Wassup fellas, I am pulling my 396 out for some new pistons...I had blo-by issues with the motor from the 1st time I ever even started it up..I bought the shortblock used off this site..from Andrew Coats.

Anyway..the motor did have some good parts in it from what I seen..the seller just didnt share that it needed rings, but thats another story.

It currently has -5cc dish pistons in it, I ended up installing LE3 heads/intake/cam set-up on it with assoiciated supporting mods and a full Nitro Daves system with the LT1 58mm plate, Racetronix kit 42lb injectors etc.. so the car is 12:1 but now that I have this kit i was going to order dished pieces to get compression down to the 10.5:1 range..I am ordering pistons anyway...kinda why I got the kit.

Now that I am pulling the motor and I plan to upgrade to a set of Diamond pistons, I ended up running across a Vortech supercharger kit (this is an Impala SS by the way) It is a T-trim that came off a car that utilized the blower for about 2 years, it is intercooled (aftercooled) and everything but I have questions about the attached pic I am enclosing here

#1 the brass fitting that is going into the intake pipe connects to what is a blow off valve from what it looks like in the pic? (I am asking) And if that is the case here..why were they feeding the blo-off valve BACK into the intake and can I change this without adverse results, this looks like a basic blo-off valve (if thats what it is) but I dont know for sure.

#2 I plan to remove the Crankcase Evac kit from my car, you guys that are running 10-12lbs of boost...how are you venting crankase (besides vac pump) does the "suck side" of the blower have enough vacuum to evac the crankcase.

#3 Do you guys have to change out MAP sensor, I heard of one available that reads a wider range of vac and pressure is this true?

#4 I plan to keep the nitrous on the car, this kit utilizes and FMU, from all my reading here, it looks like this piece is normally NOT utilized and the FI cars respond better to tuning and more injector (I have 42lb SVO's will they suffice?)

#5 Should I leave well enough alone and stay 12:1 and keep the Nitrous jetted up, would like to hit 650rwhp..car hit 524rwhp..cant remember torque with the blo-by infested set-up on a 175 shot and a mailorder tune with a built 4l60E.

In this pic I am trying to figure if that brass fitting that connects to that rubber hose is just blo-off valve entry?

Thanks

 

1) Yes it looks like a blow off valve. When you close the throttle quickly it gives the air (boost) somewhere to go. Without it, airflow would instantly stop and backfeed through the compressor wheel to the lower atmospheric pressure. Surging your supercharger can break parts.

The air has already been metered by your MAF sensor and therefore fuel has been added accordingly. If this air isn't recirculated and rather vented to atmosphere, you're going to run super rich. (Unless you're running a speed density tune as opposed to using the MAF sensor.)

2) There is no 'vacuum' at the suck side of the compressor.
There would be IF your air filter was a large restriction (which obviously it shouldn't be). The air is drawn out and replaced by atmospheric pressure just as fast, no vacuum can be created without some sort of restriction. Now technically I shouldn't say NO vacuum, as you might see up to an inch of vac. But contrary to popular belief there is not significant vacuum, those of you who do not believe me, go get a vac gauge and try it. It's a very small amount, but anything is better than nothing.

3) You can use a stock MAP sensor, but your PCM will not be able to read boost. You'll have to tune accordingly to be safe at the highest expected boost level. You can use a 2 bar sensor and make a 2 bar tune thought. Theres a stickied thread covering this in the Tuning forum.

4) Suffice for what?

5) If you plan on running 10-12psi of boost, you'll want a compression ratio of roughly 9:1 to 10:1.

 

Thanks for the reply....I was asking in question #4 would the 42lb injectors suffice or be ample enough for 10-12lbs of boost.

Boost is something I have not tried yet, I have 2 nitrous 355's a Nitroused 383 and my now pesent nitroused 396...I have never really poked my head in the forced induction forums on this board or the Impala SS board....and I have been a member of both for 5+ years.....guess I will be tuning in here more often.

Thanks

 

no, I'd get 60's.

 

i agree. I'm running 12-14 lbs on my 406 and I have 65 lbs injectors running 85% duty cycle.

 

I just looked through your car domain, amazing third gen!!!

Also yes go with 60s they are easy to control on a stock pcm also.

Jay

 

Thanks for the advice..yeah...Getting the Mototron flow matched 60's and the Kenne-Bell "Boost-A-Pump" on order...right after I get off here.

 

Where are you buying the injectors and for how much? I need me some too.

 

There is a vendor on Ebay...doing the flow matched Mototrons for $369...forgot their name though, juss type on Mototron in the search. I hardly ever do the the ebay thing..but just thought I would try it cause I picked up my F.A.S.T dual wideband from "Speedtweakers" on there brand new in box for $395 shipped...so juss gave it a try with the Mototrons, and they are cheaper than what a few vendors have them listed at....but it looks like the place that sells them on ebay is a vendor here as well.

 

My app is a 97ss 383 lt1 (all forged, 9.5:1 compression) D1 procharged MM6 camaro. It pulls 12 to 14psi. I adapted a gzms vac pump to pull a 1/3 atm crankcase vac. It really helped ring seal and blo-by reduction. Quite a added level in performance. I have some pics if you like... http://s306.photobucket.com/albums/n...p%204th%20gen/
It has work good for 2+ years and street driven. I had to design my own air receiver and oil feed back circuit for vane lube, and regulator. Also vac pump mount/ drive is on the right side motor compartment rail. There is no oil ingestion thru the blower or intake manfold. I have tried many of the vac mods on the pcv system, but, was not satisfied with the result.
Hope this helps. B.

 

That Is sweet man.....very nice work, thanks