does anyone in here with stage 4 get over 9psi of boost?

 

I don't think you will hit over 9psi with stage 4.
And with this particular blower, 8-9psi is already pushing the limits of it's efficiency. At this point and at higher boost, heat soak becomes the issue. Most people with the SVT SC mustangs swap to a kenne bell unit. Their blower is not the exact same as the stillen, but fairly close in size and efficiency. If you combat the heat soak associated with higher boost, then putting a new pulley and going more boost is ok. But this blower is peaking at 8-9psi.

 

I would be happy with a solid 8psi.

Did anyone say they were getting over 8?

 

I was reading over 8psi, but my gauge ended up to be tweaked. I swapped it out since then, and hit 8psi on my kit.

 

nice, which boost gauge are you running? I would like to get one installed before I do stage 4 so I can see what I hit before and after. I was just thinking about getting a single a-pillar pod or one of those cf pods that goes on the dash and maybe a 20psi auto meter gauge.

 

I have defi d boost gauge...I was told by the installer who test drove my car that I'm close to 10psi....so do you think that something wrong with the gauge and Stillen stage4 cannot get over 9psi....I remember someone (I think Stillen rep) mentioned that people could be seen 8.5~9.5 psi (I could be wrong)...ofcourse I want moore boost but being safe is always been my priority

 

I was running an autometer, but i have a Greddy electric now.

 

I just went & test drove the car....awesome pull ...powerband is all the way til 6.5~7K rpm.... very very happy with the kit. I was getting above 9psi on my boost gauge .....and a little louder from stage 3

 

RELIABILITY AS GOOD AS STOCK. the stillen Sc is very well designed to last , all the components involved are heavy dury components, and the way it is designed will ensure long lasting operation. I'll give you very small examples: compare with Vortech, in Stillen the blower is right on top of the engine which means no leakage is possible, also unlike Vortech , the belt is pulling vertically on the blower that is closely attached to the engine block forming a compact block, however in Vortech the belt is pulling to the side causing an uneven balance of the engine, perhaps this is nothing , but in the long run i think it is bound to cause problems. This is just my opinion on some simple mechanical issues maybe i am wrong.

 

Could be a faulty boost guage (I have an autometer), but I've got a stillen stage 4 sc and am consistently hitting 10psi at WOT. When I first had the Stage 4 installed I was only hitting ~6psi. My fuel pump went out shortly after the install and since having the new one installed I've been up at 10psi.

By the way, I had my Z dyno'd with the Stage 4 about a month ago on a dynapak. I posted 307 HP and 300 TQ. should point out that I live in Denver, so the altitude kills my #'s. I would expect you'd see much better in most places.

 

any idea what 307 at your level equates to at sea level? I have no clue what math formula to follow to figure that out, otherwise I would do it.

Also- Is your autometer mechanical or electrical?

 

with stage3, I rarely got up to 7 at WOT but with stage4, I'm close to 10psi...will get it dynoed soon...but I think dynapak read about 10% lower than dynojet so you're about 333whp which about right...one other member is getting 343

 

Actually, my first post had an error. The #'s I referenced were from a dynojet not dynapak. I also dyno'd before the fuel pump went out on a Mustang dyno. don''t have the #'s in front of me, but they were close to 294HP and 287 TQ. Unfortunately, I don't know the correction to estimate what my #'s would be at sea level. I'm assuming that I'd be in the range of ~330 HP based on what others have said??

Also my boost guage is mechanical, not electrical.

 

Glad to see you are getting over 6 psi boost now. I would love to see your new numbers with the extra 4psi!

The 307 on the Dynojet was corrected to sea level. You basically have to take 17% off of that number to get actual power to the wheels at 6000' msl for denver. The dynojet showed the uncorrected numbers at 255 rwhp. The stock Z's that day were getting 233 rwhp corrected for sea level, and 190 - 195 uncorrected rwhp.

I would imagine you would see at least 330 - 340 with the extra boost corrected for sea level(280 uncorrected). We basically lose 2.5 - 3.0 psi up at this altitude. It stinks, basically 30% of the FI boost gets used up just getting our cars to sea level performance.

 

I was making about 8.2-8.3psi with the stage 4 kit then I added Kinetix high flow cats and lost just about 0.8psi. I am thinking about selling the kit but if I don't I am going to have a new pulley made to get that boost back.

 

That does suck. I live in Phoenix (1100ft) but drive up to Prescott a lot which is about the altitude of Denver (5300) and I loose ~3psi of boost. It is amazing how slow my car feels up there but at least everyone's cars are slower up there.

 

The Cobra and Lightning blower is almost twice the displacement. M112. It is very typical to have the blower ported and taken to 16-17psi. Now I run a Whipple 2.3L @ 20PSI.

-Mark

 

Stillen now supplies an itty bitty spacer that angles the idler pulley. So far no squeeks.

 

Hmm... thats good to know. Shortly after I reinstalled a stock sized belt I got some slip over 5000 rpms im assuming because the belt was broken in, stillen told me to anticipate that and so I just got back under the car, tightened it down and havent had anymore slip since. If I ever to get it again I may call stillen and ask for that spacer and then reinstall the idler pulley.

btw- any way to get a better belt than the gates k040220 for the actual blower.... seems like ive been tearing through a new one every 6-9k miles. Guy at one of the shops said its due to the pressure put on that belt in conjunction with the extreme heat under the hood from the blower.

 

In the procharger world (FI C5), the gatorback belts are not good. I either get Gates or NAPA. They slip less and last the longest.

Good to hear nice things about Stillen. I'm looking for usable power the roots blower gives.