CharlieUK

Hi Guys, just another query that I'd like to pick your brains about if I may. I haven't added many mods to my FD, speed wise, but from what I have been reading lately I'm a bit scared that I could be runnig the engine lean.

Here's what I have so far,

Blitz cat back exhaust.
HKS intakes inc blow off valve.
& as mine is a Jap import, apparently it doesn't have a pre-cat.

See, not that much but I've read that at this stage if you had a pre-cat that's been removed aswell, then you need a computer (I'd opt for a PFC) to alter the fuel intake.

I'm thinking that maybe as my stock ecu would have already been adjusted for not having a pre-cat then maybe I'm not running lean.....what do you guys think?

Thanks for any help, peace and good will to all, blessed be the RX7.

Ps, my next tune was going to be an efini y-pipe and FMIC, is that a good way to go?

N3philum

iTrader: (16)

I ran a racing beat catback and Apexi dual intakes on my car for about 2 years with no problems.

Mahjik

iTrader: (1)

The stock ECU has enough fuel to support full bolt-on mods at 10 PSI.

CharlieUK

ok, I don't even know what PSI im running now, I don't have a boost guage.....was thinking is it necessary to get a boost guage if you have a PFC as that reads boost?

do you think it would be advisable to get something like a PFC before I invest in a FMIC and efini y-pipe? also I'd like to install AI soon aswell, I like the concept mostly to keep temp down in the combustion chambers.

Ceylon

iTrader: (3)

If you pay the postage, I can send you an old school mechanical HKS boost gauge free. They are a must with these cars really.
Getting a PFC & a decent tune is a wise idea

CharlieUK

Thats really nice thanks alot, if your near(ish) London I could collect, but if not I will happily send the postage cash via paypal, I can't think of another way to do it.

Montego

iTrader: (1)

The PFC reads boost. But IMO its not the best mod you can buy at this time.

Get a quality boost gauge, better yet a boost controlleras that is something that you will need in the near future. Because as you add mods the likely hood of experiencing boost spikes increases dramatically.


The key term here is 10 psi. Stop and think about things for a bit. It's all about A/F ratio i.e. oxygen molecules VS fuel molecules. Now mazda took steps to accomodate for ambient temperature whether it's hot or cold. That's why it runs rich. It's when one increases the boost levels where the A/F ratio gets all jacked up and all of the sudden the stock ECU is not providing enough fuel.

So in essence when you add a cold air intake and or a FMIC, all you are doing is making the air cooler and thats something mazda engineering already took into account. That is why you can add bolt ons and as long as you keep the car at 10 psi SOLID you will be fine.

Mahjik

iTrader: (1)

You really need to take a step back.

Start by making sure the engine is healthy. You have several posts suggesting your car won't start and that it might have damaged coolant seals. Get that sorted first. Next, get the standard reliability items taken care of including some way to monitor boost.

CharlieUK

yes tis true, I am perhaps jumping the gun a little, however I would sort the engine and make it roadworthy before I buy any mods. I appreciate the concern though, its nice to see RX7 owners showing concern for one another...ahh

Sandro

iTrader: (1)

If you want/like to have full control and supervision on your motor, mods, and tuning, you should/could invest first on:

- PFC
- Datalogit
- O2 WB with loggable 0-5V analog signal
- laptop, preferably with serial input port
- Joining Chuck W. Yahoo group
- Learning and becoming proficient on using the amazing full potential of the above

- Sandro

CharlieUK

That's another question that I have, if you have the PFC and a Datalogit to hook up a laptop, is there a need for the commander aswell, can you do the same with the laptop and software that you could whilst using the commander?

Dudemaaanownsanrx7

iTrader: (23)

You can do more with the datalogit and a laptop then you can with the commander. All the commander is good for at that point is small adjustments and a very nice gauge setup. And no you don't need a PFC if adding an intercooler. Only when increasing the boost past 10 psi will you start running into issues with the stock ECU, and fuel system. (if you're still on stock twins)