Im running a vortech v1 Si trim and its close to maxing out and im only seeing 10 lbs of boost with my setup shifting at 6300.

motor is a 355 with cnc ported heads custom blower cam.No intercooler.My crank is 6.5 with a 2.75 pulley.I was expecting around 12-14 psi with this combo but im peaking at 10lbs.

.My new combo thats going on the car is giong to have advanced induction 200cc heads and ported intake manifold with a monoblade with methonal injection.Now that more cfms are going to be pushed threw the motor am i only going to see around 8 lbs or will my car stay at 10lbs of boost sense im adding a monoblade and methonal?

Would it be worth shifting at 6100 and getting 2.50 pulley witch is the smallest one available?

Im looking for more boost.

Any input is appreciated thanks!

 

How is the intake for the inlet setup, maybe restricted? According to your current setup, your spinning the blower to 51373rpm at 6300 redline. New setup of 6.5crank/2.5blower/6100rpm will spin to 54717rpm, should net a little more boost. Bearings are rated to 55000, so your getting close to the limit. Bigger heads and porting intake are going to drop it down, not sure how much. Also, i've notice outside temp/humidity can make a significant (2-3psi) difference.

 

I thought it was the inlet tube also so i removed it and still peakd at 11lbs.I bring my car to 6400 rpms to shift so my blower rpms are at 52189.09.With the 2.50 and me shifting at 64 id at 57408.You think its b worth shifting around 61 so i can get more boost out of the blower?or should i just stick with the current set up so i can rev a little higher?

 

Mine's setup to make more boost at lower rpm. I'm shifting at 6k. Then again, i'm still on the stock motor and no reason to spin it higher.

 

I've been trying to get 600rwhp for some time now,this is a 396 lt1 with everything to do the job.This is with procharger disc,the camaro made 563rwhp,so we on hooked the exhaust from the longtube headers and we lost power.So Bret the tuner guy said lets on hook the intake from the blower and try that, so we did and the power went to 630,boost went from 12psi to 17psi and we didn,t even tune it for the extra boost,will do the tuning in the spring,
me and the wife are in Florida for the winter,to cold home.
The procharger intake is quite restricted.Hope this might help.

 

Yep, always remember boost/psi can be thought of as a meassure of restriction. If the blower is pushing the same volume of air into less restriction then boost goes down. Doesn't mean that power goes down, we hope it goes up even with less boost.

You need to spin the motor to where the cam makes peak power. Granted with a belt driven turbo it makes more power the higher you spin it too. Better flowing head/intake/tb will shift your power band higher too. I would say either spin the hell out of the blower or start saving for a bigger one

I would do the 2.5 pulley too, but that is just me. Going a hair over 55k probably won't be an instant grenade, but there is always a chance.

 

Lets not forget guys, the faster you spin the s-trim, it becomes inefficient. I think peak efficiency is 73% or something, check the website. Past that you start generating loads of heat, which is NOT good for a non intercooled vehicle. Now i use meth injection instead, and im adding a 2nd nozzle to combat this, but be careful about maxing out an s-trim w/o cooling the charge and adjusting timing. S-trim is great blower, but I seem to have hit the same wall you have @ 10 psi on a hot day, with the 7"/2.75 combo. Im switching to a 383 and slightly larger cam, and expect to lose ~2 psi, but like jay said, loss of boost doesnt always mean loss of power, and until I can upgrade the blower, I think spinning it faster is just pointless at this stage. It is what it is, spray it with a 100 shot and have fun to the best of its abilities. It will like that, if yer bottom can hold it.

 

My blower is the si trim witch is more effient then the t trim.I just bought the snow performance stage 2 meth kit and a monoblade soo the boost should go up by a lb or 2 with a good power increase.I mite have a custom 90 degree inlet tube made to see if the spikes the boost up more.I just dont know where to get one made

 

If you find one, let me know because i'm looking for one too!

 

Check out this page, especially under timeslips:

http://www.noid.org/~lj/

Though he was running in the 9's at 140 mph with an S-trim, he did find that going from the 2.95 to the 2.75 pulley didn't gain him any boost. It doesn't say on there, but I remember him reporting 10-12 psi max.

 

I ordered this 90 degree inlet instead of getting one made.Looks like it should work greaT.And its only 20 dollers

http://www.sfxperformance.com/parts/SPT9598.htm

 

I hope it works for ya, but it looks too big like it'll hit the steering u-joint to me.

 

I have one of those elbows on my dryer. It wasn't $18 though.

 

Or the header. Let us know if it works out

 

it clears the header and u joint but has a funny angle to it so i might have to cut an inch off it to raise it a little bit to fit anouther 90 pipe on it.ill let you no how it goes