TT Conversion - Single or twin BOV's?

[JMA-RUF]

Gents,

I was just wondering, it looks like the 993TT doesn't use, or have dual BOV's (i.e. one for each turbo).

Does the 993TT only use a single BOV post intercooler / pre-throttle body?

I'm trying to decide whether I use dual BOV's or just a single one straight after the intercooler / before the throttle plate.

Discuss please?!?

[930gt-40r]

James,
If going for recirculating setup- I would use the Tial recirc valve (most have not seen one, but it looks like a water bong...) But the reason that I would use this unit is that you can be rest assured that it will flow enough for your two turbos. Now if you want to use traditional porsche aftermarket aluminum diverter valves, I would use one for each turbo because they are small. For reference- I am pretty sure that the 993TT uses two from the factory and am 100% sure that the 996TT uses two as well. I would go with the Tial because it flows more and one recirc valve is less plumbing than two.

[JMA-RUF]

Thanks, Kris.

I actually have two 50mm Tial style BOV's that I was planning to use. One on each turbo charge pipe (pre-IC), but was wondering if that's overkill for a relatively low boost application running 1.0-1.2bar.

I wouldn't mind just having the one 50mm BOV post-IC for simplicity sake, that's all.

[930gt-40r]

It is over kill- but hey who's counting? are you going to run a mass air?

[mb911]

Originally Posted by 930gt-40r

James,
If going for recirculating setup- I would use the Tial recirc valve (most have not seen one, but it looks like a water bong...) But the reason that I would use this unit is that you can be rest assured that it will flow enough for your two turbos. Now if you want to use traditional porsche aftermarket aluminum diverter valves, I would use one for each turbo because they are small. For reference- I am pretty sure that the 993TT uses two from the factory and am 100% sure that the 996TT uses two as well. I would go with the Tial because it flows more and one recirc valve is less plumbing than two.

are you referring to the Q?

[930gt-40r]

This is the "alpha Q"
now tell me this doesn't look like an implement for the consumption of cannabis
Now if doing a mass air metered car, this would be a great product.

[JMA-RUF]

I have two of these:



I guess I might as well use what I have. Just think it's overkill having one for each turbo. I would have prefered to use one 50mm BOV post IC, instead of two of these

[red9]

What did finished set up look like?

[beepbeep]

Originally Posted by JMA-RUF

I have two of these:



I guess I might as well use what I have. Just think it's overkill having one for each turbo. I would have prefered to use one 50mm BOV post IC, instead of two of these

That takes to much space and will make your motor run too rich if EFI utilizes any sort of air-measuring device other than speed/density. Single bosch plastic BOV works fine as long as turbo discharge is siamesed.