JyRO

iTrader: (3)

Guys,

You all helped me a lot with giving me all the info about how much boost is too much boost. I think I may be on to a reason as to why the car may be overboosting. See if you guys think this may be reasonable.

As I said, I bought this car from my cousin. He told me that he bought this car used with a no good motor, but the car had lots of Pettit racing stuff on it. Once he bought the car he put his previous RX-7's engine in it out of his previous wrecked blue '93 that he bought back from the insurance company.

Here's my idea: Maybe the silver Pettit car (my car) when it was on its previous engine, had some turbo work done to it and was running a Pettit ECU that worked well for that turbo set-up. But then the engine went bad and the car got sold. Then my cousin put his old engine and turbos in the new silver car. And since then the turbos are blowing too much boost. Maybe its do to a difference between the old engine's turbo(s) set-up, and the new engines turbo set up.

Does that sound reasonable?

- JyRO

dgeesaman

iTrader: (7)

Take out that ECU and check to see if it's a Pettit model. Go to Pettitracing.com, RX-7, Management section and you'll see one. If it's a Pettit, that could definitely explain some of the boost issues, but the good news is then it should be enriching the fuel mixture to cope with it, too. Call them with the ECU info and they should be willing to advise what is/isn't possible with that chip.

Dave

JyRO

iTrader: (3)

That's the next step. It would be real nice if I could call Pettit with the VIN # and they could come up with a list of modifications (with details) that were done to the car. I don't know if they have those kind of records, but that would be nice. Anybody know what they'll be able to tell me? I'm not at home now and don't know the VIN or I would call them now.

- JyRO

JyRO

iTrader: (3)

A couple updates:

1) The ECU said it was a re-manufactured unit for Mazda. So basically a stock ECU.

2) I put the stock airbox back on, it seemed to have negligible results for slowing down the boost spike (+ 11 psi). However, I mentioned sometime back that there was some kind of groaning/buzzing kind of noise that I was hearing off the throttle and the engine slowing down. The groaning/buzzing is still there and happens at ~3,700 rpm as the engine is slowing, but now the groaning/buzzing is much quieter (due to the airbox). I'm just guessing the noise may be the secondary turbo being shut down or valved off or something. For those of you running the stock airbox, where does or what does the hose coming off the inside (center of the vehicle) of the airbox hook to? Mine is just hanging open at the back side of the SMIC. But I'm thinking there's more to it than that ... and I couldn't find any detail about it in the FSM.

3) I called Pettit racing, and the guy I talked to said that I should put the main cat back on the car to control the overboost. He seemed to say that an aftermarket ECU / ECU programming wasn't the answer. He said that when they modify a car they never take off the main cat because it does a good job to control overboost. Do you guys have any opinions on re-installing the main cat?

- JyRO

adam c

iTrader: (2)

You need to do some reading, to learn about your car. Start with the stickies at the top of the 3rd gen section. Lots of good info there.

Anyone that knows anything about these cars (not you), knows that removing the main cat causes increased boost.

You really need to educate yourself about your car.

JyRO

iTrader: (3)

I'm doing all the reading I can, learning as I go along. I'm about a month into this. Your reply helped me zero. If you can't be helpful, then just don't add anything. I read the stickies that I think apply. I didn't remove the main cat either, it was removed before I bought it. I bought the car barely running (boost leak) and crashed into a telephone pole around 4 years ago, then half assed put back together. Then it sat for 4 years or so.

So far I've got the boost leak fixed (based on the stickies), lots of maintenance done (based on the stickies), and I'm following other advice given in the stickies about what to do when buying a new car. Things are getting done, but from time to time, I need opinions and not critisizm.

- JyRO

Cgotto6

iTrader: (8)

That noise you were hearing was your airpump probably. By putting the stock airbox back on it would definetly quiet it up.

Search more...Post less.

adam c

iTrader: (2)

I told you that your boost problem was caused by the removal of the main cat. I also told you that you should read the stickies. Both of those are helpful suggestions.

Don't come to this forum and expect your mommy to do everything for you. And if you get criticized a little along the way, too bad .

JyRO

iTrader: (3)

Oh yeah, I really benefited from that info. Done with your useless smart ***.

- JyRO

Cgotto6

iTrader: (8)

How could you not benefit from that info. Hes potentially saving your *** from buying a new motor...I suggest you dont come on here, knowing nothing, and calling senior members smart asses. Doesnt usually make friends.

From what it sounds like, you dont know **** about this car. Most people dont when they first get one. Just take your time and read as much as you can about it. Start with the stickies and FAQ's. Theyre actually a big help. Trust me.

MakoRacing

iTrader: (12)

Actually he did give you good info. and for that & remark your going to get by many forum members.
Have a nice day

JyRO

iTrader: (3)

Like I've mentioned (in other topics), I don't know crap about this car. I'm less than a month into it. And I mentioned in this topic that I'm reading all the info I can find.

What I don't know from reading the stickies (yet), is if others have removed their main cat, or bought a car with it already removed, and have the same boost problems as this car.

He WAS being a smart-*** by saying that I expect my mommy to do everything for me. She doesn't ... she only changes my diapers!

Cgotto6

iTrader: (8)

Here, ill make this simple for you. IF YOU ARE RUNNING A MIDPIPE, without taking the precautions to do so, YOU WILL HAVE BOOST PROBLEMS!!

Happy?

JyRO

iTrader: (3)

Oooooh, OK. Now I get it.

You guys are years into this. I am in information overload. I wish I already knew everything like you guys. I'm so unknowledgeable about this car, I don't know if I should pack the muffler bearings or flush the tire coolant.

As for my current train of thought. My overboost is dangerous. I would love a stock boost pattern 10-8-10. I don't know if I'll ever register this car and drive it on the street. Most likely it will only see track duty.

So for me, no cat needed. I don't care about the stink, don't have to pass emissions even if it were registered. I want the simplest most reliable fix to this problem I can get. I have the stock exhaust in the work shop including the main cat, but don't see that as the simplest most reliable (or lightest) way to fix the problem.

I was reading from a search about Ranger Yi's problem, and his use of a restrictor plate. Some of you guys may not like the idea of it, but from a purely mechanical standpoint, I think it may meet my needs the best.

adam c

iTrader: (2)

I was just about to offer a helpful suggestion, but then I realized that I am a smart *** (as opposed to a dumb ***), so I will just keep it to myself