Tuning 120hp + vl36= turbo surge ...flutter?

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Tuning 120hp + vl36= turbo surge ...flutter?

aurick86

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As the title says I have replaced te turbo on my T-jet 120 hp with a vl36 ( second hand with new internals, blanced...etc) No other mods except a Ragazzon downpipe.

The car has not been mapped yet. Just done the first test-drive yesterday.

At about ~4000-4500 rpm with load 3rd gear there is a lot of sound.. like turbo flutter, and there seems to be less power ( probably less boost).
No EML yet.
Can somebody post some pictures of the turbo wastegate solenoid.. maybe i have the boost lines mixed up.

I will be making some logs today with MES.
 
Hi Aurick,

I think the vl36 reaches the preset boost and the ECU simply opens the wastegate. The solenoid allows pressure from turbo outlet to push the wastegate open, when switched off, it allows pressure in the actuator to be sucked-back by turbo inlet, closing the wastegate; pretty straight forward ! I believe they've been clever enough to use different Ø so one can't mess-up with the piping ??
Should be fixed by the remapping (higher preset max boost pressure)...

Regards, Bernie
 
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Bernievarian
So basically you are telling me that at the moment it's working as it should.
The turbo is pushing to much air for the ECU settings; the ECU compensates (over-compensates) through the boost controller solenoid, leading to opening&closing of the wastegate leading to "turbo flutter".

I am going to be checking a few things today.

What is strange is that of all the people that upgraded to the vl36, nobody mentioned anything about the turbo flutter.
 
So here is a log:
b.PNG

The drop off is he factory deverter valve/ BOV

As i read it it seems that the boost solenoid has no impact on boost pressure.
The turbo flutter i hear might be the air through the turbo or it might be the throttle plate limiting air to the intake (resulting in a whistle).

So today i am going to make sure the wastegate can move, that it is operated with pressure...
I will check the boost solenoid to make sure it works.
Check all the lines to the turbo-solenoid

Any other suggestions?

I could also port the wastegate opening a little... but that is a lot of work so i will try to avoid that for now.
 
Hi Aurick,

at least that's how I understand it should work in a logic way, does that make sense ?
Would be nice to compare the expected (desired) boost pressure and the actual boost pressure together with engine speed, turbo actuator and BOV solenoid...
Do it once starting from stop up to 5th gear , shifting gears below 4K rpm and another one hitting the 5K so we can see hopefully what happens and maybe have a better understanding.

Regards, Bernie
 
Bernievarian
Thank you Bernie!

The solenoid allows pressure from turbo outlet to push the wastegate open, when switched off, it allows pressure in the actuator to be sucked-back by turbo inlet, closing the wastegate;

The solenoid boost hoses were wrong:
At higher rpm the wastegate was not regulated at all....just as it would be with no hose.

I tried moving the wastegate= ok.
then i tried the solenoid hoses =ok.
then i pulled all the solenoid hoses and trie blowing through them.... 2 of them were communicating (with the solenoid off).
 
Hi Aurick,

seems like you got it ! Is it all ok now ?
The solenoid (electro valve) is like an inverter with wastegate actuator as the common; ON communicate with high pressure (turbo out), OFF communicate with low pressure (turbo in)... The pipes you found communicating with solenoid in OFF were then the actuator pipe and the turbo inlet, right ??

Could you make a log the same way you did before so we can compare ??

Regards, Bernie
 
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I had mine switched around.
With solenoid off the actuator would communicate with the pressure nipple.
with solenoid on the actuator would communicate with the turbo inlet.

The correct way:
Solenoid off: the actuator communicates with the turbo inlet.
Solenoid ON: the actuator communicates with the pressure nipple.

I will make a log these days.
I want to compare with the log i made with the vl37 turbo (4th gear WOT pull ~ 5000rpm)
 
Hi Aurick,

I guess it is running better now ? :-D

Regards, Bernie
 
Hi Aurick,

Pleased you got it sorted, if you get chance is there any chance you could graph the boost pressure pre remap and post remap? Be very interesting to compare it against the graph for the vl37 you added to​ my thread.


Cheers

Ben
 
Flutter is back.



No log.
At first I thought the WG solenoid had popped some hoses. Not the case. It seems that it's broken inside. Electrically still works.. clicks but doesn't seem to function correctly.
The wg doesn't see pressure any more....big boost... flutter.

Can somebody tell me if this is correct?
paintastic20170416_120318.png

If it is then the pressure side is blocked.

Now I'm driving around on spring pressure...a hose between the turbo pressure nippe and the wg. Max boost 0.3bar
 
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Hi Aurick,

the little thing gone bad :-(... If you run the engine with a direct line from pressure to WG, it WILL regulate (kind of). There are regulators on the market that works on spring/adjust needle combination, never played with that so no clue about how easy to set and how precise at work they are; Anybody got some experience ?
You should definitely replace the defect EV to get more than the 0.9 bar it boosts at the moment.

Regards, Bernie
 
Definitely will replace it.
But it will take a few days to get it...

Now I am waiting on somebody to confirm or not on the sketch of the solenoid connections.


Nother sure how I broke it..maybe the first time I connected it wrong and the ecu kept the valve at the max 78% duty cycle.

Again: it's only mechanically broken the solenoid part still works... the valves inside don'the.
 
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Hi Aurick,

never opened one but pretty sure there is not much inside. I believe the solenoid is not designed to be ON for a long cycle (as it has been with the pipes inverted) so it may have heated too much and get distorded, locking the plunger in OFF position...
Only theory though ! Could you carefully Dremel it once replaced, or send it to me and I would do the job ??

Regards, Bernie
 
Bernievarian
Yes probably the long amounts of time the solenoid was on.. might be the reason it broke.

I will take it apart soon, maybe tomorrow, it seems to also be glued in place along with the tabs.

I have ordered a new one ...hope it will be in stock and will be able to get it tomorrow.
 
Small update:
Still no tune on it ... but i do have it booked for next week for a tune on a mustang dyno.

Got the new wastegate control solenoid, the correct way to install it is like in the sketch posted.

Original vl37 turbo:
vl 37 turbo pressure2.PNG

Did a few pulls
here they are:

New Vl36 turbo:
vl36 4th gear good.PNG

One time it did this strange thing, the solenoid did not control the boost pressure.
No control over wastegate though solenoid, boost control through throttle plate (even if the accelerator pedal was pressed all the way)
vl 36  ovrboost- no controll.png

Then an error and diverter valve opening to release boost :
err1.PNG


After the error boost will be limited, through throttle plate angle + no wastegate solenoid => straight pressure from turbo to solenoid, there was probably some ignition at work as well :
vl 36 after error- boost limit.png


So as you can see only replacing the turbo did nothing, as there is the same intake pressure. ~0.87 bar in overboost and 0.5 bar at 5k rpm.

There might be a small HP improvement by removing the CAT ( and i do mean small... like 0.1 hp )
 
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Thanks Aurick, graphs and outcome pre map are as you predicted :)

I'm still debating whether or not to go vl36 or td04. Could the city button be reworked in a T-Jet to work as a sport button like on the Abarth? Sorry for going off topic.

Looking forward to seeing how it goes after it's mapped.

Cheers

Ben
 
Reguarding the CITY/SPORT button...as far as I am aware YES. It is possible to set the city button to change between maps.

My vl36 experience until now the car feels like peak torque moved in the rev range ...about 500 rpm higher... is visible in the graphs.
It'still quite acceptable but I wouldn't want much more lag...so the TD04 might beven to much. Maybe if you find a ball-bearing double scroll TD04.


Don't expect massive power outputs from my t-jet, the guys I chose are known for smooth, safe tunes with moderate power increases.
 
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Update time:
Max power:
max power.jpg

And a comparison with the results of the car with the turbo and downpipe but no tune:
power before and afer.jpg

(these were measured on a Mustang dyno)

No logs yet but pressures at the turbo (not in the intake) were: overboost pressure at 3000-400 rpm about 15-16 psi, and boost at 6000 rpm about 12 psi.


And some bad news:
WP_20170427_14_41_25_Pro.jpg

They were new plugs.. but maybe the distance was off on this one? maybe because of the ~850 km i did before the tune? maybe o manufacturing error?
maybe the tune?

I will keep an eye on the spark plugs, every 200-500-1000 km for a while... even so should only be a problem at full load/boost.
 
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