FrankenTurbo Build (Stock rods now bent again)

[Jim_Coupe]

Hi,

Thought i should write som about the misery ive been through for the last couple of months.. It has been some really learning months for me and exhausting aswell. So im gonna share my experience.

Im gonna start from the begining....

In oktober last year my 1.8T (longitudal) sufferd a timingbelt crash. Wich ment that all of my exhaust valves were bent. So i decided to get a new head.. I have an ANB engine.. so i ordered an AEB head.. Why? because im stupid and cannot read.. So when i got the head i first realized that i had recieved the wrong head when i saw the BIG badass intake ports.. ??
But im a 20V I5 guy so i thought hmm ahh flow is nice.. and it was a cheap head asweell. So i swpped it in along with an AEB intake manifold and a South.. something gasket.

I wasnt really happy with the K03 so i decided to Buy an eBay K04 just to try and se.. And as if that wasn enough i ordered a tubular manifold from eBay aswell.. just to make sure i have some nice flow.. When all things where put together the car started and didnt run very nice.. it missfired and ran really bad. I used VAG-COM and found out that the O2 sensor had been damaged.. probably during the installation some how.. I changed the O2 sensor and the car ran okey but not very good.. Later I discovered that the FPR also had been damaged by me a was spraying gasoline into the engine wich is not good for anytyhing.. I emtied the engine on oil and changed the FPR and it was upp an running again.. The K04 turbo gave a nice pull and felt really nice..

But after like 2 days of testing a knocking sound appears in the engine.. My first thought was that one of the lifters must be damaged. But the knocking sounded more ditinct and hard puncing.
I used a stetoscope and litened to the head.. heard notting!! listened to the block.. and there it was.. klonk klonk klonk.. with a metallic sound..

Weeeell what do you do when you hear klonking sound from the bottom of the engine Time for Lift Out !

[Jim_Coupe]

After the timingbelt crash

[Jim_Coupe]

AEB manifold vs. APU/ANB



AEB head with Tubular Exhaust manifold. this manifold works.. but you have to relocate O2 sensor. and its hard to reach the downpipe bolts.. but there is work arounds.



eBay K04 wich worked great after all.. I pushed it to 1.1bar went okey.. but notting I would dare to use on a car holliday 500km from home..

[Jim_Coupe]

Well.. I gott bored of that K04 turbo.. and Ive heard alot about the FrankenTurbo so i decided to get one and also weld a 3" downpipe with a race kat to really get a good floow in this engine

But before using that FrankenTurbo i really wanted to sort out that god damn knocking sound from the bottom end in the egnine..

This was what i found few hours later !

Bent rods ! Why?? at this point i only had my clues


One rod was so bent it grineded the block for me.. (Making the way for a larger crankshaft maybe hmm)

[Jim_Coupe]

The Bent Rods must have been the result of mulitple missfires and more HP... I must say i was really satisfied with the output from this 1.8T so i must have been around 230hp atleast.. i compared it to a non chipped audi S2..

Because my first thoug about the klonking was bad bearings i had bought new bearings and so on.. but hmm it turned out to be the rods.. any way lucky me who have two Audi 20 I5 engines on shelf.. so i swapped in 4 rods from the Audi 7A engine.. same rods as the Audi S2.. ehmm so it seems and wheights..

results =

[Jim_Coupe]

Okey now we are going into stage 2+ i think... just to reveal some data..

Engine data:

1.8T
Stock rods
Stock pistons
FrankenTurbo F4H-L
440cc Delphi injectors
4Bar FPR
K04 Map
Forge DV
AEB head with manifold
Tubular Exhaust
3in DP
100Cell race kat
2" exhaust from DP. SuperSport.
4" intake filter..
3.5" MAF Bosch





Results:

After testing i still got multiple missifres with this new setup.. What in the name of JESUS is this i thought to myself.. I changed fuel filter.. No change.. i change FPR No change..

Finally i Changed fuel pump to STOCK from that old aftermarket ****.. THEN this car pulled my to the moon.. Holy ****. really good power.. i was so suprised. Now it felt like my chipped audi S2..
But this was worrying at the same time i feelt somewhere in my body.. will this hold togheter??

[Jim_Coupe]

No it did not... Results now is following..

Now the same klonk sound is back.. and engine feels unbalanced.. same sympthome as when you have a bent a rod.. so what to do what to do....


The turbo also started to whine more than normal 2days ago.. The sound is described more like a turbo whining but with lower frequency.. this ca be a leak in the system this is not totally invetigated yet!

Some say you have to change oli feed line to feel safe when changing turbo.. But whats worries me is that i have used my eBay K04 and pushed that one for more days thatn this FT with same sotware and same amount of boost. Anyway this I belive is not a big problem i think.. there is repair kits aviable.. but is it hard to repair by your self?

anyway now i have to lift the engine again.. to solve this.. H-Beams are on the way..

My conclusion is..
Bad fuel pump = No fuel = Lean mixture = Missifre = devastating for the engine internals..

anyone who disagrees ?

[Blackfin]

Bent rods are caused by boost spikes at low RPM, something a K04 excels at. Basically, the thing spools faster than the PCM's control loop can keep up. The solution is a simple MBC plumbed in parallel to the N75 valve to act as a "safety valve." It reacts quickly enough to squelch rod-bending torque spikes but, if installed properly, doesn't interfere with the PCM's normal control of boost.

[AmIdYfReAk]

Install some damned drop in rods already!

[schwartzmagic]

What I want to know if why weren't you running logs to make sure you air to fuel ratios were okay?

Or at least had installed a Air/Fule Ratio gauge (wideband gauge).

[Jim_Coupe]

Theres so many things you should have have from the start.. AFR gauge is one good thing to have.. i logged the lambda value in VAg-COM thats how i found out that mixture was to lean.. but then it was to late..

But now it seems like boost spikes at low rpm is the thief..

[Jim_Coupe]

Bent rods are caused by boost spikes at low RPM, something a K04 excels at. Basically, the thing spools faster than the PCM's control loop can keep up. The solution is a simple MBC plumbed in parallel to the N75 valve to act as a "safety valve." It reacts quickly enough to squelch rod-bending torque spikes but, if installed properly, doesn't interfere with the PCM's normal control of boost.

There you said something.. the bent rods came short after boosting at low RPM.. hmm one BIG lession is learned here i think.. i was acceleration on low gears.. on an entrance to a bigger road..

How do you adjust this MBC correct then ?

[DMVDUB]

I'm going to say you should have sold the block you took the rods from and bought a piston / rod combo from IE. Then you would have no worries and more room on your shelf

[Jim_Coupe]

one other thing i noticed was that the boost preassure was pending up and down when boosting..
it was like pssssSSSSSssssssSSSSSsssssSSSSSSsssssSSSSSS... hard to explain.. it behaved almost like swinging.. this could be a leak but alos maybe it could be the N75 ?? hmm.. wierd.. stuff anyway..

[Dub-Nub]

one other thing i noticed was that the boost preassure was pending up and down when boosting..
it was like pssssSSSSSssssssSSSSSsssssSSSSSSsssssSSSSSS... hard to explain.. it behaved almost like swinging.. this could be a leak but alos maybe it could be the N75 ?? hmm.. wierd.. stuff anyway..

that explains the bent rods. Its called surging. Its like grabbing someone and shaking them, but in the case of the engine its alot more forceful. This most likely bent your rods...again

[the_q_jet]

just install some IE or Scats and call it a day.

[Blackfin]

There you said something.. the bent rods came short after boosting at low RPM.. hmm one BIG lession is learned here i think.. i was acceleration on low gears.. on an entrance to a bigger road..

How do you adjust this MBC correct then ?

The MBC is set to a boost pressure just slightly higher than the maximum boost the PCM is set for (e.g. if you've got a GIAC tune, you might set the MBC for 22-psi or so). Ensure you use decently sized vacuum lines in this setup to ensure a good volume of air can move to the wastegate actuator when needed.

Read this:
http://www.boostvalve.com/overboost.html

and this:

http://www.boostvalve.com/1.8info.html

[Jim_Coupe]

okey Turbo surge.. hmm.. why does this appear.. ive heard of it before but ive never had reason to involve myself :S i thought this swinging in the boost was caused buy a leak..

but istn surge a more osscilating sound ?

[Jim_Coupe]

just install some IE or Scats and call it a day.

They are on the way

[dirosama]

okey Turbo surge.. hmm.. why does this appear.. ive heard of it before but ive never had reason to involve myself :S i thought this swinging in the boost was caused buy a leak..

but istn surge a more osscilating sound ?

Was your boost going up and down rapidly at WOT?

[Jim_Coupe]

Well... no it went upp down with 1 second period time.. not very fast. this appeard for example when i have reached stabilized boost when WOT on fifth gear.. but also when accelerating from lower gears

BUT speaking of surge.. when i accelerated WOT from like 2nd or 3rd gear i feelt a small jerking motion in the car.. this may have been surge.. One more thing when running WOT on low gears it feelt like.. "hmm so much boost at this low RPM" ?? it almost feelt like the turbo feeded the engine with to much air.. feelt like the car was riding with air as propulsion... with some sort of rubberband effect... no easy to explain but hmm..

[Blackfin]

okey Turbo surge.. hmm.. why does this appear.. ive heard of it before but ive never had reason to involve myself :S i thought this swinging in the boost was caused buy a leak..

There are two issues here: Boost spiking and surging.

Spikes occur because of a mismatch between the mechanical and software aspects of the control system. Simply put, the turbo is capable of building boost at low RPM faster than the software and control hardware (e.g. N75 valve and the PWM signal driving it) is able to keep a handle on it. An "analog" back-up like a MBC is often able to intervene to deal with spikes if the control loop is too slow.

Surging is an oscillation of boost levels. Its peaks may involve damaging levels (akin to spiking) but it's the oscillatory nature of the boost that is really notable. Generally, this condition comes about because of a poorly designed control loop. In engineering terms, it's known as an "under-damped" system and in these engines usually results when one or more components or elements is changed without regard to the rest of the system. For instance, a "chip" to up boost and/or a high-flow manifold and/or a K04 turbo and/or a "race" N75 valve etc all represent changes to a system that muck up the carefully tuned feedback and feedforward system that the car came with originally. The control system may "hunt", requesting boost, seeing too much and then taking a bunch away, seeing it drop too low and then asking for a bunch again... It's a PID (proportional/integral/differential) controller and unless every parameter is properly matched and tuned to the hardware, you will likely have instability in the control system.

A MBC can help mitigate the spikes and may dampen the system enough for the PCM to get control of it quickly. Different N75s -- valves that flow and bypass at different rates -- may help too. But without dyno time under controlled conditions it's tricky to re-tune the control systems to get rid of surge completely.

[Jim_Coupe]

Thank for makin that explanation blackfin.. It all make make really good sense. PID loops are tricky sometimes .. And I think i have got a really good picture now.. I should know this because im working with PID regulators in PLC´s time to time.. but with cars it feels more difficult and demands more experience in the area..

I think my loggin in VAG-COM no confirms what you said abov.. i my loggs i can se "Actual boost Go Up" before even the requested boost has woken up.. then i see requested boost trying to calm it all down abit.. but fails because the spike has already occured.. this must mean that the feedback signal (MAP sensor) is abit lazy :S

[badger5]

that explains the bent rods. Its called surging. Its like grabbing someone and shaking them, but in the case of the engine its alot more forceful. This most likely bent your rods...again

sounds more like N75 control loop trying to control and failing... oscillating PID control (or out of control more like)

surge sounds like a chuff chuff chuff sound on spool

[Jim_Coupe]

Well ive been watching a few videos about surge on youtube now.. think i know what surge is now...

In my case the control loop seemed to be abit Texas. The software I think was not made for this amount of boost at this early point.. the PID loop or boost curve must be updated for applications like this.. or use an MBC

[Jim_Coupe]

H-Beams are installed and engine is up and running again... The whining sound from the turbo.. se pic below... Turbo was damaged by an UFS (unidentified flying stone) or something. Mybe the filter wasnt clean enough.. But FrankenTurbo has a really good replacement kit ..
HURRAY for franken turbo.. payed 150 buck for a new central compartment replace kit great deal.

But to be sure that I wont damage the new repaired FT.. I threw in my old eBay K04 just to test with just to be sure everthing is OK.... Now the car is up and running again.. and I feel really safe with H-Beams now.. In a month or so im gonna throw the FT in again and make a new try with the FT.. Hope things will hold together becuase i relly want to feel that FrankenTurbo pull again

some pics

[redefine6]

Good to see you`re back up and running Jimmy. Throw a MBC in parallel with the N75 and that should fix your rollercoaster ride on the boost gauge.

Quick question: I`m pressed for cash and was thinking of throwing in an ebay k04 to replace my tired k03s. Hows that turbo been thus far. Do you have a link

[Jim_Coupe]

So far so good im peaking 1.2 bar and stable at 1.0bar.. 2000km without problems so far..
The Peak effect is ok.. but instead you can pull the K04 longer to the redline.. thats nice.. and it was cheap

And the MBC seem´s to make this more stable..

The diffrence i feelt with the FT was that the FT was more wild at start and also pulled nice to redline.. have a sick flow in this engine.. the respone is unbeliveable nice with AEB head, tubular mani and 3" DP.. But with all this stuff i have, i can really feel the restriction in the K05-015 small turbine inlet compared to the FT. anyway i think the K04-015 is very ok for a daily driver..

i can PM you if i could find the link..

[Jim_Coupe]

Just a question.. I have now connected the MBC in parallel to the N75J valve.. but it doesnt seem that i can lower the pressure.. shouldnt I get lower boost with the MBC fully open ?

[AmIdYfReAk]

Boost to the waste gate is what opens it/lowers it.

opening the MBC totally leaks out as much boost as possible,

So you'd want it closed, tight.

[redefine6]

Just to clarify, MBC in parallel with n75 should resemble this:
http://www.boostvalve.com/images/OVB_1.jpg

[Jim_Coupe]

How about just use the boostvalve and skip that N75.. i dont trust my tune..

[doug@frankenturbo.com]

You just need to get the car's ecu flashed for the turbo. Look at the terrific boost control possible when running the right software.



This is Motoza but forum sponsors C2 Motorsports or Malone can deliver equally solid base files to hold you over until your builds are complete. Stage 1 files are cheap. There's no reason not to do it.

[Jim_Coupe]

Right now im boosting 22 PSI on the K04.. But the boost control seems to be out of control.. Probably surge..
The boost swings up and down still when partial throtel... Its almost like the ECU see´s to much bost to fast and tries to take it down.. but then pressure waves up and down.. I have a bleedervalve in paralell wich make no diffrence.. if its closed or open.. hmm and i have connected it accorging to boostvalve.com.. Its a bleeder valve from ebay.. maybe its not that godd.. But the N75J should not wave the boost up and down as it does now..

Maybe i should throw that N75 out and just use a boostvalve from boostvalve.com ?

[Jim_Coupe]

You just need to get the car's ecu flashed for the turbo. Look at the terrific boost control possible when running the right software.



This is Motoza but forum sponsors C2 Motorsports or Malone can deliver equally solid base files to hold you over until your builds are complete. Stage 1 files are cheap. There's no reason not to do it.

Yepp thats a nice curve..