MR 2 Turbo dump valve nightmares

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APDevelopments
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MR 2 Turbo dump valve nightmares

Post by APDevelopments » 06/08/17 22:32

Hi.
Could somebody tell me what the actual purpose of a recirculating dump valve is.
My MR2 turbo is totally standard but it keeps blowing the damm hose off.
It has blown one of the main hoses off twice today. I've changed clamps everything.
I could buy a new one with better pipe mounts so the clamp could grip it better but what would happen if I removed it completely?
Many thanks

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Re: MR 2 Turbo dump valve nightmares

Post by MR2DI4 » 06/08/17 22:55

When you suddenly close the throttle under boost, that air has to have somewhere to go or it does nasty things to the turbo. The stock bypass valve is the best one to use by the way its designed but the weakness is that little bit of plastic valve mounted beside it which should be replaced. Make sure you put it in the right way around.

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Re: MR 2 Turbo dump valve nightmares

Post by benckj » 06/08/17 23:26

Best idea is to get rid of it all together. It only wastes the pressure already built up by compressor and has no real purpose.

Join a BOV delete club as its growing by the day. I haven't run one in 4 years and never looked back. Can now hear the turbo spooling nicely and have more power between shifts.

Search the US forums if you are a doubter and want more info. Don't buy into any of those stories about turbo surge protection.

jim

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Re: MR 2 Turbo dump valve nightmares

Post by jimi » 06/08/17 23:33

In your opinion ;) other people (including Mr T) have different thoughts on the matter :)
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Re: MR 2 Turbo dump valve nightmares

Post by pbmr2 » 06/08/17 23:53

The bearings in the turbo could take a kicking long term. Little worried to bov delete with the ceramic turbine. stalling or even resisting the intake compressor would slow the turbine side which would still have gasses hitting it. however if the boost pressue spikes then the wastegate opens anyway, which would help some.
Know someone who broke 2 turbine wheels in 6 weeks, but he was running a bov.

Ran no bov on a couple of Nissans for a total of about 60k miles but that was over 2 cars. they don't run ceramic turbines, one of them was a roller bearing turbo. had no issues but not the same setup though.

APD, you don't say what year or rev your car is?
If it's rev3+ you could just vent to atmosphere. Which pipe is it popping off?
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Re: MR 2 Turbo dump valve nightmares

Post by APDevelopments » 07/08/17 8:00

Hi Guys.
I've attached a photo of the pipe at fault.
I know my engine looks mental. It's actually totally standard (stock).
As my MR2 is actually a Lamborghini kit car having a hiss everything I change gear (shift) would be just wrong.
I've even gone as far a superglue and a clap to fix the pipe on but it still blows off.
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Re: MR 2 Turbo dump valve nightmares

Post by shinny » 07/08/17 8:19

pbmr2 wrote:
06/08/17 23:53
Which pipe is it popping off?
Echoing this question as the most pertinent missing information. Although for the rest of this post, I'm going to assume it's the hose between the IC hot pipe and the BOV as that seems the likely culprit to me.

Can you heard the valve operating? Could it be that the valve isn't opening and the hose proves to be the weak point with the pressure spike? Alternatively, is there enough movement of the engine on its mounts for the pipe to be popped off by the movement between the IC pipe and the BOV?

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Re: MR 2 Turbo dump valve nightmares

Post by benckj » 07/08/17 10:14

Do more research on the BOV deletion. Not one example of a blown or worn turbo from its elimination. Once it's removed and blocked off you can thank me.

Jim

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Re: MR 2 Turbo dump valve nightmares

Post by shinny » 07/08/17 12:03

benckj wrote:
07/08/17 10:14
Do more research on the BOV deletion. Not one example of a blown or worn turbo from its elimination. Once it's removed and blocked off you can thank me.

Jim
You may or may not be right about the BOV delete, but have you read the OP's posts? He says he doesn't want obvious turbo noises on his Lambo replica; the only way to achieve that is a recirc. The turbo chatter that would result from a BOV delete making his "Lambo" sound like a Subaru rally car is clearly not the solution here!

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Re: MR 2 Turbo dump valve nightmares

Post by TonyleFrog » 07/08/17 13:04

pbmr2 wrote:
06/08/17 23:53
APD, you don't say what year or rev your car is?
If it's rev3+ you could just vent to atmosphere. Which pipe is it popping off?
It's a Rev 1.

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Re: MR 2 Turbo dump valve nightmares

Post by pbmr2 » 07/08/17 16:58

wow truely an epicly long build thread, just read the whole thing. The amount of hours spent on it is crazy.. How many windscreens? Think he's had more than me now lol.

So the stock bov intake pipe is poping off from the DV end?
Does the DV/bov work?

Is the car making more turbo noises just before the pipe pops off?
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Re: MR 2 Turbo dump valve nightmares

Post by APDevelopments » 07/08/17 19:12

Hi guys.
Thankyou for your replies.
Yes my Lamborghini has been a long journey and this Sunday was its first ever real outing.
So there's bound to be a few teething troubles with any kitcar.
Considering the amount of work I've done to it a hose blowing off isn't serious. Just annoying.
When it blows of I'm not giving it the full beans either which is strange.
Because it's the stock dump valve there isn't much of a flange to clamp the hose to so this is the problem.
You can here the turbo spooling up but then the cars so loud you can't hear anything else except for the roar this thing makes.
It's no fart can. My zero silencer on 3" tubing straight but 12" cherry bomb only works really well on the mr2 turbo.
It may not be the fastest but "censored" it's loud. I went through a tunnel just below it's 8.5k rev limiter in 1st gear.
Sounds completely mental. Sounds like a super bike than any car.
I will be opening up a YouTube channel soon on the car when I get my GoPro. So you will be able to see what I mean.
She's more Lamborghini then mr2 now really and she gets lots of attention where ever it goes.
Photo attached of the beast.
Many thanks
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Re: MR 2 Turbo dump valve nightmares

Post by benckj » 07/08/17 21:39

Because it's the stock dump valve there isn't much of a flange to clamp the hose to so this is the problem.
One solution worth checking is to clamp off the vacuum feed to the BOV. In this way the BOV will not open and you can check to see if the 'sound' is correct on your set-up. Just use a small vice grip to clamp the line and have another burst through the tunnel.

Hopefully the main hose stays put during this experiment as there will be limited pressure surging on system.

BTW the car is looking amazing and wouldn't pick it for a MR2 kit. I need to look at the rest of your build to understand cars evolution.

Jim

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Re: MR 2 Turbo dump valve nightmares

Post by Rev5v6 » 07/08/17 22:30

benckj wrote:
07/08/17 10:14
Do more research on the BOV deletion. Not one example of a blown or worn turbo from its elimination. Once it's removed and blocked off you can thank me.

Jim

I love it when someone turns up out of the blue and says something like this. :clapping:

Nearly as much as Jimi's non replies to any discussion on text speak and not chasing forum traffic elsewhere. :th:

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