ncrowe

New procharger installed - when under boost it sounds like my grand national - normal? sounds like a turbo spooling up - I have the factory airbox on the car

ALso, a few times when I am accelerating the car jerks - hard to explain, but my first thought was I was not pushing the accelerator pedal (maybe I was a little light on the throttle) and the car would feel as though its coming out of boost quickly and jerk - but I don't hear the blow off valve when it happens......

I was reading another post about a boost leak - maybe?

What can I do to check to make sure no boost leak, etc?

I did adjust the throttle boost with my diablo tuner that came with the kit to 10% maybe I should go all the way to 20% (thats the way I had it before the install of the procharger)

FYREANT

To check for boost leak you need to make a boost leak tester. Heres a link to the one I made when I had my Evo IX. Basically, build it, connect it, pressurize it, see if pressure drops. If so, listen for a hissing sound, tighten clamps, repeat.

http://www.evolutionm.net/forums/evo...er-5-02-a.html

robertf97

That is a really cool idea on the boost leak tester, thanks for posting.

RpeterK

If you were to have a leak I highly doubt that it would be something that would cause the car to jerk. It is going to be something subtle and also pretty consistent.
If you decide to do a pressure test then I would also remove and cap the charge tube going to the throttle body. There is no sense in stressing it and it may not be completely closed anyway as the blades are usually adjusted slightly open to prevent them from sticking.

You probably have certain parameters that are not adjusted correctly that cause this to happen under the right circumstances. Make sure your vacuum line going to the blow off is kink free and if all the clamps are tight on your ducting you should be good and not need to pressure test.

runutzzzzz

I'd suggest you call ProChargers Tech Support team. They are a great group of people there.

robertf97

Did you get helical or straight cut gears?

ncrowe

Helical - nice and quiet

Turbo C5

I also have the Procharger on my car and I have noticed a similar condition on my car. It only happens at a particular throttle position and rpm. Approximately 3/4 throttle and 4500 rpm. Never at full throttle, or any other position.

Turbo C5

I also have the Procharger on my car and I have noticed a similar condition on my car. It only happens at a particular throttle position and rpm. Approximately 3/4 throttle and 4500 rpm. Never at full throttle, or any other position. To me it seems more like something in the tune than dropping off boost. Do you have the stock tune?

0vividracing

Was there any resolution with this? Interested to hear the problem since it seemed common with a few people here.

Ben@WeaponX

are you guys running the atmosphere vented race valves? the red valve has a set screw on it to adjust the opening/closing. i'm guessing you're reaching the point where the valve shuts to force ALL of the air into the IC and engine and that is what you're feeling

3 Z06ZR1

Mine with an A&A kit did the same thing for a bit and then straightened
out on it's own. The throttle is dumping closed for some reason.

0ProChargerTech

First and foremost.... if you load the 10% throttle tune thats in the Diablo, it will mess with the TQ tables that we have programmed into the car. And can cause very bad throttle results...likely the root cause of your "jerk". Do not add anymore percentage, or you could end up with a run-away like condition in a parking lot.

That throttle "boost" is already built into our tuning, to match the airflow and TQ of the blower.

Ideally, just leave the tune as it came from us. There should be no reason to modify it. There are hundereds of Dyno pulls, days of road corse testing, track testing, and many many BETA cars to develop that tune.

FYREANT

It is my understanding based on what i have read on this forum that your bundled tune is rather conservative. That being said, it may not be ideal for those looking for a more aggressive tune. Thats my .02 though..

0ProChargerTech

Its as aggressive as we can make it, taking in account the variation of fuel quality across the US. So if your in California it would be considered VERY aggressive, but if you are in a place that has high quality 93, then it might be a little conservative.

However what I can say is, its crazy the number of people running the "stock" tune that we send. (Even lots of very well known big name shops) since it flat out works great, and is very repeatable. (Much like dodge kits)

We know of some supercharger companies that send out the tunes with VERY soft settings, that can leave 50-60HP on the table. THAT is not the case with ours, we want customers to get the best bang for the buck, and spent a good deal of time getting it there.

You can always run the stock tune, and then if you want to have a shop custom tune it to see if they can get a bit more out of it, you can since its not locked, or hidden in anyway.

Translator

I was under the impression that you all had two different tunes; one for 91 octane, and one for 93 octane; depending upon the state? Is this not the case? By your post, it appears like your tune is identical, regardless if shipping to 91 or 93 octane states?

0ProChargerTech

We have one tune, inside the programer its labeled "ProCharger"

If a person is installing a tune labeled 91 octane, or 93 octane, that is NOT a tune to be used with a supercharger, and that is just the generic Diablo tune that comes in the programmer for a stock C7. If any tune is installed other then the one labeled "ProCharger" that would be disaster for the engine.

Just like GM sends all C7's out with the same tune, no matter what state you live in, we do the same. Tuning for specific fuels to maximize power potential is up the customer and a shop. But as stated, there really isn't "that much" to be found.

FYREANT

I'm in southwest Florida and I like to think I get pretty good 93 octane gas here. Don't get me wrong, my planned mod list does include a line item specifically for "ProCharger" as I love your all in one package, but I do think it would be prudent to offer an option to use a 93 octane specific tune directly offered from ProCharger. I guess I would consider that to be like the last 5% of a perfect setup.

mkr1966

I'm with you. We have Shell 93 in Iowa with no alcohol and would like also to have Procharger do a tune for that fuel with the Supercharger.

0ProChargerTech

The suggestion to both of you, is run it with the supplied tune.
I think you might be pleasantly surprised.
We used 93 with no ethanal when testing our supplied tune.

Sure a guy could add a degree or two of timing while on the Dyno.
And "maybe" sneak a couple more HP out of it. However we wouldn't suggest leaving it like that, since we all know how much harder a car can get loaded on the street then a dyno.

Our tune wasn't just Dyno tested, not just street tested, but also spent hours and multiple days on a road course at WOT. That way we could ensure the safest, and most powerful tune possible.

Due to C.A.R.B. reasons, and other factors us (as well as others) will only have one tune supplied.