The other day I was on a camaro tech page and saw a how-to on a mod that allows the TB to open the buttefly more by grinding at the bump stop on the TB linkage . Has any one tried it? also What is involved in porting or polishing the TB? Can I do it or will it cost me some bucks?

 

As far as the bump stop grind goes, you will need Auto-tap to help you in that, so you don't go to far with it, or so I have heard. I have not done that one. On the portrd T/B, one of our site sponsors "Jantzer Performance" can help you there. Unless you are good with a dremal, let someone do it. I had mine done by someone that knows a lot about a certain popular Vortec motor <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> . I did notice quicker throttle response after I installed it.

 

I just did this on my buddy's 4.8 GMC and it's the same as the 5.7 LS1. You could use a voltmeter if you don't have the auto-tap and just grind it down to 4.65 volts since the limit is 4.7.

Hope this helps.

 

Where do you connect the voltmeter at?

 

Yeh where does that voltmeter go?

 

If you were to look at the TB from the front of the truck there are two wire harnesses on the right side. The bottom one is the TPS which has three wires forming a T pattern. The base of the T is the wire that you want to poke into (Blue wire on a 2000 GMC). Once you tap into it with the key on the "On" position, you place your ground and open the TB by hand (requires about 3 hands) and read the voltage. Typical voltage from factory that I have seen is about 4.4 V. You just grind the bump stop until you reach 4.6-4.65 V. *Warning* if you go past 4.7 V. you will throw a code. If you guys would like some photos, I'll try to take some in the evening and post them up.

Hope this helps.

 

photos always help thanx for the info! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

I'll see what we can do about the photos. We used a real accurate volt-meter, to my surprise. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> The mod only took around 45 minutes to complete and it really made a difference at WOT and from a stop. Johnny let me know when you want to take the pictures sometime today or later this week.

 

That's cool, I just took a pic of my TB. Here are is a quick pic of the TB.
<img src="http://users2.ev1.net/~johnnydoris/TB.jpg" alt=" - " />