Higher boost levels when its very cold outside.

[Chris_Sag]

Hi. My car was tuned at the dyno for 16psi 16g stock fuelsys and 98oktane in the summer, i know this sound mutch but my EGT were fine and no timing taking away from the engine. But in these days it is extremely cold outside around -20Celcius, and when I floor the pedal, boost raise to 20psi. Is this normal or dangerous? The air the engine gets is so cold that it is not dangerous for to high EGT ect?

 

[gravityforce]

the colder the air the more dense the air, if the car seems to handle the higher boost Id say leave it alone, otherwise just turn down the boost if it bothers you.

 

[Chris_Sag]

I dont have any sort of logging mounted in my car so i dont know what is going on under my hood.. But it seems to run very fine and no check engine light appers from my knock senor.. I also have done a lot of reading in here, and now i cant understand that I am able to run on 16-17psi on a 16g with stock fuel system, is it because of the 98oktane maybe? Or should i doubt on my mechanick who said it runs greate...? Would not my ECU told me if it was knocking or something? Run in emergency mode or fuelcut of some sort? Have had some bad experiences with mechanicks and workshops so I trust nobody..

 

[gravityforce]

the stock ECU wont tell you if it knocking but if it sees knock it will pull timing in order to save itself, the end result would be a loss in power.
The boost your hitting has been done before on stock setups, its just varies from car to car, plus the cold is helping alot Im sure.
If I were you I would play it safe and take it easy untill you can log and see where everything is at, are you redlining if so are you able to hit redline without any hiccups ?

 

[95TalonOwner]

If you have a stock ECU, how did your mechanic "tune" it?

 

[LiquidX]

You need to turn your boost down. On stock injectors you are running very close to 100% IDC if not already there. Once it hits 100% the injectors are no longer pulsing but are spraying constantly. That will alter your ARF to a leaner ratio by adding boost which may be how you got "tuned". Keep the boost to 15psi or less for that reason. I wouldn't be concerned about knock with the 98 octane however.

Also unless you have an EPROM ECU that has a tunin program installed, a flashable 98/99 ECU, Evo flashable ECU, stand alone, or a piggy back then you were not properly tuned at all.

This should help you uderstand the IDC a little better on the stock fuel system.
http://www.dsmtuners.com/forums/articles-tuning-ecu/366003-injector-fuel-pump-supported-airflow.html

 

[99gst_racer]

-20 celcius in Florida?

 

[Kapok6]

-20 in Florida? That sucks.

What do you AFR's look like? Are you getting any knock?

 

[Chris_Sag]

The car is imported from Florida to Norway, and here its cold! On the dyno the boost was set after EGT and AFR, but no tuning for the fuel. The car consumes a lot of fuel and before the boost was raised my tuner said it was running pig rich. He mounted a recycle bov and turned up the boost and said it runned greate..

 

[LiquidX]

The car is imported from Florida to Norway, and here its cold! On the dyno the boost was set after EGT and AFR, but no tuning for the fuel. The car consumes a lot of fuel and before the boost was raised my tuner said it was running pig rich. He mounted a recycle bov and turned up the boost and said it runned greate..

Our cars have a rich fuel table from the factory. Your AFR is lean because your IDC is at 100% and you have went above it by over flowing the injectors. It is not a safe nor proper way to tune at all.

It's good to see that you do have a recirculated BOV installed, I'll give your "tuner" props on that part anyway but turn the boost down. In my honest opinion you should be at wastegate pressure for a 16g on a 2g fuel map if running on a stock fuel setup.

You have the information in front of you both on this thread and on the site. Take it or leave.

 

[JusMX141]

-20 celcius in Florida?

Yeah no shit....-20*c = -4*f, and it hasn't even been that cold here in Western PA yet this year.

Something's wrong with this picture.

The car is imported from Florida to Norway, and here its cold!

Ahhh, that explains everything. Update your location, homeboy! I'd be proud to represent DSM's in Norway if I were you!

 

[Chris_Sag]

Yeah no shit....-20*c = -4*f, and it hasn't even been that cold here in Western PA yet this year.

Something's wrong with this picture.


Ahhh, that explains everything. Update your location, homeboy! I'd be proud to represent DSM's in Norway if I were you!

I am proud! Only 10registed GST in the country and 4 GSX so the knowledge about the car is very poor up here. So thank god for this site...

But than i adjust my wastegate down to around 15psi and it should be ok? Have driven around like this for a year and tought it was all good... I have a auto tranny so its kind of hard reaching the redline before it changes, maybe that is what who has saved me for melting or something?

My tuner also said that the car was getting 160% to mutch fuel in some areas and mounted a new man.FPC to reduce the pressure for a more correct AFR, and suspect the car to have a bad aftermarket chip or something, but we all know that this is not possible on the 97ECU. Unfortunatley i dont know what have been done to the car when it was in the US, but the 16g was mounted here in norway, so it all points to that the car was stock when it was imported.

 

[Rockyp]

Your turbo will be fine, maybe not the injectors. It was -58 F last week up here and the only problem i had was my upper intercooler pipe popped off because my rubber got too cold. First timer, scared the hell out of me.

 

[Chris_Sag]

You need to turn your boost down. On stock injectors you are running very close to 100% IDC if not already there. Once it hits 100% the injectors are no longer pulsing but are spraying constantly. That will alter your ARF to a leaner ratio by adding boost which may be how you got "tuned". Keep the boost to 15psi or less for that reason. I wouldn't be concerned about knock with the 98 octane however.

Also unless you have an EPROM ECU that has a tunin program installed, a flashable 98/99 ECU, Evo flashable ECU, stand alone, or a piggy back then you were not properly tuned at all.

This should help you uderstand the IDC a little better on the stock fuel system.
http://www.dsmtuners.com/forums/articles-tuning-ecu/366003-injector-fuel-pump-supported-airflow.html

If i not should be concerned about knocking with 98octane what should i be conserned about? My EGT?

 

[Slow91Laser]

I would be concered about the AFR's i didnt see where you stated you had a wideband, if not i would get one asap as it's always good to see whats going on.......

 

[Chris_Sag]

It was hooked up to a wideband and all sorts off logging at the dyno...

 

[16g DSM]

yes but having a wideband in your car is always a good idea to see what's going on all the time and not once a year when you go to the dyno. besides you could pick up on used for around $150. Money well spent

 

[Chris_Sag]

If i get a wideband and it do not show me lean numbers is everything ok than?

 

[LiquidX]

To know what's really going on you need to log your car. Sure, a sideband can point you in some directions and everyone should have one when becoming serious about engine health and tuning.

It's possible that tuning your boost down a few psi could show richer AFR and be in the "safe" zone according to that but without seeing what the motor is doing (injector IDC%) you could still have them at 100% but with less air coming in.

IMHO this guy ripped you off as all he did was turn up your boost for you.

Also how is your octane measured? Is it like in the states with (RON)/(MON) or is yours just the (RON)? If it's not the average then your 95, 98, and 100 is equivalent to our 89, 91, and 93.

 

[viperlp01]

Turn the boost down or don't go boosting on it right away. Assuming you have a manual boost controller that is a ball and a METAL spring. When the metal is cold it is "stiffer" than before. This causes a higher pressure to unseat the ball to send pressure to the wastegate. The engine bay will eventually warm up the boost controller and allow the spring to become more relaxed and should bring you closer to your target boost level.

In michigan it gets cold and I would see about 2 psi more if I got on it before my car had enough time to warm it up.

 

[Chris_Sag]

No mbc just running wastegate pressure, so i have to adjust the arm on the wastegate, I have a Ebay MBC but i dont know if I can relay on it or how to hook it up.. Can someone draw me a picture of how to hook this sort of mbc up with the T-fitting blocked in one end ect. Than i could just adjust my wastegate to minimum and use the MBC to set the boost to around 15psi without increase spool time?

 

[laserspeeddemon]

Something is really not adding up here. How are you running 17 psi on the factory boost solenoid?

 

[JusMX141]

Solenoid has to be frozen or not working.

 

[LiquidX]

Do you even have an aftermarket boost gauge like an Autometer; something other than the stock gauge?

 

[Chris_Sag]

Yes i have a aftermarket boost gauge, analog... But the boost is adjusted on the arm to the wastegate on the 16g.

How many lbs/min do the small 16g pulls at 15psi?