Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner
1 - 20 of 24 Posts

·
Registered
2003 gmc envoy_slt
Joined
·
140 Posts
Discussion Starter · #1 ·
I made a custom air intake today. 3" ABS tubing and a 45degree coupler,1 Rubber coupler to connect to the throttle body, connectors for hoses and maf, and some ABS cement. Total cost was under 30$ and it sounds great. Makes the envoy sound like a dang race car. If you cant find ABS in any hardware stores i suggest calling a modular home or mobile home repair company, thats where i got mine at. Stores here dont stock it since it doesnt meet building codes in michigan. I will take pictures when i can.
 

·
Registered
2003 gmc envoy_slt
Joined
·
140 Posts
Discussion Starter · #3 ·
well after about 600 miles no codes have come up so the MAF must be working properly. The sound is amazing and it got .8MPG better gas mileage at 75MPH cruisecontrol on the highway for about 100 miles. Same trip i made 1 week ago without the air intake. So needless to say i am very pleased with this. I kept the stock airbox in tact over top of my drop in KN filter i have on it. 3" SCH40 ABS tubing is what i used however when you put the tube on and do the 45 to go to the throttle body it doesnt quite line up perfectly so you have to do some bending at the 45 if you want to use the stock airbox. Also the coupler at the throttlebody itself will be slightly off but the bend in your rubber or silicone coupler will take care of that fine. Pictures will be up soon hopefully
 

·
Registered
2003 chevy trailblazer_ls
Joined
·
1,236 Posts
well after about 600 miles no codes have come up so the MAF must be working properly. The sound is amazing and it got .8MPG better gas mileage at 75MPH cruisecontrol on the highway for about 100 miles. Same trip i made 1 week ago without the air intake. So needless to say i am very pleased with this. I kept the stock airbox in tact over top of my drop in KN filter i have on it. 3" SCH40 ABS tubing is what i used however when you put the tube on and do the 45 to go to the throttle body it doesnt quite line up perfectly so you have to do some bending at the 45 if you want to use the stock airbox. Also the coupler at the throttlebody itself will be slightly off but the bend in your rubber or silicone coupler will take care of that fine. Pictures will be up soon hopefully
2003 doesn't have a MAF. It is a MAP system. It is easy to do a CAI on models up to 06 when they started the MAF. At that point, airflow into the MAF sensor needs to be exactly as designed or it will throw off the data tables and cause drivability and power issues.
 

·
Registered
2003 gmc envoy_slt
Joined
·
140 Posts
Discussion Starter · #6 ·
MAF or MAP whatever it is its working. i just travelled the same trip again and now have confirmed atleast a .8mpg increase in gas. averaged 23.1 on the highway this time instead of 23.0 and this time i had my driver window down and my moonroof open. Same speed and pretty much the same weather.
 

·
Registered
2003 gmc envoy_slt
Joined
·
361 Posts
Home depot $35.00 cai

Home depot $35.00 cai
Here are some pictures before and after. I used a 45* and a 22.5* to make sure I could access my Trans. dipstick. I didn't notice much difference in IAT between insulated an non insulated except on freeway.

Parameter DIC ambient temp IAT Ins IAT uns

Parked i driveway coolant temp 185 84 125 130
20 min. stop and go not exceed 45 85 104 105
20 min. freeway between 65-70 85 93 97







More pictures are posted in my profile. I'm not sure about leaving the insulation on. I may remove the insulation, paint it black, or wrap it in Black Duct tape. Also I'm toying with some way of fabricating a "RAM AIR" duct.
 

·
Registered
2003 chevy trailblazer_ls
Joined
·
1,236 Posts
MAF or MAP whatever it is its working. i just travelled the same trip again and now have confirmed atleast a .8mpg increase in gas. averaged 23.1 on the highway this time instead of 23.0 and this time i had my driver window down and my moonroof open. Same speed and pretty much the same weather.
Only reason we're making some deal about MAP and MAF is because of the difference on the various year TrailVoys. Do the same as you did on a MAF system and it would probably be in limp home mode right now. With MAP, it works fine, as the engine can't see what happens before the throttle body EXCEPT the air temp -- and cooling that increases efficiency, which the computer adjust for and supplies fuel in accordance with, hence the reason we do this mod.
 

·
Registered
2006 chevy trailblazer_ls
Joined
·
206 Posts
i did me one up also, but i used pvc and painted it with that krylon high temp paint came out pretty good. Yea definantly can tell performance difference. Also got an increase in gas mileage got extra 20 miles till the gas light came on than before. Whats wrong with pvc RedMonte85? if its big issue this may be my prototype for fit and i change materials.

 

·
Registered
2003 gmc envoy_slt
Joined
·
361 Posts
What is your reasoning for ABS over PVC or CPVC. If there is a safety issue please let me know.
I did a Google search on "ABS vs PVC" and neither are considered "Green".
PVC will burn until the flame is removed where as ABS will continue to burn with toxic fumes.
PVC is impervious to petroleum whereas abs is not.
The glues are different.
PVC must use PVC two step glue.
ABS must use ABS glue and every joint must be glued.
ABS can warp at hi temperatures (rated -40F to +180F).
Couldn't find temp range other than max operational temp is +140F
 

·
Registered
2003 gmc envoy_slt
Joined
·
140 Posts
Discussion Starter · #12 ·
ABS is good up til 240 degrees i think, pretty sure on that. PVC however may take alot to "ignite" like abs but it doesnt need to ignite to let off fumes, where abs does not. Hydrogen chloride is what PVC emits when heated to high temperatures(probably close to the temps ur engine puts off 170-210). Hydrogen chloride is not only extremely fatal to breathe but it is also corrosive. There has been alot of arguements with building codes due to PVC's release of hydrogen chloride. Many firemen die to the gas when a building is burning up because of all the pvc used. Im not sure at which temperature the gas starts to emit but 180-210 has got to be pretty close. Maybe im wrong. I just didnt want to take the chance with mine.
 

·
Registered
2003 gmc envoy_slt
Joined
·
361 Posts
Hal i hope thats not PVC or CPVC that you used:O. If it is i would take it off my vehicle immediately. I guess it could be white abs :D never seen that though
I want to thank you for your input regarding ABS vs PVC. My googling has been very enlightening. According to the MSDS sheets the melting points are: ABS 400*F and PVC 390*F. When heated to decomposition 735*F PVC evolves carbon monoxide, hydrogen chloride and other toxic gases. ABS heated to decomposition 735*F evolves carbon monoxide and other toxic gases. Other sources revealed that "other gases" for PVC included Dioxins and ABS included a form of cyanide gas.
However I do think I would lean more toward ABS. I will probably redo mine with ABS or aluminum pipe sometime in the future. Surprisingly PVC with certain plastisizers and additives is used for everything from baby bottles to shower curtains. Scary! :thx
 

·
Registered
2004 chevy trailblazer_ls_ext
Joined
·
1,061 Posts
i bought one of the ebay intake kits plus i used flexible 4" tubing to channel air from the towhook opening to the airfilter. I have a R/C nitro car temp gauge that i was thinking about using and see what the temps are with the ebay intake and ram air and then without.
 

·
Registered
2003 gmc envoy_slt
Joined
·
361 Posts
i bought one of the ebay intake kits plus i used flexible 4" tubing to channel air from the towhook opening to the airfilter. I have a R/C nitro car temp gauge that i was thinking about using and see what the temps are with the ebay intake and ram air and then without.
Any Pics. I used a scan tool to monitor the IAT sensor. Was the flexible 4" tubing the drainage type. dryer type or?
 

·
Registered
2005 chevy trailblazer_ls
Joined
·
68 Posts
What I did is I kept the original intake and used a 2.5in (I think) PVC cap to plug the whole on top. I had to grind the threads down a bit to make it fit. Then just added silicon on the edges to seal it. Works great and doesn't take too much time!!
 

Attachments

·
Basic Vendor- Skid Plates
2007 chevy trailblazer_ls
Joined
·
3,700 Posts
2003 doesn't have a MAF. It is a MAP system. It is easy to do a CAI on models up to 06 when they started the MAF. At that point, airflow into the MAF sensor needs to be exactly as designed or it will throw off the data tables and cause drivability and power issues.
I think you've got it backwards... MAF measures actual flow. MAP calculates flow based on air temp, intake manifold vacuum/pressure, and RPM... When you make changes, the MAF sees the change in airflow and accounts for it... Anything you do to change VE on a MAP system will throw the calculation off...

Mike
 

·
Registered
2005 chevy trailblazer_ls
Joined
·
68 Posts
debo, you have no heat sheild? you might want to gut the airbox or something you blowing hot engine air in the intake, getting more flow but not cool air.
Hmm... never thought about that. What effects does that have on the engine? Am I better off just putting the airbox back on without gutting it?
 
1 - 20 of 24 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top