Wait so he will help me?

 

a gm stage two tune limits the boost in first and second gear. this could be his issue, its part of traction control. boost is also limited if the computer see's kr, high iat2z, and so forth which i know you know. A very good possibility is he could have a air bubble in his sc coolant system, or his ic pump is having issues. belt slip, bad tensioner, you know, has he checked all this yet.


thanks

 

It does not limit boost in 2nd gear. You are correct about 1st gear though. Boost is limited to 10 psi in order to maintain some sort of traction. You will see full boost in 2nd, 3rd, 4th, & 5th all the way until redline / rev limit. You are also correct about high IAT's, but it isnt boost that gets limited its timing. Anything over 160ish *F, and timing is pulled thus reducing power output.

Belt slip / bad tensioner are possible as well.

 

Thats a lot of timing I don't think I've ever been close to that but I did have a performance issue a little while ago and they had to replace the charge pump so I wonder if it wasn't bleed completely, how do you bleed it?

 

what i do to bleed mine is take the cap off the he coolant resivour. then either let the engine run so the pump is working or jump the pump relay so you dont have to idle it. it will take a little while but sooner or later it should bleed it all out. by the way i have the hatrickstu cooling mod. search for it i would highly recommend it.

 

Noo noo the 160*F is the temp of your IAT2's, not the timing Your timing is pulled once it gets near the 160*F mark. Sorry for not making that clear.

It's tricky to bleed the coolant if you have the stock fill neck. The Opt B tank is a nice option to have, because it constantly bleeds the intercooling system, and makes it more efficient.

x2 !!

 

wut is the boost he is running, that is wut i want to know lol

 

Yeah, now that you mention it, I dont think he told us yet.

 

becuz he could just want more boost and with heat in the 90 degress his car isnt gonna boost as much because the warmer less dense air.

 

lol its not close to that here lol....im boosting 15 almost 16 and on this same setup that ive had for 2 to 3 years its always been 18 to 20......im boosting as much as when i just have the stage 2 pulley ...but i think the cat is partially plugged so im going to run a backpressure test tomorrow....it seems very logical that that could very well be it because ive prolly done a good deal of harm to it in the past 20k miles.... the light had flashed before the motor blew and now it might finally be going....sometimes it just takes time....but i will let you know what i find out when i run the test.....

 

I'm from the school of thought that a plugged cat would make boost higher. think about it. when you resist flow, pressure builds. when you open up flow, pressure drops.

I could prove it mathematically using the Bernoulli equation, but whats the fun in that.

blow air through a coffee stirring straw, then blow it through a milk shake straw, which one makes your cheeks expand bigger (moar pressure), which one is more restrictive (ie more plugged)?

lemmie know if you wanna datalog.

 

Yep same thing I said. Check your supercharger rotors and the housing for bad scrathed deep yadda yadda

 

Kyle, have you changed your tune? Are you running the same tune as you were when the dude from Cincy tuned it, or are you running the straight Stage2 tune?

 

Is this Kyle from Wadsworth?

 

yes mike hello....and yes beef i have hp tuners pro and would not have had my engine warrantied if i did not change it back to the stage 2 tune so yes it straight stage 2......and if the cat is plugged yes and no on the boost the more restriction the more boost but at the same time theres a certain point where to much restriction also back flags and it wont have the ability to even make the boost so it could go either way.....but i took it to the dealer today and yes just as i suspected it has a plugged and broken cat....so monday they will order one and it will be in thursday so prolly friday i will know if that was all of the issue..

 

The superchargers ability to make boost is directly proportional to the engine RPM. So the only way you could be making less boost with a supercharger is if you were at lower rpm assuming no boost leaks or BOV issues. which isn't the case.

The other major factor is restriction. The more restriction, the more pressure, all the way up to the point where its 100% restricted (potato in exhaust pipe). There's no tipping point where you would lose boost w/ more restriction.

Bernoulli equation.

 

then if you are right i must have a bad supercharger.....but all i know is there was 3 different gm techs that told me if the cat was plugged then i would loose boost pressure and sure enough it is plugged...but if that doesnt fix it i dont know what else it would be ive been up and down and the only other thing i could think of is that something is internally wrong with the blower

 

maybe it has always been plugged so u were used to the higher boost. then it cleared itself out a little so the boost dropped a little. that would solve both sides would be right. boost did go down but it is still clogged up???


maybe???? its my shot in the dark answer.

 

2 questions here...why the hell are you runnin that 2.8 again on that gm tune? How many diff ppl have to tell you its a bad idea? Next question is, when you got the new engine, did they also replace the blower or is it the one off the other engine? This is definately not a cat issue unless your cat got clogged and all of the catalyst got blown out your tailpipe essentially giving you a catless dp.

 

no on both engines it ran the higher boost.....and yes its clogged...and yes they replaced the blower...and now it is barely running 15psi.......

 

I'm tellin ya, if the cat is clogged, its gonna raise ur boost pressures to more than the gauge can even read since you were at 18 psi in the first place. You've got to have a boost leak somewhere or ur getting belt slip. If the new cat doesn't fix this problem, I would replace the belt since its the next cheapest thing to do. Then, if that doesn't fix it, start lookin for a boost leak.

 

well thats just it the first thing is i went for a boost leak....and its fine there is not a leak anywhere in the system.....cause even i didnt believe the exhaust thing when i heard it.....but then when explained made perfect sense

 

just run it open headers

 

just to help with the bleeding of the laminova system there is a bolt on the top left of the stock h/e if you are looking down at it from above. open that up and start filling the site glass. this will help you alot.

 

They cant be more wrong. Higher boost levels are a good indication of a plugged cat