How do you tell a Pettit Unlimited vs Stocker
 

Yup! I just bought a "Pettit Unlimited ECU" and didn't see an external difference in the boxes. I was told that disconnecting the throttle sensor would not trip the check engine light on the Pettit so I tried that and it came on. Well, now I'm wondering if there is anything else I can check to see if it "still" might be a Pettit.

I've been searching but what A/F number would constitute running lean? What is a good level while running under high boost (10,12,14 type psi)?

Thanks

Victor

The Pettit ECU's usually have a long Pettit sticker wrapped around the outside of the ECU case. Other than that, you have to open up the case and look to see if there is a daughterboard soldered on the main board.

There was a thread a while back that had the inside of an M2 ECU pictured. It would be similar to that (if you can locate the thread).

mine didnt have a sticker.

Hook it up. if you hit 14.7psi with no boost controller than its probably tha real deal :bigthumb:

I have a downpipe and a catback and can probably hit 14 psi with my stock ECU, put I don't want to. Likewise if this a just a stock ECU instead of the Pettit, I don't want to lean out and pop my engine.

No sticker but I'll check for the daughter board this weekend.

I was also thinking of getting on a dynojet and checking the a/f which is why I need to find out what is considered a lean, normal, rich mixture. Any help with this would be much appreciated.

Victor

Mine has three stickers on it. Two on the sides to seal the top and one on the top.

Here is a pic

https://www.rx7club.com/attachment.p...postid=1751751

one more

https://www.rx7club.com/attachment.p...postid=2651786

The limited chips. they replace the unlimited ones if you whant to, on the first pic.

https://www.rx7club.com/attachment.p...postid=1751772

You definitely don't want to run more than 10psi (stock)with the stock ECU, you will lean out and pop your motor very fast, tha's something you don't want to happen.
Get a boost controler and keep the psi on stock level till you get any aftermarket ECU.