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73-87 Chevy _ GMC Trucks => Performance => Topic started by: mpullen66 on January 29, 2012, 09:23:41 pm

Title: TBI Mods
Post by: mpullen66 on January 29, 2012, 09:23:41 pm

I was looking at the Ultimate TBI Mods. One of the mods is to remove the spacer that sits on top of the throttle body and use a non drop air cleaner assembly. I was looking at mine and noticed there is a hose (tube) that runs from the drivers side valve cover to the back of the spacer.

My Question: What do I do with the hose (tube) if I were to remove the spacer???


1987 lwb,2wd, 350,700r4

Thanks
Mike

Title: Re: TBI Mods
Post by: bake74 on January 30, 2012, 05:59:36 am

     I just did some mods to my 2000 GMC crew HD 4x4 with the TBI 454.  (It is the "classic" version model).  I put an air raid throttle body spacer and K&N Cold air intake (have not got to the Gibson exhaust yet). 
     When I got it, it was pretty gutless and drove slow without much responsiveness in my opinion.  I have had it about 1 month and when I first got it I floored it at a stop sign taking off just to see what it had.  Disappointing is the word I would use.
     So Yesterday, wife and I were driving and she wanted to see what changes it made.  Same test, but this time the rear tires broke and left burn out marks, surprised me, I thought it would just take off faster.
     I owned a 99 expedition once that I did the same mod to and it improved my MPG by 3, it had the big 5.4 liter engine, so I am hoping to improve my GMC by at least 2 - 3 MPG.

Title: Re: TBI Mods
Post by: mattgood on January 31, 2012, 10:30:24 pm

I have used a tbi spacer before on my 91 sierra, but never removed the plate at the top. If you plan on driving your truck in cold weather I would advise against this as it somewhat works as a heat riser and your throttle body could possibly ice up. If that's not an issue you could just buy a breather to put in the valve cover and see how it goes.

Title: Re: TBI Mods
Post by: frotosride on February 12, 2012, 01:14:42 am

If you do this mod you have to use the hose...this is the crankcase breather tube and it evacuates the potential explosive gases inside the engine and also maintains a negative pressure throughout the engine which helps in piston ring seal. All you have to do is make sure it sees vaccume from the engine. How you do this isn't as important as that you do it.

Title: Re: TBI Mods
Post by: mpullen66 on February 12, 2012, 07:28:33 pm

Thank you for the help

Title: Re: TBI Mods
Post by: aaronwilliams on February 26, 2012, 07:39:39 pm

Bake74 is this the spacer you are talking about? http://www.airaid.com/ProductDetail.aspx?ProductID=200-550

Im not very familiar with mods for tbi but my 95 suburban gets around 10-12mpg depending on my mood.

Also, what did you get for an intake? can I just do a k&n filter element?. The guy i bought the suburban from drilled a bunch of holes in the filter cover (probably useless attempt at improving flow?) so ive been considering an intake upgrade for a while.