CBV or not CBV? - Pre Tune.

[jellison]

Looking to get my R mapped in the late summer / autumn.

Been reading up a little on people tunes and what done to get there. I do not want to go overboard (keep it fairly simple as worked on last one (T5), with just a Jetex and a Tune (Southwest in car Tech nr Bristol), where that gained ~60bhp and similar torque with just this on a 150k car (one owner so history known (father) - car was a missile!).

Have read the CBV has a diaphragm that can fail (my car is 89k). What is the value in a) popping in a yellow spring and replacing the std diaphragm with a new OEM one at the same time (http://www.vivaperformance.com/cbv-upgrade-replacement-springs/) or b) or replace with an after market CBV (i.e. ipd / viva, etc ala http://www.vivaperformance.com/cbv-upgrade-kit-s60r-v70r-s60-t5/).

Only mod planned for the engine pre tune, will be and IPD cat back exhaust (new plugs and possibly coil packs) and the above (maybe some vacuum hoses).

Presume tuner needs to know all what has been done before working his magic.

I'm leaning more towards changing spring and new OEM Diaphragm.

Opinion...

[LeeT5]

Volvo do not sell the CBV springs and neither do they sell the CBV on there own, you'd need to buy a whole turbo!

Also, I don't believe the CBV springs shown on the Viva website are intended for use with a stock diaphragm. They are intended for use with cars running much higher boost than stock and alloy CBV.

The CBV is intended as an upgrade over the stock CBV with a rubber diagphragm as it is common that the diagphragm degrades over time, being rubber they can crack.

Therefore, if you just replace the CBV with an alloy type and your car is totally stock, then it's adviseable to use the green spring as this has the same rating as the stock spring.

If your car is heavily modded, tuned mapped and running higher than stock boost, then obviously, you'd need to switch to an aftermarket CBV with a stronger spring as you don't want that extra boost leeching away because the stock or green spring cannot hold the valve closed.

My car is mapped peak boost @ peak torque around 21psi and I run a yellow spring on a Forge CBV.

This is the valve with yellow spring spring that I have fitted to my car. As you can see, you'll save a fortune on import costs over the Viva version!

https://www.forgemotorsport.co.uk/Direct_Fit_Piston_Recirculation_Valve--product--1006.html

[jellison]

Volvo do not sell the CBV springs and neither do they sell the CBV on there own, you'd need to buy a whole turbo!

Also, I don't believe the CBV springs shown on the Viva website are intended for use with a stock diaphragm. They are intended for use with cars running much higher boost than stock and alloy CBV.

The CBV is intended as an upgrade over the stock CBV with a rubber diagphragm as it is common that the diagphragm degrades over time, being rubber they can crack.

Therefore, if you just replace the CBV with an alloy type and your car is totally stock, then it's adviseable to use the green spring as this has the same rating as the stock spring.

If your car is heavily modded, tuned mapped and running higher than stock boost, then obviously, you'd need to switch to an aftermarket CBV with a stronger spring as you don't want that extra boost leeching away because the stock or green spring cannot hold the valve closed.

My car is mapped peak boost @ peak torque around 21psi and I run a yellow spring on a Forge CBV.

This is the valve with yellow spring spring that I have fitted to my car. As you can see, you'll save a fortune on import costs over the Viva version!

https://www.forgemotorsport.co.uk/Direct_Fit_Piston_Recirculation_Valve--product--1006.htmlSo if I had a similar tune to what I had on my T5 I could leave as is (the stock CBV and spring).

The boost is via the mapping right? The spring is to control the pressure on lift off to stop the Turbo being harmed?

Did find a video of changing the spring in the std CBV (looks fiddly and probably something (if required I'd get someone that is very familiar with to do).

I presume my old T5 would have had a lot more most to be 60odd bhp up on std. The tune would give more boost (how else would the power go up?). If I was looking to get a similar rise from the R to the T5 50-60bhp (including the benefit of the catback), std CBV or std CBV but with a fresh (as you are in there - presume this is just an OEM part) and yellow spring?

I'm a lot better with NA race engines....

[LeeT5]

So if I had a similar tune to what I had on my T5 I could leave as is (the stock CBV and spring).

The boost is via the mapping right? The spring is to control the pressure on lift off to stop the Turbo being harmed?

Did find a video of changing the spring in the std CBV (looks fiddly and probably something (if required I'd get someone that is very familiar with to do).

I presume my old T5 would have had a lot more most to be 60odd bhp up on std. The tune would give more boost (how else would the power go up?). If I was looking to get a similar rise from the R to the T5 50-60bhp (including the benefit of the catback), std CBV or std CBV but with a fresh (as you are in there - presume this is just an OEM part) and yellow spring?

I'm a lot better with NA race engines....

Kind of. Boost follows Torque on V70R/S60R. Torque is governed by many things including throttle position, air temp, intake air temp, Engine load, knock control etc

You really need to do a lot of reading up on how Turbo chargers work and the corrolation between wastegate and CBV before you make your decision.

If your car is anything other than stock, then my advise is to upgrade the CBV.

[MoleT-5R]

Volvo do not sell the CBV springs and neither do they sell the CBV on there own, you'd need to buy a whole turbo!

Also, I don't believe the CBV springs shown on the Viva website are intended for use with a stock diaphragm. They are intended for use with cars running much higher boost than stock and alloy CBV.

The CBV is intended as an upgrade over the stock CBV with a rubber diagphragm as it is common that the diagphragm degrades over time, being rubber they can crack.

Therefore, if you just replace the CBV with an alloy type and your car is totally stock, then it's adviseable to use the green spring as this has the same rating as the stock spring.

If your car is heavily modded, tuned mapped and running higher than stock boost, then obviously, you'd need to switch to an aftermarket CBV with a stronger spring as you don't want that extra boost leeching away because the stock or green spring cannot hold the valve closed.

My car is mapped peak boost @ peak torque around 21psi and I run a yellow spring on a Forge CBV.

This is the valve with yellow spring spring that I have fitted to my car. As you can see, you'll save a fortune on import costs over the Viva version!

https://www.forgemotorsport.co.uk/Direct_Fit_Piston_Recirculation_Valve--product--1006.html

you beat me to it Lee. Forge cbv has to be the best way forward as it comes with 2 springs and as you said saves a fortune in import costs. I'd also consider a custom cat back system as this to would have good savings over an IPD item and give greater choice in finishers etc. Neither of these items I would see really necessitate a new tune, but would want to be mentioned when getting a new tune though.

[jellison]

Will do some reading, talk to the mapper and parts for Volvo (Jamie). Sounds like I might be homing in on what you have.

No rush.

Forge CBV is this a bolt on replacement?

Thanks Lee.

[MoleT-5R]

Will do some reading, talk to the mapper and parts for Volvo (Jamie). Sounds like I might be homing in on what you have.

No rush.

Forge CBV is this a bolt on replacement?

Thanks Lee.

yep bolt on replacement, quality job like all there stuff.

[jellison]

Thanks Mole.

I have looked into a custom Catback (via a guy in Kent that has done a few exhaust for me). His view was that it would be more than a Jetex type price and about the same as the IPD imported (I do really like the look of that with the one big bore pipe over the 2 as per the Jetex.

Like I say only tweaking to the engine will be a catback, probably this Forge CBV and a tune, then enjoy it. If I get similar uplift in engine numbers (that I had in my T5) I think that will be me happy with the car for many years, then just maintain.

PFV do the Forge CBV http://www.partsforvolvosonline.com/product_info.php?products_id=6602

[MoleT-5R]

Thanks Mole.

I have looked into a custom Catback (via a guy in Kent that has done a few exhaust for me). His view was that it would be more than a Jetex type price and about the same as the IPD imported (I do really like the look of that with the one big bore pipe over the 2 as per the Jetex.

Like I say only tweaking to the engine will be a catback, probably this Forge CBV and a tune, then enjoy it. If I get similar uplift in engine numbers (that I had in my T5) I think that will be me happy with the car for many years, then just maintain.

PFV do the Forge CBV http://www.partsforvolvosonline.com/product_info.php?products_id=6602

Fair do's mate, you've obviously done your research, It's just to carriage and import costs that put me off stuff from the usa, but then again if you ordering one item you may as we plunder IPD for everything you can and get it all sent in one order, cost a bit more but save on future shipping costs

[jellison]

Yep. I remember when the dollar was 1.8-9 to the pound. I used to order so much stuff from the US back then. I did 2 lots of full drivetrains for a TVR LS6 and trans swap for a Chimeara back in the mid 2000's and then about 5-6 years back got a v.special one off V8 for a later TVR racer (must have been more like 1.5 then), a lot different at 1.2! It used to be like smarties, mmmm what shall I have next!

[960kg]

Have read the CBV has a diaphragm that can fail (my car is 89k). What is the value in a) popping in a yellow spring and replacing the std diaphragm with a new OEM one at the same time.

Only mod planned for the engine pre tune, will be and IPD cat back exhaust (new plugs and possibly coil packs) and the above (maybe some vacuum hoses).

Presume tuner needs to know all what has been done before working his magic.

I'm leaning more towards changing spring and new OEM Diaphragm.

Opinion...

It all depends how much money you want to throw away??

The rubber diaphragm in the standard CBV on a V70 T5 is what i believe to be the most reliable part of the whole entire Volvo!

Yes, i did buy a Forge CBV after wondering what the difference would be and quite honestly there was NO difference.....and i used 20psi for around 3 years before i sold it on.....the Forge only used for a couple of months as i changed to an 18T from the std. V70 16T and used 20psi on that also.

My diaphragm had done 160,000mls and it still looked good as i do think the oil that can get on it from the turbo and PSV system keeps it supple and it will not be dry to get cracked.

If you think your spring has weakened and think it is not sealing correctly you can do what they do in the USA called the "Nickel Trick" but a 10p is roughly the same size and does fit in the space to help strengthen the spring.

Of course as always each to his own?

[MoleT-5R]

It all depends how much money you want to throw away??

The rubber diaphragm in the standard CBV on a V70 T5 is what i believe to be the most reliable part of the whole entire Volvo!

Yes, i did buy a Forge CBV after wondering what the difference would be and quite honestly there was NO difference.....and i used 20psi for around 3 years before i sold it on.....the Forge only used for a couple of months as i changed to an 18T from the std. V70 16T and used 20psi on that also.

My diaphragm had done 160,000mls and it still looked good as i do think the oil that can get on it from the turbo and PSV system keeps it supple and it will not be dry to get cracked.

If you think your spring has weakened and think it is not sealing correctly you can do what they do in the USA called the "Nickel Trick" but a 10p is roughly the same size and does fit in the space to help strengthen the spring.

Of course as always each to his own?

Fair point Keith, mine did split, but that had done about 230, 000 if still original, I blanked and went the bov valve route and moved on in the end to a turbosmart re-circ bov plumbed back into the intake, it seemed a great improvement over the previous one. Unfortunately that didn't last long as another forum member had more need of it than me, so it's the other side of the world on Jamest5r's T-5R

[jellison]

Thanks.

On the spring. Assuming it will be mapped to get say 350+bhp, that will take X extra boost.
To get to that level are we then saying you'd definitely go yellow spring?

As if we assume my T5 at approx 60bhp over the std 250 had a good bit extra boost to get there via the remap, that had no spring changes, maybe a question for the mapper?

The spring does not prevent the boost dialled in but is there to aid the turbo when lifting off, the stronger spring helps here?

[don kalmar union]

Which 'R' are we talking about here the earlier ones or the S60R/V70R p2?

Don.

[LeeT5]

Will do some reading, talk to the mapper and parts for Volvo (Jamie). Sounds like I might be homing in on what you have.

No rush.

Forge CBV is this a bolt on replacement?

Thanks Lee.

NO need to thank me in thread, though it's appreciated. Just click on the 'Thanks' button, bottome left of each thread window :wink:

[LeeT5]

Which 'R' are we talking about here the earlier ones or the S60R/V70R p2?

Don.

Later P2 R Don :smile:

[M-R-P]

I have a good/used OE k24 valve if you want it.

[htomi]

I have the forge cbv, however my car hasn't been tuned. It is bolt on. However its a pain in the hole job to install. As you're planning to map your car I'd suggest to get the turbo inlet hose replaced at the same time as the factory plastic pipe can crack, plus it has a restricted flow vs the Snabb or do88 piping.
Most importantly, I'd suggest get the block shimmed as a very first thing to do to prevent the well known cylinder-wall crack, then add an FMIC or at least a do88 Intercooler to the pack and you should be good to go with the tune.