Rebuilt K04

[Ninkumpoop]

Anyone have a rebuilt K04 in their cars? I have a boost controller I'm going to install with the K04 I just received in the mail and was wondering how much I can boost before things start going haywire.

 

[Captain KRM P5]

the upper limit of theturbo by our recommendation is no more than 22psi or 350whp. obviously the upper limits of the engine are different as well. it all depends on what you are going to use to tune the car, if anything at all.

 

[Ninkumpoop]

So...20 PSI with factory internals is a safe bet? I'm normally going to keep boost very low besides those moments when I really need to beat someone in a race. I'm not planning on getting a tuner for my car just yet (mostly because I'm flat broke). Plus I was told by a couple of my school instructors, both of whom are well experienced with tuning cars, that the ECU should compensate for the extra/under boost and set my A/F ratio accordingly without running too rich/lean. Is that true, as well?

 

[Captain KRM P5]

So...20 PSI with factory internals is a safe bet? I'm normally going to keep boost very low besides those moments when I really need to beat someone in a race. I'm not planning on getting a tuner for my car just yet (mostly because I'm flat broke). Plus I was told by a couple of my school instructors, both of whom are well experienced with tuning cars, that the ECU should compensate for the extra/under boost and set my A/F ratio accordingly without running too rich/lean. Is that true, as well?

i wouldn't push alot of boost or make any bets on engine safety until you have a reliable way to monitor and tune. your instructors are, with some caveats, correct. the ECU will compensate for lean and rich mixtures based on sensor inputs, within reason. there is only so much safeguard and leeway programmed into any computer before you can exceed the allowable parameters. the ECU isn't designed to give people a free pass at increasing boost, its designed to adjust operation for a variety of internal and environmental factors such as air temp, air density, elevation, fuel quality, load, manifold pressure. this is what allows a manufacturer to sell a car in california the same way they'd sell one in alaska. you have a very broadly programmed ECU that accommodates this wide variation of multiple factors. this is the same reason why an "off the shelf" map will almost never provide two different cars with the same gains nor provide the best gains. so in short, yes the ECU will compensate to some degree, but its able to do so for reasons other than allowing you or me the ability to make more power arbitrarily.

 

[Ninkumpoop]

Sorry to ask again but what would be a safe parameter for boost on a stock internals motor such as mine?

 

[Captain KRM P5]

without tuning and knowing what you have on the car, i'd not jump too far past 18psi honestly.

 

[Darth Vader]

Flat broke + increasing boost = becoming flatter broke. Leave the engine alone until you can find a way to do this properly.

Add small things to maximise what you have, like stiffening up the motor mounts and shifter bushings, maybe a used SRI or a CAI or a quality inexpensive bypass valve like Forge, a used downpipe, etc. There's alot to be gained from the boost levels the engine is currently producing.

 

[Mid_Life_Crisis]

Flat broke + increasing boost = becoming flatter broke. Leave the engine alone until you can find a way to do this properly.

Add small things to maximise what you have, like stiffening up the motor mounts and shifter bushings, maybe a used SRI or a CAI or a quality inexpensive bypass valve like Forge, a used downpipe, etc. There's alot to be gained from the boost levels the engine is currently producing.

What he said. Plus a reworked turbo will spool quicker, which will improve throttle response and probably yield a few more ponies at the same boost levels. I would swap out the turbo by itself first and drive it that way until I could afford a tuning solution. To be honest, I would have bought a tuning solution first, then started saving for power add-ons.

 

[Ninkumpoop]

I currently have a cat-less TBE, SRI, and a BOV (VTA). I actually would've bought a COBB AP but the guy I was supposed to buy it from stiffed me after saying he'd sell it to me and sold it to someone else. Yes, my car is a tid bit faster with my current mods but I still want a little more until I find myself another job. I gotta at least smash by friend and his damn Mach1 Mustang. He's pushing 280WHP and 300WTorque. I should be able to at least inch past him with 18PSI. Thanks for all the advice, guys.

 

[Darth Vader]

"...but I still want a little more until I find myself another job. I gotta at least smash by friend..."

This line is the classic famous last words of all budget hop ups, man, trust me, BTDT. Don't budget hop up a car you need as a daily driver to FIND your new job.

My greatest budget hop-up car of all time was my '88 5.0 Mustang I just sold. At different times over 13 years, I'd turbocharged that car with two junkyard turbos, I nitrous kitted it, I ebay supercharged it, built a JY rear disc kit for it, etc. etc. I built so much stuff out of JY crap on that thing it was amazing. It was a challenge like the one you note, let's see if I can keep up with or beat my high dollar friends in my low buck car. It was very satisfying but ALOT of work.

In my somewhat advancing years now, I still like to play with the car a bit but, I ain't so worried about beating anyone and, I'm pretty happy Mazda did a damn good job with this car. It ain't no Mustang 5.0 where you had to modify EVERYTHING to make the car remotely decent.

 

[MSMS3]

Change the vent to atmosphere BOV to recirc and you'll pick up some power, especially right after you upshift.

With your mods and correct MAF metering (recirc of your BOV) and if you go to heat range 7 plugs (one step colder) you are probably already able to put down 265-270 wheel horses now and about 290 lbs of torque. You're probably lighter than the 'stang. If you have your mods installed correctly you should be able to run with him and maybe pass him up top, depending on his gearing and tires. You'll never be able to match him at launch without drag radials. FWD will screw you every time, but once you get into 3rd gear, you'd be surprised what you can do.

"Tad bit faster"? You should be up about 40 horses over stock now. With basically the same mods as you except for a CAI (but stock BPV and stock CBE) I'm running 13.4 quarters at 106-107 under good conditions. That's with crappy launches, but good power up top, and being sure to shift at 5,500 rpm.

IMHO, you are chasing the wrong thing trying to push boost above 18 psi on stock tune. You can easily get into the 12's with drag radials and getting rid of that VTA messing up your AFR's.

 

[Darth Vader]

Hey MSMS3, remind me, have you actually tracked your car or are those 1/4 mile times g-tech?

 

[Sphincter]

Hey MSMS3, remind me, have you actually tracked your car or are those 1/4 mile times g-tech?

He's always promoting his g-tech, and I think all his stats are from it, and I bet you his 1/4 mile time is from it too.

 

[MSMS3]

Yeah, back in the spring after the DP install and the track reopened. Got in three runs on a Friday evening test and tune. 13.4 at 106 (first run luck - pretty exciting for me) followed by two slower 13.6 runs trapping 104's. Gufport Dragway is at sea level and has a reputation as a quick track.

I use the G-Tech to tune and practice launch - still crappy at that. I don't promote it. I just think is is a very useful tool that shows data in a way you can't collect any other way. It is not a substitute for the strip timers.

 

[Darth Vader]

I got a DP and a Forge coming...I haven't got the car over 99 mph so far at the track WITH a CAI. I'm running 4th right out the back door. You on stock street tires?

I'm at Mission Raceway in British Columbia, also a sea level track with a good rep.

 

[aaronc7]

I tried riding out 4th for the first time last time I went to track... I had my best time and trap of the night. but it was also the only run i had no knock, so I can't stay for sure yet if riding out 4th helped me or not. I ran 13.7 @107.7 mph..but I also have a tune so power does not die at 5500. Stock tune you don't really wanna go too far above that as the ecu kills power so aggressively.

 

[MSMS3]

Stock street tires. I flat shift every change except 1-2, trying to consistently shift at 5,500, although I'm sometimes a little later than I want. I think you'll see trap speeds jump with the DP.

 

[cpolly69]

I currently have a cat-less TBE, SRI, and a BOV (VTA). I actually would've bought a COBB AP but the guy I was supposed to buy it from stiffed me after saying he'd sell it to me and sold it to someone else. Yes, my car is a tid bit faster with my current mods but I still want a little more until I find myself another job. I gotta at least smash by friend and his damn Mach1 Mustang. He's pushing 280WHP and 300WTorque. I should be able to at least inch past him with 18PSI. Thanks for all the advice, guys.

not only will running you bov recirc. get you some more power and correct your afrs (like these guys said) it's also better for the life of your turbo

 

[ericrapp]

D the stock tires are the killer. people like em. I did not. Get youself some dinged up wheels for cheap and run some soft compound tires. you can sqeeze a 225/40 on the stock wheels if you want to. The tires at the drags are huge. Maybe, yes, the biggest bang for a car that has power already. My car after some similar mods jjust went up in smoke. Every time. as soon as i was in boost 1st 2nd and half of third and my eigth mile and 60 foot sucked. i went to softer tire and one step wider. The difference is substantial. It's the tires. edit.... Oh s***. my point was, that eighteen pounds of boost is enough to have the car really fly.

 

[Ninkumpoop]

K thanks, guys. I guess I'll set mine to 18 lbs when I eventually install it in a few weeks. I'm going to have to wait for my friend to free up his schedule to help me out with it. I'm lacking the tools and money to pay anyone to install my stuff.

On a sidenote:
If anyone near Los Angeles is willing to help me install the reworked K04, turbo inlet piping, and the boost controller, I'd be willing to reward with the same thing I was going to give my friend (a couple boxes of pizza and a decent case of beer).