How to Add Horsepower to the 2004 GXP - Page 9 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Bonneville GXP/ Northstar Powered Cars Discuss your Bonneville GXP and/or any other Northstar powered Olds or Cadillac... Including the 3.5L Twin Cam V6 (Short Star ) 4.0L and 4.6L Northstar V8's. Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 04-16-2006, 11:35 PM   #81
Member
Posts like a V-Tak
 
Join Date: Jan 2006
Location: St.Marys,Ohio 45885
Posts: 89
Thanks: 0
Thanked 0 Times in 0 Posts
cballweg is on a distinguished road
Default

I did put a K-N air filter in today and noticed the pipe coming in to the airbox and it looked like another maybe1 inch hose coming into the bottom but i didnt investigate anymore since I wanted to get the gas filter changed also but I believe a bigger pipe coming into airbox would definately help.I would make sure the airbox was air tight so no underhood hot air would get in if you modify it.Thats why the factory makes them this way and I believe a lot of people make a mistake installing open cone air filters.As to the aftermarket mass air flow sensors they say they help on a modified car such as bigger cam and ported heads since you need more air and gains are more limited on a stock car since the factory has determined what the motor needed for air.I just read where they installed a ported throttle body on a Trans Am and it only got 5 HP on the Dyno but they left the stock mass air flow sensor with screen intact and this might be a bottleneck.Before I installed the aftermarket Mass air flow sensor on my TA I did remove the screen on the stock one and it ran fine.Others have claimed they noticed more power with the larger descreend aftermarket Mass air flow sensors and stock throttle body.I do think the screen is very restrictive just looking at it.but does the stock motor need more air?thats the question.Maybe you can use more air wth the Nitrious.If bigger cam and ported heads it would for sure.I did try to push screen out and it would not go.You would have to tap it out probably with something and possibly bend or tear it.My TA had little bumps holding it in on one side which would have to be removed with a dremel to safely remove it but I just knocked it out with a screwdriver.If you remove it be very carefull to not damage the thin wires inside the sensor that detect the airflow or it will be ruined. Hope this helps
cballweg is offline   Reply With Quote
Old 04-16-2006, 11:38 PM   #82
Member
Posts like a V-Tak
 
Join Date: Jan 2006
Location: St.Marys,Ohio 45885
Posts: 89
Thanks: 0
Thanked 0 Times in 0 Posts
cballweg is on a distinguished road
Default

Also if you take the screen out dont run withou an air filter or you will have bugs and other debris going into motor and that would be bad,I wouldent run without air filter even wih the screen in.
cballweg is offline   Reply With Quote
Old 04-17-2006, 01:19 PM   #83
Administratus Emeritus
Certified Car Nut
 
GXP Venom's Avatar
 
Join Date: Jan 2006
Location: Purgatory, Pennsylvania
Posts: 16,538
Thanked 7 Times in 4 Posts
GXP Venom is on a distinguished road
Default

Yes the airbox for the Northstar is well engineered but I wouldnt discount what the N/A guys are doing. their airbox is much smaller and single stage and doesnt have the size or intake location of ours. And I'm sure when you start modding the */C with smaller pulley wheels the flow issue is further confounded. And I wouldnt be surprised that some better flow to the Northstar can be achieved by bringing that tube up to tube up to the size of the intake, even a little bigger. Like I said before as time permits I'm gonna open the whole thing up and see if a 3" tube can be fitted between the two sections of the airbox. You arent refering to the wire harness that runs through the box in a plastic tube are you? Only other tube i've seen in mine.(and cant figure out why they ran a harness through the air box...perhaps cooling?) I also want to see about removing the Maf screen it definately restricts flow being same size in and out, and i dont see need for either unless the effect thru the screen on turbulence gains more than restriction. Engineering issues like that make for patience and discussion before just ripping out things. Too many people think they know more than automotive design engineers and in Northstars case the engineering is "world class" But the other side of the coin is things like that middle tube may be great air flow for 275 Hp but not for mods that make more Hp. So.... if you cant do mods that can change the rating of Hp then the other mods are useless.

The TB rebore is an owners call, as you mentioned... real dyno tests I've seen only show gains in the 6-9 Hp range and thats not much. There are alot of bullshit claims about TB rebores and rice pipes and even CAI and FWI systems and I see so many exagerated claims of 20, 25 Hp gains .... but no dyno evidence. I truly dont think you can feel a 6% gain with the foot test and the body cant sense that slight increase in G-force or acceleration. And track times vary. I wouldnt put faith in any mod unless I have seen real authenticated dyno evidence. And owning a rather new $40,000 vehicle makes me hold that position stronger.

Needing more flow for nitrous is a misconception.... Nitrous is artificial flow and provides all the oxygen needed....nitrous is not a fuel , and does not burn, it is as safe and as inert as bottle air. Nitrous works because it holds twice the voloume of oxygen as air and it cant be broken down untill it reachs hot compressed tempertures inside the engine. the backfires and explosions come from the gas itself thats sprayed into the plenum and then once the gas detonates, the temp rises enough to let the nox let go of it'* oxygen and further stregthens the detonation. A variety of things can set this off, generally plugs get so hot they act as glow plugs and wrong valve timing allows for some fire to set off the extra gas in plenum, then pure oxygen that comes from gas ignition makes for a big bang. A big plus with nitrous would be bigger exhaust valves and thats not possible in our engine.
GXP Venom is offline   Reply With Quote
Old 04-17-2006, 10:58 PM   #84
Member
Posts like a V-Tak
 
Join Date: Jan 2006
Location: St.Marys,Ohio 45885
Posts: 89
Thanks: 0
Thanked 0 Times in 0 Posts
cballweg is on a distinguished road
Default

It could be the tube that the wire harness runs through.I didnt have time to look it over so I really dont know.It could be that the wire is going into the computor in the airbox.I dont know where the computor isI know my GTP Grand Prix had the computor in the airbox to keep it from the hot underhood air and the aftermarket cold air boxes seperated these so it would not restrict airflow since it was right in the path of the incoming air and quite restrictive especially after you insalled a smaller pully to raise boost levels.I will have to tear it apart some day and look.
cballweg is offline   Reply With Quote
Old 06-14-2006, 12:35 PM   #85
Member
Posts like a V-Tak
 
Join Date: May 2006
Posts: 82
Thanks: 0
Thanked 0 Times in 0 Posts
1999Daytona500PaceCar is on a distinguished road
Default

I took my airbox out completely yesterday to detail it and the engine bay area underneath it as well as just to see what this thing was all about. And of course, I had my K&N Filter ready to install! It was kinda like that Dodge truck commericial for the MegaCab... GEEZ, that'* a BIG airbox! No wonder there is no off the shelf CAI for these things. Anyway, after looking over everything thoroughly and noting the obvious that the tube linking the 2 halves of the airbox was the limiting factor - I decided to remove it all together and give that a try. As I am sure you have all noticed, the tube is a seperate piece from the bottom of the airbox and it simply slides into its grooves and locks into place with a single plastic piece at the bottom. You just remove the lower portion of the airbox - the computer simply slides out and you can place a towel over the engine and lay the computer to the side - you do have to remove that little housing that holds the - not sure but I think it may be the cruise control module(?) up near the fender and kinda above the rear of the airbox - and move it below the STB and back out of the way - also remove the Throttle body and lay it back on the towel as well as you don't have to unplug it - then remove the 3 star headed bolts that hold the lower portion of the airbox in place and slowly and carelfully remove it from the engine bay. You will see there is a small piece of plastic that pushes through from the tube piece and kinda pops into placeon the underside. Just take a pair of pliers and sqeeze the split ends together and it will simply push back through.and the tube is removed. Now, instead of this little bitty 2 inch or so tube feeding air through to the filter - you have an opening you can put your fist through! It is not smooth like the tube - but this much larger opening will allow so much more air to move through it that it seems it can only be benefitial. But if you decide to replace the tube for whatever reason - you can simply pop it back into its original location without anything more than removing the 2 top halves of the airbox.

I know, I know - you want pics. I have a couple as well as a couple of the upper portion of the airbox that is the lid to the filter where I cleaned it up quite a bit with the Dremel near the opening leading to the MAF. I will have to download them and see if I can figure out how to post them. But feel free to email me if you would like me to email you the pics. Talk to ya'll later...
1999Daytona500PaceCar is offline   Reply With Quote
Old 06-14-2006, 12:37 PM   #86
Junior Member
 
Join Date: Apr 2006
Location: Purgatory
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
Bonneville92V688 is on a distinguished road
Default

Please do not dig up old threads. Start a new one with a link to this thread. A admin will be here to lock it.
Bonneville92V688 is offline   Reply With Quote
Old 06-14-2006, 01:43 PM   #87
Member
Posts like a V-Tak
 
Join Date: May 2006
Posts: 82
Thanks: 0
Thanked 0 Times in 0 Posts
1999Daytona500PaceCar is on a distinguished road
Default

Sorry, didn't even notice the dates on the previous posts. Thanks for the tip...
1999Daytona500PaceCar is offline   Reply With Quote
Old 07-23-2006, 01:52 PM   #88
Administratus Emeritus
Certified Car Nut
 
GXP Venom's Avatar
 
Join Date: Jan 2006
Location: Purgatory, Pennsylvania
Posts: 16,538
Thanked 7 Times in 4 Posts
GXP Venom is on a distinguished road
Default

This is NOT an old thread Bonny94, it is a sticky, given the status because of the amount of information in it. Carry on Daytona. I really want to see those pics
Going to take the plunge and gut mine out soon as well as getting the non restrictive MAF
GXP Venom is offline   Reply With Quote
Old 05-04-2007, 01:35 AM   #89
Member
Posts like a V-Tak
 
Join Date: Mar 2007
Posts: 31
Thanks: 0
Thanked 0 Times in 0 Posts
LongIsland2482 is on a distinguished road
Default

so its been almost a year and no-one has came up with anymore performance ideas/mods?
LongIsland2482 is offline   Reply With Quote
Old 05-04-2007, 03:07 PM   #90
Administratus Emeritus
Certified Car Nut
 
GXP Venom's Avatar
 
Join Date: Jan 2006
Location: Purgatory, Pennsylvania
Posts: 16,538
Thanked 7 Times in 4 Posts
GXP Venom is on a distinguished road
Default

People seem to keep asking that and the facts are the facts. And you have to face them. All aluminum engine that by design wont allow anything that will bring extra appreciable power, and a PCM that cannot be altered. If You want to fly...........be the first to spend alot of time and effort to put a generic turbo kit on this car and Hope you can tune it so it isnt just a paperweight. Or take the easy way out and nitrous it. Jet Chip now makes a controller that is suppose to "piggyback" the PCM and they and several companiys now make a aftermarket MAF.......but dont expect any real HP from either additions, without Boost, they arent going to do much to quicken our fat bottomed girls.
GXP Venom is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Add another GXP to the site Black05GXP Introductions for new members 9 07-21-2008 08:41 AM
Add another GXP to the forum... LiquidGXP Introductions for new members 7 03-27-2005 03:21 PM
GXP Horsepower Update sahensley Bonneville GXP/ Northstar Powered Cars 20 11-05-2004 07:31 AM
Add a 2004 Grand Prix to my kill sheet.... Merlin 91/97 General GM Chat 25 01-02-2004 06:39 PM
OMG: 2004 Bonneville GXP will OWN skza General GM Chat 52 11-26-2002 07:42 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 07:12 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.