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Blown Turbo ?!!?


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Hi all

 

Last night on my way home from work I was overtaking someone at a normal kind of speed and the second turbo never came in.

 

At about 3500 - 4000 rpm the engine seemed to go breathless and then boost pressure started to drop and kept dropping all the way to below zero on the gauge.

 

I'm taking it to Chris Wilson tonight for him to give a verdict on what could be the problem - hopefully a hose or something, but I'm fearing the worst.

 

After I limped home I spoke to Chris and he said to check things like hoses, connections, etc., but whilst the car was idling I noticed that when the revs rose for the air con there was a rattling noise from the turbo housing area. When the revs drop again the rattling disappears.

 

Is this rattling a sign of impending doom or is there still hope that it could be something easily corrected?

 

To quote Peter Kay's Mr Softy Top: "I don't f**kin' need this do ah!!"

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Originally posted by Diane Abol

We can now supply some seriously fak'orf hybrids based on stock

blowers....we are told to expect 550bhp at 1.8 from the full race spec set !!!

 

We are fitting a set to Craig Martins car now, should be finished 2night....well soon see just how good they are !!!

 

Justin,

What are the EGT's like on that sort of kit? I ask because I hear that the next bottleneck in performance on a properly-fuelled and intercooled hybrid setup is the exhaust manifold, as it's by nature restrictive due to the sequential setup.

 

-Ian

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And, back on the topic of the thread, my money is on the vac hose that goes to the exhaust gas control valve. It's here:

EGCV

 

It's the can shaped thing (and indeed, the only thing even close to being in focus).

The piccy is viewed from the drivers side suspension turret looking down under the turbos. You can just about see my gay blue vac hose coming off the shiny pipe on the right hand side of the EGCV.

 

If that hose has come off at either end, #2 turbo won't spin but the airflow valve will open. The boosted air from #1 will then go through #2 as best as it can and recirculate back into the intake side of the turbos. Causes a huge boost drop and power loss. Sound familiar?

 

It's not the only hose that can cause this, but it's one of the least noticeable and most prone...

 

-Ian

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Originally posted by Ian C

 

Justin,

What are the EGT's like on that sort of kit? I ask because I hear that the next bottleneck in performance on a properly-fuelled and intercooled hybrid setup is the exhaust manifold, as it's by nature restrictive due to the sequential setup.

 

-Ian

 

This is why Terry could 'only' run 1.6bar.

 

So whats different? A new exhaust manifold?

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Originally posted by Syed Shah

 

This is why Terry could 'only' run 1.6bar.

 

So whats different? A new exhaust manifold?

 

I doubt it's anything to do with custom exhausts manifolds.

 

Terry has his spec of hybrid and Justin has his spec of hybrid, the two are unlikely to be identical so there is no reason why they should need the same boost pressure to obtain the same power.

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Originally posted by GavinL

 

I doubt it's anything to do with custom exhausts manifolds.

 

Terry has his spec of hybrid and Justin has his spec of hybrid, the two are unlikely to be identical so there is no reason why they should need the same boost pressure to obtain the same power.

 

True, they probably wouldn't be identical, but Justin's run at 1.8bar, and that's a high old boost pressure for the stock sequential exhaust manifold.

 

Put it this way - what effect does 550bhp's worth of exhaust gas going through the stock manifold have on EGTs? As I know I've been warned that this is the next restriction and Terry got about 1.6bar, ???bhp out of his setup before it became a limiting factor.

 

I'm interested as I want to get the most out of my TT setup as I can.

 

-Ian

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The car is now at Chris Wilson's and I should know by the weekend just what the problem is.

 

Chris reckons the rattling noise might be parts of the blades that didn't get past the o2 sensor when the thing gave way.

 

I'm still hoping that it's not as bad as it seems but at the end of the day I suppose I have to face up to the reality that I could be facing a monster repair bill :(

 

When talking to Chris about possible options for replacement he was saying that as it's an auto there are certain things to take into consideration. I was thinking along the lines of hybrids that I've been reading about on the msg board, but as Chris says, I'd have to replace no.1 as well and therefore the cost would only go up.

 

I would like more low down pull from the car and was thinking that maybe the oppurtunity to explore the hybrid route would give this to me but after a chatting to Chris I'm following his advice and, if the damage is a knackered turbo, I'm going for a rebuild of no.2 to retain the same setup.

 

With this and my soon-to-be-repaired Badger damage I'm facing a winter of discontent. Now then, where did I put the details of that money making internet scam ..... :sly:

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Originally posted by Ian C

 

True, they probably wouldn't be identical, but Justin's run at 1.8bar, and that's a high old boost pressure for the stock sequential exhaust manifold.

 

 

Surely the issue is volume of expended gasses not boost pressure (boost pressure being on the inlet side of things)

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Agreed. You could run the stock ones on 1.8bar, doesn't mean you'll get more power than on 1.4 :)

 

I realised that, which is why I added "Put it this way - what effect does 550bhp's worth of exhaust gas going through the stock manifold have on EGTs? ", changing the focus onto the exhaust gas coming out of the engine, rather than the boost pressure going in.

 

So, ignoring the boost pressure for now, Justin's hybrids flow 550bhp's worth of air. Terry's experiences were that, IIRC, just under 500bhp was the best he could get before EGTs were a limiting factor (due to the stock manifold). So, my question is, irrespective of the turbos - can you run 550bhp with safe EGTs while retaining the stock sequential exhaust manifold? If so, why couldn't Terry? Are there any modifications required?

 

-Ian

 

PS sorry for the thread hijack - Gavin, maybe we should start up a thread in technical and continue this?

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Guest Terry S

I don't often disagree with Leon but I doubt it unless you sort out the manifold. Also I think you'd have to run the TTC to keep the EGT's low. There is something new in the Hybrid pipeline that will knock spots off of anything else offered but I think Leon is going to do some more R&D before putting them on anyone's car. To get the most out of these things the tolerances are very tight as you can imagine, so it's very easy to get it wrong.

 

Also there is a big difference to a turbo/s being able to flow enough are for XXX bhp & actually doing it.

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Terry,

Glad to have you in on this - you were running 440cc injectors at the time, right? Could that have had an effect at full boost, i.e. you were edging on running lean and thus raised the EGTs, whereas more fuelling would have kept them down enough to run higher power?

 

Just being devil's advocate :)

 

I'm getting an EGT gauge soon so hopefully I'll be able to do some research into this...

 

-Ian

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Guest Terry S

Ian you:flame Dev

 

You have forgotten that I was also running two additional 550cc's. Trust me I had enough fuel;)

 

Glad to hear that your'e getting an EGT. Did you get it from my friend?

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Guest Terry S

TTC won't help the header. VSV's are a royal pain in the arse.

 

The cost of a one off header was too high, & I have a thirst for power. It would have been OK for a while but now I can just keep bolting on bigger turbo's or bigger AR exhaust housing's when I need more power. I can exhange my new turbo now for a bigger one, & the exhaust housing are about £150. I can even have a turbo for track days/street & another for drag events. Just change a map in the ECU & off we go. That's a BIG benefit over BIG Twins:p

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Originally posted by Terry Saunders

Ian you:flame Dev

 

You have forgotten that I was also running two additional 550cc's. Trust me I had enough fuel;)

 

Glad to hear that your'e getting an EGT. Did you get it from my friend?

 

Heh. Yes, I had forgotten - apparently I *don't* recall correctly! OK, well, as you had direct experience with a potent hybrid twin setup, I'm inclined to take your EGT warnings into consideration, and assume that I can't go past 500bhp with the sequential manifold.

 

Of course, I have a spare one sat in the garage that may be hacked around by someone if that would help...

 

EGT gauge is indeed coming from your contact, thanks for that, I can't believe the difference in price!!!

 

I would love to go big single, especially with you and PW and Registered Nutter doing mad things, but it's such a colossal amount of money (to do it properly) I can't, so I'm aiming for the best bangs-per-buck sequential setup I can get :)

 

-Ian

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