Single Turbo RX-7's Questions about all aspects of single turbo setups.

Tial wastegate question

Old 11-22-14, 09:21 AM
  #1  
Senior Member

Thread Starter
iTrader: (2)
 
Join Date: Jun 2003
Location: Pittsburgh
Posts: 281
Likes: 0
Received 0 Likes on 0 Posts
Tial wastegate question

Trying to find out why my engine decided to let loose. I found the top nipple on the waste gate was able to be moved with little effort, like the bolt had come loose a little, didn't have play up and down, wasn't that loose but I could turn it with ease. Could this allow an over boost? I am using a boost controller

Thanks
arutha is offline  
Old 11-22-14, 09:44 AM
  #2  
Racing Rotary Since 1983
iTrader: (6)
 
Join Date: Oct 2001
Location: Wisconsin
Posts: 5,352
Received 47 Likes on 30 Posts
you will need to look elsewhere.

the top of a Tial resists the WG opening. if it were leaking the WG would open more easily.

HC
Howard Coleman CPR is offline  
Old 01-11-15, 06:57 PM
  #3  
Rotary Freak
iTrader: (8)
 
rx72c's Avatar
 
Join Date: Jun 2003
Location: Australia
Posts: 2,608
Likes: 0
Received 0 Likes on 0 Posts
Have a look at the Tune?
rx72c is offline  
Old 01-12-15, 11:39 AM
  #4  
Senior Member

Thread Starter
iTrader: (2)
 
Join Date: Jun 2003
Location: Pittsburgh
Posts: 281
Likes: 0
Received 0 Likes on 0 Posts
Actually found that both the top and side were movable. Can I use some type of thread lock on those?

So far I am two for two this past year with motors, both due to over boosting. Have a Blitz SBC controlling boost with the Tial. Both times at a track, I am pretty confident the tune is not at fault, car was tuned for 15psi on 93 octane (by a reputable tuner), but was running on a full tank of race gas with 2 stroke added and the controller set to 12psi. I run the race gas as an extra safety precaution and OMP is still in use. Not that either of these cause over boost... The car was fine for the first two days at the track and then this happened. So looking for the cause and can't seem to find anything other than blaming something around the wastegate. Might do away with the boost controller and just use springs to possibly simplify things but not sure it's necessary?

And I am about to do my first rotary rebuild, I can't afford to keep paying others to do it.
arutha is offline  
Old 01-12-15, 11:53 AM
  #5  
Senior Member
 
Join Date: Oct 2012
Location: Manassas
Posts: 340
Likes: 0
Received 2 Likes on 1 Post
While eliminating the boost controller will simplify things, that wouldn't have changed the outcome in this instance.

The plumbing to the waste-gate, as you have already learned, is very important. Certainly worth extra attention to detail to make sure it's bullet proof. Safety wire or lock-tite are good ideas. Also find some way to insure the hoses aren't damaged by the heat.
Vicoor is offline  
Old 01-12-15, 07:24 PM
  #6  
Sponsor
RX7Club Vendor
iTrader: (41)
 
IRPerformance's Avatar
 
Join Date: Apr 2003
Location: NJ
Posts: 10,978
Received 49 Likes on 44 Posts
Get a mityvac and apply pressure to the side port of the wastegate. It should open.
__________________
http://irperformance.com
Engine builds, single turbo kits, parts sales, performance upgrades, maintenance, tuning
732-662-1794 [email protected]
Brand new Mazda oem 13brew motors available. $4699 NO CORE FEE. VERY LIMITED. Check out our new turbo kits http://www.irperformance.com/product...zda/rx7/turbo/
IRPerformance is offline  
Old 04-01-15, 08:16 PM
  #7  
Senior Member

Thread Starter
iTrader: (2)
 
Join Date: Jun 2003
Location: Pittsburgh
Posts: 281
Likes: 0
Received 0 Likes on 0 Posts
Finally took the motor apart, both rotors had an apex seal break, could it be anything other than over boosting to cause that?
arutha is offline  
Old 04-02-15, 08:37 AM
  #8  
Arrogant Wankeler
 
Slides's Avatar
 
Join Date: Nov 2006
Location: Newcastle NSW Australia
Posts: 384
Received 16 Likes on 15 Posts
Pre ignition could have caused it, could have been a lean out or over advanced or that it just wasn't tuned to the load it got to on overboost which caused one of the conditions mentioned.

Surely if running a track car with an aftermarket gate which will hold much more boost than target without applied diaphragm pressure (ie just EMP trying to open it) you would run a tight overboost cutout to rule out that possibility?
Slides is offline  
Old 04-02-15, 09:45 AM
  #9  
Senior Member

Thread Starter
iTrader: (2)
 
Join Date: Jun 2003
Location: Pittsburgh
Posts: 281
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by IRPerformance View Post
Get a mityvac and apply pressure to the side port of the wastegate. It should open.
I tried this and it will not build any pressure, seems to bleed off as fast as I can squeeze the mityvac. It bounces to about 2psi and is gone.
arutha is offline  
Old 04-02-15, 09:51 AM
  #10  
Senior Member

Thread Starter
iTrader: (2)
 
Join Date: Jun 2003
Location: Pittsburgh
Posts: 281
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Slides View Post
Pre ignition could have caused it, could have been a lean out or over advanced or that it just wasn't tuned to the load it got to on overboost which caused one of the conditions mentioned.

Surely if running a track car with an aftermarket gate which will hold much more boost than target without applied diaphragm pressure (ie just EMP trying to open it) you would run a tight overboost cutout to rule out that possibility?

Afraid I am new to this but I do know the boost controller is set to cut boost just over 15psi which it is tuned for. Had boost set for 12psi on the controller. The wastegate springs are for 10psi but the controller overrides that from my understanding?
arutha is offline  
Old 04-02-15, 11:01 AM
  #11  
Senior Member
 
Join Date: Oct 2012
Location: Manassas
Posts: 340
Likes: 0
Received 2 Likes on 1 Post
Originally Posted by arutha View Post
I tried this and it will not build any pressure, seems to bleed off as fast as I can squeeze the mityvac. It bounces to about 2psi and is gone.
If it won't hold pressure, you've found the problem. Take it apart and inspect the diaphragm. Likely to find it torn, not seated properly, or some other cause of leakage.
Vicoor is offline  
Old 04-02-15, 02:07 PM
  #12  
Rotary Enthusiast
 
Join Date: Jun 2005
Location: sydney
Posts: 966
Received 26 Likes on 24 Posts
^^Not necessarily....and a tial or similar won't hold pressure anyway. With a mityvac, you're probably only going to get the valve to lift off the seat before the air bleeds down between the valve guide and stem, no matter how quickly you pump. Need something a bit bigger pump wise, or a low regulated compressed air source.
billyboy is offline  
Old 04-03-15, 06:09 AM
  #13  
Rotary Specialists
RX7Club Vendor
iTrader: (11)
 
Banzai-Racing's Avatar
 
Join Date: Jan 2008
Location: Indiana
Posts: 4,611
Received 75 Likes on 61 Posts
Billyboy is correct. Tial, Turbosmart and others will not open or hold pressure with a Mityvac.
Banzai-Racing is online now  
Old 04-03-15, 05:11 PM
  #14  
Rotary Enthusiast
iTrader: (9)
 
R-X-R's Avatar
 
Join Date: Jun 2011
Location: Syracuse,NY
Posts: 767
Received 2 Likes on 2 Posts
who is ur tuner?
R-X-R is offline  
Old 04-03-15, 07:00 PM
  #15  
Senior Member

Thread Starter
iTrader: (2)
 
Join Date: Jun 2003
Location: Pittsburgh
Posts: 281
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by R-X-R View Post
who is ur tuner?
Tuned by Ray at PFS, must admit I am not worried about that though. Probably another issue, just not sure what.

I took the wastegate apart and it looks fine from what I can tell, I do not see any tears or holes in the diaphragm. I emailed Tial and they did state that the top port should hold vacuum, which it doesn't, the side port will leak down far too fast like the others mentioned. Guess I'll mention that to them and see what they say.

I'll keep looking, just not sure what to look for, fuel pressure was good and tested it afterwards as well.
arutha is offline  
Old 04-04-15, 04:29 PM
  #16  
Rotary Enthusiast
 
Join Date: Jun 2005
Location: sydney
Posts: 966
Received 26 Likes on 24 Posts
The wastegate should only be able to leak through the diaphragm, nipple or flange where the halves bolt together. Putting a few pounds of pressure in through the top with a bit of dish washing mix around the valve stem in the outlet port and the other two points should identify if there's an issue with the wg.

Whole host of possible causes for things to go awry, short of logs, you're only going to get guesses - and here's my contribution, did you get into a boost cut, if so, how was it set up?
billyboy is offline  
Old 04-04-15, 11:57 PM
  #17  
Senior Member

Thread Starter
iTrader: (2)
 
Join Date: Jun 2003
Location: Pittsburgh
Posts: 281
Likes: 0
Received 0 Likes on 0 Posts
I dont think I hit the boost limit and I have to admit I don't remember feeling a ton of power either but I was about to brake so it could have been a quick spike that I didn't really notice I guess. Something I do remember was a sound that I thought was a boost leak, that sound happened a few minutes before too. This happened on the second track day and at no time before did I notice that sound.

Just throwing things out there in case it helps

Last edited by arutha; 04-05-15 at 12:12 AM.
arutha is offline  
Old 04-05-15, 04:39 PM
  #18  
Rotary Enthusiast
 
Join Date: Jun 2005
Location: sydney
Posts: 966
Received 26 Likes on 24 Posts
Probably wouldn't feel much in the way of power increase, typically on these things, over boost is only a few pounds more before a hard cut.....which can be felt and heard....inadequate solenoid to wg plumbing can be the culprit there, especially on track.

I doubt you'd hear a boost leak above wind, tyre, engine and exhaust roar, unless it was gross. Exhaust leaks on the other hand, you can generally hear them if they're mildly bad, even pin holes are evident at idle, but can't offer much in the way of suggestions otherwise.
billyboy is offline  
Old 04-05-15, 05:11 PM
  #19  
Senior Member

Thread Starter
iTrader: (2)
 
Join Date: Jun 2003
Location: Pittsburgh
Posts: 281
Likes: 0
Received 0 Likes on 0 Posts
There was definitely a sound under wot and at the same time power was affected, a few minutes earlier that session, lift off the gas and then back on and it was fine again. But didn't happen the previous sessions and I was on the last day. Not sure it was a leak at all, just a fluttering sound, possibly I hit the boost cut and then it started working fine again until the end.
I have an apexi pfc, would a datalogit be able to run during events to be reviewed later or does it have to have a laptop to do anything? Just trying to find a way to help figure these type of things out in the future. I need to do some research.

Sadly I still don't know the cause and am worried that even though the items check out visually and with the limited tests I can perform they could just fail again.

Thanks guys
arutha is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Ian_D
Single Turbo RX-7's
25
10-14-15 12:31 PM
_Tones_
Adaptronic Engine Mgmt - AUS
9
09-11-15 12:28 AM
Nosferatu
2nd Generation Specific (1986-1992)
7
09-05-15 02:13 PM


Thread Tools
Search this Thread
Quick Reply: Tial wastegate question


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: