AHF TDI turbo modification?

musari

Member
Joined
Sep 20, 2009
Location
Turkey
TDI
2001 Bora 110 hp AHF
I have 2001 bora(jetta) TDI 110 hp AHF engine. I want to make turbo upgrade. I search the forum and found some informations which are confused me. my engine has a turbo vnt15 single manifold. which turbo can I put on my car instead of vnt15 the orijinal one. actually is vnt17 suitable for my engine or which type of vnt17 is suitable(easily adapted to my engine)? I heard hybrid type of vnt15 which is vnt15/17 hybrid, what kind of things to be done for hybrid vnt15/17?
 

musari

Member
Joined
Sep 20, 2009
Location
Turkey
TDI
2001 Bora 110 hp AHF
Is there realy no one that can help me? If anyone have opinions about turbo, please help me. I have a turbo problem these days and I have to do something to my turbo repair or modify or replace it.
 

cog

Veteran Member
Joined
Feb 6, 2008
Location
MIDDLESBROUGH... U.K
TDI
98 GT.TDI 11O
look at my sig i have a bolt on vnt 17vb from the pd 150 fits straight on but needs an adapter to hook to stock pipes kermatdi do the one i have ,
the 17/22 hybrid is the best bolt on turbo it needs no adapters and is compltely plug and play . just a little more expensive.
do not even consider a vnt15 hybrid that turbos just too small to spend any more money on for so little gain .
dont forget a 17 vnt needs a re-map and bigger injectors for you to feel the real benefit .
then you,ll need a much better clutch:D
 

musari

Member
Joined
Sep 20, 2009
Location
Turkey
TDI
2001 Bora 110 hp AHF
in your application you use vnt17( gt1749vb) pd150. is it true?

For teh first step, I want to reach 130-140 hp, so I think I don't need to change injectors and vnt17/22 hybrid turbo for this power.

another important issue is that I have power loss a little bit. turbo pressure can not reach maximum level which is 2000mbar(vagcom level). pressure is now 1700-1850mbar. when I fully throttle sometimes pressure reaches 2000mbar but not for a long period. another interesting thing is that when I fully throttle at 2000 rpm, sometimes pressure go up to 1700mbar and then it increases to 1900mbar in parallel with engine rpm. also maf level is not high enough. it is nearly 680-800mg. I think it is not normal for TDI's. what do you think? what is the reason for this problem ( fluctuation of pressure)

note 1: I changed maf sensor. Bought a maf made in china. can china made maf sensor cause this problem?

note 2: turbo repairment made 17.000km ago. Is it possible that turbo has soot in 17.000km and make pressure go down?
 

cog

Veteran Member
Joined
Feb 6, 2008
Location
MIDDLESBROUGH... U.K
TDI
98 GT.TDI 11O
re-map should net you 145bhp

as for the turbo could be a number of reasons . have you checked all your pipes . it doesnt sound like s big intercooler pipe but more like possibly a vacum pipe off or cracked thats giving you this small drop in boost.
did you feel this power loss staright after the turbo repair or was it there before
 

musari

Member
Joined
Sep 20, 2009
Location
Turkey
TDI
2001 Bora 110 hp AHF
new map loaded to my ecu and I gain 143hp 300nm tork. but after 1 month turbo began to work loudly then revision was made to it. my turbo has no capacity to give 143hp, so I think that I have to change my turbo. Anyway, power loss began 4 monthes ago and 3 monthes ago I changed all the vacuum pipes and cleaned map sensor. then pressure became a little bit good but in a short time it became again low. after revision, turbo presuure was very good provided constant 2040mbar. also I think intercooler pipes are good now. what about the china made maf sensor, can it make this kind of pressure loss?
 

musari

Member
Joined
Sep 20, 2009
Location
Turkey
TDI
2001 Bora 110 hp AHF
thanks. today I tested maf and its level is ok for today, but boost is low again. anyway one thing that I forgot to tell is that, my car in these days has smoke not so much but also not little. (when I chiped my car, there was also very huge constant smoke behind me after fully throttling.) I thought that if I change turbo with vnt17 or vnt15/17 hybrid it colud be good for smoke. is that helpful or not? or can it be another reason such as pump or injector problem for smoke with a stock hardware?
 

cog

Veteran Member
Joined
Feb 6, 2008
Location
MIDDLESBROUGH... U.K
TDI
98 GT.TDI 11O
you shouldnt have smoke with stock nozzles and tune to 140-145 bhp the boost from that should be enough to burn off any smoke even at max fueling with 205s
can you hear the turbo if you lightly press the accelertor (about quarter throttle or less say in second gear from about 1000rpm you should hear a like a whistle or turbo boost whine at about 1500rpm after a remap on a vnt 15 . sounds a bit like a supercharger whine . its fairly faint and you have to be going slowly to hear it but if its notthere i would say the problem still lies with your turbo. as a remap with stock size nozzles shouldnt smoke . equally if you have low boost also and all of your pipes are in tact and conected and tehres still smoke . id be hard pushed to think of anything other than the turbo .
 

musari

Member
Joined
Sep 20, 2009
Location
Turkey
TDI
2001 Bora 110 hp AHF
Now without any remap I cant hear any sound from turbo when I press the accelerator lightly, but in second gear at nearly 1600rpm turbo sound starts. when remap loaded, turbo sound started at 1400-1500 rpm. but I had never heard any sound form turbo when lightly press. but I had never heard sound like this before when my car was good.

after remap my car smoked very much and this is the reason for me to replace it with the stock hardware. I think pump should be repaired and also turbo should be cleaned. your opinion?

also n75 can cause this kind of low pressure. but I am not sure. today I tested my car and when I fully press accelerator, boost goes up to 1800 then goes down to 1700. in this period engine thinks should I go or not. then boost goes up till 1900mbar. rarely boost go up to 1900-2000 at this time car is go very well. I can say that pressure flactuates very often and I am not sure turbo soot can cause this or not.
 

cog

Veteran Member
Joined
Feb 6, 2008
Location
MIDDLESBROUGH... U.K
TDI
98 GT.TDI 11O
with re-map your boost should be spiking at around 2400mbar and holding about 2100-2200mbar . you deffinatly have a bosst problem not a fuel problem id leave the pump alone as you know theres fuel there due to the smoke. but yest in a turbo recon an n75 valve would not be touched and could be the source of the problem .
has your actuator rod been altered at all . and is is giving full movement
 

musari

Member
Joined
Sep 20, 2009
Location
Turkey
TDI
2001 Bora 110 hp AHF
actuator rod altered but I am not sure it moves fully. I tested n75. engine is started. I cancel boost pipe and rod goes up. when I switch the pipe to n75, rod goes down but slowly. this shows that n75 is working but I think it cant fulfill his task perfectly.

after remap, my boost incresed to 2200 not above and turbo didnt give peak boost it gave constant 2200mbar pressure that was all(reason is hardware. I ask to the loader man. he downloaded a hardware which could give constant boost only). with this pressure turbo statted to sound while fully throttling. the man downloaded remap hardware reccomend me to shorten the actuator rod in order to lower the smoke. it was effective a little bit but it also damaged turbo shaft and turbo started to sound then I repaired turbo. in these days I plan to load a new remap, but firstly I have to solve this pressure problem then I can load.
 
Top