Rx7-AIII

Is it safe to use a mid pipe with the PFS purple. Do I need extra boost control or should I get the turbo's ported.
Thanks

cewrx7r1

iTrader: (2)

The PFS PMC is a piggyback computer to the ECU. You have to tune it for your mods. Thus if you replace the cat with a MP, your engine will consume more air for the same boost thus requiring more fuel. This means "YOU" have to add more fuel. This appplies to mod that affects the engines breathing capacity.

Porting and higher boost also requires "YOU" to retard the timing more.

sbrx7

This is a kind of gray area I have run into in tuning. I'm running an intake, M2 Medium IC, DP/MP/CB, PFS PMC, RP fuel pump, pulleys, etc. Following conventional wisdom, I added a ton of fuel into my system and resulted in making my car run like crap. Why? Because it was so obscenely rich. Until I put my car on a dyno with a wideband, I had no idea. It was so rich it was off the scale. Here's the part that will make most people scream BS. I have NO fuel added in over the PFS base maps, and NO boost creep. Do youself a big favor, dyno the car, find out what YOUR car likes, and run it that way. Just because Joe Anybody had to add a bunch of fuel in, doesn't mean you will. If I had it to do over again, I'd go to the dyno as soon as I had control over something, i.e., when the PFS unit was installed. Anything else is pissing money away and guessing.

My two centz.

Steve Bertok
94 MB touring, lotsa mods, lotsa power, lotsa fun

Wade

iTrader: (1)

Steve Bertok,

I found my car doesn't need any extra fuel added at Max Boost either with a late model PMS, verified by wideband lambda.

Wade

sbrx7

Wade,

I believe it was your urging on "the big list" that got me on the dyno in the first place! My unit is also a later model, wonder if Peter did something differnt with the maps. I dunno, but I'll take this chance to thank you in a public forum for your urging to take it to the dyno. BTW, I was looking at my A/F numbers on my dyno sheet the other night, looks like I may have some more room to lean things out a bit. Of course, my engine is getting tired, so no need to beg it to expire!

Steve Bertok
94 MB touring
www.panicmotorsports.com

Sidestick

iTrader: (1)

Just to put in my 2 cents, I'm running K&N cones, stock turbos & engine, DP, MP, GReddy SP catback, PFS PMC. I get a spike to 15-16psi at turbo transition . Not too comfortable of a feeling. However, I drove it this way for years without blowing anything up. I finally got around to restricting the outlet by the DP/MP joint, no more spiking.

ronarndt

Steve- I also found I did not need to richen the mixture beyond what was already on the PFS maps. I have one of the newer versions- about 6 months old- may be the fuel maps are revised from earlier versions. Have you purchased the datalogging software from PFS? I have been considering getting it, but have had difficulty getting someone at PFS to answer the phone or return my messages to ask them a couple questions about exactly what parameters the software will record.
Ron A

sbrx7

ronarndt, I do have the data logging software, but my computer is an old pentium with insufficient RAM. I can only record about 15 seconds of data then it starts getting holes in it. One of these days I'll have a better computer. One of these days after I stop spending money on my project cars. And honeymoon. And...well you get the idea. It is a really cool program though, recording a lot of stuff you just can't watch when driving. It records everything you get on the keypad, displays it on one screen rather than three, and expands the points that you can adjust things to 500 RPM increments rather than the 4 set points. It'll never be a replacement for wideband testing on a dyno, but is certianly useful.

sidestick, How old is your PFS unit? I don't get big spikes like that, maybe 1-2 psi, and no creep so it's just a flash of extra boost. Not even enough change to register on the A/F on the wideband. I'll also add, I have the RB dual tip catback, which may be a bit more restrictive than some, keeping my spiking (and noise levels) down to a tolerable level.

For what it's all worth,

Steve Bertok
94 MB touring

Sidestick

iTrader: (1)

I have the 99 upgrade from PFS. Been running it about 1.5yrs. now. Unfortunately, my car is one of those that has the unexpected fuel cut.

ronarndt

Steve- Appreciate the advice. I'm alway reluctant to take the PR from the manufacturer of a product, since it is going to be pretty one-sided. I still have to find out what the shipping charges are for the thing. I think I saw somewhere that PFS was moving part of his shop. Plus I saw him on some articles about the 3 rotor that he is promoting. Maybe that's why no one is answering the phone.

Wade

iTrader: (1)

Ron,

Check out my webpage for some info on the PMS and the datalogging software at www.wvinter.net/~flanham/wlanham .

One thing is for certain, you will want to deal with EFI systems directly, not PFS. EFI systems gives excellent support in my experience. Their website is www.efisystems.com. efidoug@mindspring.com is Doug Wallice, the owner of EFI and the creator of the PMS. He can answer just about any question you can dish out. Be warned, he is brief with his replies. You can always ask me questions privately, I try to help. My email is wadelanham@hotmail.com

Wade

Wade

iTrader: (1)

You might want to try this. The creator of the PMS says the stock ECU lowers the fuel cut if it detects knock for awhile, also if the temps get too high. The fuel cut ends up being below the PMS clamp. This is why track cars run into the problem more often than street cars. He says they have proven that using race gas or a rechipped ECU (which removes the knock detection and/or fuel cut) will fix the problem. Sounds like it's worth a try.

Wade

Sidestick

iTrader: (1)

Thanks Wade! I'll try it.

Sidestick

iTrader: (1)

Hey Wade, I also have a J&S knock sensor on my car. Do you think it's ok to just unplug the stock knock sensor?

Donovan

Question.. Do you mean the maps that come with the box from PFS or do you mean the maps that are on the E PROMS ( If there are any) Does the box come with maps already installed or is it PFS that sets the programs.
What I mean is if I set the fuel to 0 accross the board is there a sub program or is that basically back to stock?
Thanks.

sbrx7

If you set the fuel to "0" across the board, you are at the PFS base maps, not the stock base maps. You should find the PFS base maps to be, as with all tuners, conservative on the side of rich.

Enjoy!

Steve Bertok
www.panicmotorsports.com

Wade

iTrader: (1)

Whether or not you disable the stock knock sensor is up to you of course. Personally I would probably be okay with disabling it on my own car because of the J&S, but that's my car and my risk I'd be taking.

I'm not sure exactly what you would need to do to disable it though, simply removing it would probably throw an ECU error code at a minimum, it might even make the ECU act strange or go into limp mode. If you wanted to try disabling it, you could remove the sensor from the engine and wrap it in some padding or something so knock is not detected by the stock ECU. This might allow you to see if it fixes your problem with the PMS fuel cut.

I would try to find an alternative if possible and keep the knock function of the stock ECU. If your water or air temps are really high, you could try some tricks to lower them, which might help. Also, keep in mind that if your car actually is knocking (and causing the stock ECU to lower it's fuel cut), then you have another problem to deal with (other than just the PMS fuel cut).

Wade

Wade

iTrader: (1)

Steve and others,

Just to clarify, zeros across the board means no fuel added over the stock ECU (your quote above suggests that even with all zeros, there is additional fuel added to the stock ECU's settings).

I don't want to encourage anyone to zero out all their maps because they think it will be fine for their car. I can't stress enough that any modified rx-7 should spend a little time with a wideband lambda in 4th gear to make sure the a:f is ideal. Every car is different!

That said, I plan to soon add information from wideband testing a few various FDs with various engine management and settings (from PMS, stock ECU, and Apex'i Power FC), including my own. I will also provide some of my maps to my web page for the sake of information, or so others will have a basic map to use until they can get their car properly tuned.

Wade

Donovan

Thank you Wade!! Thank you thank you! I have such a hard time finding help on the dang box.The maps (when you post them) will be a great help in finding a base to test from. I am in a area that has really no one near and no place to tune the car so I have relied on mostly guessing (not safe!) and trying to look at the key pad and driving!! I have full open plumbing DP MP CB so the stock 02 sensor I'm sure is not reading correctly. I think I may be fouling the plugs but I am afraid of taking fuel out.

sbrx7

Wade and company,

If I follow you correctly, then the only thing my PFS unit is doing is massaging the wastegate. Are you sure there's no extra fuel? Reason I ask is I can't believe the RP fuel pump is providing that much extra to use stock fuel maps and cover my modifications. Even with my extra fuel dialed out, at big revs, say 7500 or so, the A/F ratio takes a big dive toward rich even now.

I hope anyone following the thread is up on the part about wide band testing being the only way to go when moving fuel settings! Perhaps I need to clarify, add fuel to be sure you are rich by the wideband, THEN AND ONLY THEN, can you safely start backing fuel out. This isn't a ten minute, three pulls on the dyno process, I spent almost three hours strapped to the dyno, and honestly, I was nervous when I started mashing that "-" key on the pad. But when the A/F curve finally started rising, I was relieved to have the independent numbers of the wideband to be my guide. As the night wore on, the numbers on the display came to match the numbers on the wideband. WHEW!

Moral of the story, DO NOT start from "0" added fuel!!!!!!!!!!!!!


Steve Bertok
94 MB touring

silver93

can someone clarify, if you leave all PT settings at zero, are you at the stock ECU original settings, or not?

Also, do you guys have a final "poof" type noise out of the exhaust when you turn the car off?

jagjack

I think it depends if your purple box
started life as a PFS or EFI box.
I think if it originally sold as an
EFI box, 0 fuel would mean you're
running on stock maps.
Not positive though.
Jack

silver93

mine is a gold box bought from PFS and has the PFS sticker on it -
anyone else know?

sbrx7

Whoooooaaaaaahhhhh Nellly!!!!!

silver93 wrote

"mine is a gold box bought from PFS and has the PFS sticker on it -
anyone else know?"


We're going to need another voice to speak up on this one. The only thing I know about the gold boxes is they exist. I'd certainly hate for you to start making changes that may or may not apply to your unit. All the info I have been sharing has been in relation to the PFS purple box. I know the gold is an earlier version, but have no idea of how it changes the parameters of engine operation. I don't think this forum is really old enough, but you may search the archives and see if you can come up with some info on the gold boxes. Someone may come along and slap my hands and tell us different, but until then, I urge you to take my comments for reference purposes only!!

Sorry if I mislead you!

Steve Bertok
94 MB touring

silver93

no, you didn't mislead me - i knew you were referring to the purple in your posts - thanks though!
anyone out there?