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New Turbo bypass and wow

4K views 27 replies 11 participants last post by  Saab_Love 
#1 · (Edited)
So i finally got my car back from the family shop today after 3 weeks.. It didn't feel right even with my tune... it was slow as hell.. fixed a few things.. down pipe, MAF (3rd one is the charm), Tranny lines... Ended up being a bad dump valve even though it didn't pop a code... replaced it and wow what a difference.. finally consistant boost!! Wheel spin! woot!!


 
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#2 ·
I know how you feel. I've had trouble holding constant boost for a while now and kept hearing a hooting sound and couldn't decide what it was. Finally, I replaced the bypass valve and have had constant boost since. It definitely runs smoother.

What tune are you running?
 
#3 ·
Did you post the probelm on here Jm?

The hooting is a very common sign of the diaphram in the valve splitting, thats why many people go for a forge item with no rubber diaphram.

Many people refer to the valves as hooter valves because of this - we should have been able to diagnose it for you!
 
#4 ·
Chris,

I never really described the issue here because I originally thought it was something with the transmission. I figured it was normal, but then saw someone talking about the hooting and replacing the valve with a piston valve. I purchased the hyperboost version and it has been excellent. It has a very quick response time. Now I just have to drop the Sump and clean a little and I think my car will be able to last another 5 years (only about 20k miles....my car gets me to work and back).
 
#5 ·
The sump drp is definitely worth the time and effort - good luck! ;)
 
#12 ·
So even though I just paid 90 bucks for the family shop to replace this.. its still hooting a bit.

So im changing this..




to THIS...



Is there anything I need to know when replacing this? I read that a few people popped a light because they had the wrong springs in it. This was the kit from GS so it should come with everything.
 
#13 ·
#15 ·
It may well give you a sharper, more crisp sound as the pressure is "dumped".
 
#16 ·
I replaced all my 3.5mm vac hoses a couple of months ago due to the "hooter" noises gone till the other day. A hose connection that I'd broken and tiewrapped had come loose. The offending part sits on the TB held in by 1 bolt, the other end of the hose connects to the "T" junction between the boost controller and the dump valve. Does the 93 on a similar age run the same parts, as no 95's in salvage yards near. but there is a couple of late 90's 93's.
Job for Saturday.
 
#17 ·
So what you are saying is that the noise could be coming from something else? I also replaced all my lines about 2 months ago. The noise happens at very light throttle loads around 30-40 mph when accelerating. It used to happen A LOT more often than it does with the new bypass from the shop, but it still does occur... so I was told the forged was the best solution to this problem
 
#18 ·
You're referencing balooga whale sounds, not hooting owl, I believe. (Hahaha, yes , I am laughing when I write this...)

Usually mine does this when i'm at the line between vacuum and boost, on that 'razors edge', on low throttle applications (however infreqent those are)...

Cheers.
 
#27 ·
Keep in mind if you use #1 you have to add more preload to the spring to avoid boost leaks, since the boost is pressing against the bottom of the piston using that method. With a forge you would probably want to use the yellow spring, or use washers to preload the green. I have an adjustable hyperboost, and I have to screw a good bit of preload in it to make it hold 20psi. Pretty easy to test if you have a boost gauge: start with the highest spring and work your way down to the lowest. Do some back to back highway runs and stick with the lowest spring that lets you achieve max boost.

The cool thing about it is that since the boost pushes at the bottom of the piston, as soon as you let off the gas the boost helps to press the valve open and you get a much crisper, faster and louder bypass sound, if you have an open air intake. It may be placebo effect but it feels like the initial boost response is better mounted this way as well.

Also keep in mind not all Forges are piston valves... they also sell diaphragm valves (same type as the stock bosch), which have been known to hoot and have their diaphragms tear as well, especially when run in the #2 configuration.
 
#28 · (Edited)
So I face this backwards and put in the yellow spring?? I dont understand. Why can't I just put it on and leave it? It's a family car.. I need it to work without problems.. I dont have time or money to take it back and forth on the highway... and I dont have a boost gauge.
 
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