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Discussion Starter #1
Is it absolutely required to have a 5bar fpr to install a K04 turbo or can you run a 4bar. Am having difficulty with my K04 at high rpm's, is the Fpr the problem?
 

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PassatWorld Staff
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The 5 bar may or may not help, you'd have to try it. Some people it really helps, some it makes little difference because the ECU's fuel trimming operations trim the extra fuel out.
If you bought a kit, it should have the correct chip for 4-bar operation, or it should require a 5-bar.
If you are DIY and not changing programming then the 5-bar would be a good thing to try.
 

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If you have an AEB engine with stock injectors (210cc/min) you will need a 5-bar FPR and proper programming (GIAC, for example) to provide the fueling needed to run in the upper boost range of the K04. This is because the AEB is limited to a maximum pulse-width by the ECU. No amount of programming can get past this limitiation, so the options are:
A) Increase fuel pressure of stock injectors to spray more fuel per injector opening interval
B) Upgrade injectors to spray more fuel per injector opening interval

A is the cheaper solution and is used by the AWE K04 Kit.
 

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Help us out with info like MY, type of chip, exhaust, etc. Otherwise you'll get s**t answers and you may detonate your way to a new engine before you get things right. :shock:
 

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Discussion Starter #8
98, AEB, no chip , stock injectors, 4 bar fpr, had to buy new MAF, forged diverter valve, and already installed K04 turbo, If I need the bigger injectors where do I get them, As with the 5Bar FPR where would I get that too? Have spent around $1700 already, How much more do I have to spend :cry: :( :eek:
 

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Hmm.. with no chip you shouldn't be seeing any more boost than normal. Actually, it should spool slower than the stock K03 due to the larger compressor wheel.

I would suggest you contact Todd at AWE-Tuning (www.awe-tuning.com) and purchase their GIAC K04 software and 5-bar FPR. This is the setup I have on my Passat and it pulls hard as hell with no surging (after the initial peak boost). I will install an N75 J valve to smooth the boost spike when I do the timing belt work.

Do you have an aftermarket exhaust & downpipe? AWE strongly suggests using one with the K04... actually they REQUIRE it.
 

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How did you spend that much? New K04's are only $750 or so...
 

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krautlvr said:
98, AEB, no chip , stock injectors, 4 bar fpr, had to buy new MAF, forged diverter valve, and already installed K04 turbo, If I need the bigger injectors where do I get them, As with the 5Bar FPR where would I get that too? Have spent around $1700 already, How much more do I have to spend :cry: :( :eek:
Click on my "website" button to see what I have done with a stock ECU. I'm running a very stable 15 lbs boost using a Dawes MBC, a modified MAF assy, the stock 4 bar FPR and 310cc injectors. I've had a Cartech FPR in the loop off and on - currently it's off, and I'm getting great results.
Four Big Caveats:
- 1) I have a VAG-COM and have closely monitored engine parameters whilst adding all this extra boost and fuel to the engine.
- 2) I have greatly increased the volumetric efficiency of the engine via COAM (Colorado Outlaw Airbox Mod), port-matched intake manifold, Random hi-flow CAT, and port-matched exhaust manifold. If you try to run 4bar w/310cc injectors using OEM manifolds and stock CAT, it's going to run too rich.
- 3) I'm still using a K03. A K04's effect on my mods is unknown (for now...)
- 4) At WOT I'm a lot leaner than I'd like to be (14:1 midrange down to 13:1 at redline). A chipped car is usually too rich at WOT (10:1, 10.5:1, if you're lucky 11:1) 'cause the chip makers want to be SURE your engine doesn't blow up. Ideally, it should be 11.5 or 12:1 for a forced-induction engine. In the near future, I'll be using the Cartech hooked up to my kickdown switch to alleviate my WOT lean-ness.

How much more do you have to spend?

- 1) The recommendation above to get the GIAC K04 chip from AWE is a good one. That'll set you back the cost of the chip - I dunno how much. $400? $500? $600?, plus the cost of a 5-bar FPR.

- 2) A better way is that GIAC has special K04 software for use with a 3 bar FPR and 310cc injectors. It's file PC16.01.03A. This will get you enough fuel to really make the K04 shine - JEM has this file and he loves it (Herman, have you tried this file yet?). But then you'll have to buy a 3bar FPR (about $65) and the four 310cc injectors ($100).
 

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A 5 bar should fix you up at top end but may run rich at idle. $80 from Neuspeed for a 5 bar and you can find out. The problem is the K04 flows more air even at the same boost level as the K03. It sounds like you're trying to save $$ and you can get a deal on a K03 chip from Wett, APR or Neuspeed, you could probably use it with the 5 bar FPR as long as you're sticking with the stock exhaust. Check to see if Wett is including the K04 programs for the $295 sale price.

Last I heard AWE gets $695 for a K04 chip when bought outside of a kit. If you go that route, definitely get the file that Rusty is talking about above.
 
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