Low Primary Boost
 

Hi guys,
finally got a boost gage(after 3months of fd ownership)

During acceleration I get 7", at constant highway speeds no boost at all , to and after 4500rpm still no more than 7".

Any help would be appreciated and if there is a good write up on the care and feeding of the engine/turbo/fuel/ecu/vacuum/electronics I'd like to know about it.

Thanks

Jim

ok first boost is read in psi.

second your not boosting when your driving at a constant speed. the only time you'l boost is under accleration and under WOT you should be getting ~10psi on the primary until you hit the transition which is ~8 psi then back to 10psi.

The engine shouldn't boost at constant speed unless you're going uphill pretty good.

Check the gauge - usually they read in Psi on the pressure side and in-Hg on the vacuum side. So I think you're actually getting 7psi.

Run the 3rd gear test (35->80mph hard on a highway) and see if you get any higher than 7psi. Starting at 40mph in 3rd, hard throttle should put you immediately at 10-11psi, then a quick dip to 8psi at 4500rpm, followed by 10psi up to redline. That's the 10-8-10 pattern.

Care: just don't hit into the turbos until the engine is warm (at least 5min) - accelerate slow enough to stay under 0psi. Make sure you have a few minutes at the end of every drive with no boosting, or idle it for a couple minutes before shutting it off. And change your oil every 2-3k with new filter, and fuel filter every 15k.

There is a boatload on www.scuderiaciriani.com, www.maxcooper.com/rx7, www.rx7turboturbo.com, and http://www.autosportracetech.com/RX-7/rx7stuff.htm
Dave

Thanks for taking the time to reply.

PSI not Inches --I know that!

Will be reading the info on the websites this evening.

My main question is -- what limits the amount of primary boost? Wastegate, bov,????

Thanks again.

Jim

For F@#% sake, read dude. Has life been handed to you on a silver platter? Must you be spoon fed??

Search this site, search the internet, and READ.

See how low my post count is? That is because I spent the first 4 years of owning my car researching and looking up all of the stuff that these really great people wrote out in websites and FAQ's (mainly because they were tired of hearing/answering the same DAMN QUESTIONS!) and not being "that guy"

:bash:

wow dude...the only thing i can say calm down.

im really digging your car, but is this not a forum? as many newbies on the forum, hes just nervous as he found a problem.

yeah we can tell him to search and such, but we dont have to say it in such a harsh way. =)

Fitz you obviously work for the USPS - and I do prefer to be spoon fed thank you very much. I had searched the archives and gone to a few other sites but hoped to find what I needed -some recent websites for information.

The good people you mention that have taken the time to post extensive write-ups are my heroes. The browsers who see the subject of my post have the option to open it or skip by - like you should have done you pompous ass.

Jim:

Re: Low Primary Boost
 

7PSI all around, could be lots of stuff but it sounds like missing pills. Try this

I would concur with Houdini, missing wastegate and precontrol pills, or you're not letting the car warm up to 178degrees F. That's when the ecu(stock based) will advance the timing and allow the solenoids control the boost. If water temps are below this level you may get erratic boost and poor power, boost is limited to default below 175 degrees.
Art

Thaks to the links that were posted I went to work and found the following. The coupler hose on the y-pipe was split and the check valve to the pressure tank had come apart.
After I replace these I'll let you know how it goes.

Thanks for all of you that took time to reply.

Jim

I wasn't able to connect to the following sites. Is there new addressses for these?www.scuderiaciriani.com, www.rx7turboturbo.com.

JIm

The links are bad. Look at the browser when it fails to load, there is a dumbass comma at the end of the first and a dumbass period at the end of second.

i just have a quick question about my boost problem.
when i boost, my boost is only ready 7 to 8 only; do you guys know what happen ??? and my idling is usually a little bit high in between 1100 to 1500rpm ....

Happy days are here again. The coupler hose on top of the y-pipe was indeed cut through and leaking at about 6-7 psi. I also found the check valve into the pressure tank had come apart so I had no pressure in those lines.

Replaced both and wow!.

Thanks to all who replied except old what's his name.

Jim

one of the best site for trouble shooting your turbos...

http://www.autosportracetech.com/RX-7/rx7stuff.htm