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Boost Bypass Mod????

JCG's-GTP

JCG's-GTP

New member
I read something on ZZP about this. Can someone enlighten me on what this does and if so will it work on 04+
 


Yeah, don't touch it. It's not going to help your performance any, and might actually cause you problems by building knock.
 
TDCRacing said:
what you runnin now a days? 1/4 mile wise
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Haven't been to the track yet. Let alone a 1/4mi one. Progress on the car lately has been slow, still need to finish up re-wiring the nitrous and doing the 'cable mod' on the rear suspension so I can actually get some traction before I even think about bringing it to the track again.
 


so people say this mod may bring up some locked up kr, but what about doing the reverse? how do you adjust the bbv?

this may be my knock problem since i get 5 psi almost instantaneously.
 
You lossen the 2 screws that hold the bbv on and slid the bbv as far up as possible wich would cause it to engage later in the throttle....
 
Believe DONT DO THIS MOD! Why? Sure it generate boost faster, but the main problem is when you do so, the current fuel injectors can not handle the influx so well and will produce more KR than the "mod" is worth. I did it on my old SC before I did my swap with one of Brian's ported and polished SC's.

But IF you are stuck on wanting to do this mod, I would mark EXACTLY where it was before you move it. Cause if you don't, its a buggar to get back into the factory set position.

And going in reserve of the mod won't help either. If you are getting 5* of KR now? You can expect a lot more afterwards with this "mod." So choose wisely which direction you want to take. I personally would hunt down your current problem with KR than moving the BBV.
 


if anything id do the opposite of what this mod is supposed to do. im thinking my knock is from a bad tune, its a dhp 1.5 file with deleted codes for my egr and p0300. never got it tuned after last fall when i finally got her running again.

i havent put my ssic on, but at some point i want to do that as well as finding someone local to put a nice tune on my car. i can tweak the fuel on my own from day to day with my afc, but my PE and timing are probably way off from what they should be. im lucky if i get 18 mpg right now, haha.
 
Bio248 said:
if anything id do the opposite of what this mod is supposed to do. im thinking my knock is from a bad tune, its a dhp 1.5 file with deleted codes for my egr and p0300. never got it tuned after last fall when i finally got her running again.

i havent put my ssic on, but at some point i want to do that as well as finding someone local to put a nice tune on my car. i can tweak the fuel on my own from day to day with my afc, but my PE and timing are probably way off from what they should be. im lucky if i get 18 mpg right now, haha.
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wow i just did a little work on my tune...34mpg on the highway and 22 in the city...45* timing ftmfw
 
TDCRacing said:
wow i just did a little work on my tune...34mpg on the highway and 22 in the city...45* timing ftmfw
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Yeah, I have the boost bypass mod reversed on my car. And I have my tune set so that the SC won't come in until 30% throttle. 45° cruise timing. Last tank of mixed driving and I got 29mpg. Probably 50/50 highway/city driving. I can't wait till the next road trip and I can see how well it will really do.
 
I wonder what kind of performance gains...if any,could be acheived by doing the reverse boost bypass mod...so in other words not much boost until 30%tps....what do yall think...maybe traction wise at the track?...just thought i'd throw it out there
 


I was reading that the BBV mod is for the cars that don't come from the factory adjusted properly. It said at full throtle that if your boost guage on the DIC isn't reading full bars, then you make the adjustments to give you full boost. If you are already there, don't touch it. I made the mistake of doing it before I read the whole article and lost alot of power. Luckily I could see where it was originally and got it back right. I'll see if I can find it and put it in the tech section.
 
BADAZGTP said:
I was reading that the BBV mod is for the cars that don't come from the factory adjusted properly. It said at full throtle that if your boost guage on the DIC isn't reading full bars, then you make the adjustments to give you full boost. If you are already there, don't touch it. I made the mistake of doing it before I read the whole article and lost alot of power. Luckily I could see where it was originally and got it back right. I'll see if I can find it and put it in the tech section.
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This is probably true, mine initially was not adjusted right. I figured out it had to do with where the stop for the BBV on the SC was set at. Not the actual BBV.
 
i drove around with my BBV closed all of the time, for who knows how long. Since the car was tuned for the valve being closed, I had no KR issues. Naturally if you adjust the valve and don't add extra fuel there would be KR.

As far as the valve not being adjusted right from the factory, seems odd. IIRC the tool used to set the BBV is a fixed position tool. There is no adjustment. Looks like it works like a jig. Put it on and tighten up the nuts, and then remove. Time to go pull out the and look at the procedure again.

Just looked up the install process and it would be real difficult to get it wrong, but anything is possible.

I'm certainly with everyone else on not messing with the BBV. All of that boost even with the right fuel made taking off from a light without spinning the tires really difficult. Basically a waste to have that much boost at the bottom on an engine with so much torque.
 
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This is what I found on this mod from ZZP. Of course there are instuctions on how to do it, but all the way at the bottom where these few words that most of us would probably overlook:

This modification won't help everyone. It does help you for gaining hood clearance after adding an intercooler. It also helps some cars achieve full boost that were having problems with the bypass not closing all the way during WOT.

There is another article that I read on this that better explains it, but haven't found it yet.
 
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