free hit
counters
Low boost ..... one broken wastegate actuator diaphragm.... a bit confused - Induction/Turbo/Manifold/Exhaust - The Lotus Forums Jump to content
pureguava

Low boost ..... one broken wastegate actuator diaphragm.... a bit confused

Recommended Posts

Hello

muddling through the V8...... it's acceleration was nothing close to the S4S so I suspect a problem with boost.....no CEL showing.....

hooked up a boost gauge and went for a spin and not getting over 5 psi - gets to 5 psi quickly but goes no further.

Hooked up a mityvac to the wastegate actuators and the left one is not moving at all..... took it out and rust fell out of capsule and obvious leak from the diaphragm 

i will order 2 new ones but the question is - why no overboost ?  If all the pressure is venting out of the left capsule then i suppose it's an open system and all the boost is just leaking out from there and not into the plenum?   Would this be correct ? Might plug the bad wastegate hose and go for a gentle spin - I would expect overboost in that case?  Your thoughts welcomed!

Share this post


Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.

Just replace - don’t drive it 


Only here once

Share this post


Link to post
Share on other sites

I know that's the better idea      Will replace but I think I have found the boost problem which is nice !  

  • Like 1

Share this post


Link to post
Share on other sites

Don't experiment with overboost - it's not a condition that you want.

It's most likely that the wastegate is being opened by the exhaust gasses which are acting on the wastegate flap.

Just get some replacements, set-up the correct mechanical base boost setting and go from there.

  • Like 1

1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

Share this post


Link to post
Share on other sites
1 minute ago, mike_sekinger said:

Don't experiment with overboost - it's not a condition that you want.

Unless you are of course seeking some modern art mechanical table decorations and a raped bank account  - then overboost is fab  


Only here once

Share this post


Link to post
Share on other sites

Haha great advice .....  I will wait for the actuators     If I need to be scared by boost (safely)  the S4S will suffice!   

But my question is - would a leaking diaphragm lead to low boost rather than the over boost that many have suggested?  - sure the wastegates won't open but will the pressure generated just leak out!?  is this a big enough leak to stop overboost? 

Share this post


Link to post
Share on other sites

Depends if it’s stick open or shut 👍

check the wastegates fully close and move freely 

Ps - the s4s is the better one 😂


Only here once

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...