What's stopping me from Running 15 lbs of boost?

[pwayzjellyroll]

Running 15 lbs of boost? My compression is 190-195 for each one I can't remember exact numbers but they were ALL in that range. I have a mechanical boost gauge, Joe P. MBC, Dejon 1gMy intake. A high flow cat with 2.25" piping and a ractive muffler. Anything here that I need to add/change/fix that could hinder this possibility? Thanks - Alex

 

[talonz27]

i would suggest doing a boost leak test just to make sure its all good to start with. what turbo do you have? im guessing a 14b.

 

[kenamond]

And get a logging device. You may be able to run 15psi safely, but I wouldn't unless I could monitor knock and O2v.

 

[pwayzjellyroll]

And get a logging device. You may be able to run 15psi safely, but I wouldn't unless I could monitor knock and O2v.

This is where I'm at the point that I know nothing. Should I not up my boost at all without a logger? What are my options for one, are they expensive, hard to use for someone who has not done it before? Any links to information would be appreciated.

 

[boostnhard]

no you shoudlnt boost 15 or more without a loggin divice, but theyre not able to monitor knock. they go from $500.00 - $2000.00. I would suggerst a dsmlink for about $550.00.

I getting one soon!

 

[Ludachris]

People have done it without consequence (including myself) but it's not the smart thing to do. If you're going to start playing with boost levels you should start monitoring knock. Check our Tech/DIY sections and read through all the information there (linked in the top navigation).

 

[1stGenRocks]

no you shoudlnt boost 15 or more without a loggin divice, but theyre not able to monitor knock. they go from $500.00 - $2000.00. I would suggerst a dsmlink for about $550.00.

I getting one soon!

you should look at his profile before posting. he has a 1g so he can get a logger cable, an old palm and the free software and have a logger for <100 that can monitor knock.

 

[bling5tatus]

uggghhh, dsm link this dsm link that....

I would get a logger cable from pocketlogger.com, yes it costs a little bit of money, but if you don't like spending money on your car you should maybe get rid of it now while you still can.

Their cable is high quality and the software is very nice and you get support from the forums as well. Loggers do not cost 500 dollars, that's ridiculous. If you read up on your car, you'll learn that there are a bunch of penny pinching ways to go faster, but you have to be smart about what you're doing, which means getting a logger BEFORE messing with your boost.

 

[PieEyedPiper]

Are you still running the stock 6 bolt? Those compression numbers are pretty astronomical for a stock 1g engine.
Has the engine been built at all?

 

[kenamond]

This is where I'm at the point that I know nothing. Should I not up my boost at all without a logger? What are my options for one, are they expensive, hard to use for someone who has not done it before? Any links to information would be appreciated.

It's really not that complicated, and ignore the post about high-cost logging; you have a 1g which means it's as cheap as possible.

You get a used PDA for $50 or less off of eBay (search around, as there are good ones and bad ones). Then you get the logger software for free (MMCd is free and adequate). Then you either buy or make a cable that plugs into your car's diagnostic port.

When you get it all set up, you want to do a 3rd gear pull somewhere with a lot of road and not a lot of traffic. On my 2g manual AWD, I hit 95mph at redline in 3rd, but I'm not sure of a 1g. Anyway, that's faster than any speed limit in the US, so this is at your own risk.

Why 3rd gear? What you're doing is recording engine diagnostic information from about 2k rpm to redline to find out if your car is "happy" or "sad" with the current setup (boost level in your case). The logger can only sample engine data at a certain speed/frequency. I get 8 to 10 samples per second logging 4 different types of information during the pull. The more engine parameters you're recording, the less your logger is able to record per second. If you log a 2nd gear pull, you go from 2k rpm to redline way too fast to get enough data to deduce if your engine's health. So you do a 3rd gear pull which is slower, so you get enough data.

Typically, you record rpm, knock count, injector duty cycle (IDC), and front oxygen sensor voltage (O2v). The rpm tells you where you are in the test. Knock count tells you if you're knocking (duh!), and knock is bad and should be avoided or minimized. Injector duty cycle is the percentage of time the injector is open letting fuel in. When IDC hits 100%, it's maxed out and cannot add any more fuel. This probably means you are running lean. Lean is hot. Too hot leads to knock and also leads to your motor literally burning its own metal as a fuel (oxygen is left over, the situation is very hot, and metal+oxygen will burn if hot enough). Another measure of a lean condition is low O2v readings. On a 2g, the reading is supposed to be above 0.9v or even a bit higher. If it drops to 0.8v, 0.7v, 0.4v, etc., you're leaning out which is bad, as I already described.

So you do your 3rd gear pull at 10psi with the logger recording those different pieces of information, and you look at knock (usually means the air/fuel mix in the combustion chamber is getting too hot and lighting itself on fire before the spark tells it to light), IDC, and O2v and see if everything's hunky-dorey. If everything's good, up the boost to 11psi and repeat. Keep going until you hit 15psi. If it's still good, you're good.

Keep in mind that colder days will flow more air and could lead to a lean condition that didn't show up on a warm day. Also, if you run at 15psi for a long time, you could heat-soak your intercooler and start knocking - that may not have shown up in your 3rd gear pull. But you can test all of this by doing 3rd gear pulls in different conditions and one-after-the-other.

So that's the basic idea. Not too hard, and if you post your log results, folks can help you wade through the data.

As I recall, the whole logger setup can be had for under $50. All depends on the deals you find for the PDA and cable (which you can make yourself if you're up for a bit of soldering).

 

[pwayzjellyroll]

Are you still running the stock 6 bolt? Those compression numbers are pretty astronomical for a stock 1g engine.
Has the engine been built at all?

The head had been replaced from another 4g63t. It was done before I had the car so specifics are not to known on it.

I will also start looking into getting a PDA and everything else I need before I go ahead and turn anything up. I'd rather be safe then sorry!

 

[nightspeed87]

Are you still running the stock 6 bolt? Those compression numbers are pretty astronomical for a stock 1g engine.
Has the engine been built at all?

Thats what I was thinking, on stock 1g pistons my highest cylinder is at 160, the rest fall in the 150s.

On 1g timing maps you will be easier to knock with compression that high I guarantee it.
Go ask a 1g guy running 2g pistons without anything to tune the timing maps and he'll tell you that even on 15lbs he's already seeing knock. Sorry to sound like the bearer of bad news I mean everyones car is different but I did the 2g piston thing before and for it to let me boost the way I want I had to get a keydiver chip to run 2g timing maps.
1g maps are way too aggressive. And your compression seems even higher than a stock 2gs compression to be honest they normally average around 170-185, sounds like your almost in the non turbo compression range.

DONT turn the boost beyond stock boost levels UNTIL you get a logger because something sounds funny
with your set up... Perhaps you have a head that was shaved way too low or something but if you get some good
tuning solutions ( NOT SAFC ) Such as chipped ecus or dsmlinks then you will have problems running high boost.

 

[pwayzjellyroll]

Thats what I was thinking, on stock 1g pistons my highest cylinder is at 160, the rest fall in the 150s.

On 1g timing maps you will be easier to knock with compression that high I guarantee it.
Go ask a 1g guy running 2g pistons without anything to tune the timing maps and he'll tell you that even on 15lbs he's already seeing knock. Sorry to sound like the bearer of bad news I mean everyones car is different but I did the 2g piston thing before and for it to let me boost the way I want I had to get a keydiver chip to run 2g timing maps.
1g maps are way too aggressive. And your compression seems even higher than a stock 2gs compression to be honest they normally average around 170-185, sounds like your almost in the non turbo compression range.

DONT turn the boost beyond stock boost levels UNTIL you get a logger because something sounds funny
with your set up... Perhaps you have a head that was shaved way too low or something but if you get some good
tuning solutions ( NOT SAFC ) Such as chipped ecus or dsmlinks then you will have problems running high boost.

Ok so after doing my own compression test and not relying on my mechanics results as I did not see him do it I came with the following numbers. From left to right facing the motor not sure if the left is #1 or not 160-150-155-155 I guess these numbers are pretty good right? Feedback is appreciated

 

[TiradoCC]

Those are great numbers for a compression test man!

 

[nightspeed87]

Glad to here, number one is the first one on the left from the order you read them, that one is usually higher due to carbon build up due to that being the richest cylinder.
In comparison my last compression test results ( in the same order you did it ) were
160,155,150,149..... So yours was a little better than mines.
I believe according to the manual shouldnt be more than a 14psi difference between your lowest and highest cylinder and a real important part on doing a compression test is counting how many cranks each cylinder takes to get to full compression and not just the overall max number...
That will give you an idea of how much leakdown each cylinder has.
On my gst ( rebuilt with 6k on it ) it took only about 4 to 5 rotations and it was full compression. That engine has no blow by...
On the awd 1g, it took a sad 9 or 10 cranks to achieve those numbers I read above.
That motor has over 100 k and some blow by...

 

[boostnhard]

you should look at his profile before posting. he has a 1g so he can get a logger cable, an old palm and the free software and have a logger for <100 that can monitor knock.

So, can i do that in a 2g?
i need to monitor knock(we all do) whats the best way to do it? faster and cheap

 

[polen]

get a aftermarket ignition. My car was bogging at 10 psi of boost because it wasnt burning all the gas. After i added my ignition i can run 18

 

[PSITSI]

get a aftermarket ignition. My car was bogging at 10 psi of boost because it wasnt burning all the gas. After i added my ignition i can run 18

Umm, Buschur was running 9's on stock ignition, so I don't see that as necessary. I am running 14psi on a bone stock engine (except for MBC) with no problems. No logger, nothing. Only problem is I hit fuel cut on cold mornings. Please don't start telling me how unsafe this is, because I don't really want to hear it. Besides, when your ECU senses knock, it will retard timing. At 15psi, you shouldn't create enough knock that the ECU can't take care of. Just make sure your engine is healthy. Use good plugs, maybe with a colder heat range.

 

[shadrach]

get a aftermarket ignition. My car was bogging at 10 psi of boost because it wasnt burning all the gas. After i added my ignition i can run 18

You have my old car, and I ran 19psi on the street and 22+ on 110-leaded on on the stock ignition system, no problems ever.

I also replaced the plugs and wires around at 57000 miles, so if those were the same parts a fresh set would have done the trick.