So, about a month or so ago i posted and asked about putting a secondary wastegate, or pop-off valve in to help my over boost issue, and i was told that i can not do this and after quite some time and attitude i was given a valid reason why not. I was also told that i needed to pull the turbos and just port the wastegate and that would fix my problem. Well...after i strongly expressed that ive heard people doing this and not fixing the problem, and against my better judgement, we pulled the turbos (which was an absolute pain in the.....) and i ported the wastegate per the write-ups i found. I also ground out the cast that the flapper would hit allowing it to open roughly twice as far as stock. Absolutely sure that this was going to fix it, we went back together with the whole thing.

However.......turns out the horror stories i had heard about it not working were absolutely true. It did nothing for my car, except put it out of commission for the time it took to do this process. It still goes into an over boost situation so fast its rediculous. If somebody can explain to me why this didnt work like i was told it surely would, i would greatly appreciate it. All i know is that i went through a lot of BS to get those turbos off without breakin anything, and the same for goin back together, for nothing, and im not at all happy about it...

 

You should have left them off and installed a nice single turbo kit, my TiAL 44mm external wastegate works very well

 

Did you take the pills out of the wastegate line? I was oveerboosting also and did every thing you did, porter the wastegate, behind it added a hiflow cat and still boosting 14 psi. Took the pill out of the waste gate line now I am at 10 psi.

 

On a more serious (and helpful) note...... supposedly the smaller-diameter exhaust gaskets work well to induce a little more restriction and help keep boost in check.

what exactly is happening with your boost? how are you measuring it?

 

+1

I love how the OP keeps blaming everyone on the forum for his problem. Apparently he doesn't realize that #1 there is already a lot of information on this topic, available throughout the forums. and #2 no one is going to want to help a noob with a bad attitude.

@ the OP: you didn't post any photos of your work. You didn't describe anything else that you did. Have you checked all solenoids and vac lines? Did you remove the "pills" as hondasr4kids described? Do you have any sort of boost controller installed in the system - if so how do you have it set up?

I have a pretty modified motor but I still run the factory twins. Everything is ported. My twins are non-seq. I have full intake & exhaust. I ported my wastegate as you were instructed and I don't make more than 10lbs when my boost controller is turned off, which is the same thing has having the pills removed from the factory lines.

You might want to lose the bad attitude if you expect to get help from people on this forum. Your frustration with your own car is no excuse to blame the forum. I read through your previous thread and there was plenty of good advise in there.

 

If it is over-boosting very fast as you described, something isn't operating right. I had creep and spike issues with my twins before I went single as well. I ended up going with a dual MBC setup that worked very well.

To defend the previous advice. Installing pop-off valves to continually control boost is not wise either. The root of the problem is in the system or your mods.

GL

 

perhaps you should take your car to a rotary shop and pay them to fix you car? It's generally a bad idea to bitch about free advice.

 

Dude i was giving you attitude before because you didnt even know the correct term for the part you were talking about. You were trying to put a part made for a supercharging application onto you turbo car. Even after I was explaining this you still tried to validate it.

Read some damn archived posts, try some of the MANY fixes and be on your way. Believe it or not, your not the first person to have this problem, probably more like 5000th or something.

But on a serious note, take Rich's advice and look into a little bit of exhaust backpressure via a smaller gasket. There was many posts about this, search and you will see what were talking about. You are modifying the car, so some stock parts will need to be modified to keep everything under control. This is nobodys fault other than your own, you wanted more hp and this is the kinda **** you deal with.

 

Porting the wastegate is only half the equation, IMHO.

If you're still using the stock ECU without a boost controller, it's likely the stock ECU is not sending the correct duty cycle to the boost control solenoid to open the wastegate completely. Remember the stock ECU was designed to work with a stock system, so the preprogrammed boost control settings may not be right for your modified car. The RX-7 was produced and sold in the early 90's which means the ECU design was probably finalized in the late 80's... the boost control is not nearly as sophisticated or adaptive as what's found in an EVO or STI for example.

A bright guy (username 'arghx') wrote a good explanation of how the stock ECU controls boost (and sequential switchover), including how the vacuum lines are routed and how the wastegate solenoids are plumbed.
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/why-engine-so-damn-complicated-part-1-sequential-turbos-demystified-841821/


A quick easy test would be to un-plug the wastegate control solenoid's electrical connector, that should result in as little boost as your setup will allow. It may also throw a check engine light and/or put the car into limp mode when the ECU detects the solenoid is disconnected. An easy way to avoid this would be to get a 330-ohm resistor (does Radio Shack still sell that sort of thing?) and connect it to the wiring harness in place of the wastegate solenoid.

 

Now there is a great post^. If you are still getting too much pressure after doing the test above, i would look into exhaust backpressure changes. Do that test first though to determine if you may be able to just add a MBC or equilivant.

 

remove everything in line from the primary turbo nipples to the wastegates and put on straight hoses. Run the car...this will result in as LITTLE boost as possible on your setup and should bring you below 10 psi.

If not the only thing you can do is add restriction to the exhaust by way of restriction plates (similar to what Goodfella mentioned with the smaller diameter gaskets) or putting a cat back on if you have taken it off

 

Let it eat.

 

This is a very very poor example of forum use IMHO. After reading this i had to go check out your original post so i could see for myself the attitude and poor advice you received and for one you didnt get any bad advice and for two nobody gave you any real attitude until you started getting obnoxious. Just about 85 percent of the attitude you received was not because you made the mistake of calling the pov a wastegate but because you gave attitude and completely went the wrong way about asking for advice. I joined this forum knowing absolutely nothing about rx-7's and after reading thread after thread i've come to know a decent bit and i have never had to start a thread asking for advice on mechanical problems and neither did you because theres plenty of threads on the same issue your having. So a little advice on not only using the forum but on getting along with fellow forum members, use the search tool, don't give attitude to members that are trying to help you like "montego" who has given a lot of great information and help to members issues, and don't be over sensitive. I'm in no way a flamer, just figure your due for a reality check. As far as the GOOD advice you received on porting the wastegate not working, think about it majority of the issues on cars have multiple solutions at times and just because you tried one and it happened to not work doesn't mean it was shitty advice and everyone who gave it to you are stupid. Search the forum and you will find you answers.

 

I'm still reading up on the pill thing, I've ported my wastegate and all and have yet to install my turbos back in but my question is;

Should I remove the pills before getting everything put back together or see if it still overboosts spikes before taking the pills out?

I don't have a proper boost controller or a new ecu yet as I'm still buying parts as I go along.

 

taking the pills out requires all of 20 minutes to do. You pull the vacuum lines off and replace them with new ones. The "pills" are little orifices (similar to carb jets) that go inside the vacuum hose to create a restriction.


so its probably easier to leave them in to start...see where you are...and them remove as needed.

 

You should have argued more. Maybe the other members would have been convinced not to respond and let you search and figure it out on your own.
Well...I wouldn't put up with it either! Next time someone offers advice, demand a money-back guarrantee or your just not going to take it. That'll show 'em they can't mess with 'ole CrewDJ.

 

I suggest you take your car to a rotary specialist. It appears that you can't fix it, and that you don't play well with others.

 

 

I wish every new comer to the forum was half as legit as you, that way every time I search I wouldn't pull up retarded threads to sift through to find real info. I seriously thank you!

 

It sounds like you confused a problem with the boost control system for boost creep.

Boost creep is exactly that: steadily rising boost with no limit. It's caused by air pressure building on the wastegate because the wastegate flow is choking. It is not "so fast it's rediculous[sic]"

Another common issue is a leak on the lines or the wastegate actuator itself. This prevents pressure from building in the wastegate actuator and the actuator opening.

Best solution I know to first diagnose the problem is to plumb the wastegate actuator directly into the charge pressure and plug the other nipple on the wg actuator. This ensures the boost is limited to spring pressure which is 7-8psi.

The good news is that your wastegate is now ported and when you get the boost control system working correctly you will not run into boost creep later on.

David

 

<------- ported wastegate not getting boost creep anymore.

 

Now that you ported the wastegate, get an electronic boost controller to eliminate all OEM boost controls. This will solve your problem 99.9%

And FYI, porting the wastegate was the correct thing to do. No bad advice was received.

thewird

 

NM posted before I saw all the thread updates