N54 GC upgrade build

135boost

Corporal
Oct 28, 2017
100
67
0
Ride
135is
Hi, first posting on this forum so be gentle I posted this on boost addict too and taught there is maybe intrest to read it here too

so to keep things short, this is my buildup and goals on DD 2008 AT6 135i
i bought the car some 1 year ago for my wife`s DD winter car in a mistake,
former owner told it`s most dangerous winter car he ever had owned
so it was left for me as a toy.

car has assembled when bought catless downpipes and vrfs race fmic.
there was some tuning software inside too with 0,9 bar boost on it.

then it started to go as usual, first jb4, then turbos with 13T-6 billet compressors,
fuel it stage2 pump upgrade and a tbi with hobb switch. and that was setup for last summer but clipped stock turbine-13T compressor and 24 psi boost didn`t satisfy me cause of concern about exhaust manifold back pressure and mismatch turbine compressor sizing so i decide to do something to the issue.

i want very broad torque curve, driveability, minor impact on lag versus stock,
and some degree of power up in a rev range

I surfed around different forums for some month before i decided to contacted Tony from VTT, even there has been horror story`s about customer care, behavior on internet etc. he seems to be a legend in good and bad and asked his opinion about the build and how to proceed it and he suggested to move straight
from my first plans of GC lites to GC`s

after discussion about it i decided to do some mods to the car, weight reduction to 3070 lbs(done), upgraded turbos, db shotguns,(yes, we have very good quality e85
here aviable all around) cold side and hot side silicons, berk street exhaust and other small bits&pieces.

i started then to order parts from VTT and there was a mess, nothing to do with VTT, a bank issue at most and my deposit went to wrong account and on that it took over a week to resolve it but i was in contact with Tony every day about issue and at first, Tonys respond time for questions was extra ordinary fast every single time, and at the end got it done.

so the mod list is now like this
- VTT GC turbos ceramic coated inside out
- VTT inlets and hot sides
- VRFS race fmic
- charge pipe with raceport BOW
- VTT double barrel shotgun
- BERK street exhaust
- fuel it twin fuel pumps
- XHP stage 3 trans software
- quaife LSD
- crank bolt capture
- split second AIC to db shotgun
- JB4
- Trebila tune to 27psi
- ethanol analyzer
- MHD programming tools
- upraded spark plugs
- n20 tmap
- apex racing wheels

there is for sure something missing but get my point of performance
level i`m after.

then to order and install , issues and pros/cons
everything i ordered came in time,except those wheels i waited for 4,5 month, issue with supplier, exhaust came in time, burger tuning parts came in time VTT parts came in time and only missing parts up to date 1 small hose clamp from VTT order.

- Exhaust fitment was perfect, sound could be more softer to my use, my verdict 9/10

- lfpf fuel pump, not a problems at all, tight fit but everything is like it should be 9/10

- FMIC fit well

- GC`s fitment is better than i expected, cast quality is much better than OEM or
that first upgrade 10/10

- Oil lines fitment was perfect, rear turbo water return line needed some few millimeters of bending to fit perfect, the line hit turbo chra clamp bolt, it`s possible to rotate it a bit but i decided not to cause it`s paint marked and i wasn`t sure about warranty if i broke that paint seal. 9/10

- Silicone inlets fit quite well, pain in the ass to torque the clamp to turbo cause of short snout this size turbos have but it fit. 9/10

- Hot side fit too, it was more my mistake cause i ordered a 2.5" version of it and vrfs has a 3" on it. hotside is "hitting cooler reservoir hose but space is limited on that position and i raised reservoir by 20mm to get enough space. fitment propably 9/10

- Double barrel shotgun fitment was all most perfect, minor grind from bracket cause
of weld on shotgun bearing house weld hit the bracket, 20 second and issue solved ( Tony has done mods to future bearing houses). 9/10

- Modded fuel rail fit as oem, the shorter high pressure fuel line could be little longer, discussed about it with Tony. 9/10

- Water line rerouting could be better but that`s for sure something every single
installer must concern about them selves , fuel lines is the same, watch that they fit or reroute those to get fitment you are satisfied on. 6/10

huge amount of small pieces is to be checked not to hit anything cause
of very tight engine bay but got everything to fit to a level i`m satisfied on.

End conclusion

My opinion to a perfect assembly time of everything is on some 30 hours to get
a running car with all those mods and to be honest, it`s not men`t for a average guy
to do at home without proper tools or resources.

I own few workshops and tool shop with huge warehouse of bits&pieces
so it`s not ever fair to compare me against average home builder on this
so it can be taught as "unlimited access to everything needed"

I must thank at the end of buildup VTT / Tony for customer service cause there was some issues on bank what caused troubles ( assume my mistake) and we have swapped some 100 emails where half was caused of that bank issue and every time weekend or not, email respond time has been umbelieveble fast ( okay, must undestand there is some 10 hour time zone difference on us).

then the bad news, i got the car running yesterday, not leaks, or other issues, not DME fault codes and then i go got at the same huge
traction issues, nothing to do with power, but to do with 15 cm of wet first snow
of the season what we got here yesterday too.

i will continue thread after i got car on dry tarmac and get it tested on street.
 
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V8bait

Sergeant
Nov 2, 2016
495
757
0
Texas
Winter and RWD doesn't really go together, should have gotten a 335xi for the winter beater sportster.

Nice build, what country are you from?
 

135boost

Corporal
Oct 28, 2017
100
67
0
Ride
135is
my position on globe, it`s Finland

# story continued from other forum#

I don`t know about power levels on old setup but assume there was something around 470 rwhp and with that
tested the car for standing mile here on a no_fly_zone day and got 274kph with limp mode at last 200m and
1/4 mile totally unprepped airport runway 200 utog street tyre combo and got low 12s with 203 kph spinning wheels for first 170m

i did some calculations on that old turbo setup TTH540 and my best guess is that there was some intake manifild /exhaust manifold pressure relation of some 2.6-2.9 so there has been exhaust manifold pressures on some +60 psi levels and that is for sure problems on stock exhaust valve springs and for sure hurt performance.

that was at the beginning reason for free flowing exhaust to get rid of all extra exhaust back pressures.

Now when discussed with Tony i got logs from him with his record breaking 1/2 mile and on these GC:s there
should be about 1.5 as relation so turbo swap shaked away some 25 - 30 psi back pressure from me.

my history with turbos starts early as 1986 when i did my first ford escort mk1 turbo build and after that
there has been some modded turbos on every single verchile i owned except one opel omega (didn`t have time for it`s turbo project )with top of it a yamaha R1 turbo motorcycle. on that there was a MCxpress turbo kit from Sweden and only 14 psi of boost. gave that 2 wheeler quite unique performance levelswith 240rwhp/175kg and boost start from 4000rpm.
every other fuel burner up to date has seen that 2bar boost on it. on this N54 i`ll try to avoid that 2bar /30psi levels.
what i really learned to hate on street driven verchiles is laggy slow spooling turbos, dyno queen as a daily drived machines is not to me, perhaps only for drag strips where you have stupidly much time to build up pressure, been there, seen that with GT45 76mm turbine exducer and 1.14 AR / T66 combo on a 2.6L 16 valve fully built volvo race engine. +600 rwhp on some 7600-7800rpm but start to build pressure from some 4500rpm and max torque was on some
5600-6000. car such it feels fun for few weeks and then you are pissed of that lag.

so on this there was as option GC lite, GC , or some other manufacturers T16/19L to T19/HL combo and
or big single and my personal vote went to twins cause of of fighting lag issue. now my consern
about GC`s is that lag, remember i haven`t drive a meter yet with the car after turbo swap because of snow bur
what i have undestand on internet discussion, the lag on those is on decent level (on the edge i just tolerate)
those TTH540`s was on that lag on their own terrotory because of that small turbine wheel sitting on stock housing.

oh, about Shotgun, i taught it`s more common choise then, as safety of the engine on my opinion it`s better
to have one injector/cyl than multiple (except throttle body) where external injector fail blow engine with super lean on that 1 cylinder and lambda trying to trim every cylinders up without undestand there is a issue on only one injector.


now with the GC double barrel combo i`m after some decent 600rwhp/600rwlbs to start with, i will post first
feels of driving on it and my opinion about lag or other issues if there is something on it.
 

135boost

Corporal
Oct 28, 2017
100
67
0
Ride
135is
Hi again, got first 10km with the car on wet so no any full wot 3-4-5-6 pulls to redline
yet but got few low rpm logs.
Lag what i was afraid of is not so bad at all, this GC`s seems to start build up
boost relative low, 1500 2psi, 1800 3psi, 2100 5psi, 2400 12psi, 2700rpm wheelspin on 5th gear
..... so stock 8psi boost level is catched on some 2200rpm levels and i think i catch boost levels those
13T/clipped stock turbines at some 3200-3300rpm and then because of reduced exhaust pressure
power levels is catched few hundred rpm sooner.

other findings on the car, noise level went up a bit, assume it`s from bigger turbines with much
more free flow to exhaust and under bonnet, that raceport did a own sound world compared to
stock circulating bow`s.

one thing about flashing the car, i have done it now for some +20 times, mods to fuel maps, mods to
ignition maps, i did even few versions of hypermiling maps to it too(no cat`s and afr targets to some 15.5-16.5 in 8 or 9 boxes of fuel maps from 1500rpm to 1800rpm and because of lean condition burn speed i increased advance to that spot with some 5-6 degree.) good for fuel economy, got it some 1 liter better on e85 but smoothness was not as good anymore with cold climates. that 16.5 is max lean what could be tested, 17 was too much and caused struggle.
nothing to do with economy, that 1 liter is irrelevant but for quriosity only.
yeah, about flashing, the dme seems to be super sensitive for voltage dropping during flashes, it eat
electicity quite much when flashing it and even with battery charger you can struggle to do it.
i have small 50 amp battery on the car and with 20 amp charger, had 4 times failed write to DME
with MHD, assume every time it`s voltage drop problem or then small battery/ big charger voltage ceiling
(550 amp charger now) issue. every time there is fail on write, you are facing full write of 38 min and i
do it every time with a 235Ah truck battery/charger connected to car and every time with success on that combo.
 

135boost

Corporal
Oct 28, 2017
100
67
0
Ride
135is
so, first feels on it, exhaust sound is more agressive, raceport BOW is keeping psiiuu sound at relatively low rpm`s
target of boost is to save transmission from torque spiking on 3000-4500rpm and after that taper it up to 27psi
like this
to 3000rpm as much they deliver, propably 18-20 psi
3500rpm 23 psi
4000rpm 23 psi
4500rpm 24 psi
5000rpm 25 psi
5500rpm 26 psi
6000rpm 27 psi
6500rpm 25 psi
7000rpm 23 psi

i think problems on those levels is to get clean logs to tune the car
without wheel spin or some other stupid erratic issues.

let`s see what happend.. more to come when i get some logs.
 
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doublespaces

Administrator
Oct 18, 2016
9,135
4,171
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AZ
Ride
2009 E93 335i
Hi, first posting on this forum so be gentle

Thank you for sharing and welcome to the board!

dyno queen as a daily drived machines is not to me

I agree fully, many people overlook this aspect.

I just ordered a double shotgun as well, hopefully it will come in the next few weeks. Its good to see someone here with experience, we like technical discussion here.
 

Tippin

Specialist
Jan 31, 2017
89
49
0
The GC's can make some serious power. I am moving a set over to my 135 from my girls car.
Tiffani.jpg
 

pysical

Sergeant
Jun 16, 2017
358
79
0
Ride
2009 335xi E90
This was done on E54 and barely touching 26psi.
Sweet. I have a 2009 335xi 6MT with GC turbos. Forged engine, and ported head. Just need another LPFP so I can get into the E85 game. Right now my 93 tune is touching 24 psi.
 

135boost

Corporal
Oct 28, 2017
100
67
0
Ride
135is
Hi Tippin, first question, what on earth does your wife do with 650whp beemer ? want to get rid of her ??
serious, do you have some logs from that e54 run just qurious to compare it to my 135.
what kind of boost pressure targets do you have on that ?
on it ? assume it`s not steady 26psi trough rev range from 3500 to 7000rpm.

my 135 is fat bastard, 3070 lbs and it still has sun roof, sheet metal hood and trunk scaled with 4 corner race scale at allmost empty fuel tank, sothose 335`s 4 door sedans must punch scale to whopping 3600plus lbs.

about pysical`s 335xi, very interesting concept with built engine and ported head, that can be my next project to do engine mods if this powerplant is giving up on that 27 psi levels and wildest idees could be to buid this 135is coupe to a xi

what to modify on that, trans from xi, front prop shaft, oil pan, front diff, front half shafts, front hubs, etc

maybe some day
 

Tippin

Specialist
Jan 31, 2017
89
49
0
Hi Tippin, first question, what on earth does your wife do with 650whp beemer ? want to get rid of her ??
serious, do you have some logs from that e54 run just qurious to compare it to my 135.
what kind of boost pressure targets do you have on that ?
on it ? assume it`s not steady 26psi trough rev range from 3500 to 7000rpm.

my 135 is fat bastard, 3070 lbs and it still has sun roof, sheet metal hood and trunk scaled with 4 corner race scale at allmost empty fuel tank, sothose 335`s 4 door sedans must punch scale to whopping 3600plus lbs.

about pysical`s 335xi, very interesting concept with built engine and ported head, that can be my next project to do engine mods if this powerplant is giving up on that 27 psi levels and wildest idees could be to buid this 135is coupe to a xi

what to modify on that, trans from xi, front prop shaft, oil pan, front diff, front half shafts, front hubs, etc

maybe some day

She drives like an asshole to be honest.

I do not have any or my old logs but @V8bait might have some of my old logs. The boost comes in progressively and it was barely touching 26psi for like 500 rpm IF that because I hit 7000rpm in manual mode
 

135boost

Corporal
Oct 28, 2017
100
67
0
Ride
135is
Hi again
There is first "full pulls" with GC`s vs old setup 13T_6 / clipped stock turbines
pulls are dialled to virtual dyno but both is on similair parameters so they should be
compareable to each other. both are with 100% e85.

few notes to pulls
- GC`s are in tuning process, thats why little shy of boost, specially low down some 18-19psi
vs 13T 22-23 psi, after that they start to be quite close to each others so the gap between
GC`s and 13T should close on 3000rpm from 320/420 to 360/420 levels and at some 3500 they should be
equal.

i got new tune yesterday but there is slippery as hell so i didn`t get new pull with more oomph low down
and targets to 25psi but it`s to come some day



GC_vs_13T-6_Clipped_stock_turbine.jpg
 
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langsbr

Captain
Apr 5, 2017
1,197
685
0
Ride
07 335i 6MT e90
Damn, where do you find the space to do full 4th gear runs? Also, I am a diehard VDyno fan, but yours are not accurate. It's good to see a delta between your original turbos and the GCs, but it has your original turbos making 635 ft. lbs of torque from 2600 - 4500. That just seems a bit excessive.

Are you sure those aren't 3rd gear pulls?

Is the weight accurate on your car? 3340 with driver? Do you have weight reduction? I know the 135 is lighter than the 335, but that's awesome. I'd kill to have my car weight that. Not gonna happen with my fat butt in the seat.
 

135boost

Corporal
Oct 28, 2017
100
67
0
Ride
135is
Hi Langsbr.

few notes, my 135is accuracy weight is 3070lbs with undet 10 liter of fuel, it`s scaled with 4 corner calibrated race scale.
about pulls, the red one is on 4th gear and maxed out 13T-6 compressor and clipped as much you can from
stock turbine wheel to reduce exhaust manifold back pressure and with some 23-24psi of boost. and 100% e85.

blue one is same situation, same road and only different was temperature and those tweaks

about accuracy of those, just keeped every variables same to get some decent readings GC vs old setup.

old setup was worse to drive cause it spiked that boost too quick and make traction
problem severe. i got that 25 psi at some 2400-2500 and with turbine grab from some 2000, there is too little between that and max boost to control traction.
on the red line, that torque spike under 3k can be a bit from wheelspin or something or from way VD read start of slamming throttle, just check lambda on that so it`s a point where i must have slam throttle to floor.

i don`t have logs from stockers to share, shame.
 
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