making boost but not accelerating

[Clonebug]

You can build one for about $20.00 U.S. since brass has gone through the roof in the last couple years due to lead-free brass.

Use this as a guide.... there are many way to build one. I posted a pic of mine on your thread on thesamba yesterday.

http://speedracer90.tripod.com/mbc/

[Dan Dryden]

It sounds like fuel starvation to me.
Reduce the boost or increase fuelling.

[advinnie]

You can build one for about $20.00 U.S. since bras has gone through the roof in the last couple years due to lead-free brass.

Use this as a guide.... there are many way to build one. I posted a pic of mine on your thread on thesamba yesterday.

http://speedracer90.tripod.com/mbc/

Im having trouble understanding how this can/will reduce the boost pressure? I see how it work the unit gets a signal from the turbo outlet pipe witch compresses the spring and depending on what position you have set the spring it will move the ball bearing opening up the out let to the stock wastegate regulator . But all I can see it doing is allowing the turbo to produce more boost by delaying the signal getting to the stock wastegate regulator?
I'm I just not understand it right?

[bazibbo]

I think that would only potentially increase boost pressure. I've run one for a bit and they're a great way of adjusting boost levels by blatently telling lies to the wastegate.

So my wastegate has ( for example ) a 7lb spring, and this is the lowest boost I can achieve. But I can stop it receiving any signal, using the afore mentioned 'dawes valve' until around 10psi, which is where I set the dawes valve. Think that's how it all works, someone shoup if it's not.



As everyone is saying, you need to be in control of your boost and get it down a lot lower - then use the valve to raise it if needed ( you will too, its addictive )

A few other bits too, also probably mentioned - above a certain level of boost, 5 or 6psi at a guess (!), you will get your standard valves blowing open. I ran single uprated springs on my standard 1600 renault 5 carb'd bug, when I started off.

Are you using the renault fuel pressure regulator with a referance line for boost.

Is your dissy locked at 24 degrees, or restricted to 24 degrees - restricted is better.

And lastly what fuel pump and fuel line setup are you using.


I had loads of fun with a standard 1600 you'll love boost

[advinnie]

Yes im using a pressure regulator with a referance line for boost.
The dissy is locked at 24 degrees BTDC
Im using electric fuel pump witch was supposed to be rated at 25psi but I can only get 21.7psi
the fuel pump is at the front of the car by the tank the line then runs to the rear through a filter and then into the boost sensitive fuel pressure regulator. Then I have one fuel line going to the carb and a feed back going back to the tank
Interesting that about the valve being blown open
and yes I do agree with everyone about lowering the boost I only ever intended to run 10 psi max NOT 20 plus psi.

[advinnie]

Hi all I have just for a quick drive after lengthingen the wastegate regulator push rod and good and bad news. Good news max boost never went over .8 bar still high but better than 1.4 now the bad news the boost was not constant it was fluctuatin all over the place witch it has never done before I'm guessing this is due to there not being enough spring pressure now and the wastegate is flapping around?

[advinnie]

By the way you lot was right my brother has just sent slme the turbo info
Manufacturer:Rover
Engine:2.0 D
BHP:114
Turbo Brand:Mitsubishi
Turbo Model:TD02
OE turbo no:49173-06100
OEM part no:2248060

[bazibbo]

No idea on boost fluctuation

On the other issue, yep, as per Chips comment 'Valve float' and might be a reason why the boost continues up but the engine doesn't want to accelerate - that's my guess.

I restricted my 009 dissy by sticking a small allen screw into it somewhere. It's mean't to be better than a locked one for starting, general manners and fuel economy - but to be fair, I've never run a locked one.

Fuel pressure - you'll need whatever the carb wants + boost pressure. So if the carb wanted 3psi and you were running at 8psi, you'd need 11psi.

My early Renault 5 based build is http://www.moler-one.com/gyvwforum/inde ... ic=2219.45 if it helps.


Not very technical are my answers...

[advinnie]

My dizzy is locked but I have no trouble at all with it starting but I will have a go of what you said and install a bolt to limit the advance to 24 degrees instead of locking it.
I will have a look at your thread in the link in a bit mate and this is the fuel pressure to boost pressure readings
Right fuel pressure readings 
Boost psi - fuel psi 
zero 3 psi 
1psi 4psi 
2 psi 5psi 
3 psi 6 psi 
4 psi 7psi 
6 psi 9 psi 
8 psi 11 psi 
10 psi 13 psi 
14 psi 17 psi 
16 psi 18 psi 
17 psi 19 psi 
18 psi 19 psi 
20 psi 20 psi 
22 psi 20 psi 
so as you can see the fuel pressure from zero boost to 14 psi boost is always 3 psi higher then as the boost get higher the difference between the boost and fuel psi reduces and around 18 psi (1.2 bar) is where the problems start and that is also the point where boost pressure is almost the same as fuel pressure does this make sense?

[Clonebug]

You can build one for about $20.00 U.S. since bras has gone through the roof in the last couple years due to lead-free brass.

Use this as a guide.... there are many way to build one. I posted a pic of mine on your thread on thesamba yesterday.

http://speedracer90.tripod.com/mbc/

Im having trouble understanding how this can/will reduce the boost pressure? I see how it work the unit gets a signal from the turbo outlet pipe witch compresses the spring and depending on what position you have set the spring it will move the ball bearing opening up the out let to the stock wastegate regulator . But all I can see it doing is allowing the turbo to produce more boost by delaying the signal getting to the stock wastegate regulator?
I'm I just not understand it right?

The boost controller can only work if you have a lighter spring in the waste gate which I'm sure was mentioned in an earlier post.

My wastegate has a 6 lb. spring which is the case for all the Subaru turbos I have used.
Since your turbo is from a diesel... that would explain the 20 lb (1.4 bar) wastegate spring.
You would need to either adjust it as mentioned in an earlier post of else find a replacement diaphram with a lighter spring.

As I mentioned in your samba thread......your fuel pump can not support the boost you are putting out. You need to lower the boost to 14 lbs or else get a better pump.
I used a stock mechanical pump boost referenced and it worked nicely up to the 13 lbs boost I ran with the carb.

I'm not sure how much flow your regulator can handle but you are close to the point where you would need a FI style pump to supply the fuel pressure......and if so you would need a regulator that can bypass the extra fuel and support the lower pressures, since a FI pump can put out 100 lbs. and enough fuel for upwards of 500 hp depending on the pump.

[advinnie]

bazibbo
wow I finally read your build thread I love it must say you did have more than your fair share of problems with that build.

[advinnie]

Hi all git the car to a tuners this morning and I'm not a 100% sure what they have done and told me.
well they said 20 psi is way way way to much for this engine although with there machine they could not detecte anyone detonation but they did say the air fuel mix was ok with a reading of 14.0 to 14.9 from idle zero boost to 11 psi boost then it just went lean what ever that means?
Also they said that the turbo was spinning up to fast ? What are they on about?
They have also told me that they have opened the wastegate just a Nat's @@@@ ti slow the turbo down and allow the wastage to start dumping it's pressure earlier. Does this make any sense to you lot cause I have a gunning feeling that they have no idea or just could be bothered with my car.

[Chip Birks]

What they say mostly makes sense to me...14.0 to 14.9 at 11psi sounds on the lean side to me. Going even leaner after that completely explains the lack of power. Sounds to me like you may need to do a little more turbo theory research.

[advinnie]

Sorry that 11 psi should of said 14 psi my bad
I'm doing as much research as I can the first time I ever land hands on a turbo was just last month. I can see what they are saying about holding the wastegate open just a little and how that will slow down the time it take the turbo to Spon up and how it will open earlier but I was thinking it might burn the wastegate valve/flap just like an exhaust valve would go if not allowed to shut?

[advinnie]

Just got of the phone to the turners cause they still haven't called back saying the cars ready and it will not be till Thursday
So far I've payed them £110 for them to just run it up and tell me it's lean and for them to open the wastegate a little. They are now going to reject the mains for me. They are happy with the idle A/F of 14.6 (I think they said) but want to aim for a much lower ratio of 12.
I now realise that I don't know as much as I thought about this turbos but I'm getting there
just one more question. Cause I'm only running a carb with no computers at all to control the fuel ratio and so on surly if the idle is good the idle is good but if they are planning richering up the mix when on boost fair enough i do understand where that is but if I come off of boost and start cruising wouldn't the mix be to rich?
I like I said earlier I think I'm starting to confuse myself here.
Anyway just want to thank everyone for all there help on this issue I have and thanks for taking it easy on a newbie on turbos