RX7SIGN

I was offered by a friend a Purple Computer Piggyback? This is a piggyback that will supposably be good for my twin turbo setup im using for now. Has anybody heard about this? Websites? I know no knowledge whatso ever on it.


I ordered a HKS Intake someone told me with my HKS exhuast and dp I may have boost creep/spike. I dont have spike right now will the intake cause this?

crazyrx7

The pfs is a piggy back ecu made by Peter Farrel. Its an excellent ecu for the car if all you are doing is putting all of the bolt ons (intercooler, full exaust, intake) for your car. I believe it has 3 boost settings on it. You shouldn't get boost creep with the intake but you might get boost spikes at transition that can damage your motor. I suggest getting a boost controller or the "purple ecu".

R.K.

Bill B

iTrader: (1)

It sounds like a Peter Farrell box. I don't know if he is still doing anything with RX-7's. In it's time it was about the only computer around.

You will get some creep with that set up. If you don't have a pre cat you will get allot.

Runnin Away

your talking about the PFS i have it in my car if its tuned properly it can improve your performance on your car. There are many websites on the web that can provide information. You can also search the forum for information

tcb100

You won't get any boost creep at all if you are running a main cat or high flow cat.

At the intermediate setting my boost is a rock solid 12 lbs. The PFS Purple is an excellent unit for the stock twin turbo setup.

GoodfellaFD3S

iTrader: (213)

Agreed on all counts.

Regarding some of the previous posts: intake setup does not affect creep. creep manifests itself as boost that rises with gear/rpms, and is a function of reduced exhaust backpressure leading to the stock internal wastegate getting overwhelmed by increased exhaust flow/lack of backpressure and being unable to do it's job efficiently, ie divert exhaust energy away from the turbine(s) in order to keep boost at a set level.

removing your precat and installing a downpipe will not cause boost creep. as tcb states, the presence of a main cat will keep you covered against boost creep.

Spike is a different story of course, but is not nearly as dangerous b/c it is a temporary condition experienced only at transition on the stock seq setup (4.5kish rpms).

The PFS box has been dubbed the "Purple Motor Eater" in the past. Having said that, my dad's R1 has been running one for years with no problems at all, and he definitely drives the car on boost/wot often. They are tuneable with a keypad, and I believe that his was tuned by the previous owner for all my dad's mods (dp, cb, intake) in addition to an intercooler (dad's is stock) so the car is running nice and rich/safe.

RX7SIGN

Hey so the purple biggyback can actually control boost?? How does 500 sound to you?

tcb100

It does control boost, fuel and ignition. I have had it on my car since 1994-95. So long as you stay away from a midpipe you will be fine. There are better units around, but not for the kind of money you are looking to spend.

Keep in mind that you don't know what the previous owner was running so the three maps are not necessarily safe for your car. The odds are that setting one is stock, that's how it left PFS in the first place but since it's user programmable, you won't know for sure. PFS had it set up to run fairly rich.

If you buy it, call Ray Wilson at PF Supercars in Frederick 301-874-0611, spend a little more money & let him tune you. Your car will be faster and your motor will be safe.

GoodfellaFD3S

iTrader: (213)

i think that price may be a bit steep. You can find new pfc's plus commander for $800 now......

jsplit

That $500 price is a little steep, Definitely let Ray tune it if you can. He's money with that box. The piggyback can also control boost apparently and I only found that out recently but again that's another thing to have Ray do.

RX7SIGN

Okay thanks guys so what is a good price for it you think? Im leaning toward saving up for the Power FC im a fan for the JDM parts.

tcb100

I would say $400 is ok with the controller. This is a budget issue. It's the cheapest unit out there now & it works just fine. You can get your car into the 11s with this unit and the usual bolt-ons - intake, exhaust, downpipe and larger intercooler - and good tuning.

There is more potential with the Haltec or Tec3 or PFC or any of the newer units. You will pay a lot more though and unless you are willing to go to a midpipe & reach for the low 11s, or plan to go single turbo, it ain't obvious to me what you gain.