some tests with bad results ¡¡

[Rocco]

Ahh, that's a pain.

I know he has very good maps for ABY's and is a very knowledgeable guy. Your RS2 injectors will be fine, take it you have a decent 3" down pipe and a minimum of an RS2 inter-cooler fitted as well as your'll need both.

What you really need is a custom map by the sounds of it, not going to be cheap but will be worth it. I have the same cost looming for my 3B set up.

As I mentioned before make sure your ignition system is in perfect condition, as the 26/27 hybrids will really push a stock bottom end and we have the dreaded spark hop to contend with our 3Bs.

I drive the car off boost if I were you till you get it sorted.

i got stock IC,and a custom 3" downpipe.
all my ignition parts should be as new¡¡ because i replaced them less than 3000kms¡¡
both knock sensors,distributor rotor,sparks plugs + their wires,new battery...only the single coil it is old

i will dont spend any $ in my engine now....because i have new plans for the next month

but i would like to discoverd what the fu_ck it is happend now,i want my car running perfect¡¡
i will take a look in Maf,small hoses,N75....
thank you for the suggestions

[20vQC]

hmmm.... tomàs... Sincerely sounds that you have a heavy boost leak or even a hydraulic lifter that is gone and after 5000rpm leave a valve opened... but I'm almost sure it wouldn't cause a boost loss down to ZERO... it should leave a minimal pressure on the intake manifold.

If you are sure is not a boost leak, now please correct me if I am wrong. you have a chip with a fuel/ignition maps for a k24-7200 that even at 2bar(absolute) you got good air/fuel ratio and no knocking of course... right? If you are using the same chip but the engine now has a K27 compressor side, at the same pressure of the k24, you are pushing far more air into the engine and the fuel map can't offer you the required fuel for the flow your k27 is pushing in. Less fuel = more temp = detonation ... Isn't your ECU engaging a "protection" mode because you are having detonation causing: N75 opens up widely, fuel cut and retarding the ignition or maybe cuting it. All this maybe make you to run off boost. Jamo? Paul? what do you say about this?

As someone said before too... test the cylinder pressure on each pot anyway! I hope you can solve the trouble soon! Mucha suerte!!!

[Rocco]

hmmm.... tomàs... Sincerely sounds that you have a heavy boost leak or even a hydraulic lifter that is gone and after 5000rpm leave a valve opened... but I'm almost sure it wouldn't cause a boost loss down to ZERO... it should leave a minimal pressure on the intake manifold.

If you are sure is not a boost leak, now please correct me if I am wrong. you have a chip with a fuel/ignition maps for a k24-7200 that even at 2bar(absolute) you got good air/fuel ratio and no knocking of course... right? If you are using the same chip but the engine now has a K27 compressor side, at the same pressure of the k24, you are pushing far more air into the engine and the fuel map can't offer you the required fuel for the flow your k27 is pushing in. Less fuel = more temp = detonation ... Isn't your ECU engaging a "protection" mode because you are having detonation causing: N75 opens up widely, fuel cut and retarding the ignition or maybe cuting it. All this maybe make you to run off boost. Jamo? Paul? what do you say about this?

As someone said before too... test the cylinder pressure on each pot anyway! I hope you can solve the trouble soon! Mucha suerte!!!

Vagcom 0 problems

yes it should be ¡¡ but i cant load more than 1.6bar with k26/27 ,so i dont know if it is more air in the intake over the RS2 turbo at 2.0bar.....

you have to know that i´ve unscrewed the wastegate cap bolt and now it is around 0.8cm higher over the waste cap ,for keep less boost pressure with k26/27 (i was some scaredd with it ,bigger turbo with stock internals ) but the last day i was testing,i screwed it ,and now it is 3mm bellow the waste cap...and the problem it is the same....

thank you¡¡

hope to solve it before uninstall my engine ,for learn¡¡

[GazzaG60]

there are a few potential issues here. id avoid WOT till tis mapped properly though.

you may just be dragging too much air into the maf for the setting in the map.

before vems when i fitted the turbo and ex manifold and limped it home on motronic. the volume of flow on setting off almost stalled it as the maf was used to the teeny weeny stock turbo.

the bigger turbo should scare you...for a bit jamo is correct it should make 2 bar easy. it flows more air meaning the engine needs to digest more therefore the pressure build-up is greater.

[prj]

you may just be dragging too much air into the maf for the setting in the map.

Motronic does not work like that.
Anyway, if you are running 3B motronic and you max out the MAF, things get ugly really fast.

This is easy to check though, attach a voltmeter to your MAF and see what the voltage is at WOT.
If it reaches and becomes stuck at 5.6V, then you have the reason.

And if that happens, then you reached the limit for 3B.
AAN is a lot more flexible.

[Jamo]

Motronic does not work like that.
Anyway, if you are running 3B motronic and you max out the MAF, things get ugly really fast.

This is easy to check though, attach a voltmeter to your MAF and see what the voltage is at WOT.
If it reaches and becomes stuck at 5.6V, then you have the reason.

And if that happens, then you reached the limit for 3B.
AAN is a lot more flexible.

Myth IMO

If that was the case Mihnea wouldn't have been able to map a few 500 bhp monster 3b's that have been about such as Audimans car.

Once the MAF is maxxed out at 5v that's it, the map relies on the mappers experience to get the right fueling above this range.

The RS2 map and K26/K27 map are very similar anyway.

Then again I dont' see all this is helping the member diagnose his zero boost

Have you taken the turbo hose off to check for play in the turbo shaft yet?

[GazzaG60]

it would need to be really bad for no boost too.

think it needs to be defined. is it alwasy 0 boost or just over a certain level. you should still see can pressure anyway.

[prj]

Myth IMO

If that was the case Mihnea wouldn't have been able to map a few 500 bhp monster 3b's that have been about such as Audimans car.

Once the MAF is maxxed out at 5v that's it, the map relies on the mappers experience to get the right fueling above this range.

Mapping beyond 350-400hp on 3B requires either modifying motronic code (and this is not mapping anymore, this is making your own ECU logic), which is very hard, because the CPU used on 3B is very slow and even slight alterations make it run too slow, so it does not work beyond a certain RPM.

Or alternatively using a different MAF or the stock MAF in a bigger housing and then mapping that way.
There is no other way, period.
On 3B the ECU basically does not use TPS. On AAN it is a completely different story, and you can map to the last column as long as the turbo does not destroy the wire on the MAF.
In 3B, Load = MAF Signal / RPM. Once your MAF signal maxes out LOAD starts dropping as RPM's increase further and the maps are read backwards, causing the ECU to inject much less fuel and advance the timing. The result are bananas.

What I have stated is not my opinion, it is a fact, verified myself on big turbo cars (minus the bananas ).
How many 3B's have you mapped to call my experiences a "myth"?

Then again I dont' see all this is helping the member diagnose his zero boost

I agree and I will be quite happy to discuss this further in PM, if you like.

[Rocco]

FRIENDS¡¡¡¡¡

YOU HAVE TO EXCUSE ME ¡¡¡

A BIG FAIL I DID READING THE BOOST PRESSURE GAUGE IN 4TH OR 5TH GEARS ¡¡

as you know..it is dangerous put both eyes at those speeds ( 4500/6000rpm) only in the gauge while i was driving alone.

Ok today´s mourning i was testing a few and i saw perfectly how the boost dropped to 0.4Bar not to 0bar as i said ¡¡

so after 4 seconds with WOT in larguer gears the boost it is going to Mechanical boost 0.4bar true?? because i have the original wastegate spring inside,not a harder one.


so with this important data...what could be??? the Motronic it is making something protection??

in shorter gears i have not problems with nothing,but in 4th and 5th yes,and always after 4 seconds more or less with WOT........1.6bar to 0.4bar in a second¡¡

[Sonic]

If you lift your foot off WOT, then re-apply, does it produce full boost again?

I had this happen to me on the autobahn the other week.

[20vQC]

0.4bar is the stock wastegate pressure if the N75 is not working! N75 failure Tomas????? try to change the n75 for another one and go for a test

[Rocco]

If you lift your foot off WOT, then re-apply, does it produce full boost again?

I had this happen to me on the autobahn the other week.

and did you solved it Sonic??

i will try to do it later,and we will see, i think that YES ,it loads again after lost the pressure to 0.4bar to 1.6bar again. but we will see...

most times i tested it, whem the boost drops to 0.4bar i dont "re-apply" it again...because i was scared of course,dont want to broke nothing ,but i believe to remember one time "re-apply" WOT and 1.6bar again

tonight i will have the true answer

thanks Andy

[Rocco]

0.4bar is the stock wastegate pressure if the N75 is not working! N75 failure Tomas????? try to change the n75 for another one and go for a test

dont know... could be yes

i have a spare N75 and another new one bought from S2_bO.... This one it is different,and seems to be stronger

i can try one of them

[Sonic]

I had the problem in all gears, re-fitted all the samco hoses and replaced the WGFV.

Problem solved, or so i thought.

But it was only at speed and WOT (chasing a 996 turbo down the autobahn, 6th gear, ~140mph and climbing up to hohe acht on the nurburgring at WOT, 5th gear, ~120mph) that it happened.

On all occasions coming off the throttle and back on worked. On the autobahn it did keep dropping back down to .4 bar again after about 10 seconds.

Not sorted yet, need to run fault codes.

[Rocco]

I had the problem in all gears, re-fitted all the samco hoses and replaced the WGFV.

Problem solved, or so i thought.

But it was only at speed and WOT (chasing a 996 turbo down the autobahn, 6th gear, ~140mph and climbing up to hohe acht on the nurburgring at WOT, 5th gear, ~120mph) that it happened.

On all occasions coming off the throttle and back on worked. On the autobahn it did keep dropping back down to .4 bar again after about 10 seconds.

Not sorted yet, need to run fault codes.

OK could be similar like mine,do you have a wideband with gauge??

and a noob question.... what it is WGFV??? i can understand that it is something in the Wastegate??