making boost but not accelerating

[advinnie]

Hi all I'm new to turbos so please bear with me.
Right I have a 1300 1973 vw beetle witch I have just finished fitting a turbo but I have hit a problem.
The timing is locked to 24 degrees BTDC and the turbo can make 20 psi of boost if Im silly in it but the problem is some times when I try to accelerate ( only in third and fourth gear) the bug will pick up speed the boost will start to come on then the engine stops accelerating but the boost is still going. Does this make sense?

[behappy]

Many you have a leak somewhere

[Clonebug]

How about you start from scratch and tell us everything about the engine.

CC's
Cam
Carb and jetting
Turbo with specs and how big the inlet wheel and outlet wheel is.

How you came about this.
What kind of engine experience you have........and so on.

No one on here knows a thing about you or your car and can't make a guess unless you give more info..

Oh......and by the way.....Welcome to the forums and the insanity of the addiction.

[advinnie]

I've been building aircooled motors for five years now everything from a stock 1200cc motor up to a 2054cc motor with 175 bhp/ 154 at the wheel all N/A engines. I no longer found it a challenge to build this type of engine so decided to start playing around with turbos.
The engine
1300cc lump
balance 69mm crank
stock cam
stock lifter
bolt up 1.1:1 rockers
Stock 1300 heads with a 3 angle valve job
full weight fly wheel
Kennedy clutch and pressure plate
All rotating parts balanced
the carb was from a renault 5 GT turbo
the turbo I have no idea where it came from I found it in my dad's garage and the only info I can find on the turbo is in the photo I've just posted.
The wastegate opens at 1.4 bar
I really can't remember what the jets are the car was sent to a garage to tune up but unfortunately they are no longer around.
Here's the photo of the only tag on the turbo <a href="http://s1303.photobucket.com/user/advin ... c.jpg.html" target="_blank"><img src="http://i1303.photobucket.com/albums/ag1 ... rmenpc.jpg" border="0" alt=" photo 20160214_214233-1_zpse1rmenpc.jpg"/></a>

[Chip Birks]

Valve float

[advinnie]

http://i1303.photobucket.com/albums/ag1 ... rmenpc.jpg

I can't seem to post photos for some reason so here's a direct link to it if it works?

[advinnie]

Valve float

Possible BUT here's some more information the car stops accelerating and nose dives and starts to kankroo when the boost gets to just over one bar. If I'm gentle with it and keep the boost under 0.8 bar she will continue to accelerate like a dream in third and fourth gear. Now here's what happened tonight I was driving a 60 mph hit a big hill I put my foot down boost started to rise to .5 bar and all was fine I started to over take someone so put my foot down even more boost went to .8 bar still all was fine then without warning it felt like the engine was loosing power it was not slowing down at all it just felt I was have to put my foot down more than I should to maintain this speed but I could clearly hear that the turbo was still on boost and the gauge was reading 0.9 bar. It felt like the car was running out of fuel?

[Clonebug]

http://i1303.photobucket.com/albums/ag1 ... rmenpc.jpg

I can't seem to post photos for some reason so here's a direct link to it if it works?

Pics need to be a max of 800X600 in size.

Looks like a MHI TD025L3-T08-3.3 turbo from a BMW Rover 75 Diesel 2.0 engine.

That would explain why the wastegate is set at 1.4-1.5 bar. Not many gasoline autos will have a wastegate set that high.
Usually they are set around 6 lbs and the computer operates an EBC for boost control.

In my opinion running that engine at 20 lbs. boost without an O2 sensor and some sort of boost control to limit it lower for testing is a grenade waiting to happen.
Your IAT's are going to be over 250 degrees and that is detonation territory for sure. If you are running lean at that boost you are going to burn something up.
You haven't stated whether you have actually tuned it or not so my guess is that carb was not meant for even half that boost level.

You certainly don't want to pound 20 lbs of boost into it without knowing a little of what the engine is getting.

I monitor advance, Boost, IAT's, AFR's pulse width and a whole plethora of other things in order to run up to 22 lbs boost.
I am pumping up to 2 gph of Water/Alcohol into the engine to keep the air temps down to 130 degrees at 20 degrees advance and 22 lbs boost. My afr's are pretty consistent at 12.0:1 when at full boost.

Without an O2 sensor you are running blind.

I have spent over 4 years trying to perfect my turbo engine so it is not a simple thing although I am just a humble blade operator and not an engine guru.
I have a set of cracked P/C's sitting on the shelf to prove I'm not a pro.

I'm not trying to be an ass about it and I certainly don't know everything about a turbo engine.

I did spend 2 frustrating years trying to get my 34 pict blow through working but finally went to FI and never looked back.

[Clonebug]

Valve float

Possible BUT here's some more information the car stops accelerating and nose dives and starts to kankroo when the boost gets to just over one bar. If I'm gentle with it and keep the boost under 0.8 bar she will continue to accelerate like a dream in third and fourth gear. Now here's what happened tonight I was driving a 60 mph hit a big hill I put my foot down boost started to rise to .5 bar and all was fine I started to over take someone so put my foot down even more boost went to .8 bar still all was fine then without warning it felt like the engine was loosing power it was not slowing down at all it just felt I was have to put my foot down more than I should to maintain this speed but I could clearly hear that the turbo was still on boost and the gauge was reading 0.9 bar. It felt like the car was running out of fuel?

I don't know the definition of Kankroo is but if yours was anything like my carb turbo it would pull great in first, second and third till it hit full boost around 3800-4000 rpm and then it went full lean at 18.0:1 afr and start pinging.
I would then have to let off. I could alway get it to work up to about 70-75 mph in third but fourth gave too much load for the fuel supply.

Check your fuel flow to the carb first. Get an O2 sensor and then you can work on jetting........until then you are guessing.

[advinnie]

Ok got you get an O2 sensor is the a good make to go for?
Also my plan was to only run 10 psi max NOT 20 psi. Is there away to lower the max boost or do I really need a new turbo?

[advinnie]

Valve float

Possible BUT here's some more information the car stops accelerating and nose dives and starts to kankroo when the boost gets to just over one bar. If I'm gentle with it and keep the boost under 0.8 bar she will continue to accelerate like a dream in third and fourth gear. Now here's what happened tonight I was driving a 60 mph hit a big hill I put my foot down boost started to rise to .5 bar and all was fine I started to over take someone so put my foot down even more boost went to .8 bar still all was fine then without warning it felt like the engine was loosing power it was not slowing down at all it just felt I was have to put my foot down more than I should to maintain this speed but I could clearly hear that the turbo was still on boost and the gauge was reading 0.9 bar. It felt like the car was running out of fuel?

I don't know the definition of Kankroo is but if yours was anything like my carb turbo it would pull great in first, second and third till it hit full boost around 3800-4000 rpm and then it went full lean at 18.0:1 afr and start pinging.
I would then have to let off. I could alway get it to work up to about 70-75 mph in third but fourth gave too much load for the fuel supply.

Check your fuel flow to the carb first. Get an O2 sensor and then you can work on jetting........until then you are guessing.

I meant kankrooing. That is when the car nose dives and then accelerate fast for a second then almost stalls, the car starts jumping around.

[Clonebug]

Ok got you get an O2 sensor is the a good make to go for?
Also my plan was to only run 10 psi max NOT 20 psi. Is there away to lower the max boost or do I really need a new turbo?

Most times it is the other way around on wastegates where you want to raise the boost.
Since yours is too high you might see if you can find and aftermarket WG that will fit in place of it that comes with a lighter spring.
That way you can make a MBC and turn up the boost from there.

I can't see your waste gate but if it is a straight rod there are ebay replacements that might work out for you. While the few I looked at weren't cheap that is one solution or else weld or bolt the internal gate shut and put a cheap external wastegate on it that comes with a 7 lb. spring.

I was planning on going that route on my re-clocking trial with my TD04L-13T.

[advinnie]

Cheers mate. I've just found this on the Web does it sound right to you lot?
Decrease the maximum boost: By increasing the length of the rod, you can reduce the preload which means, lesser boost is required to open the wastegate valve. And hence, lesser maximum boost. 

[Clonebug]

Cheers mate. I've just found this on the Web does it sound right to you lot?
Decrease the maximum boost: By increasing the length of the rod, you can reduce the preload which means, lesser boost is required to open the wastegate valve. And hence, lesser maximum boost. 

If that waste gate has that option, yes, that might be something since it is a diesel turbo.

You will have to try it.

[advinnie]

I will have look tomorrow mate and get back to you.
All found this or is this just a piece of crap?
http://www.ebay.co.uk/itm/361428613815?redirect=mobile