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Cossie T3

TCornish said:
I have to fit a compressor bypass valve/BOV if I want to use the Cossie T3, right? As there's no CBV built in. I hear of people with compressor stall when going from 13C-T3 as it has no CBV..
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I used a FORGE CBV on my T3 which is in my DD. I started without one (in my ignorance) until I began hearing nasty noises when I lifted the throttle! All the details are in my build thread. Slightly reworked some early 7 series compressor hot side pipes, combined with my 9 series OE pipe. It works well. There are multiple springs available, so choose with care.
 
Sounds good. I assume it's the 740 intercooler piping I want as it'll have the little bit that the CBV will stick into.. So it's pre-turbo piping, to the intercooler piping right?

I think I will go for a Porsche/Bosch CBV, part no. #993.110.337.50 from Porsche but in reality it's a Bosch #0 280 142 108 that I can buy for ?35-47 here in the UK. Looks good, does the job I reckon.
 
TCornish said:
Sounds good. I assume it's the 740 intercooler piping I want as it'll have the little bit that the CBV will stick into.. So it's pre-turbo piping, to the intercooler piping right?
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Yes sir, I think something like 83~85 740's that came fitted with the T3. Depending upon your FMIC, you might be able to run the stock setup without revs. The early 7's used to top mount IC, which is why the hard pipe would not work properly with my center mount IC on my 92 940.

I looked into that Porsche piece....I believe it was well made, unlike the copies which were "costed down". My FORGE was $100 shipped to my door, including 3 springs to select from.
 
TCornish said:
Sounds good. I assume it's the 740 intercooler piping I want as it'll have the little bit that the CBV will stick into.. So it's pre-turbo piping, to the intercooler piping right?

I think I will go for a Porsche/Bosch CBV, part no. #993.110.337.50 from Porsche but in reality it's a Bosch #0 280 142 108 that I can buy for ?35-47 here in the UK. Looks good, does the job I reckon.
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The Portch and Cossie and Saab 900/9000 thangs are allegedly all the same thing..only testing would solve that question and that's too hard..
I'd shop by price..
Like maybe Ford..
 
Bosch #0 280 142 108 works perfectly. I have one on my car. The 740 intercooler pipes (made until 1989) can be difficult to get hold of though. Especially the rubber pre-turbo one which will have perished to bits by now.
It might be easier just to make up your own pipework.
 
crogthomas said:
Bosch #0 280 142 108 works perfectly. I have one on my car. The 740 intercooler pipes (made until 1989) can be difficult to get hold of though. Especially the rubber pre-turbo one which will have perished to bits by now.
It might be easier just to make up your own pipework.
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Indeed. The intake hose is available here though:

http://www.do88.se/en/artiklar/lvo-740-760-780-turbo-1983-1989-intake-hose.html

They also sell the 90+ version without CBV connection, with 70mm and 80mm ID for stock or 960/16VT AMM.

Or use this: http://www.do88.se/en/artiklar/hose-take-off-25mm.html
 
I am a bit loathe to post this, it has caused days of argument on other forums, but there's no reason at all to run *ANY* sort of recirculation valve on a turbo engine. Saab first used them to quieten the noise of turbos as they thought customers would not want that. They do not reduce lag in any shape or form. If you look at high end endurance race cars like the Group C cars, or even F1 in the turbo era, they did not run them. If they believed a cheap light, simple and reliable recirculation valve reduced lag or improved turbo longevity, then they sure as hell would have used them. So blank the thing off if you so wish :) I have not run one on any performance turbo engine build in the last 20 years.
 
Chris Wilson said:
I am a bit loathe to post this, it has caused days of argument on other forums, but there's no reason at all to run *ANY* sort of recirculation valve on a turbo engine. Saab first used them to quieten the noise of turbos as they thought customers would not want that. They do not reduce lag in any shape or form. If you look at high end endurance race cars like the Group C cars, or even F1 in the turbo era, they did not run them. If they believed a cheap light, simple and reliable recirculation valve reduced lag or improved turbo longevity, then they sure as hell would have used them. So blank the thing off if you so wish :) I have not run one on any performance turbo engine build in the last 20 years.
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Post it..I say the same..I really don't worry so much about GpC or F1 cause those cars had extremely close ratio gear sets, maybe 12 to 15% rev drop on gear changes not the 25-35% we see on most street/road cars...
As usual the closest correlation would be GpN rally cars--which must run the stock ratios..

Saab DID write about reducing lag and I never heard anything about noise in any form Engrish or Swedish...But if it was to reduce lag it didn't work too well: the typical 900 T16 car didn't really wake up till about 3300-3400 rpm..
I don't like the plastic Bossh ones from a reliability point of view..They warp and bind. The diaphragm tears and leaks--and the poor turbo works its poor little heart out trying to make boost... So looking t plenty of piccies of GpA YB powered Fords and seeing no recirc thing I said fawk it and run without..And all the dozens of our US version the Merkur Xratty, NONE came with one and they work fine---more power stock than the Volvos, more boost, more torque and the turbos last just as long...
 
Chris Wilson said:
I am a bit loathe to post this, it has caused days of argument on other forums, but there's no reason at all to run *ANY* sort of recirculation valve on a turbo engine. Saab first used them to quieten the noise of turbos as they thought customers would not want that. They do not reduce lag in any shape or form. If you look at high end endurance race cars like the Group C cars, or even F1 in the turbo era, they did not run them. If they believed a cheap light, simple and reliable recirculation valve reduced lag or improved turbo longevity, then they sure as hell would have used them. So blank the thing off if you so wish :) I have not run one on any performance turbo engine build in the last 20 years.
Click to expand...

I really like my HKS SSQV which is not setup to recirculate and have zero issues with it. I'm so used to the blow off sound I don't think I would like a recirc valve.
 
damm, as soon as I finish making a bung to recirc my bov cause how crappy the car runs y'all go on a discussion about how they aren't needed? What about the whole surge or whatever it does where the common argument is that pressure builds up so high it spins the wheels backwards?
 
Canadan said:
damm, as soon as I finish making a bung to recirc my bov cause how crappy the car runs y'all go on a discussion about how they aren't needed? What about the whole surge or whatever it does where the common argument is that pressure builds up so high it spins the wheels backwards?
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I think this discussion was going in the direction of not using a recirculating valve (CBV) in favor of running a BOV for that phat sound, you still have to run one or the other. ;-)

But with a stock LH system, your car will occasionally run like crap with a BOV, your work was not in vain.
 
Chris Wilson said:
I am a bit loathe to post this, it has caused days of argument on other forums, but there's no reason at all to run *ANY* sort of recirculation valve on a turbo engine. Saab first used them to quieten the noise of turbos as they thought customers would not want that. They do not reduce lag in any shape or form. If you look at high end endurance race cars like the Group C cars, or even F1 in the turbo era, they did not run them. If they believed a cheap light, simple and reliable recirculation valve reduced lag or improved turbo longevity, then they sure as hell would have used them. So blank the thing off if you so wish :) I have not run one on any performance turbo engine build in the last 20 years.
Click to expand...

Thanks for posting it though, you've certainly made me (and others it seems) think. I've always used one based on the premise that 'Volvo knows best', but dispensing with it certainly makes things a lot simpler.
 
JerryJS8 said:
I think this discussion was going in the direction of not using a recirculating valve (CBV) in favor of running a BOV for that phat sound, you still have to run one or the other. ;-)

But with a stock LH system, your car will occasionally run like crap with a BOV, your work was not in vain.
Click to expand...

I think people have issues with the spring loaded ones, SSQV uses differential pressure
 
Chris Wilson said:
I am a bit loathe to post this, it has caused days of argument on other forums, but there's no reason at all to run *ANY* sort of recirculation valve on a turbo engine. Saab first used them to quieten the noise of turbos as they thought customers would not want that. They do not reduce lag in any shape or form. If you look at high end endurance race cars like the Group C cars, or even F1 in the turbo era, they did not run them. If they believed a cheap light, simple and reliable recirculation valve reduced lag or improved turbo longevity, then they sure as hell would have used them. So blank the thing off if you so wish :) I have not run one on any performance turbo engine build in the last 20 years.
Click to expand...

I'll be going for the CBV solely because of driveability really, and seeing the engine will be going in my daily I can't afford to reduce turbo longevity anyway. But indeed, if it was a Sunday-driver car, then yes, I wouldn't run one.
 
You can use an original one of a Mitsubishi Evo. Friend of mine drove it on his tuned Audi S3. Makes a nice sound.
Prices in UK for used valves 10-60 pound.
 
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Been offered this, but it has two 2/3mm cracks on the WG hole. Rest of the turbo a-okay and removed from the car a few weeks ago. It'll be getting a full refurb anyway, 360 bearing etc. Worth a punt, or a gamble?
 
Plus, anyone know the correct length of M10 x 1.25 studs to mount the T3? The seller has access to high temperature studs at work, so all I need to tell him is the length. Thanks.
 
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