Its too bad he got the 5.3. I've heard a few people say the 4.8 is faster. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

Hey,
PEWTER99_TRANSAM you asked what a corvette servo is. A corvette servo is kind of like a shift kit. When you shift your truck slacks. With the corvette servo your truck will jump into gear. I have one for sale for $50 if you want it. I also have traction bars for sale if anyone wants them.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Hyperheavy:
<strong> Its too bad he got the 5.3. I've heard a few people say the 4.8 is faster. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"><img border="0" alt="[jester]" title="" src="graemlins/gr_jest.gif" /> <img border="0" alt="[evil]" title="" src="graemlins/gr_devil.gif" />

 

I guess the track makes some differance but at memphis most 5.3 ext. run tall 15's at best. After they get a programmer am other bolt ons they run mid 15's. As far as non s/c harley,no problem I've outrun 2 boss 5.4s and they are reg. cabs.Good running reg cab 5.3 start at mid 15's and I know Siverado SS runs 15 flat to high 14's on a cool night.These seem slow to you F-body guys but my trk weighs 5200# and works every day.Good racing <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" /> Jim

 

When my Tahoe was stock my times were 15.9s.

 

Since I have an ext cab I thought I would mention my latest set of times at the strip. I only have a corsa exhaust and upd filter and ran back to back 15.6's in the quarter. This was my first time running at my truck at the track and the first time racing an auto tranny (at the track).

Tomorrow night Im going back to the strip to see if I can drop a tenth or two off my quarter time. My first runs mentioned above were with mild power braking and launching at less than 1000 rpms. I also did not manual shift my auto tranny.

My truck DEFINITELY launches better when power braking to at least 1000-1100 rpms, something I didnt try at the track.

I have heard from a few guys that manually shifting their auto tranny trucks resulted in LOWER quarter times. What does everyone think?

How do most of you all run your auto trucks? With automatic or manual shifting?

 

Thanks for the info everybody. Ill tell my friend with the 5.3 about the servo for 50$. Also a dude wants to run the guy with the 03 gmc 5.3. The guy has a 01 or 02 harley...non supercharged version. How much should the gmc beat it by?

 

Marine Blue, in the past I always let the truck do the shifting for me, but this past wed night I tried the manual route too. I auto shifted a couple runs, and I ran some 15.0's at 91mph which is the worst ET I've had with the truck, thanks to the temps. I then manually shifted between the 2nd and 3rd at 5700 rpms (i let it auto shift 1-2) and pulled off 2 14.9's at 93mph. I auto shifted a couple more times, and sure enough, I was right back to 15.0's.

I couldn't quite make it to the end of the quarter in second because of my MPH, but you might be able too? If that's the case you should be able to slightly lower your times. Of course if I had a programmer, I would just set the shift points and let the auto do it's thing.
<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

If manually shifting is helping, it's because you are holding out the gear a little longer. I'd use an HPP3 or LS1 Edit for that.

I have the older L31/5.7 but I did try manually shifting and it did not help I think on my truck the shift points are already higher since it was a police vehicle.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Slowtruck69:
<strong> Hey,
PEWTER99_TRANSAM you asked what a corvette servo is. A corvette servo is kind of like a shift kit. When you shift your truck slacks. With the corvette servo your truck will jump into gear. I have one for sale for $50 if you want it. I also have traction bars for sale if anyone wants them. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">$50 for a vette servo? <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

Nice truck under your user name by the way. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> Too bad I drive it daily. <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />