777rx777

How will the stock power fc setting work with these mods:

HKS dp
Blitz cb
Modified stock air box with k&n
blitz smic

Please let me know...

or should i just keep the stock ecu in and run just the
HKS dp
Blitz cb
Blitz smic
stock intake.



thanks
chris

redbase

With the intercooler, I'd say you're running a "gray area" in tuning. I notice you don't have the mp upgrade.

I have a m2 intake, dp, mp, cb and I am marginal as well (should have it tuned for MAXIMUM performance, but okay with my current mods). I plan on adding an intercooler then I'll HAVE to have the PFC tuned.

With the intercooler, my advice is to have the PFC tuned. It is too much for the stock ECU. I follow the "rule of 3" though: three mods and need ECU.

Badog

You can PROBABLY get away with richening up the middle and the upper end with the PIMS, and you might be fine for temperatures above 50F and below 14psi. But don't take my word for it. I ran with 320's with a stock base map richened up like that. But with IGN amp and upgraded fuel pump. Your results could lead to a POP. I was running 11's at 70F when I did check that map when I got a WB O2.

Dump the stock ECU as soon as you can. It's temperature correction factors are horrible for a modded car.

Good luck.

777rx777

Isn't the blitz smic just an upgraded stock intercooler? Shouldn't my car be safe with a blitz smic, dp , and exhaust.

no intake and stock ecu?

The reason why Im gonna get the blitz smic is that my stock intercooler cracked.

skotx

I'll sell ya a stock intercooler really cheap!

Badog

Dump the stock ECU as soon as you can. It's temperature correction factors are horrible for a modded car.

spoolin

you can lead a horse to water.........

Badog

...and splash him in the face with it until he licks it off his chops or kicks you in the head!

SleepR1

I think these guys are all working for Apex, so they can have free Power FCs--that or Bad Dog and Company are looking for more Power FCs to tune to earn extra cash for Christmas presents

IMO your mods are modest, and as long as you keep your boost down to 10 psi (strictly controlled), I say your stock ECU will be fine, even with the Blitz SMIC (which offers VERY LITTLE performance gain over stock).

I say this in confidence because, I presume you still have your STOCK MAIN CAT, which provides substantial exhaust restriction and keeps boost spiking down.

This 3-mod rule is a myth, especially with the stock main cat in place; I agree with Wade Lanham, that the stock ECU is tuned with very rich AFRs, 10:1 as I recall. Check out Wade's wide band data he's gathered from SEVERAL MODDED FD Rx7s.

http://www.newwave.net/~flanham/wlan.../3modrule.html

Here's my own experience with 6 plus years of these modest modifications:

-RB Intake Duct/K&N Filter/Stock Airbox/Stock IC
-Bonez Downpipe/Bonez High Flow Cat/Trust Catback
-Boost controlled to 10.5 psi spikes with a WGPC pill (larger orifice diameter)
-Magnecor 10 Racewires
-NGK BUR9EQPs all around

As you can see, I've done the so called 3-mod rule, intake, downpipe, catback, PLUS--a high flow cat, which is only slightly more restrictive than a full-open midpipe. I've maintained my boost pressure to 10.5 psi (now lower because failing turbos).

I've had ZERO problems with this setup, and my motor is needing replacement due to age and hard track use--102,500 miles.

FWIW, the current motor still runs--it just floods due to low compression (5.9s all around). Surprisingly the vacuum is still 12 to 13 ish?

If your mods list isn't complete, then I take all this back. I'm working off the list you provided below.

IMO, I posit that you can use your stock ECU safely.

If you upgrade to a REAL IC such as a Greddy 2-row FMIC, or even an ASP Medium SMIC, AND you uncork your exhaust further by going with a resonated midpipe, or full open midpipe, along with a REAL intake (CWR CAI, Rx7 Fashion CAI, Apex dual intake)--THEN, I would definitely recommend going with an upgraded ECU, like a Pettit or M2.

If you're like me, and are building a ported motor, then, the Apex Power FC will be required to retard the ignition timing to deal with the increased crank angles of the enlarged intake and exhaust ports. Even unlimited Pettit ECU will not deal with a ported motor, plus bolt-on mods well. For those of us with street ported motors, a stand-alone is mandatory, with bolt-ons, and in my case, new Japan-spec seqential twins.

But for you, you're still in the "cheap seats", so enjoy them while you're there Stay with the stock ECU and control the boost to 10 psi, and you'll be fine.

Badog

Nope. I earn the scratch the hard way. My hourly rate (real world) is more than I charge for 2 hours of tuning. And, I am real picky about who I tune.

The stock ecu's target of 10 AFR is only for about 5X10 number of cells. And, it's temperature compensation factors suck for a modded car below 50F. That 10 becomes 12s and 14s REAL quick below 50F. Mazda used a 20x20 grid of target AFR for tuning. Not just one value across the board. Take a look at Mazda's targets.

SleepR1

I'm joking of course, Tony. We all have day jobs to pay the bills, and if we can make a little money off of our hobby, so much the better Like I said, I will be contacting you for a fine-tune once my ported motor's ready to go.

Nonetheless, I still say the guy will be fine with the stock cat in place and stock ECU. I've been running 3-Plus mod on my car with 10 psi and stock ECU with NO ILL EFFECTs.

Living in Columbus, have you tracked at Mid Ohio yet? That track's the sh*t! My avatar shows my red R1 gridded with the Red run group at the Mid-Ohio Region PCA drivers ed event May 13/14 2002. You, Jason, and Kyle have to come up at the next one. As an instructor, I can take each of you two for rides.

SleepR1

Appears to be 10s in the lower right-hand quadrant, but 14s in the upper left-hand quadrant.

Not sure what this means in non-tuner terms...

How about enlightening the rest of us?

I presume the AFRs increase as temp goes down (upper left-hand quad)?

I don't know why my motor has not popped by now from running lean when cold?

Maybe there is some knock going on without my perceiving it?

How do you explain my motor running for so long (102,500 miles) with my 3-plus mods and a stock ECU (10.5 psi boost control) ?

No one can be THAT lucky?

Badog

I think we may have a bartar in the works, Manny! Sounds like a plan.

Have not tracked this Rx-7 at Mid-Ohio. All I need is some better binders. I still haven't taken the plung. Suspension is part of the way there, but needs tuned still. If I can refrain from removing a running engine for a PineApple new-build, binders it is.

Tony

Badog

High numbers = lean. Unless you put a WB O2 on the car with the stock ECU, we won't have the answer to that question! Low boost is probably the key, Manny. Once you go d*ck*ng with the boost on the stock ECU, it's hammer time. Over 13 psi seems to be deadly on a cool day and with mods.

TOEKNEE

SleepR1

Yeah, I kinda figured high numbers were lean, and low numbers were rich

Ah, the magic 10 psi number (10.5 psi spikes in my case).

Well that was my qualifying comment to the original poster asking about whether his stock ECU would be ok with his modest mods 10 psi boost control is the key.

Actually the US spec twins only boost to 9.1 psi at their max efficiency. Any more than 9.1 psi must be attributable to boost creep or spiking due to a freer-flowing exhaust tract (dp/hi-flo cat or mp/catback)?

When my turbos were healthier, my boost pattern was 10, 8, 9 psi. 10 psi at 3000 rpm, 8 psi at 4500 rpm switch-over, rising steadily to 9 psi to redline.

Now with failing turbos, there is no more jump to 10 psi. The boost just rises with rising revs. I do feel the secondary turbo kicking at switchover though, but 9 psi is all my stockers ever made.

Call me Mr. Lucky!