some tests with bad results ¡¡

[prj]

I sold him the turbo six months ago and pretty sure it was installed straight away.

In that case it would be a mechanical fault, but I read something totally different from Rocco's first post.

[hoffer76]

correction 8 months ago, turbo was installed in January.

[GazzaG60]

new light on this then.

its no illusion the eboost spools boost faster as like you say it aint bleeding any off.

i want all the boost ive paid for. i dont want to share it with everyone else.

[A80Avant]

It may be that the N75 valve when programmed right can give you all that, but people who use electronic boost controllers, can be made to have a TPS feed and rpm feed as well. So eventually you have an aftermarket ECU sort of, that controls the boost. You can take away boost as you reach the rev limiter with electronic boost controllers anyway, so there is no problem going outside the turbo's capacity. The best reason for me to have the ECU control boost is the fact that it knows and is able to take you to a safe mode in case it detects a problem (which is not often, but it can). whereas the electronic boost controller is not able to do.

[Jonas_R]

Depends on what your running with the boost controller. I use my Zeitronix alarm with the Eboost2. So if suddenly goes lean or gets to hot etc. Then it the Zeitronix alarm will activate a boost group in eboost2 that sets the boost to mechanical pressure.

[A80Avant]

and that also means that your lamda is reading correctly as well!

[Rocco]

correction 8 months ago, turbo was installed in January.

yes that´s true¡¡

but "PRJ" have the reason

i installed the k26/27 around ends of February i think,and i did not drove my car too much since this time¡

and i was playing with Vems.... and whem i used Motronic i never used my engine in the 100% of power...only i drove like my grandfather..... and i used the car most times with the shorter gears having fun 1-2-3 and a little of the 4th gear....because i was some scared about to bend rods or something similar...anyway i cant remmeber 100% if i had this current issue before but now yes,and i would like to join in a drag race the next first weekend of september... it would be my first time in a fun drag race but ...with the boost failing in larguer gears.... may i will not need them anyway,because since stoped to 402m meters how many gears i could use ?? 3rd gear around 6000rpm?? or a little of the 4th gear??

i have another "MTM" chips for 3B to RS2 step and only 1.8bar (not 2.0bar as Hamon Motors) and i have just the same problem like now......

OK GUys i have to go¡¡ time to check N75,turbo hoses....

[Rocco]

You get boost cut, because you get too much boost... more than is programmed.
The problem is not N75, the problem is the mapping.

This is because your turbo produces more boost than the RS2 turbo and I guess you need to have a lower duty cycle programmed into the chip to prevent it from overshooting boost in high gears.

Makes perfect sense.
If you have access to a chip programmer, I can probably send you a .bin file with proper N75 duty cycle. I am about to map a car with a K26/K27 hybrid myself (this week), so if the turbos are the same, you can use the map...

Of course the greater question is - is there a point? You have a new engine anyway

P.S.
All this "throw away the N75" talk is funny. N75 can easily handle 2.2 bar from my experience, the only reason you want to throw it away, is because you don't know how to map the ECU. Electronic boost control allows you to extract more power and torque from the engine than mechanical control.
Replacing rev range and TPS based programmable boost control with a single value is like putting a carburetor on your S2.

i meet i very nice guy here in Spain who is a engine tuner yes¡¡ he copied me in the past my current software.......

so if you want we can do something... and if it would be before 5 of septembrer great¡¡

i have RS2 injectors or 440/3bar injectors to use with 4bar FPR....and k26/27 of course,and 3B MAF ¡

send me all you want and many thanks¡

if not,i could buy another RS2 turbo and surelly in 90% the engine will work perfect as in the past

does someone borrow me a RS2 turbo for a month?? cash waiting if it is necesary¡¡

[Rocco]

OK , i´ve tried another n75 valve and the engine it is continue having the same problem.

whem i reach around 180km/h in 4th gear with WOT,,,my boost drops to 0.4bar , i supossed it ¡¡¡

PD: in summer time ( 27-40ºC ) it is better manage richer AFR values in WOT over the winter time ???

[prj]

Motronic enrichens mixture automatically based on IAT

[vertigone]

By the way, prj could you confirm that iat will give less boost in winter than in summer temp ?

[prj]

By the way, prj could you confirm that iat will give less boost in winter than in summer temp ?

Depends on your chip. But in stock form, yes.

[Rocco]

still having boost cut to 0.4bar (wastegate boost) whem i am driving with WOT more around 4 seconds in larguer gears 4 and 5. in third gear i experience it too,but it takes more time than 4 seconds for make the boost cut


now i am using correctly RS2 turbo and full RS2 setup with a correct RS2 software, but this is not the problem,because 1 month ago i was having the same problem with a different turbo like k26/27

Vagcom did rnot says nothing,my car dont have any errors or faults

and it seems that i have not any boost leak¡¡

what the fu_ck can be??

any sensors failing?? but the Vagcom dont say nothing about them¡
all my engine sensors are surelly old, only i have the knock sensors complete new.



i´ve tested 2 old N75 valves...and nothing happens...all the same

may i have to spend 1000€ replacing every engine Motronic sensors??

i will try to make a video with a cousin and upload it to youtube,where you will can see how it cuts¡

[vertigone]

Hello Friend !
What about your fuel system ? injectors and fuel pump ?

[Jon441cc]

Bingo, Fuel pump may be an idea