wastegate question

[arjunior45]

Does anyone knows what happen when the “middle” hose {the one towards the wires} of the wastegate is stuck?
It happen to a friend of mine – with the other Q4 – and he saw 1.5bar from 1600rpm!

Can someone explain this?

Cheers

Nick

[AlfaJack]

Do you mean the skinny hose that is connected as part of the pier-burg valve system?

If so, and its only my guess, the pier-burge valve does not get a reading and its cuts out the ECU from managing the boost so the turbo gives all it can :? :?

[arjunior45]

Do you mean the skinny hose that is connected as part of the pier-burg valve system?

If so, and its only my guess, the pier-burge valve does not get a reading and its cuts out the ECU from managing the boost so the turbo gives all it can :? :?

yes, this is the one {skinny one}!
Well, do you think that it will be possible to remap the ECU so that to have more boost at low rpm? Just a question as I think that it will be great to have 1.1bar {as an example} at 1600rpm!!!

Cheers

Nick

[serge]

hmm hat seems strange to me
the pierburg valve just limits the boost, but it changes nothing in turbo respond. maybe your friend accelerated from low rpm in 5th gear?

[AlfaJack]

yes, this is the one {skinny one}!
Well, do you think that it will be possible to remap the ECU so that to have more boost at low rpm? Just a question as I think that it will be great to have 1.1bar {as an example} at 1600rpm!!!

Cheers

Nick

I was speaking to a guy who used to have a 16v Fiat Coupe Turbo, he said if I got a bleed valve this could be achieved - however I also read that its very risky as the ECU does not have any safety management over the engine :?

[arjunior45]

hmm hat seems strange to me
the pierburg valve just limits the boost, but it changes nothing in turbo respond. maybe your friend accelerated from low rpm in 5th gear?

No, he saw this +1,5bar at all speeds and he is the type of quy who does not speed his car in extreme way! But he was very threaled of how the car was accelerating!

Nick

[arjunior45]

yes, this is the one {skinny one}!
Well, do you think that it will be possible to remap the ECU so that to have more boost at low rpm? Just a question as I think that it will be great to have 1.1bar {as an example} at 1600rpm!!!

Cheers

Nick

I was speaking to a guy who used to have a 16v Fiat Coupe Turbo, he said if I got a bleed valve this could be achieved - however I also read that its very risky as the ECU does not have any safety management over the engine :?


if everything in the Q4 is controlled by the I.A.W. then there must be a certain addres in the .bin file that could make this valve work as "bleeding" at low rpms and then, at higher rpms, like a normal {not bleeding} valve!

I think that this will be more than great! Don’t you think?

Nick

[155-tbo]

I removed my pierburgvalve totally off, because it was broken. And now I have "bleedvalve" on my car and I still have protection, because map-sensor whistle game off, when you have 1,5 bar boost. Thust me I have tested that :lol:

I set my manual valve so, that now I have 1,0-1,2 bar boost depence, what gear I drive. The engine running very well and mixture is ok. If you have Squadra tuning chip, the chip will raise boost to 1,0, so I have almost same pressure, but I have it all the way 2500-7000. My bleedvalve system just kidding wastegate to guess, that it doesn´t open so early.

I think I have now better system , than pierburg, because pierburg system is electrical and we all now, what they say about Italian car and electric :wink:

[arjunior45]

I removed my pierburgvalve totally off, because it was broken. And now I have "bleedvalve" on my car and I still have protection, because map-sensor whistle game off, when you have 1,5 bar boost. Thust me I have tested that :lol:

I set my manual valve so, that now I have 1,0-1,2 bar boost depence, what gear I drive. The engine running very well and mixture is ok. If you have Squadra tuning chip, the chip will raise boost to 1,0, so I have almost same pressure, but I have it all the way 2500-7000. My bleedvalve system just kidding wastegate to guess, that it doesn´t open so early.

I think I have now better system , than pierburg, because pierburg system is electrical and we all now, what they say about Italian car and electric :wink:

nice!
Don't you have any problem in accelaration? Do you have costant 1,0-1,2 bar all the way up to 7000rpm?

But I insist for the "map mod" as I'm going to use 4 different maps {in a 27c1001 eprom} and, as "maxiboost" and others, I'd like to have a map with no overboost and 0.6bar boost, the original {101.05} map, hfalex's map and maybe a map like Evocars "trackday"! So I need to have this "bleevalve" system through the map at least for the "trackday" type map.

Cheers

Nick

[MaxiBoost]

Dear friends ,

Q4`s turbo ( TB03 ) CANT create 1.5 bar at the 1600 rpm ,it is imposible .

If you open wastegate hose from wastegate valve or on pierburg (when wastegate always close or without pressure control its same to hose stuck ) turbo create maximum pressure depends your rpm but never possible create high pressure at 1600 rpm !

You need small turbo for it ,maybe ball bearing maybe VTN turbo I dont know .

Electronic pressure control always better than manual ,if you disconnect your pierburg valve you never use turbo overboost drive .

Pierburg NOT only control turbo pressure ,if your engine has any knock! degrease boost pressure low too .Also you can control turbo pressure with eprom .

Read pictures pls ,


Wastegate valve and hose number 10 .
http://img92.imageshack.us/img92/5472/400404nj.jpg


http://img92.imageshack.us/img92/7898/400418kd.jpg


http://img98.imageshack.us/img98/7619/400428ua.jpg


http://img98.imageshack.us/img98/9489/400438fu.jpg

[arjunior45]

Dear Hakan,

I'll try to make my friend stuck the hose again and we are going to meassure the boost at various rpm - up to the point the IAW is going to "safe mod" and then I'll tell you the results.
Wish I could check it with my Q4 but I'm still away from home - for another time.

Cheers

Nick

[Juan AR155Q4]

I agree with MaxiBoost. It´s really difficult to have that pressure at so low rpm.
I have the original turbo with a T4 compressor. And with blocked wastegate (always closed) there was no boost under 3000 rpm.

[FletchQ4]

yep gotta agree with above, the boost is created by the exhaust pressure and at 1600rpm there just isnt enough to get them figures.
if i bought a car with a bleed valve fitted id remove it straight away because temptation would have me turning up the boost all too quickly.

[155-tbo]

nice!
Don't you have any problem in accelaration? Do you have costant 1,0-1,2 bar all the way up to 7000rpm?

Yep! I have constant 1,0-1,2 bar boost all the way up to 7000 rpm or to the rpm limiter. I think my car accelaration is better, than with original pierburg system.(my pierburg system never work :? ) Ofcourse I have also 3" stailess steel exhaust pipe all the way from downpipe to the end. No CATS and two freeflow mufflers. With my "bleedvalve" and this exhaust I get little over 1,0 bar boost about 2500 rpm and when rpm´s rise I get little more boost and it stays about 1,2 bar. No peek boost at all !!! Car has better accelaration.

But you make your own modification. My oppinion is that It´s better have lot of boost at low and then it raise, when rpm gauge shows red. Then you shift up and there is lot of boost in the engine. 8)


if i bought a car with a bleed valve fitted id remove it straight away because temptation would have me turning up the boost all too quickly. No no no. No temptation att all :wink: Always remember, that when you modificate yours cars. Keep the head clear and think what you do.

Somebody say in this topic, that with bleedvalve system you don´t have any security about engine knocking. Thats why we need better chip and air/fuel gauge. You don´t just raise you boost up, you have to also get more fuel to the engine. more fuel and more air= more power, that´s for sure.

You can also ask to Jarkko. His over 320 hp Q4 has also "bleedvalve" Turbosmart. Ok, it´s not a bleedvalve, but not original pierburg! Engine has never knocking, because he has remapped his fuelmaps. With standard Squadra tuning chip the engine did NOT knock. Only little lean about 6000 rpm, but it doesn´t KNOCK. And he has on the dyno over 1,3 bar boost. Think about that.

When you raise your boost with chip, why is it safer, than with mecanic modification? Turbo get more work and exhaust temperature raise, every part in your engine gets more strain, no matter how you raise your boost.