Blow off valve nipple???????

[Elanlover]

I don't know who can help me here but.....................

I purchased a set of intake pipes for the Elan from Top End Performance some time ago, installed it and have been using it without any issues. This package is essentially a steel pipe and K&N filter to replace the lumpy hose and stock air filter running to the turbo. It also includes a steel pipe running from the throttle body to the connector that runs to the intercooler (I assume). Mounted in the middle of this pipe is the blow off valve.

This valve is a bit noisy for my liking (silence is better) but I realize that any BOV will make some noise. I was calling around to see what could be done to reduce this noise. I initially thought I'd replace it with a recirculating BOV and plumb it back into the air intake so it won't vent inside the engine compartment and make noise. Bad idea I'm informed by Top End. That would cause the turbo to stall which is exactly what we are trying not to do. I hang up then think........Ok, what if I plumb it back through a hose and let it dangle in the old air intake area now open after removing the OEM air filter cannister...............

So, I call Turbo XS, the manufacturer of the BOV and explain what I'm trying to accomplish (reduce the noise essentially). He asks me a few questions abou the setup. I throw in (because I suddenly remember that I always wanted to ask this) "What does the nipple at the top of the BOV do???"

"What? he says. "It isn't connected to anything??" No I say, its just installed as it came out of the box. "Then its not doing anything at all for you right now". Apparently, that nipple needs a 6 mm hose running to the intake manifold (source of vacuum?). I'm worse than a newbie in this kind of discussion so........anyone know what this means?????????

Where would I run this too????? Should I run this somewhere????

Thanks all!

[F1 LOTUS]

You can probably 'T' into the vacuum line on the end of the intake manifold (drivers right). This would cause the valve to open as the throttle closes, otherwise you just have a pressure-relief valve?

[Monty]

There should be a spare nipple at the back off the intake manifold, all u need is a lenght of 3mm hose which u should be able to get from your local motor factor.

[Doug]

are you saying you have NO connection from the engine to the valve to trigger it? if so then yes you need to set up the line. The HKS on my car has 2 nipples and you do not have to plumb then both . . .

[Elanlover]

Thanks for the replies all. To state again, there's no hose from that nipple (trigger Doug?) leading anywhere in the engine bay. Soooooo.....guess I better get one rigged up.

I'm pretty sure I heard the guy from Turbo XS say that it was a 6 mm hose. Monty, 6mm or 3mm? I suppose it depends on the BOV wouldn't it? Can't be too expensive so perhaps I'll just get a length of both. Should I be looking for any specific type or specs for hose?

As for the location to connect it..................where would this superfluous nipple be on the intake manifold? Or where is the line that I could "T" into?

Thanks everyone for your help. I suspect I'll be increasing my sparse knowledge regarding intake "stuff" shortly I'm happy to learn whatever I can/need to make Elan ownership fun. I am somewhat of a newbie when it comes to engines et al. so please be patient.

[ESM]

... I initially thought I'd replace it with a recirculating BOV and plumb it back into the air intake so it won't vent inside the engine compartment and make noise. Bad idea I'm informed by Top End. That would cause the turbo to stall which is exactly what we are trying not to do. ...

What??? How would this cause the turbo to stall? I admit I haven't given it too much thought but when the valve opens it will equalise the pressure on each side of the compressor wheel and that won't stall it. Sounds like you got some duff advice to me.

[Elanlover]

... I initially thought I'd replace it with a recirculating BOV and plumb it back into the air intake so it won't vent inside the engine compartment and make noise. Bad idea I'm informed by Top End. That would cause the turbo to stall which is exactly what we are trying not to do. ...

What??? How would this cause the turbo to stall? I admit I haven't given it too much thought but when the valve opens it will equalise the pressure on each side of the compressor wheel and that won't stall it. Sounds like you got some duff advice to me.

The guy I spoke to at Top End suggested that. However, the guy at Turbo XS didn't say anything really. That was becuase he heard I didn't have the nipple connected so he just said to get the one I have installed working before looking to do anything else.

Any help to offer on the post just before yours???

I realize I'm probably asking questions that make people's eyebrows raise in that "great, another person who wants all the answers handed to them on a platter" position (we need a smiley for that) but I am really a bit lost on this issue. Will try to do as much research as I can. I do have the engine and parts manuals that I scanned but I didn't see what I was lookng/asking for in there.

[F1 LOTUS]

...

Any help to offer on the post just before yours???

.

From TEP's website

Follow the silver/blue hose from the BOV top to the 'T' you'll need to insert

[Elanlover]

This is the exact picture I've been staring at for the last hour! Here was my problem with that picture though.

If you follow the blue hose it T's into another blue hose which runs off somewhere. I've never seen a blue hose under the hood (not that I've looked hard for one) so, I was assuming that both the hose leading from the BOV AND the hose it T's into were custom and part of the install. Unfortunately, the pic doesn't show you where the second blue hose leads at all. I figured out the first part and T connection but thought I'd have to run another hose (2nd blue hose) myself leading somewhere that couldn't be seen in that picture.

Are you saying that there is an existing hose that's stock that it right there as the picture describes (but probably not in blue) that I can T into???? If so, this just got a lot easier than I thought.


Many, many thanks.

[F1 LOTUS]

There's a tube that comes out of the 'D' end (of DOHC) of the manifold and goes to the orange trandsucer for the boost gauge, in this picture it is blue and has brass 'T' piece for the blue hose going to the BOV. All your hoses are likely to be black, the blues must be a TEP upgrade?

[Elanlover]

Thank you immensely Brian. This helps a lot.

[Doug]

I never used it but I think there is a blanking plug on a nipple on the rear of the intake manifold that would be easier to plumb into without having to splice in . . . just find it and plug in.

[Elanlover]

I never used it but I think there is a blanking plug on a nipple on the rear of the intake manifold that would be easier to plumb into without having to splice in . . . just find it and plug in.

Thanks Doug. I plan on fixing this up Saturday morning so I'll have a look for that first. If you'll forgive me, the "rear of the intake" isn't a well known area for me As I'm looking at the engine bay from the front of the car with the hood up where would I look for the rear of the intake and this nipple? Just want to make sure I'm orienting myself correctly to the intake manifold (although I fear you're going to tell me that it really is AT THE REAR as I look at it............... ).

[mailman221]

Elanlover, I installed this same setup from Top End a few weeks ago. As your standining in front of the car on the upper left side of the engine mounted on the engine bay is a round orange boost gauge sensor. It will have a green wire connected to one terminal and the other wire going to ground. On the opposite end of this sensor is a black vacuum line approx. 7" long that goes directly to the side of the manifold. It is this line that you need to cut dead in the middle.

Insert a "T" where this cut was made. Then run a new vacuum line from this "T" to the nipple in your BOV. This new line will need to be about 4' long. I ran mine behind the manifold to neat up the engine bay, but most seem to run their's in front of the manifold and secure to the throttle cable housing. Just make sure it doesn't lay on the manifold and burn a hole!

Top End did not provide me with the "T" so I took my BOV with me to a local auto parts store to get the proper size hose and "T".

Hopes this helps and enjoy the upgrade.

[Ultimatt]

As some of the other guys have intimated, there is an unused blanking plub on the back of the intake manifold. That's the bit with 'DOHC' on it

From what I remember, I think it was to the right hand side of the manifold and had a rubber blanking plug, held in place by a spring clip. Thats' from memory, so don't shoot me if it's different in your case.

Either way, there should be one plug / nipple not used by a hose connection. This can be used to plumb your BOV pipe into and prevents the need for splicing other hoses.

I have had my recirculating Bailey Motorsport valve fitted for several years now and have not noticed problems with the turbo stalling on change due to the recirculation. Am I correct in thinking that the stalling was the previously audible twittering the turbo made on gear change? If so.. denfinetely not there any more

Matt

[Elanlover]

All great info/adivce folks. I really do appreciate it immensely! May have to sign up for abasic mechanics course at some point to ensure I don't hammer away at something important in the engine bay

I'll be playing around with the car Saturday morning and will poke around for the superfluous nipple to avoide the T connection if possible.

[F1 LOTUS]

...poke around for the superfluous nipple to avoide the T connection if possible.

When you find it, take a picture will you?
Happy hunting

[Doug]

It'll look something like this:

[F1 LOTUS]

[Elanlover]

I looked long and hard for that nipple Doug but couldn't find it. And, to add insult to injury, I could not find the other nipple anywhere. I suspect its well hidden in that maze of cables and wires that run around that area. In the end, I cut into the hose running to the transducer and voila! All is well!

Interestingly enough, before I did this I was seeing boost on the gauge reaching just at or under the 1 bar level after installing Alan's chip. He and I both thought that the gauge just wasn't readning accurately. Now that there's a T conection running to the BOV I'm seeing no more than .9 at most but often running around .8 - .85.

I wonder if the BOV is affecting max boost in some way? I've installed all 6 washers they provided in the BOV body to increase the "tension" in it so I don't think its leaking. Hmm................

Now that its installed though I do see a difference. It used to be that under full throttle, then release, the boost gauge would drop to 0 immediately. Now, it only drops to about .25 before I hit the next gear (then rises right away of course). Must be finally doing the intended job.