OK so here is what happen .


I installed a Down Pipe , and boost tubing . ( CIA )


I have the clamps as tight as they possibly can go . I havent checked it with a boost pressure tester. The car feels faster somewhat but I notice instead of spiking 25 PSI most of the time it will build boost as the RPM's go up and in fith gear I used to be able to get it to spike to 25 PSI at WOT in the lower RPM band and then go back to 22.5... Now in second gear it will spike 25 psi and drop .. Instead of spiking and dropping it now acts like its Building boost and fluctuates a bit .


IS this because I haven't re-tuned it for the new boost tubing .. Because the new tubes are a lot bigger and thats why I am seeing this ? Also the DP has freed up the airflow so I am seeing a little less pressure maybe ?.. I have HPtuners and damn Stevo is gone , everyone else wants an arm n a leg to tune it remotely . I can't really hear the BOV make as much noise as it used to .. Maybe its stuck ? How do I check that ?

 

well first of all you car isnt suposta be making that much boost lol .... our cars go into overboost at 22.35psi so if ur reli boosting that hard check it out although i herd they were fixing it but i havnt herd anything about it being done

 

I think it is more of a guage lag then anything .. That guage is just dumb sometimes ...


In seconds gear it goes to about 22.5 and then I saw it drop close to 18 lbs close to 5000 rpms... WTF

 

so u have hp tuners now? i think 22.5 is what most of them see i wouldnt suggest running 25 psi anyway but not retuning after is probly why but u said it feels faster so faster with less boost is a good thing

 

Yeah I have HPTuners pro I have had it for a while, I put 6k + miles on it witha good tune and it has worked great.

it just says 25 PSI for a short amount of time like a milisecond because the guage is slow .

 

The reason it is falling off up top is probably your desired airloads up top. It is because the motor can breathe better now. PM Me.

 

lol all of our guages are slow speed, tach, boost, even the last time i got gas and started it up it went to half a tank then 5 min later it was close 5/8

 

Sounds like a normal tune characteristic. My car spikes 23-24 and drops to 21 then down to about 18-19 at high RPMS, thats your turbo running out of air.

 

Awwww that isn't what I wanted to hear LOL but reading on google for hours it sounds like thats what is happening .. Damn ..

I am still under the assumption that a direct bolt on replacement turbo does not exist ..


Is the turbo wheel upgrade worth it at 800 bucks ? atleast that might let it hold past 5000

 

My logs show 249 kPa ( 22 psi) until 6600 rpms then it drops to 235 ( 20 psi) at 6800 then to 230 kPa (19 psi) at 7000 rpms. Wheel upgrades are prone to compressor surge unfortunately.

 

To date, I have had only one person call for support on the compressor surge issue. Hiltu, and he's coming out to see what I can do with it. It will only manifest on the cars that are on the low end of the stock hp spectrum, and only if your trying to run 19-20psi before 4k. After that it's free range, and will hold high boost out higher in rpm.
It's a possibility, but one out of more than 20 (<5%) is hardly "prone". Please dont spread misinformation.

As far as whether it is worth it for a completely remanufactured turbo with the highest flowing components that will fit inside the stock case, that's really up to you.

The KO4+ is aimed at people who want the absolute highest flow availbile from the stock turbo casing. For either racing purposes, or for those who get abused by the police everytime they leave their house, It is designed to appear stock, yet flow over 400hp when pushed to the max.

Cobaltoverbooster get's harassed for anything non-stock on his car in california. There are many more of our customers that made the decision based on the same thing.
If you dont face that issue, then buy a stage kit instead. They are capable are making more than 500hp and the Gt3076R (stage 1) has full boost just 1000rpm later than stock.

 

has the K04+ been fixed to run fine or is it still causing surge?

 

Do you mean Jared's car? Cause as I just stated, he is the only one that has approached me with an issue so far.
So for 95% of customer's thus far there was nothing to be "fixed".
If your car dyno'd pretty low to begin with and your trying to run more than 18psi below 4k rpm, then defitnily order the clipped turbine option. It will eliminate the possibility of low rpm compressor surge. It will also make more top end power with the clip.

 

About what does 18psi in the K04+ equate to versus 21-22 on the stock turbo?

 

For WHP at that instant do you mean? Of course it will be slightly less than 3 more psi with the stocker. The stock turbo is optimized for midrange power.
The KO4+ is all about making similar power downstairs, but holding it out up top. Once you have gotten past 20lbs/min then you can crank to boost to 30psi if you want. you'll be safely out of the range of surge.
I dont wanna Jack Princessturbo's thread, but id be happy to post the true stock compressor map along with the Ko4+'s. If you understand how to read them, it will illustrate what the hardware is capable of.

 

Separate thread perhaps? Yeah, I'd love to see the k04 and k04+ compressor maps.

It was basically just something I've wondered about. I've known of the existance of the k04+ for some time, but haven't been able to really understand it's actual true potential vs stock.

Sorry if I keep covering the same thing again, but just wanted to make sense of what you said: So you'd probably follow the boost levels of the stock k04, but would stay at a max of 18psi until the 4k RPM mark (which would be ~20lbs/min?) after which you can crank it to 30?

 

For the most part, yes. The main benefit of the larger compressor wheel is improving the top end power. If you have sufficient octane, then 30psi will make some bitchin top end power. Jared is coming by sept 4th, we'll see what I can do to solve his problem and what we can make using the overboost beta. My dyno is a real hearbreaker(Dyno-mite), so dont expect dynojet numbers though.
Start another thread and I'll post up the maps.