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View Full Version : Max boost at k04 setup?



amx2k
11-21-2014, 01:15 PM
What will you say is max safe and efficant boost on k04's?
My setup is:
K04-015 turbo, modified alittlebit of a company here in Sweden
3'' downpipe with no cat
3'' exhaust
Saab/Opel C20LET 380cc injectors (red top)
Stock 4bar fuel pressure reg
3'' MAF
Proper software tune from a tuner in Sweden.
ADR cam-shaft's
Forge 008 valve
Uprated silicon hose from LMM til turbo

Castrol 5w40 magnatec oil, change every 5000km/3100miles.

Mine is running about 23psi/1.6bar at 4000rpm and hold 18-19psi/1.25/1.3bar at 58-6000rpm..

I do not run trackdays or something, just regular streetdriving..
Will it be safe?

Have been running like this since about July, no problems yet..

Car is running pretty well, do leave 'regular' k04 setups behind and I'm not very far from GT28 setups.. (with stock rods)

fed0ra
11-21-2014, 01:30 PM
What will you say is max safe and efficant boost on k04's?
My setup is:
K04-015 turbo, modified alittlebit of a company here in Sweden
3'' downpipe with no cat
3'' exhaust
Saab/Opel C20LET 380cc injectors (red top)
Stock 4bar fuel pressure reg
3'' MAF
Proper software tune from a tuner in Sweden.
ADR cam-shaft's
Forge 008 valve
Uprated silicon hose from LMM til turbo

Castrol 5w40 magnatec oil, change every 5000km/3100miles.

Mine is running about 23psi/1.6bar at 4000rpm and hold 18-19psi/1.25/1.3bar at 58-6000rpm..

I do not run trackdays or something, just regular streetdriving..
Will it be safe?

Have been running like this since about July, no problems yet..

Car is running pretty well, do leave 'regular' k04 setups behind and I'm not very far from GT28 setups.. (with stock rods)

23 psi is generally considered the upper limit of the K03/K04 without E85 or meth. You are pushing it, and a good FMIC and/or WMI would definitely help things. I wouldn't go over 23 psi, though.

BlueBoostedAudi
11-21-2014, 01:33 PM
When I had a ko4 I turned it up til it wouldnt go up any more! Just made sure I was getting enough fuel and keep turning it up... I ended up w 27psi tapering down to22-23 if I remember correctly

MetalMan
11-21-2014, 01:33 PM
That seems fine, but probably the highest boost I would choose.
What is your intercooler setup? I think the biggest "problem" with running too much boost on a K04 frame turbo is high IAT, but a proper intercooler will help.

amx2k
11-21-2014, 01:40 PM
At the moment, when it's about -10 degrees Celsius here in Sweden, the stock one, can't see that the IAT are very high, about 25-35 degrees at the most with these temps we have here now.

Are these 380cc injectors big enough?
Have testet with a wideband lambda at the A/F ratios was about fine, that was on 1.4bar than..
I don't have 1.5-1.6bar for a long time, maybe just a sec or something before it drops a littlebit..

DiertyEuroSpec
11-21-2014, 01:52 PM
Get bigger intercooler. You will need it when summer rolls around.

MetalMan
11-21-2014, 02:04 PM
Are these 380cc injectors big enough?
Have testet with a wideband lambda at the A/F ratios was about fine, that was on 1.4bar than..
I don't have 1.5-1.6bar for a long time, maybe just a sec or something before it drops a littlebit..

What is the maximum injector duty cycle? If your maximum injector duty cycle is above around 80%, then your injectors are too small.

amx2k
11-21-2014, 02:18 PM
I will get a bigger intercooler soon, had order one, but got the wrong kit so returned it.
My IAT is not so bad? What is the MAX in C for IAT ?

I have not seen at the duty cycle for the injectrors yet, will take a look tomorrow..

rockersteady
11-22-2014, 06:09 PM
Ill chuck in my 2 pennys

Can you elaborate on the K04 you have fitted?
You asked max boost and max efficiency. They are different. You want to make the most HP or most torque?
Max boost for efficiency (and biggest area under the torque curve) will be about 18psi on a modified k04 tapering to as low as 12psi at limit 5800rpm.

This will also achieve Best HP (and greatest torque area) by restricting/ holding n75 duty cycle to 80% . You need to let some gas out of the cylinder head and restricting it thru the k04 outlet will only raise reversion. (Exhaust gas cant get out, mixes back in the cylinder, will over heat, will raise cylinder temp, and cause knock = HI boost but LOW torque)
You can run higher boost and achieve a higher torque figure but it will output short bursts only.

The secret is less boost allows you to run more timing and this will generate more torque for the longest time on the small turbine turbos.

M-Hood
11-22-2014, 07:03 PM
Most of the J31 K04-15 (2000 A4) owners were pushing 25-30psi, the K04-15 tends to do best at 25psi. No matter what, after 20psi the K04-15 really can't hold that boost to redline so the boost tapers in the upper rpm.

pichno
11-25-2014, 07:36 AM
Most of the J31 K04-15 (2000 A4) owners were pushing 25-30psi, the K04-15 tends to do best at 25psi. No matter what, after 20psi the K04-15 really can't hold that boost to redline so the boost tapers in the upper rpm.

Interesting. I wonder why Dave with Motoza said 18psi is what my 01 is best at then? We've done numerous logs at different settings and that's what he found as optimum. Any input?

pichno
11-25-2014, 07:37 AM
Ill chuck in my 2 pennys

Can you elaborate on the K04 you have fitted?
You asked max boost and max efficiency. They are different. You want to make the most HP or most torque?
Max boost for efficiency (and biggest area under the torque curve) will be about 18psi on a modified k04 tapering to as low as 12psi at limit 5800rpm.

This will also achieve Best HP (and greatest torque area) by restricting/ holding n75 duty cycle to 80% . You need to let some gas out of the cylinder head and restricting it thru the k04 outlet will only raise reversion. (Exhaust gas cant get out, mixes back in the cylinder, will over heat, will raise cylinder temp, and cause knock = HI boost but LOW torque)
You can run higher boost and achieve a higher torque figure but it will output short bursts only.

The secret is less boost allows you to run more timing and this will generate more torque for the longest time on the small turbine turbos.

Yup, near redline my K04 setup is around the 12psi mark, but definitely feels healthy all around.

amx2k
11-25-2014, 07:51 AM
I don't have any more information about the k04-015, than it's been modifyed, I see about 1.25-1.3bar/18.1-18.8psi at 6500rpm, that's a littlebit more than a regular K04 does I think?
Have been racing against another A4 with a regular k04, and I did left him good behind.

I have got my hands on this intercoolerkit for a low price, will I make any big difference in performance after mouting this?
I had FMIC on my last A4, that was only chipped and 2.5'' exhaust, can't say I felt so much difference after I fittet te intercooler to that car, but that was just chipped k03, 16psi..

I do want to make as much HP as possible, I'm on stock rods and clutch so the torque is not so important, if you understand what I mean.

http://forum.vacn.no/attachment.php?attachmentid=217691&d=1415556564

amx2k
11-26-2014, 10:26 AM
Not many answers to get here.. Are you all sleeping guys? [:p]

fed0ra
11-26-2014, 10:51 AM
I don't have any more information about the k04-015, than it's been modifyed, I see about 1.25-1.3bar/18.1-18.8psi at 6500rpm, that's a littlebit more than a regular K04 does I think?
Have been racing against another A4 with a regular k04, and I did left him good behind.

I have got my hands on this intercoolerkit for a low price, will I make any big difference in performance after mouting this?
I had FMIC on my last A4, that was only chipped and 2.5'' exhaust, can't say I felt so much difference after I fittet te intercooler to that car, but that was just chipped k03, 16psi..

I do want to make as much HP as possible, I'm on stock rods and clutch so the torque is not so important, if you understand what I mean.

http://forum.vacn.no/attachment.php?attachmentid=217691&d=1415556564

Considering the boost you are running I would say you will see a benefit. Lower IATs mean denser air means more power. Plus it will be less prone to heatsoak in the summer or after harder runs, so you will keep your performance day in and day out.

It wouldn't be a bad idea to invest in water-meth injection while you are at it. That will cool things down substantially.

amx2k
11-26-2014, 11:02 AM
Water-meth injection is not very normal over here, what does that do ?

B5nDisciple
11-26-2014, 11:09 AM
Water-meth injection is not very normal over here, what does that do ?

https://www.youtube.com/watch?v=HkPFZWd8wj4

amx2k
11-26-2014, 11:22 AM
No I don't wanna bother with that, could easy installed another turbo than..

B5nDisciple
11-26-2014, 11:37 AM
No I don't wanna bother with that, could easy installed another turbo than..

Well it's a good alternative to getting a new intercooler which could actually cost more depending on what setup you went with. The only drawback (IMO) is having to make sure the tank is filled all the time. For me it would only make sense to have water-meth as a dedicated track car or weekend warrior. But some people run it in their daily and just get used to the extra fluid type to keep tabs on. You can use a proper windshield wiper fluid, so it's not hard to come by.