soon as I have the time to do it. Good luck!

 

I got .1bar cold weather spikes with trust sp cb, hks dp and apexi pipes (on japanese high octane fuel).

Every car is indeed different

 

Oh ya, I've got MBCs on both the pre-spooler and wastegate.

 

Great log! What hardware/software did you use to make it?

 

great, now another question...


what about those same mods with the full non-sequential mod as well? its going to be flowing more CFM all other things equal if those flappers/butterflies are removed...

 

Technically Non seq should flow more, but in real reasults the margin of gain is too small to be seen. At least thats what im pretty sure of...

 

also, Gadd... were those AFR's measured with a stock cat in place? and where was the o2 reading from? (like the stock location or tailpipe sniffer?)