Are pre-tuned ECU's worth it?
 

I was wondering... are those pre-tuned ECU's worth buying?

Like the ones Pettit offers, or the RX7 Store, that sells pre-programmed PowerFC's.

Are these worthwhile investments for people that, for whatever reason, have no access to a dyno, or don't have any rotary specialist to tune their cars?


Any comments/info/feedback will be greatly appreciated!


-D

there have been people on here that have run 10's at like 123mph with that pettit ECU... i've only heard good things about the pettit ECU

i've always thought they are pretty sweet and i want one. the powerFC doesn't cost too much more and is totally tunable though, so people usually go for that.

get a powerFC with a base map done to your specs. you will want to be able to change things in the future, trust me.

and having the commander is handy.. you can watch your water temps, intake temps, injector duty, boost among other things.

Check this thread:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/pettit-unlimited-vs-m2-116858/

Also, but still on the same discussion.

IMO, a Pettit ECU is a great, cheap way to keep things running a little more rich when you start bolting stuff on. A PFC is obviously a much better choice if you plan on running a midpipe, etc, but for 350 bucks, a Pettit Unlimited goes a long way at helping me rest a little easier with my little SMIC, catback, hi-flow cat, & intake. :)

I have a Rotary Performance ECU setup with for SMIC, DP, Mid-Pipe Catback, No Airpump tuned for 14.5 Psi for stock turbos. It runs very very strong!! Its very safe considering it runs rich for the setup I have. Dont get me wrong a Power FC is a very good option but like any computer, its only as good as the tuner. If you dont have anybody to really tune it for you locally, and you dont plan in going with single / upgraded turbos anytime soon, then go for a Rotary Performance Flashed ECU or a Pettit Unlimited ECU. My .02 for whatever its worth.

Carlos - Evil M5

New, pre-tuned ECUs don't make much sense any more since the PFC is now about $700. However, used they are a pretty good deal.

In addition the the ability to tune, the PFC improves driveability, kills the nasty 3k hesitation problem, and provides very nice monitoring with the Commander. The only real downside is that the base mod map that comes with the PFC is very conservative so you will likely need a tune to extract the most from modifications. With all the standard bolt-ons (no mid pipe - instead a high flow SMB cat) the base mod map ran very rich under boost on my car (10:1 AFRs or richer) and the timing was very conservative. So, unless you tune it yourself, you have to factor the price of a tune into the PFC option. As others have said, it depends on your future goals.

The PFC (or any other standalone actually) is only as good as the tuning. I don't trust mail order tunes. I've seen too many that weren't good including those from vendors on here. In some cases, I've seen worse driveability with poorly tuned PFC than with the stock ECU. Its not a panacea.

I'd sooner trust the pre-tuned ECUs such as those from Pettit and rx7.com.

Overall, it depends on your mods and your goals and the resources available to you. The initial purchase of the PFC might only be $700 as moconnor claims but to tune you need a datalogit box and software ($300) and a wideband ($300-500 depending on model). Then you need the knowledge to tune and the ability to recover from a mistake that can result in a blown motor. Tuning requires knowledge, not just the ability to use a computer.

I wonder if the M2 or Pettit maps are available - that would solve the tuning problem. Both these maps are proven, as in they don't tend to blow engines and people have reported some impressive dyno numbers with them.

What are your modifications? A Power FC is always going to be the better choice over say a Pettit upgrade.
Most of the Power FC's I have sold and that is hundreds have been premapped ranging from stock car to full bridge single turbo car. Most customers want a good map to get them going until the car can be tuned on a dyno.

I understand the base map thing... the problem here is that I cannot get it dyno-tuned.

Mods, at the moment, would be:
- Downpipe + Midpipe
- HKS Hi-Power Exhaust
- Pettit CAI

... and would like to add in a near future:
- Pettit Coolcharge 3 IC
- RX-7 Store's Ultimate Fuel System
- HKS Twin Power Ignition
- Nippondenso Supra TT Fuel Pump
- RX-7 Store's T04Z Turbo Kit

Stock ports.

How much *reliable* power would I be able to do with these 2 setups + a PowerFC programmed by you guys?

SR motorsports sells pfc with map- That was my first computer nice 11 sec
tune on pump

If you are thinking of upgrading to a TO4Z in the near future you will need the upgraded Fuel Rails / Injectors, Upgraded Fuel Pump, Large Intercooler and a an ECU to tune it all (thats without saying about an upgraded clutch and upgraded radiator and other misc. upgrades). In this case you go with the Power FC ( or Microtech etc ..). There is no sense waisting your time with Pettit or RX7.com Reflased stock ECU. The Reflashed stock ECU are good for a setup similar to what you have now in the car, with stock turbos and a good SMIC. Depending on your setup I have seen 285 rwhp - 330 rwhp on a stock ported engine. I have seen as high as 380 rwhp with 99 turbos and a nice street port engine(with reflashed stock ECU). In other words all you need to ask yourself is how soon are you going to be upgrading to a TO4Z. If its within a year to a year and half, jump for the Power FC and get your setup tuned. You may want to check with Steve Kahn for tuning since I know he does group tuning for the Power FC in different cities. He is considered by many the best in the Power FC tuning business.

Carlos - Evil m5

By the way, what exactly are your Rwhp / rwtq goals??

I agree with what others have posted. I just got a PFC and the monitoring of the car's systems is worth it just to me. No tuning on it yet and it does run conservative like others say, which is good. Got rid of my 3K hesitation as well.

However, a Pettit Unlimited is SUPER conservative! I've spiked 17-18psi during the transition with stock twins, full-bolts ons(HF-cat in place of MP) in 30 degree weather many times with no ill-effects. 15psi dyno-runs always showed AFRs in the low 10s. I have one for sale BTW :biggrin:

For your current modifications I can provide a map that would be almost spot on. Once you go single turbo and upgrade the fuel then you would need a tune on a dyno.
Another way to do it if you dont have access to a dyno is buy a datalogit and wideband. You can email me your logs and from that I can send a map that is going to get your A/F very close. It may take a couple of changes but it works well. I have done it for a few customers overseas that cant get to a dyno or tuner.

The thing is, I may be able to get it to a dyno, but down here in Argentina there are no rotary specialists... in other words, I wouldn't know if I should trust them.

I like the idea of using a Datalogit :)

Do you guys offer that kind of support?

I dont sell the datalogit but I can email changes based off your logs.

^ you should sell the datalogit, it's a nice complimentary product of what you already sell

rx7.com sells the datalogit

has anyone dyno'd on this forum with a pettit ECU that can post a dyno graph of the AFR's with their mods list?