Bump Stop Mod

**KM02SS** · 09-06-2006, 10:37 AM

I don't have access to the tool to give me TB blade % open, is there any way to do this mod w/o it??

**89LX** · 09-06-2006, 10:49 AM

I performed mine when I had the TB out for P&P. I didn't have a meter either. I place my TB perfectly level on the work bench and open the blade. You will see it is less than horizontal before you start removing metal on the stop. I gradually removed metal until the blade appeared slightly less than horizontal position (full open). Do not go over the horizontal plane or you are hosed. Money gifted LS1 owners will probably have a fit with this solution but worked for me.

**KM02SS** · 09-07-2006, 05:39 AM

Yeah I figured something like that might work, thanks.

**jag42420** · 09-07-2006, 08:26 AM

I'd like to try this mod as well. The article I commonly see referenced (http://www.installuniversity.com/ins..._bump_stop.htm) says you need to check the voltage to do this correctly. I would assume that erring on the safe side of 90 degrees (without being able to check voltage) would maybe not be as effective but offer better than stock? Is there anyway to use a voltmeter instead of diagnostic software?

**89LX** · 09-07-2006, 01:51 PM

The "before and After" pictures on install university is what convenced me to go ahead without the tester and hold short of 90 degrees. I figured it would fall short of the maximum allowed with a meter/tester but better than stock. As you know all these free mods are accumulative in nature and as a result don't feel the results of minor tweaking after one mod. Mine is certainly opening wider than before and that was my mission.

**Ripper415** · 09-09-2006, 09:40 AM

I've been thinking of doing this mod and the port and polish too. About how long did each one take you from start to finish? Since this is my daily driver, I need to figure out if I can do both in the same day, or should I just wait for the weekend. From the limited number of mods I've done on my car already, I've found out that whatever time you assume it will take to complete is usually not enough, especially if it's your first time doing it.

**89LX** · 09-09-2006, 04:32 PM

I manage to P&P the TB and MAF in two evenings. I suppose it would have been done with a fulls day work. P&P the TB was made pretty fast with a small bench drill press with a sanding drum used. The most time cosuming was probably cutting out the vanes with a hack saw. It was pretty scary to start with (for me) but once started of course pressed on. Like everything else how long has a lot to do with what you want the finished product to look like (smooth, real smooth or slick and near flawless. I would grade mine real smooth. I did not plug with epoxy like some do. Seems a little unnatural and no reported measurable documented gains I could find. I also didn't want the epoxy to come out over time and go down my motor. Good luck

**jag42420** · 09-09-2006, 04:48 PM

My SLP lid will be coming tomorrow. I'll be doing the throttle body port & polish then. I'm going to go slow and take some pictures. I'm also going to try and replace the bellows with a smooth hose if i can locate one when I get it off there to size it up.

I'm not sure of the MAF P&P. It looks a bit more scary. I know it doesn't take much to scramble the sensor...

**89LX** · 09-09-2006, 05:02 PM

Most say the MAF is not that important and stock will support all but the heaviest Mods. Seems like I have read up to 500HP.

**jag42420** · 09-11-2006, 01:19 PM

Can anyone tell me if this reader ( http://www.harborfreightusa.com/usa/...o?itemid=94217 ) will read the voltage or degrees described in this article http://www.installuniversity.com/ins..._bump_stop.htm ? It's only $75. I'd consider buying it to use for code reading anyway, but if it would help with a mod, even better.

**Red WS6 00** · 09-12-2006, 05:56 AM

You could read the voltage with a simple volt meter. you need to not let it read above 4.7V as the PCM will throw a code. I set mine to 4.68volts, I filed down the pump stop then added an adjustment screw.
Although that OBD scanner may come in handy for other things i wouldn't buy it just to do the throttle body bump stop mod.

**jag42420** · 09-12-2006, 06:59 AM

Cool deal. I was wondering about using a voltmeter...

**Red WS6 00** · 09-12-2006, 07:59 AM

More info on the voltmeter method is in this link, sorry, need to copy and paste as I havn't done enougth posts yet.

ls1tech.com/forums/showthread.php?t=420817&highlight=writeup

**jag42420** · 09-12-2006, 11:24 AM

Thanks.

**edbird** · 09-12-2006, 06:45 PM

Here ya go....check this link first before you do this.It's the best write up with the largest pics ever!http://www.ls1tech.com/forums/showth...=bump+stop+mod