tuning my newly rebuilt 420 aftermarket turbo motor

[lilbayz311]

my car is finally all rebuilt but it has been throwing like 4 different codes. absolute manifold pressure, 02 sensor not detected, and multiple cylinder missfires. i got big cams so it idles rough sort of like a muscle car i have heard from multiple people. one problem is that i cant get it to idle any higher than it did stock. even adjusting the screw on the throttle body makes it higher for a min. but then it seems that the ecu overrides it no matter what and it goes right back down to jumping around between 700-900rpm which rumbles the whole car due to the size of the cams. NO im not downgrading my cams they are stage 3 crowers even though it doesnt say for use with turbo thats not the problem. i called crower and asked them what they thought about using these cams for my setup after telling them what all i had done and they asked ME how it ran. it pulls harder than i ever could imagine and easily spins the tires in second gear if i nail it too hard as long as im above 2000 rpm these cams are better than any turbo cam out there. i got advice from a local mechanic he asked me where my mass sensor had gone. i bought the car with cold air intake already installed and it had no mass sensor. this particular mechanic told me thats my problem and to get one "it will fix the majority of your problems he says" What do YOU think? it never turned on the check engine light before when i was n/t runnin it without the mass sensor. it runs well besides the idle and it occasionally dies when accelerating (no idea why?) but i promise its not from going lean. i have multiple ways of telling how rich/lean it is. we have pushed 16psi of boost already which was quite a rush. i plan on getting these problems worked out before i drive it much more. if anybody has any ideas please let me know

[Blitzeclips]

Originally Posted by lilbayz311

my car is finally all rebuilt but it has been throwing like 4 different codes. absolute manifold pressure, 02 sensor not detected, and multiple cylinder missfires. i got big cams so it idles rough sort of like a muscle car i have heard from multiple people. one problem is that i cant get it to idle any higher than it did stock. even adjusting the screw on the throttle body makes it higher for a min. but then it seems that the ecu overrides it no matter what and it goes right back down to jumping around between 700-900rpm which rumbles the whole car due to the size of the cams. NO im not downgrading my cams they are stage 3 crowers even though it doesnt say for use with turbo thats not the problem. i called crower and asked them what they thought about using these cams for my setup after telling them what all i had done and they asked ME how it ran. it pulls harder than i ever could imagine and easily spins the tires in second gear if i nail it too hard as long as im above 2000 rpm these cams are better than any turbo cam out there. i got advice from a local mechanic he asked me where my mass sensor had gone. i bought the car with cold air intake already installed and it had no mass sensor. this particular mechanic told me thats my problem and to get one "it will fix the majority of your problems he says" What do YOU think? it never turned on the check engine light before when i was n/t runnin it without the mass sensor. it runs well besides the idle and it occasionally dies when accelerating (no idea why?) but i promise its not from going lean. i have multiple ways of telling how rich/lean it is. we have pushed 16psi of boost already which was quite a rush. i plan on getting these problems worked out before i drive it much more. if anybody has any ideas please let me know

Wow. 16psi right off the bat? That's absolutely HORRIBLE. That motor probably still hasn't sealed the ringlands yet, let alone has it been properly broken in. How long have you had the motor? You can DESTROY that motor much more easily right now, then any other time.

What feul set-up are you using again? PLEASE POST THE ENTIRE LIST.

The crower cams are NOT better then any other cam made for turbo applications. You may think so, but have you driven with turbo cams, in a turbo car yet? Not only that, but cams are made to efficiently utilize airflow. Crower 3's are made to utilize airflow of a NON TURBO car. Do you think a non-turbo car and turbo car flow the same rates air? Heres a hint : Forced induction.

You need a missing link because your factory ECU is reading excess pressure in the manifold, resulting in the "dead" feeling because ypur car goes into 'safe mode' and prohibits anymore feul consumption.. The missing link or FCD, ( feul cut defender) will bypass the ECU signal, allowing the axcess air to flow without feul cut. Contact Velocitapaola, he sells high quality FCD's for a great price. So, that should fix one of your problems..

Based on what you said above, I have no idea where to start for diagnosing your problems. I hope you installed everything correctly. Seems like you are rushing into things, which is not the way to go. many people have gone boost happy with fresh motors and cracked their new pistons by jumping the gun. I'd advise for you to slow down.

And for the love of god, please learn to type better. I have to re-read half your sentences to get an idea of what you're saying..

[absolute_DSM]

Is the engine broke in? You could break it in with 16 PSI. Motoman theory.

And let me get this right... you dont have a MAF?

What are you using to tune? (logger, AF gauge, computer...)

[totaleclipse_05]

Breaking a motor in with boost is not bad for it.

[lilbayz311]

good advice thank you. how long should i break it in for and whats an ideal way to do so? do you have any advice to make it idle no lower than around 1200rpm? and lastly, should i get a mass airflow sensor? if so where could i pick one up? yeah everything was put together tits by my mechanic brother in law otherwise i think it woulda blown up pushing 16 pounds i cant wait to see how good it runs when its actually tuned right seems how it pulls so damn hard now. i cant wait to run the quarter mile. There is always going to be some bugs to work out on a newly built turbo conversion car ya know

[DSMcrazy3]

Originally Posted by lilbayz311

and lastly, should i get a mass airflow sensor? if so where could i pick one up?

No you shouldn't.(I can't believe no one has addressed this yet) That code for manifold absolute pressure is coming from your type of MAF, which is a MAP(Manifold absolute pressure) sensor. Take the advice and buy Pauls FCD, once that's on it that code should go away. If not, replace your sensor.

Originally Posted by lilbayz311

i cant wait to see how good it runs when its actually tuned right seems how it pulls so damn hard now.

Reguardless of what Crower says I agree you should have gotten turbo specific cams. As stated the reason it seems so right with them is just because you're making an incredible amount of more power which you aren't used to. Consider swapping those cams for more efficient ones.

[Blitzeclips]

Originally Posted by lilbayz311

good advice thank you. how long should i break it in for and whats an ideal way to do so? do you have any advice to make it idle no lower than around 1200rpm? and lastly, should i get a mass airflow sensor? if so where could i pick one up? yeah everything was put together tits by my mechanic brother in law otherwise i think it woulda blown up pushing 16 pounds i cant wait to see how good it runs when its actually tuned right seems how it pulls so damn hard now. i cant wait to run the quarter mile. There is always going to be some bugs to work out on a newly built turbo conversion car ya know

Well it's your fuel set-up that concerns me with pushing 16psi. Not only that, but breaking a motor in under boost like that is NOT GOOD for the motor. If the rings don't seat correctly, you can cause alot of damage because the engine still wouldn't be functioning properly. Why would you risk blowing your $3000 motor because you got boost happy? PM Xavier ( XMasta19) and ask him what happened to his first two rebuilt motors...

Proper break in is a HUGE debate over basically personal preference. Some people do 500 miles on the highway, 300 in the city vs. 800 in the city and 200 on the highway. These aren't exact claims, I'm just trying to illustrate the particulars for you.

Personally, I have had alot of experience with breaking in motors. With race bikes, cars, and even 10 seconds Novas.. Heh. Those are fun. Anyways, %100 of the time we start off crusing below %20 of the motor's powerband. Basically, break down the 8k RPM limit for our car, by 5. That's around 1600RPMs. We (My brother, friends, well known mechanics- whom all work for the state's largest cycle shop- and I) stay under that %20 of the powerband for about 100 miles on the highway. Then we continue to move up in these intervals of %20, %40, and so on.. Halfway through the process we change the oil and inspect it for abnormal debris. Which usually indicates premature wear of the bearings, or other compnents in the motor. Not a good sign. Anyways, we switch from highway driving to city driving between these two. Usually resulting in about a 600 mile drive. When I first put my built motor in, I drove all the way to Ohio, about 800 miles from where I live. In the process we stopped about 5 times, checked the oil, coolants, plugs, everything.

I waited 1.5 years to boost my car while driving with the built motor. Not because I had to, but I chose to. Better to have something go wrong then(n/a), then when I'm pushing more boost, adding more and more pressure to the engine.

Anyways, that's how I broke in many motors, not only me but many others guys with reputable skills also. The process varies for everyone, like I said. But hopefully you see what I'm saying.

[awddynamite]

all my motors that i have built for actual racing are broken in the same day, running up the rpm band in 4th gear from 1500 to 4000 1500 to 4500 ( not in boost ) 1500 to 5000 getting up to about 6k rpm, doing this for 30 min and taking it back to the shop, change the oil get back on the freeway do it again using the whole rpm band for about 45min then run back to shop cahnge the oil take apart the oil filter looking for anything big or wrong, compression test and leak down test, and the car is ready for action after about doing that three times with no boost and then one freeway drive with boost from 1500rpm to 4000 etc etc etc, i was told by an old school nhra-er who now has his own machine shop here that there is no need to wait for 1000miles or whatever, he has instructed us to do it this way for about the last 6years now and not once have we had a motor go bad on us, either the rings are gonna seat or they arent. i could go on and on but i have sworn by this method for awhile now being VERY VERY SCEPTICAL at first and he has not let me down on any advice.

SORRY FOR THE RAMBLING. this is easier to say and explain in person than it is on a f-ing keyboard.

[Blitzeclips]

Exactly. ^^^^^ Well put, I'm glad you broke them in with no boost. I was afraid I was the only one who felt this way..

That also shows we all have different techniques. Not meaning all of them will work, but you need some sort of effective way to break the motor in without inflicting unecessary damage.

[totaleclipse_05]

I have read numerous times the most critical time for piston ring-to cylinder wall breaking in is within the first 20-30 minutes after the first startup. From what I've compiled to properly break-in an engine is to first, start it up, check for any leaks, and get all the air out of the cooling system. Once this is done, take the car out and do about 10 pulls, going in 3rd gear and doing 30-60mph pulls. Once you get to 60,let it slow down to 30 with engine braking(not using the brake pedal, just letting off the gas in gear), as the engine braking helps put a good load on the motor. It's within this time that the rings do MOST of the breaking in on the cylinder walls. If you just baby it around for 500, 1000, 1500 miles, then the motor will probably not have as much compression as it could have if the right procedures were followed. It really doesnt take long for the rings to bite into the roughed honed cylinder walls. You want to force the rings into the cylinder walls as soon and as much as possible for best ring break-in.

Also I read that a lot of people don't know that rings don't seal by their normal tension. When the piston is traveling upward compressing the air/fuel mixture, the compressed mixture gets BEHIND the rings, and forces them to the outside (the cylinder wall). When you put more load on the motor, it puts more outward force on the rings.

I'm not trying to argue, I'm sure breaking in a motor is a very opinion-based procedure. A lot of threads I have read about engine break-in, people run about 10-15 psi when doing it. I personally haven't rebuilt a car engine yet, but I plan to follow these instructions when I do.

[Locke]

When seating a piston ring, the ONLY ting we are trying to accomplish is to form the ring evenly to the cylinder wall. The ring is ground by the hone of the cylinder. The ring will continue to form against the cylinder until the hone is in smoothed down. This is why you always hone the cylinders when re-ringing. Compression on the top of the ring will force it down, and at a gentle angle, so that forming can occur on the upper edge of the ring. The same with vacuum, slightly angling the ring upwards, to form that part of the ring.

Irregularities between the ring and the cylinder wall create high pressure contact points between the two. This obviously means there are points between the two that have either low contact pressure, or an actual gap. We dont want this, we are aiming to form the ring to a point where pressure is equally distributed against the cyclinder wall, the best metal to metal seal possible.

Ideally, you would want the hone to become smooth the same moment the rings are properly seated. This is where all the debate comes in, as far as how and how long to break in a motor.

That is just how it is.

I personally like Motoman's technique, attacking the rings when the hone is the roughest, although I am personally unsure whether this will result in removing too much metal from the rings. It will surely seat the rings.

These are my thoughts on cams. May not be completely thought out, but seem solidly grounded.

As far as NA cams vs. Turbo cams, the differences are basically less overlap, less duration, and more lift on the exhaust. The smaller duration with higher lift on the exhaust cam will add velocity to the gas, spooling the turbo faster. Overlap causes moment of vacuum in the exhaust, and moments of pressure in the intake. Moments of vacuum against the turbo will slow it down. Not by much im sure, but enough to slow spool time. Moments of vacuum would happen like pulses of less pressure in the exhaust, which would affect the turbine similarly to how surge affects the compressor.

I believe big NA camshafts in a turbo car will be fine, allowing more flow, though adding spool time. Overlap can be pulled out a bit by adjustable cam gears, depending on the duration of lift.

Something to think (or debate) about.

Ohh, and yeah, you dont have a MAF, and never did. Your MAP sensor, though, is located on the passenger side of the intake plenum. Your car would not run without it. An SAFC may help you smooth out your idle.

[Shadow98]

[quote=DSMcrazy3;151139866]No you shouldn't.(I can't believe no one has addressed this yet) That code for manifold absolute pressure is coming from your type of MAF, which is a MAP(Manifold absolute pressure) sensor. Take the advice and buy Pauls FCD, once that's on it that code should go away. If not, replace your sensor.


Exactly what I was thinking before I saw your post.

[lilbayz311]

just fyi, my engine is all tuned now and running great! no we didnt do anything special breaking it in. we just took it easy at first and slowly boosted higher the longer we drove it and felt comfortable what the gages were showing. Our first test drive we drove to a city an hour away and pushed 16 psi on the way home. that was where my a/f ratio gage went lean. i thinks its mainly all in how well the engine was built and put together that determines whether its going to blow up or not in the first couple hundred miles.

[Blitzeclips]

Originally Posted by lilbayz311

i thinks its mainly all in how well the engine was built and put together that determines whether its going to blow up or not in the first couple hundred miles.

No, not at ALL.

You could have the most built motor on this site.
But if you run it lean, it will blow.
Simple as that.

You WILL blow that motor by running it lean, no matter how well it is built. Doesn't matter what you have, think, or say, it WILL detonate if you starve it of fuel. It WILL . Heed my warning.

What fuel set-up do you have for 16psi? Can you please list it..

[Locke]

I agree, Blitz. Fully built race-only engines are routinely destroyed by the same problems that destroy our engines, detonation.

An updated/complete profile would be nice.

[lilbayz311]

dude thats obvious i didnt know i had to clarify that it couldnt be too lean i thought that was a no brainer. thats kind of what i meant by saying how we felt comfortable ### the gages were showing us. i will update my profile once i get a digi camera and the time to take some pics that are decent quality unlike the ones takin from my phone so that i can back up my whole list

[Blitzeclips]

Originally Posted by lilbayz311

dude thats obvious i didnt know i had to clarify that it couldnt be too lean i thought that was a no brainer. thats kind of what i meant by saying how we felt comfortable ### the gages were showing us. i will update my profile once i get a digi camera and the time to take some pics that are decent quality unlike the ones takin from my phone so that i can back up my whole list

You said it DIRECTLY after mentioning how the car was running lean.

What is your fuel set-up???

[lilbayz311]

so for everybody who thinks it is HORRIBLE pushing 16 pounds of boost when you break an engine just know that it has been done successfully and maybe you shouldn't be as paranoid about breaking your engine in as long as you don't exceed its limits in any way. (ex. fuel going lean, overreving) if im planning on boosting upwards of 25 psi when i get fuel for that much boost, why not break it in under the same conditions thats its going to be running in for the rest of its life? I personally think that not boosting a newly built turbo motor for a whole year is absolutely HORRRRRRRRRRRIBLE! lol