I've notice that my first boost is up till 12 lbs to 13 then when it hit 4 to 5 thousand RPM it drops a significantly to 5lbs or 4 lbs. then it'll fluctuate around there untill redline... Happens on all gears.. What could cause my car to run like this??

Because sometimes time after time, boost will come regular just like normal, pattern 13, 10, 12.....(NORMAL))

But now, when boost pass 4k to 5k RPM it'll drop to 5lbs and fluctuate around there till redline....

I'm thinking it's the top end secondary turbo.. or just a hose.. Hoping just a hose!!
Thinking about doing a vacuum hose, seloinoid hose job.

Have any of you guys bought anything from www.hosetechniques.com..????

Are there hose any better??

Thanks

 

list your mods and you conditions such as mileage? oh and 13,10,12 isn't normal that's far from normal, 10-8-10 is normal.

 

Well when I bought the car ,13,10,12 was the pattern I've always have, so I don't know much about it,

Anyways here are a couple of modification:

HKS Dual Mega Flow Intake
HKS SSQ blow off valve
3'' Downpipe
HKS turbo timer type-1
Remapped Fuel Computer Installed
Underdrive Pulley Installed
Autometer Boost Guage Installed
Aluminum Coolant Recovery Tank installed

Thanks

 

What fuel computer? Sounds like a solenoid problem but I could be wrong, there are alot of things that can go wrong under the hood of a 7.

 

got similar problem.
i had a crack in the joint between the Y-pipe and the crossover tube, had to put a new coupler. But end up to be my turbo that were done. Check if you got an oil leak or if your car smoke. Or dissamble the pipe that got to the Y-pipe to see if you got lots of shaft play.

 

No oil leak,

The car will smoke a little puff of white smoke every morning when I start the car... They say this is normal for the car??

But I'll check on the Y-pipe and the crossover tube!!!

Thanks

 

Don't forget to read everything on this site:

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

 

You might want to check the TCS (turbo control solenoid)for crossed electrical plugs. The TCS sits in front and underneath the UIM. Unplug the two electrical connections and switch them. Take it out for a run ( make sure the engine is properly warmed-up) and go WOT. See if the pattern changes to higher boost at secondary turbo transition at about 4500rpm. Good Luck.

 

Yeah, the white smoke is normal, especially if it's cold outside.

Read the autosportracetech website, it has more info on your turbo control system than you'll know what to do with.

Your issue sounds like it has something to do with the TCA, or turbo control actuator. It controls the pre-spool of the secondary turbo. Basically it starts venting exhaust gas to the secondary turbo before the turbo is allowed to add boost to the intake, to get it up to speed. If the TCA opens slowly or doesn't open, when the secondary turbo is allowed to add boost to the intake, it could do as you described and never actually build boost.

Try driving WOT up to about 5000 rpms, then quickly let off the throttle and get back on it. If your boost climbs instantly to 10 (or whatever your "normal" boost is after 4500 rpms) then it's probably a TCA related problem.

 

i also have the same problem my car is stock and after all my modes its the same my is doing one thing his is not whe i go past 5 rpm it gose to 5 pssi and makes a shhhhhhhh nosie i did a hose rap and checked all my rubber cupalso checked the little check val i am thinking it might be where the y goes in then one way goes to 1 turbo and the onther way gose to anther pipe then into the back turbo where the two silver tubes come to getherits lose could this be my problem