Author Topic: bosch maf not allowing full boost?  (Read 7004 times)

Offline gti_shaun

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Re: bosch maf not allowing full boost?
« Reply #20 on: 22 March 2010, 23:25 »


i did a log on my maf before and it peaked at 175 g/s this it right for 225bhp right?
have you tried a n75 valve darkgti?
Think thats where i may go next, just hate shelling out money and not knowing if its gonna fix it.

so just to confirm you fault is the same DARKGTI when it used to come on boost it just flew stright up to 21psi stayed there for a bit the dropped to 18ish, then next gear same again etc etc

NOW the boost does not seem to fly up as quick and gets to 18 psi and stays there, but im pretty sure the needle on the guage flutuated like it wast to boost higher but cant, then drops to 14psi(1bar) as the revs go higher.

Offline gti_shaun

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Re: bosch maf not allowing full boost?
« Reply #21 on: 22 March 2010, 23:29 »
oh forgot to ask topher, is 21-22psi right for the ko3s with pipe clamped? what does yours blow? i thought it should of been higher but i guess they are not the biggest turbo in the world.lol

Offline master_oogwai

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Re: bosch maf not allowing full boost?
« Reply #22 on: 23 March 2010, 15:06 »
Latest update.

Due to R-Tech being 117 miles away from me and I really wanted the car looking at asap, I made a journey to see the lads at AmD, as they are half the journey away from me. I asked them to fit a new standard n75 valve for me and put the car on their rolling road. The results were interesting, though the power and torque curve were not very smooth. This time, the torque tailed off at 5000rpm whereas at R-Tech, it tailed off at 5500rpm. On the road, the car is still a little jerky.

However, the dyno results:

1st run - 239.2bhp/259.8lbft
2nd run - 231.4bhp/251.5lbft   

At R-Tech, the car made 209bhp/240lbft

Fairplay, you would need to take in account of the dyno, weather and so on, but now I dont know what to think?? +30 bhp from changing the n75, even though the car feels no different on the road??

Think I need to run the car on someone elses RR for a third opinion.

Offline topher

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Re: bosch maf not allowing full boost?
« Reply #23 on: 23 March 2010, 16:28 »
wouldn't read too much into it pal, bavs car made 252bhp on their rollers with one of our mild stg2 maps. Another mate of ours with a 400+bhp polo seemed to be 50bhp more powerful on amd's rollers than anywhere else *shrug*

Offline master_oogwai

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Re: bosch maf not allowing full boost?
« Reply #24 on: 23 March 2010, 17:00 »
wouldn't read too much into it pal, bavs car made 252bhp on their rollers with one of our mild stg2 maps. Another mate of ours with a 400+bhp polo seemed to be 50bhp more powerful on amd's rollers than anywhere else *shrug*

What would you advise then topher? shall I bring the car back down to you guys for further investigation?

Really hoping for the issue to be resolved, but I am at a loss now.
« Last Edit: 23 March 2010, 17:02 by master_oogwai »

Offline richw911

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Re: bosch maf not allowing full boost?
« Reply #25 on: 23 March 2010, 18:08 »
RR lottery  :wink:

MKIV Mod Squadâ„¢ a part of the headlight police.

Offline master_oogwai

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Re: bosch maf not allowing full boost?
« Reply #26 on: 23 March 2010, 18:16 »
RR lottery  :wink:

I agree, but the differences are huge.

One is saying the car has an issue and the other is saying the car is fine  :undecided:

Offline gti_shaun

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Re: bosch maf not allowing full boost?
« Reply #27 on: 23 March 2010, 21:44 »
so does your car still not feel right not boosting fully then?

^^^^^^^^^Anyone tell me if my air flow reading is ok and if the boost is high enough with the actuator clamped off^^^^^^^^^^^^

Offline topher

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Re: bosch maf not allowing full boost?
« Reply #28 on: 23 March 2010, 21:54 »
wouldn't read too much into it pal, bavs car made 252bhp on their rollers with one of our mild stg2 maps. Another mate of ours with a 400+bhp polo seemed to be 50bhp more powerful on amd's rollers than anywhere else *shrug*

What would you advise then topher? shall I bring the car back down to you guys for further investigation?

Really hoping for the issue to be resolved, but I am at a loss now.

Does it not feel right to drive anymore? I think we're at the limits of internet assistance now dude. I'm not sure if i'll be at r-tech much the next few days so probably best to call up and speak to Nick.

gti shaun i think you need to start a new thread because i've no idea what you're asking or what your issues are :grin:

Offline master_oogwai

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Re: bosch maf not allowing full boost?
« Reply #29 on: 23 March 2010, 22:50 »
wouldn't read too much into it pal, bavs car made 252bhp on their rollers with one of our mild stg2 maps. Another mate of ours with a 400+bhp polo seemed to be 50bhp more powerful on amd's rollers than anywhere else *shrug*

What would you advise then topher? shall I bring the car back down to you guys for further investigation?

Really hoping for the issue to be resolved, but I am at a loss now.

Does it not feel right to drive anymore? I think we're at the limits of internet assistance now dude. I'm not sure if i'll be at r-tech much the next few days so probably best to call up and speak to Nick.


Fair enough mate. Think I will give Nick a buzz. I would like to see if there are changes on your RR now that both maf/n75 have been changed.

The issue is like gti_shauns new thread. Before maf swap, you hit the gas and the car goes, like that night on the test drive with you after the map. After the swap, the car seems to lag so you dont get that instant hit. At first, I put it down to the warmer weather, but its the same whether it is cold or not.