New LS1 Owners - Newbie Tech - TB Bump Stop Mod. Question....

How much HP is to usually to gain in this Mod.. I read that you need to stop grinding the bump stop till you read around 4.6 Volts. Was bored and going to do it today. So, will doing this improve HP? Or should i even bother?

Since it is a free mod, and its easy. Every little bit helps. I would do it, but I dont have autotap.

You could do it with a volt meter, you dont NEED atap. Just be carefull

Since it is a free mod, and its easy. Every little bit helps. I would do it, but I dont have autotap.

"Autotap" Is that kind of like LS1 Edit?

HOw do you do it with a volt meter? I have a nice Fluke voltmeter and could handle this with good directions!! :chug: :eek2:

Run a search for the voltmeter version of the TB bump stop mod. We just discussed this not long ago. I believe in the newbie forum too.

FWIW, I think this is a great mod.

I haven't done it, yet. But I think I heard you use a voltmeter with the black going to an engine ground, and the red going to the blue wire coming out of the TB. I'm not exactly sure though, so check around first.

I haven't done it, yet. But I think I heard you use a voltmeter with the black going to an engine ground, and the red going to the blue wire coming out of the TB. I'm not exactly sure though, so check around first.

Here is a good HOW TO website. Thats why i was asking about HP gain. Is it worth it? And "autotap" It doesnt mention any kind of diagnostic to the CPU.
If your pedal is to the floor and you grind dowm the bump stop on the TB to give you more open throttle. Wouldnt you need more pedal room to smash down to the floor board? Anyways.. It seems simple..

http://www.ls1camaro.net/sections.php?op=viewarticle&artid=26

Thats the site i used. Make sure you TB is opening all the way to the bump stop,have someone floor the gas and check. Who knows about hp, but you can see with the bare eye it opens more.I would think 2-5hp depending on what your voltage was to start with.Its free and its easy like the egr mod.

Thats the site i used. Make sure you TB is opening all the way to the bump stop,have someone floor the gas and check. Who knows about hp, but you can see with the bare eye it opens more.I would think 2-5hp depending on what your voltage was to start with.Its free and its easy like the egr mod.

Im guessing that you can do the WOT from under the hood to get a pre/post reading with the volt meter. Was going to use some alligator clips to free up my hands. So, i can just push the TB wide open from under the hood. Same concept right?

Yea I think you might see 2-4 HP all factors depending...but where you will really see the gain is in throttle response/chrispness...do it it's one of the best free mods...good luck

Wes

Im guessing that you can do the WOT from under the hood to get a pre/post reading with the volt meter. Was going to use some alligator clips to free up my hands. So, i can just push the TB wide open from under the hood. Same concept right?
I said that because you were worried about the pedal going all the way down. Yea do it by hand on the mod then check with the gas pedal when done.

When you put the one end of wire in the TB what do you do with the other end? is that the end you ground? If so where do you take the reading? at the TB??? They have pics of the TB they should have pics of the whole mod.

Measure the blue wire[while its plugged in with your jumper wire] put it to + on the voltmeter, Ground the other side of volt meter, I used the battery ground wire.

Measure the blue wire[while its plugged in with your jumper wire] put it to + on the voltmeter, Ground the other side of volt meter, I used the battery ground wire.

could you notice any difference?

Be careful to not exceed 90 degrees (that's what the volt meter is for, measured by the TPS). If you grind enough away to where it will allow you to exceed 90 degrees on the throttle blade, then the computer doesn't like that too much. =)

Be careful to not exceed 90 degrees (that's what the volt meter is for, measured by the TPS). If you grind enough away to where it will allow you to exceed 90 degrees on the throttle blade, then the computer doesn't like that too much. =)

From what i have read, anything over 4.7 volts will throw a code. So, i guess i wil stop at 4.6. Need to go buy a dremmel tool.

It can be done with a couple different files if you have the time. It takes a while but you are less likely to take off too much, Thats how i did it on a buddys car. I really cant tell if it mad a difference. I would think at high rpms i would have to...

It can be done with a couple different files if you have the time. It takes a while but you are less likely to take off too much, Thats how i did it on a buddys car. I really cant tell if it mad a difference. I would think at high rpms i would have to...

Yea, i dont think that it would be a Mod. if it didnt benefit in one way or the other. Just gonna wait till i go over to a buddies house to use his power tools (dremmel) :hail:

Im guessing that you can do the WOT from under the hood to get a pre/post reading with the volt meter. Was going to use some alligator clips to free up my hands. So, i can just push the TB wide open from under the hood. Same concept right?

Not really...slack in the gas pedal and cable will give false readings. Have a helper sit in the drivers seat and mash the pedal, then take the voltmeter reading. You want 4.69 volts DC or less. 4.7 volts will throw a SES trouble light.

Not really...slack in the gas pedal and cable will give false readings. Have a helper sit in the drivers seat and mash the pedal, then take the voltmeter reading. You want 4.69 volts DC or less. 4.7 volts will throw a SES trouble light.

ok.. i just figured that when your pedal hits the floor (WOT) its hitting the floor. So i guess when the pedal will not go down anymore its because of the TB Bump Stop? See what im saying? IF your pedal hits the floor you have no more room on the fllor board to go anymore. So, why would grinding some metal off your TB give you more pedal? Not trying to sound stupid but do you know what im saying? Or are we talking about microns here?

Would this mod do ANY good with the new drive by wire throttle bodies??? Seems like the electronics would just override the grinding of the bump stop, or would they? Just getting ready to do this and thought about this...didn't wanna waste my time!! Or anyone elses with the DBW TB! :judge:

ok.. i just figured that when your pedal hits the floor (WOT) its hitting the floor. So i guess when the pedal will not go down anymore its because of the TB Bump Stop? See what im saying? IF your pedal hits the floor you have no more room on the fllor board to go anymore. So, why would grinding some metal off your TB give you more pedal? Not trying to sound stupid but do you know what im saying? Or are we talking about microns here?

Not microns, but thousands of a inch depending on how much you're off. Slop in the gas pedal assembly and its cable will give false readings as well as the carpet bunched up, not allowing full pedel travel. Make sure everything is clear and then have a helper mash the pedel. Take the voltmeter reading at this point, then grind/file the bump stop as needed.

On my 98, the throttle body was only opening up about 3/4. I noticed a pretty good difference when I did it. I also shortened my EGR tube, because it's directly behind the throttle body and there is no reason for it to be that long. Just file the stop until the throttle body is physically all the way open. Stop and check voltage periodically to not exceed 4.7VDC. If you go further than all the way open, then it will be partially closed when it is floored. You want the blade of the throttle body all the way open when it is floored. Don't measure your success by volts (just don't go over 4.7VDC or it will throw codes!). The idea of this mod isn't to increase voltage from the TPS, but to get the throttle body to open all the way. Take a look at it with a buddy holding it to the floor. If it's already going all the way open, there is no reason to do this mod. Make sense? Good luck! Oh, and as stated before - make sure you use a buddy to hold it to the floor. I got different readings when I opened it up by hand.