Boost Loss due to outside temp???

k_rhayes · 11-10-2009, 10:16 PM

Iv been searching for an answer for a while and came up with nothing so now i am posting my question.

My question is....well let me start with the scenario then i will ask my question.

I live in socal orange county, and when i wake up early in the morning (7am) it is usually in the 50's outside. When i drive my car i can usually hit 16 lbs of boost.

Later in the day when the temp outside is over 60 and 70 i can only hit about 14.5 lbs of boost.

so my question is do i lose boost due to the outside temp being higher??? Or is it that i am losing boost due to heat soak in my tmic???

mod list
cobb stage 2
invidia n1 catted tbe
ss autochrome tmic
perrin intercooler hoses
spt short ram intake

I appreciate any feed back. My goal is to consistantly boost at 16 lbs.

Again thank you to all who reply to my post

newtothegame · 11-10-2009, 10:21 PM

With that setup, the best way to constantly hit 16 PSI is to go and get a protune done. Having that aftermarket IC, you arent getting anything from it since the AP doesnt account for it in its map. And if you go and get a protune, think about getting some type of 3 port BCS (i.e the grimmspeed unit). Im running a 20G with all the supporting mods (check my profile) and when its colder (denser air) I tend to hit above my target boost, maybe only .5-1.5 PSI depending on how Im driving.

Even when I was Cobb stage 2 (just a TBE and Cobb SRI) I would occassionally hit more boost when it was colder out, but not all the time. In short, it happens, but if you want a more consistent car, get a protune.

k_rhayes · 11-10-2009, 10:31 PM

Cool, thanks for that....protune is deff something i want to do.....its just to bad my wife has cut me off spending money on my car lol. I was just wondering maybe a heat sheild would help, but doesnt sound like it.

Thanks for your help bro!

blk05WRX · 11-11-2009, 02:14 PM

I would run a heat shield. I actually run two. I have the stock one that's modified to fit over my DP, and the SPT one.

newtothegame · 11-11-2009, 02:47 PM

Running a heat shield (or two) is nice. But the whole overboost or more boost with changes in weather will not be solved by heatshields. I run my stock heatshield only with my 20G setup, the underhood temps do get warmer, but only when sitting still for prolonged periods of time.

OP, Im sorry to hear about being cut off (my wife just gave me the go ahead for a new set of rims and a new transmission). Best bet is to tell her you need it for the safety and longevity of your car.

booosted09 · 11-11-2009, 03:14 PM

^^^Those are good words of advice...if you really want it..Just make something up..she wont know any better. lol

newtothegame · 11-11-2009, 04:47 PM

Im just speaking from experience. The only problem that doesnt work for me anymore. She is learning about the car, which is good. She actually understands why I want the parts now, lol.

turmic · 11-11-2009, 06:22 PM

+1 to having a OTS map and a different than OTS map set-up (TMIC and whatever else) means you should get a protune if you want it to run better/more consistant.

Also, If you're charge is colder....which is a result of the I/C air being cooler with the TMIC and colder temps. Its easier for the car to raise the psi a lil. But, your map should be a lil more consistant than 2 or more psi.

VD5505 · 11-11-2009, 07:58 PM

You are going to boost higher when the outside temp is cooler c ause the air density is higher, Then when it is warmer outside the air quality is expanded more. Your ECU doesnt know enough that it is colder outside to keep the wastegate from hitting the targeted boost levels you want, If you go get a protune your problem will be fixed. As of now with your list of mods You will be gaining alot out of a protune and that will be a whole new car!!

newtothegame · 11-11-2009, 08:00 PM

Well said VD5505, thats what I was trying to get at. Now mind you a protune doesnt solve the issue entirely. But it will help immensely.

VD5505 · 11-11-2009, 08:22 PM

sorry i should of said it will fix it better than what it is now, but newtothegame is right it will help alot.

newtothegame · 11-11-2009, 08:28 PM

Quote:

Originally Posted by VD5505

sorry i should of said it will fix it better than what it is now, but newtothegame is right it will help alot.

Not a problem. I just know from personal experience. Im tuned for 18 PSI with my 20G when its cold I see around 19 PSI. Just making the OP understands that it does help, but not to be worried if he sees slightly higher boost levels afterwards.

k_rhayes · 11-12-2009, 06:50 PM

how much does a pro tune usually cost.....that will be a hard one to explain to the wife about how it will pro long the life of my car. If i had the chance to spend any money right now i would do the tune. iv heard upwards around $400. is that about right?

newtothegame · 11-12-2009, 06:55 PM

It really depends on the tuner and how long it would take. It cost me roughly $350 for my tune with a 20G. With the tune you could possibly get multiple maps also (i.e. higher and lower boost settings). Right around $400 sounds about right using the AP though.

VD5505 · 11-12-2009, 07:00 PM

I would say $400 would be about right, you will love your car after a protune its a whole new feeling. My first protune was only about $280 and i did that up in Chicago at GRD Tuning and that is a great place to go to.