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-   -   DISABLED WASTEGATE (https://www.gmforum.com/forced-induction-105/disabled-wastegate-190778/)

07-23-2003 09:07 PM

DISABLED WASTEGATE
 
out of curiosity, i removed the vac hose on the wastegate actuator sunday just to see how it would do. it worked great. im going to the track sat. and gonna try it there too. i have an autometer boost gauge in the car and when i nailed it, i got 17 psi. :shock: i was soo shocked. im gonna coat my tires with pro blend tire treatment for this weekend. i tried it out in front of my house without the treatment and with the vac line off, i had the TC on and it blew right past it. smoking the tires. i also just installed a MSD DIS 4 system too. next will be the boost retard box and the programer so i can take some timing out for the launch and then have it come back in.

dbtk2 07-23-2003 10:37 PM

So your not worried about the fact that you are probably getting massive knock retard, and are risking blowing up your engine? Just making sure. If you want to run 17psi boost effectively you will need a bigger blower, an intercooler, a really good exhaust system headers and all, and a lot of nice internal engine mods. But anyways, have fun with your 17psi!!!

zzzzzeke 07-23-2003 10:40 PM

hmmmmm, sounds like jeffrey just got shut down :wink:

07-24-2003 06:45 AM

well ........ our stock SC motors come with alot of internal goodies already. im running almost 15 psi now at WOT . this is a race only mod also.as far as knock retard, our pcm takes care of that, plus i have 3 heat ranges colder in plugs, a water/alcohol injection system, a cold air intake, running 115 oct. race fuel when im at the track, and to top it all of, my TB. CAI, and air filter is completely insulated from the heat from the engine compartment. if you look at the aftermarket roots style superchargers, they dont have a wastegate at all. and last but not least, i can richen or lean out my A/F ratio with my mini AFC 2.0 within the entire air flow range. also i do pull and read my plugs after EVERY run that i make to see if there are any signs of detonation and ice my SC down before every run too. i have my DIS4 system set up to take 3* of timing out starting at 5000 rpm's too.
with a series 1 motor, we are limited to what aftermarket HP we can get daddy to buy so we can borrow his car for the weekend if we mow the grass. im trying just about anything i can think of to gain HP before i go the next step and add a nitrous system, a boost retard box, and a window switch to activate the nitrous :wink:

zzzzzeke 07-24-2003 05:10 PM

i was just playin' jeffrey :wink:
you seem to know what's going on :D

07-24-2003 07:16 PM

after doing a little research on the wastegate on our cars, here is what i found out.
the wastegate is used to do 3 functions.

1) to limit boost using the pcm and the boost control sol.
2) to reduce noise at cruising speed and at idle
3) to reduce paracitic draw when boost is not needed to improve fuel economy

first , i already disabled my boost control sol. long ago
second, myself , i really love the whine of the SC coming alive :wink:
and third, if i was concerned about fuel economy, i wouldnt be racing it. and spending $4.50/ gal for race fuel to do it.

zekkke, i know you were just funning, my goal is to get a series 1 in the 13's without nitrous{ im hoping}

dbtk2 07-24-2003 07:29 PM


well ........ our stock SC motors come with alot of internal goodies already. im running almost 15 psi now at WOT . this is a race only mod also.as far as knock retard, our pcm takes care of that, plus i have 3 heat ranges colder in plugs, a water/alcohol injection system, a cold air intake, running 115 oct. race fuel when im at the track, and to top it all of, my TB. CAI, and air filter is completely insulated from the heat from the engine compartment. if you look at the aftermarket roots style superchargers, they dont have a wastegate at all. and last but not least, i can richen or lean out my A/F ratio with my mini AFC 2.0 within the entire air flow range. also i do pull and read my plugs after EVERY run that i make to see if there are any signs of detonation and ice my SC down before every run too. i have my DIS4 system set up to take 3* of timing out starting at 5000 rpm's too.
The stock SC motors come with stronger crank, rods, and pistons, the engines really aren't all that much stronger, and the things that were strengthened didn't need to be. The heads still suck, the pistons still aren't that great and with too much boost will break, and that is the Series II, I don't even know how much stronger that is than the Series I. With the GTP we are running 14.96psi at WOT on race gas with an Intercooler, Headers and Full Exhaust, High Ratio Rocker Arms, Intense Pushrods, Comp Cams 85lb. Valvesprings, and a lot of other goodies, besides the fact that it has the M90 insted of the M62 (or whatever it is) so it is much more efficient anyways. We only run 14.3psi boost on the street. Any more boost and we would have major problems even on the Series II with some built up valvetrain parts. The guys running 11's are only running around 12psi boost, so our 15psi is stretching it even. Yes, the pcm takes care of the knock, but it does it by pulling a bunch of timing so you lose power by raising your boost, so what is really the point, besides the fact that if it starts seeing big problems it uses the wastegate to drop the boost so the engine doesn't blow up, so you are ridding of a major safety device the factory installed. The 3 range colder plugs may be helping you a little, but we have 2 range cooler in the GTP so its not much of a difference, and yes you have a water/alcohol injection system, but those aren't nearly as effective as an Intercooler, which the GTP has, so this doesn't give you any advantage that would allow you to run more boost than we do. Our CAI, and the air tube are completely insulated also, so its not like that is giving you an advantage either. You don't really have any systems that are helping you run that much boost, yeah you can run that boost for a while, and it MAY give you better performance depending, but in the long run you will end up replacing pistons, valves, head gaskets, and things like that, and the M62 is SO inefficient at 17psi that you may not even be making more power than the 15psi or whatever you usually run.

But it is your car, do whatever you want to it, I'm not gonna stop you.

07-24-2003 08:04 PM

stock Sc motors come with forged steel rods, steel crank and forged pistons. i have 110 lb vlave springs installed too. the water alcohol injection also cools the intake charge plus helps with detonation by absorbing the heat in the cylinders.

willwren 07-24-2003 08:57 PM

dbtk2, the only REAL difference between the M90 and the M62 is the CFM rating. At 90CFM per revolution, the M90 on your Dad's car doesn't have to spin at the same rpm level as the M62 to produce the same boost. This means that the M62 produces more heat because it has to spin faster. How much more heat? Beats me, but we could probably do a comparison between them sometime.

So the M62 has a smaller pulley to fill the greedy cylinders, where the M90 doesn't need to spin that fast.

Both are over-capable of supplying the L67.

As far as water alcohol injection is concerned, I'd love to see an effieciency comparison between one and an intercooler. The injection has added benefits that the intercooler can't provide, but I'm sure the intercooler is more efficient at cooling the intake charge.

As a point of comparison, my water alcohol injection gave me an additional 2 psi of boost with the stock pulley last summer. How much boost did you gain when you installed it on the GTP? That might be a starting point for the comparison. BTW, that was WITHOUT alcohol. Just water injection.

Jeffrey, how much boost difference do you see, and what ratio are you running in the mix?

07-24-2003 09:09 PM

im running 50% distilled water and 50% methanol. i have seen no gains in boost pressure with the W/A injection but it does elim. detonation conciderably. also when i make a run at the track, my engine is cold, the SC is iced down between rounds, and i add ice to my washer bottle to get the water/alcohol mixure as cold as i can, plus all the incoming air is through the opening where the left front headlight was. the air box and intake tube is fully insulated. just by doing the insulation, it cut my intake air temp by 40* .
there is absolutely NO air going into the TB from the engine bay. all is from outside the car and i also made a heat shield for the TB to protect it from the crossover pipe.
i did raise the pressure switch that the water/alcohol injection kicks on, i have it set at 10 psi now. so at 10 psi and about, the injection turns on and fogs the intake charge through a NOS dry fogger nozzle with a .016" jet in it


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