I have been looking at different ways to reduce the "inake restrictions on my set-up. I'm contemplating installing a Granetelli MAF in place of my stock piece, since Rich K stated that boosted cars are extremely sensitive to intake restrictions.

Are the Granetelli's calibrated differently for the increased airflow, or are they just "snakeoil"?

The end to my means is attempting to increase boost without additional stress on the S/C, thus generating more heat.

P.S. I'm at 4500 feet above sea level and only seeing 4 lbs of boost on the stock set-up.

VR,
JD

 

AFAIK, the GMAF comes with recalibrated MAF sensor that normally will run a little richer than stock while a ported MAF will run a little leaner. Many people are saying that the stock MAF is good to upward of 500hp. I did ported my MAF though.

I doubt if the MAF ends are your problems or only problem in giving you only 4#. 4# at what rpm?

What trim of Vortech SC do you have? What pulley combinations are you using?

What size is your motor?
When I was running 6" and 3.125" on the 350, I saw 10# with my S-trim. But when I went to the 396, AFR heads opened up more, and a different cam, the boost droped to 6#.

You should also checked to see if your bypass valve is leaking. Are you still using the dryer hose intake tube, then you may consider getting a Brad Brand Hard intake tubing, which may be good to give 2# by some people. Is your boost guage vacuum source good?

good luck

 

I'm only seeing 4lbs because i'm at 4500 ft above sea level. For every 2000 ft in elevation, you lose one pound of boost. I'm running the S-trim set-up and all is functioning correctly. the motor is stock displacement with massaged LT1 heads.

My objective is to get the boost back up to 6 #'s without changing the pulleys (if possible). I haven't done anything with the set up yet, nor have I replaced the dryer hose (looking at fabbing up my own). I still am skeptical over whether or not that one foot of "Dryer" hose is the restriction as i've heard. The "Brad Band" tube is over $200 and on a six month back order.

 

The dryer hose is a big restriction on every supercharged car... Don't underestimate its effects... I mean it can look all nice and peachy but when you nail it that thing sucks in fast and you can't be under the car to see it... Power pipe and bigger filter would be the first 2 things I would do.

 

That make sense to me now. I didn't even think of it collapsing. Again, the fabled Brad band pipe seems a little overpriced, anyone fab one up themselves and have dimensions/ parts list?


I already ahve a K&N on the set-up; Do you recommend something different?

Thanks in advance,
JD

 

What Omar means is a bigger air filter. There are some people who are using a 9 inch or even a 11 inch air filter and found that they have gotten more boost. I am still using the 6 inch at the moment that comes with the kit. I would definitely go to the bigger when I have a chance.

good luck

--Hugh

 

Well im runing 13psi@6300 (Miami 2ft maybe) with the dryer tube and have had no problems. Im going to lower my rev limiter to 6000 so i have less boost. I dont think your problem is there or in the air filter. 6psi on a S-trim is nothing. Do you have black dust around the blower? What size are the pullies?????

 

It's a stock S-Trim. I know why i'm only getting 6#'s; i'm at 4500 feet above sea level. for every 2000 ft of altitude increase, you'll loose 1# of boost.

I'm just trying to get it back up to 6#'s without spinning the blower any faster (more heat). If I can't get it back up to 6#'s by changing to the GMAF, swapping out the Dryer hose and filter, i'll have no choise but to go with a different pulley set-up.

 

I have the same s-trim on my 96Z28. and I also only see about 4-5# of boost. Sick puppy- have you had any problems with using a 100 shot of nitrous?? I went the aftercooler route, and it made a huge difference in IAT temps. I would also like to add a few psi to get back where we would be a sea level.. why dont you want to change pulleys? because of the warranty or something? btw I live up in Plain City ut... like 20 min away from roy.