Rob Karloff Posted March 5, 2008 Report Share Posted March 5, 2008 Alright gents, new minor issue. I've got a check engine light, code P0172...running rich. I recently put in a boost control to increase boost (from 7lbs stock...according to the boost guage) to 14 lbs. It has the capability to be turned on and off (back to stock). I'm assuming this is relation, looking for confirmation. Should I be worried about anything or can I just clear the code and move on? Thanks.Coolant temp sensor is a good bet on this, and it's a good idea to replace both that and the thermostat at the same time. Installing any kind of tuning or boost pressure modification device without doing a "Stage 0" on your engine is asking for trouble... Link to comment Share on other sites More sharing options...
defgh1 Posted March 5, 2008 Report Share Posted March 5, 2008 The biggest advantage of an ECU upgrade is it modifies the fuel and timing for the increased pressure to safely increase power efficiently. By just adding a boost controller you are depending solely on the variable fuel pressure regulator to provide sufficient fuel to prevent the motor from melting! In addition, the stock ECU is sensing the higher than stock pressure and dumping addition fuel to try and protect the motor. You are trying to operate the stock ECU in an area it believes there is a failure in the boost regulation. The result is even though you have increased the pressure you are not realizing the full benefits of the increase since the ECU has not been optimized to take advantage of it and is operating in a protection mode. IMO, at 14 psi you are taking a risk. Bottom line: you can do it on the cheap or you can do it right!Doug H Link to comment Share on other sites More sharing options...
gdizzle Posted March 5, 2008 Report Share Posted March 5, 2008 The ECU has fuel maps up to 14psi, after that you're going to see fuel cut. Don't be surprised if you start seeing spark blow out as well. These cars at higher boost should be gapped down to ~.024" on copper or OEM plugs. You need to tred carefully though, as you CAN bend a rod at 14psi. It's not common, but it CAN happen. If you don't have a WBo2, GET ONE.IMO, at 14 psi you are taking a risk. Bottom line: you can do it on the cheap or you can do it right!Doug HAmen. When you cheap out, you get this..... Link to comment Share on other sites More sharing options...
Rob Karloff Posted March 5, 2008 Report Share Posted March 5, 2008 The result is even though you have increased the pressure you are not realizing the full benefits of the increase since the ECU has not been optimized to take advantage of it and is operating in a protection mode. IMO, at 14 psi you are taking a risk. Bottom line: you can do it on the cheap or you can do it right!Amen.Amazing how many people seem to believe that more manifold pressure automatically means more power.... You can make as much boost in the intake as you like, but how much of it makes it into the cylinder is down to the cam specs. Not to mention the temperature and density of said air!I'm almost fed up of people asking why I'm going to all the effort of fitting a FMIC and Porsche brakes to a stock motor too.Doug's bottom line is also why I'm spending ~$600 that I don't really need to on a chromoly input shaft and aftermarket 1.76 gears for the 2-speed Powerglide box I'm having built for my Holden HQ musclecar! Link to comment Share on other sites More sharing options...
gdizzle Posted March 6, 2008 Report Share Posted March 6, 2008 Amen.Amazing how many people seem to believe that more manifold pressure automatically means more power.... You can make as much boost in the intake as you like, but how much of it makes it into the cylinder is down to the cam specs. Not to mention the temperature and density of said air!I'm almost fed up of people asking why I'm going to all the effort of fitting a FMIC and Porsche brakes to a stock motor too.Doug's bottom line is also why I'm spending ~$600 that I don't really need to on a chromoly input shaft and aftermarket 1.76 gears for the 2-speed Powerglide box I'm having built for my Holden HQ musclecar!Also, these heads flow like butt and require major porting above ~310hp. Link to comment Share on other sites More sharing options...
AlexD Posted March 6, 2008 Report Share Posted March 6, 2008 Interesting. How much does porting cost? Anyone ever had it done? Link to comment Share on other sites More sharing options...
gdizzle Posted March 6, 2008 Report Share Posted March 6, 2008 Interesting. How much does porting cost? Anyone ever had it done?Depends on where you go and to what extent you go. Link to comment Share on other sites More sharing options...
JRL Posted March 6, 2008 Report Share Posted March 6, 2008 It also depends on the engine and the engineering that has gone into it.You can "port and polish" a standard head on any car and that car will run a bit better, but when a head has had some engineering done regarding airflow and volume, you can possibly make some healthy hp gains.Unfortunately the 5 cyl Volvo head is a SOB to remove ($$$) and reinstall Link to comment Share on other sites More sharing options...
gdizzle Posted March 6, 2008 Report Share Posted March 6, 2008 It also depends on the engine and the engineering that has gone into it.You can "port and polish" a standard head on any car and that car will run a bit better, but when a head has had some engineering done regarding airflow and volume, you can possibly make some healthy hp gains.Unfortunately the 5 cyl Volvo head is a SOB to remove ($$$) and reinstallIt is? Link to comment Share on other sites More sharing options...
defgh1 Posted March 6, 2008 Report Share Posted March 6, 2008 It is? I would gladly trade you a Volvo head replacement for doing a pair of Stealth Heads! Doug H Link to comment Share on other sites More sharing options...
AlexD Posted March 6, 2008 Report Share Posted March 6, 2008 The I5 isn't that bad Try a GMC Astro van, had to do that last month and I think I would rather die than re-install it. Link to comment Share on other sites More sharing options...
pm2000541568908310 Posted March 6, 2008 Report Share Posted March 6, 2008 The I5 isn't that bad Try a GMC Astro van, had to do that last month and I think I would rather die than re-install it.Interesting what we would all trade for. I would rather die than have an Astrovan. -mk Link to comment Share on other sites More sharing options...
gdizzle Posted March 6, 2008 Report Share Posted March 6, 2008 Interesting what we would all trade for. I would rather die than have an Astrovan. -mk Link to comment Share on other sites More sharing options...
AlexD Posted March 6, 2008 Report Share Posted March 6, 2008 Interesting what we would all trade for. I would rather die than have an Astrovan. -mkI deny any and all responsibility for the GM products we own, I married into them. The Asto van has a "logical" reason, it's the work van that we use to haul crap around on our property in the mountains and it'll be what transports coustruction materials come spring when we actually start construction.Still, I think I'd rather have a full size van. Link to comment Share on other sites More sharing options...
boost_mama Posted April 11, 2008 Author Report Share Posted April 11, 2008 found some pics of the husbands CR-XOh, by the way, that paint color is VOLVO C70 GOLD. Link to comment Share on other sites More sharing options...
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