***Boost Gauge Update****
I hooked up the boost gauge today. I did several 2nd gear roll ons from about 2k RPM. From about 2-3k RPM there is little to no boost maybe 1-2lbs max. Around 4500 rpm i only saw maybe 3-4psi. From about 4500 to 5500 it got up into the 5-6 range and around 6000 rpm i did see 7psi. This is all with the bpv still hooked up. Tomorrow i am going to cap it off and see what happens. I'll let you guys know. I was kind of hoping to see it hit 7psi around 4k and pull the rest of the way.. i guess i'm not expert though.. maybe thats just the way these superchargers build boost with the pulleys.. gradual increase and max boost is attained at max rpm? Anyone else have any ideas?
****** Update *********


So i got the supercharger installed on friday. Pics first i suppose, then i'll give my impression.





So to be honest, my initial impression was.. "hmmm" Could of just been because of the hype and the talk on the boards about how some people say its crazy.. but i would tell anyone that is getting it not to expect some huge power boost feeling. Stock the car felt pretty torquey up to around 4.5rpm then it kinda dies off.. now it just feels like it continues to pull that hard the rest of the way up. The tires will break loose in first gear from a slow start roll on.. thats pretty cool haha.. i do have 18's on there though which may be a tad harder to spin.

The rubber hoses that they use for intake plumbing are extremely flexible and bendy.. you can pretty much squeeze them with your hands and pinch them shut.. under boost i'd imagine they ballooning up and we are probably loosing psi that way.. which may explain why someone said they only saw 5psi on their boost gauge. I think a hard pipe kit would help in that area.

Overall i'm still very very pleased and definately think its worth it.. my car is completely stock other than the kit, and the kit was designed to be pretty modest.. but more importantly is the potential now that is available... that is what really makes it worth it.. to me atleast I am going to drive around for a couple weeks and then dyno it.

 

Cool man. I do suspect a leaky air bypass valve "the one everyone complains about" if you or they are only seeing 5 psi.

 

Do you know where ZPI capped it off at to help that? there is a small hose coming off the top that goes to a T-splitter and then 2 larger hoses connecting to it. Maybe i'll try capping it to see if it responds better. I'll probably try to pick up a boost gauge this week.

 

I think they plugged the whole thing off and eliminated it. The line or lines going back to the intake tract before the throttle body, try pinching them shut with say a clamp and see if anything changes feel wise...

 

nice man. Cant decide anymore to go turbo or SC.

 

congrats on your purchase man I would suggest getting your boost gauge first before attempting the bypass valve "mod" to see if there is a difference in measured boost.

 

I bought a boost gauge today, i'll get it installed tomorrow and keep everyone posted on how she boosts.

 

cool.

 

Updated some boost gauge info in original post.

 

post a pic of the installed boost gauge

 

Sounds like a boost leak. The cool part is when we go to smaller pullies, the whole rpm band will be helped with this type of sc! Every psi added at redline will be a psi across the whole band at every rpm.

 

Zoltiz had simular results with the boost coming on late like that.. except he said he only saw 5psi max. I wish i knew how it was "supposed" to boost.. when max psi is supposed to be attained and such. does ZPI have any insight here? I was under the impression that superchargers werent supposed to have lag?

 

It is not "lag" Psi is totally RPM dependant on a vortech.

For example...

5000 rpm will always be = X boost. "can vary a little with vvti"

3000 rpm will always be = X boost.

Anyways change the pulley and psi across the whole band changes. That is why a pulley change will be such a critical mod. If you change it up to say 10 psi at redline "3-4 psi more total boost" then at 3K rpm you should have close to the same increase if not a little more.

 

Ahh i see.. Thanks for clearing that up. I've always been around people with turbo's, these superchargers are a new ball park for me Why do you think it doesn't create any boost or such low boost all the way to 4000rpm? That why you're saying you think there is a boost leak? But then that might not explain why it is able to reach 7psi at 6000 rpm.. would think that it would leak up top. hmmmmmm

 

Does not seem like a leak if you can hit full boost at redline. But vortechs just respond like this. If they came out with a roots type blower you would have boost instantly at almost any rpm but they are a pain in the **** overall and I have not had any good luck at all pushing roots blowers. Hell I tore through around 4 eaton m62's on my last test engine. Damn things just were problematic. Vortechs have proven to be great blowers reliability wise when pushed close to there limits. So I am very happy trd used one!

 

You are only talking about 50hp more. I understand that 50 at the wheels is a nice little change but you are comparing this supercharger to turbos that are putting out 100+hp easily. Most of them are putting out 120+whp. I honestly dont know what i want to do yet. I think im gonna get the dextra exhaust and header when it comes out and see what happens w/ the supercharger and turbo game next year.

 

Actually zpi's so called test showed 212 whp. Bone stock the tc runs about 145-150 whp. So we are looking at a 67hp change with an intake on the sc which is about right. Just under 10hp per psi. Knowing that, at 10 psi we should be at 240-250 whp with the sc. At at 10psi knowing how a vortech works, the whole powerband will be sick! What allot of people fail to realize also is that the sc will net instant boost when transitioning from on off throttle changes. Examples are auto cross, short track racing, heavy cornering in general. That is why I prefer a sc hands down when it comes to my personal style of driving. If the gentleman above was only seeing say 2 psi at 3500 rpm then with a pulley change and say an abv change he should be at 5-6 psi at 3500rpm. Hit the gas at 3500 while crusing off boost and response will be instant.

 

I'm not too familiar with the TRD kit just yet, but superchargers in general do not reach FULL boost till later in the RPM band and sometimes not even until you reach the higher gears. When people talk about SCs having less lag, or no lag, compared to turbos that does not necessarily mean that you will see FULL boost at 2000RPM.

Long story short, you are seeing 7psi which is good. We just need to wait a bit longer and see where most people actually see full boost levels

 

Gears do not matter to any supercharger I have ever run, and I have used pretty much all of them! Engine rpm vs sc rpm is all that matters and the style of blower. With a proper sc setup, there is NO LAG. X amount of engine RPM will always = x amount of boost. If you get 5 psi from it at say 3K rpm, then it will give you instant boost of 5psi at 3K rpm period every time you nail the throttle. That is just the way they act. Other things can have effect such as the position of the intake cam or ex cam depending on the engine vvti, vtec etc..., intake temp, headwork etc can also play a roll in total boost....

Full or total boost is as always rpm / efficiency range dependant with a supercharger. All this talk of lag / spool up on superchargers is getting funny on this forum.

 

The TRD kit doesn't reach full boost 'til later in the rpm, roots and twin screw type get full boost at LOW rpm. So, to say in general that s/c's don't make boost 'til "later in the RPM" is not right.....Centrifugal s/c's do that, not the other two types. And, "sometimes not until higher gears"??? Do you know how a s/c works??? The impeller is turned by the PULLEY that is connected to the CRANK PULLEY by a BELT. Therefore "gears" have NOTHING to do when the boost comes on, boost is determined by pulley size and engine rpm.....it may FEEL different in different gears depending on the gear ratio of that gear and the final gear ratio.....but boost is the same. Talk to some '03 and up cobra, lightning, and cobalt SS drivers and ask when there boost comes in.....you might be surprised when the boost hits on those eaton's.