TFatC's 99T - The madness continues! - SaabCentral Forums
*
Home Saab Pictures Saab Classifieds Saab Dealer Listings Saab Forum Saab Forum


Go Back   SaabCentral Forums > Saab 99 & 90 > 99 & 90 Workshop

99 & 90 Workshop 99 & 90 Technical Forum

SaabCentral.com is the premier Saab Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools Display Modes
  #1  
Old 8th April 2003
TFatC's Avatar
TFatC TFatC is offline
Saab Crazy
 
Join Date: Oct 2002                                                
Location: Aberdeen, Stavanger or Offshore
My Saabs: 96 V4, Sonett TS, c900 Lynx, Carly etc
Posts: 580
Default TFatC's 99T - The madness continues!

First, sorry, no pics as my cheapskate brother does not have a digital camera. Can't say too much as he paid for and collected the car last night

First reports are very encouraging. It came with a HUGE history file and every MOT certificate. The car had 1200 spent on it not very long ago. The interior is immaculate, new headlining a couple of years ago, a few rust scabs but nothing too serious. Half a tank of petrol

The car is on 4 Ronal alloys with good tyres, and came with 4 Incas with better tyres . My brother drove it home last night, did not break down and hit 90 for a while.

Only problems encountered so far, the tacho is intermittent (suspect a dodgy connection) and here is where I ask for help. The turbo obviously needs setting up as it boosts into the red before the waste gate opens, in effect switching off the turbo! My last 99T 12 years ago did this after I had the head done, but rust killed it before I had a chance to investigate.

So, what is causing this, and how do I put it right? All advice gratefully received.

Must be a good car, my brother has no taste in cars (he is an accountant! ) and drives an Audi S4, admittedly with ABT bits and 320 bhp, and he LIKED my Saab!
Reply With Quote Quick reply to this message
  #2  
Old 8th April 2003
tom's Avatar
tom tom is offline
Saab Crazy
 
Join Date: Aug 2001                                                
Location: Finland
Posts: 590
Default

the rev clock is propably a dodgy connection at the induction coil.

we want some pics!!
Reply With Quote Quick reply to this message
  #3  
Old 8th April 2003
Ken Ken is offline
SaabNut!
 
Join Date: Aug 2001                                                
Location: Derbyshire, UK '88 900T8; '93 900 SE lpt
Posts: 474
Default

I think I remember a friend telling me that the wastegate on those works on some type of diaphram thingy which often weathers & splits
Reply With Quote Quick reply to this message
  #4  
Old 8th April 2003
AndyH AndyH is offline
Active Member
 
Join Date: Mar 2003                                                
Location: Crich, Derbyshire, UK
Posts: 42
Default

And here is that friend Ken!

Yes it could be one of a couple of things. The wastegate is essentially a valve which opens when a certain exhaust manifold pressure has been reached. This is actuated by a flimsy rubber diapragm which due to the hot exhaust gasses eventually perishes. It is almost certain that this diapragm will need replacing. This means that the wastegate does not open and the engine shuts down to prevent a catastrophe!

Also if the diapragm has been gone for a while the valve can also stick. This can be released with a few gentle taps of a hammer, but be careful, I broke mine a few years ago, and they are not easy to find....saab were quoting over 200 for one a few years back, but they are nolonger available I don't think.

Try an independent specialist for the diapragm, saab will charge you about 50...and when you see it you will realise how much of a rip off that really is!

This problem can in the future be prevented by actuacting the diapragm with the inlet manifold gasses rather than the exhaust...this prolongs the life of the diapragm sunstantially, and prevents the tail off of boost at high revs.

Hope that helps!
Reply With Quote Quick reply to this message
  #5  
Old 8th April 2003
nutcase's Avatar
nutcase nutcase is offline
Super Moderator
 
Join Date: Mar 2003                                                
Location: The Nut Hut
My Saabs: 1978 99T in black; 1983 99GL in Beige
Posts: 11,250
Default

Sounds like a great Car How long until you get your mitts on it?
Pictures! :P
I expect my wastegate will have similar, if not worse problems having stood for so long.
Reply With Quote Quick reply to this message
  #6  
Old 8th April 2003
TFatC's Avatar
TFatC TFatC is offline
Saab Crazy
 
Join Date: Oct 2002                                                
Location: Aberdeen, Stavanger or Offshore
My Saabs: 96 V4, Sonett TS, c900 Lynx, Carly etc
Posts: 580
Default

Collecting the car around the 24th April, and will post pics when I get back. Must be OK, my brother claimed it still looked "quite smart" this morning!

AndyH - Welcome to the madhouse. In fact WELCOME with capital letters as it sounds like you know a bit about these turbo things, and there are a few of us here who have just obtained one needing various amounts of work. Hope you enjoy typing....

Personally, I know almost nothing about modern cars (anything post 1970 is modern in my book!) so hope you will forgive my ignorance.

Is it much of a job to change this diaphragm?
Is it much harder to convert to inlet manifold activation?
Does a waste gate do the same job as a dump valve?
Would it be possible or even beneficial to install a dump valve instead? I would like to tune this one a bit (alright a lot) and intend fitting an intercooler very soon. Of course, the hooligan sound of a dump valve going off on "an old mans car" also appeals.

Thanks for your help so far

Nick
Reply With Quote Quick reply to this message
  #7  
Old 8th April 2003
nutcase's Avatar
nutcase nutcase is offline
Super Moderator
 
Join Date: Mar 2003                                                
Location: The Nut Hut
My Saabs: 1978 99T in black; 1983 99GL in Beige
Posts: 11,250
Default

Oh nick, shhh! You'll get me tempted into mods like that - but I think I should get mine going first!

I *think* wastegates and dump valves are totally different things. Wastegates limit the amount of boost produced, and dump valves drop some stored gas into the exhaust when the revs drop for gear change, so the power is ready and waiting as soon as the throttle is pressed again.

Could someone confirm/elaborate? I'm not to hot on turbo's myself

Richard
Reply With Quote Quick reply to this message
  #8  
Old 8th April 2003
AndyH AndyH is offline
Active Member
 
Join Date: Mar 2003                                                
Location: Crich, Derbyshire, UK
Posts: 42
Default

Yes wastegates and dump valves are very different! Wastgates stop the pressure from getting too high...hence the boost needle should go up to the end of the orange and then the wastegate starts to open to stop it going into the red causing pinking and eventual terminal problems!

A dump valve opens when you take your foot off the accelerator and releases the pressure which builds up in the inlet manifold, until you put the boot in again. This pressure stalls the turbo meaning you have to wait until the boost builds up again from scratch. So basically it should mean a bit less lag.

Changing the wastegate actuation to the inlet manifold is apparently really easy, but i'll dig out the exact instructions...sounds like a 30 min job.

The wastegate diapragm should be easy, but is often a swine! Its all located in the lump of metal which sticks out of the pipework between the turbo and exh manifold. You undo the four securing bolts on the wastegate cover and then you have to slacken a large shallow nut which is essentially the boost control nut, the tighter this is the more boost you get. Problem is that if the valve is free it simply spins round and you can get no grip on this crucial nut, and you often have to strip the whole thing down to get access. Too complicated to type about tonight! Let me know how you get on!...but get this nut off and you are there.

BTW for tuning water injection is the way forward, you will probably not manage to find room for an intercooler. Both do essentially the same job of cooling the inlet air.

A typical kit is betweem 200 () http://www..se available from Julian at elkparts http://www.elkparts.com or 400 for an Aquamist system http://www.aquamist.co.uk I would love to try any one of these, apparently they are amazing...at least 185bhp!!
Reply With Quote Quick reply to this message
  #9  
Old 9th April 2003
TFatC's Avatar
TFatC TFatC is offline
Saab Crazy
 
Join Date: Oct 2002                                                
Location: Aberdeen, Stavanger or Offshore
My Saabs: 96 V4, Sonett TS, c900 Lynx, Carly etc
Posts: 580
Default

Thanks Andy, at least I now understand the differences. Had not thought of water cooling, will look into it!
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the SaabCentral Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 09:44 AM.



Powered by vBulletin® Copyright ©2000 - 2014, vBulletin Solutions, Inc.

top of page | sitemap | email us



copyright © 2003 - 2011 saabcentral.com, All rights reserved http://www.whiter.co.uk - valid xhtml - valid css
SaabCentral is an independently run website and is not affiliated in any way to Saab Automobile AB.


Garage Plus vBulletin Plugins by Drive Thru Online, Inc.