FIRST ROUND OF MODS FOR MY Z

[Can'tHave2MuchHP]

Originally Posted by incon3037r

So my final numbers are listed on the dyno sheet below. I was hoping for more, but considering my baseline was low and the blower was only making 8 psi with the 9.55 lower and running 91 octane, I don't feel too bad. I'm sure if I add a 2.75" upper, port the snout w/ along with a larger throttle body, I can pick up some additional boost and hit 650+.

You should be making 13-14 PSI of boost on that. Stock engines can make 8 PSI. Time to trouble shoot IMO. It could be something easy, check the bypass valve (Search it up on google) adjustment. Or it could be something hard, leaking supercharger.

609 RWHP is relatively easily achievable with pulleys, intake, and headers.

[incon3037r]

Originally Posted by Can'tHave2MuchHP

You should be making 13-14 PSI of boost on that. Stock engines can make 8 PSI. Time to trouble shoot IMO. It could be something easy, check the bypass valve (Search it up on google) adjustment. Or it could be something hard, leaking supercharger.

609 RWHP is relatively easily achievable with pulleys, intake, and headers.

I've seen similar numbers as mine from other members with similar modifications using a 2.55 upper which should produce around the same psi as my 9.55 lower on a stock motor.

I also thought my psi was low, but figured I lost boost from less restrictions. They list the 9.55" as making an additional 4-4.5 psi over stock, which would be around 13 psi. At the same time, I've heard headers cause you to loose 2 psi or so and with the cam, no cats, cat back and cooler intake charge, I would think I'd possibly lose another 2 psi, putting me between 8-9 psi. It probably also doesn't help that my baseline was on the low side. Had it been higher, I'm sure my final numbers would of also reflected it.

Others members also make more boost and power than I did with the use of higher octane fuel and both upper and lower pulley, such as 2.55/8.6 combination. I figure if I add a 2.85 upper to my 9.55 lower then I should hopefully be around a similar 13-14 psi, which should hopefully net me in the 650+ range on 91 octane.

I'll definitely look into the by pass adjustment, boost leaks and cam overlap to make sure I'm not losing any boost.

[JANNETTYRACING]

Originally Posted by Can'tHave2MuchHP

You should be making 13-14 PSI of boost on that. Stock engines can make 8 PSI. Time to trouble shoot IMO. It could be something easy, check the bypass valve (Search it up on google) adjustment. Or it could be something hard, leaking supercharger.

609 RWHP is relatively easily achievable with pulleys, intake, and headers.

This.

Originally Posted by incon3037r

I've seen similar numbers as mine from other members with similar modifications using a 2.55 upper which should produce around the same psi as my 9.55 lower on a stock motor.

I also thought my psi was low, but figured I lost boost from less restrictions. They list the 9.55" as making an additional 4-4.5 psi over stock, which would be around 13 psi. At the same time, I've heard headers cause you to loose 2 psi or so and with the cam, no cats, cat back and cooler intake charge, I would think I'd possibly lose another 2 psi, putting me between 8-9 psi. It probably also doesn't help that my baseline was on the low side. Had it been higher, I'm sure my final numbers would of also reflected it.

Others members also make more boost and power than I did with the use of higher octane fuel and both upper and lower pulley, such as 2.55/8.6 combination. I figure if I add a 2.85 upper to my 9.55 lower then I should hopefully be around a similar 13-14 psi, which should hopefully net me in the 650+ range on 91 octane.

I'll definitely look into the by pass adjustment, boost leaks and cam overlap to make sure I'm not losing any boost.

18% should produce exactly the same boost weather it is upper or lower.

Headers only decrease boost between .5 and 1 psi

Air intakes increase boost by same amount so it becomes a wash.

Cams will lower boost about 1-2 psi.

Belt slip is very common with upper pulley changes.

I never change the upper in any of our power upgrade packages.

Upper pulley changes are a last resort change when maxing out the blower.

Ted

[Can'tHave2MuchHP]

Originally Posted by incon3037r

I've seen similar numbers as mine from other members with similar modifications using a 2.55 upper which should produce around the same psi as my 9.55 lower on a stock motor.

I also thought my psi was low, but figured I lost boost from less restrictions. They list the 9.55" as making an additional 4-4.5 psi over stock, which would be around 13 psi. At the same time, I've heard headers cause you to loose 2 psi or so and with the cam, no cats, cat back and cooler intake charge, I would think I'd possibly lose another 2 psi, putting me between 8-9 psi. It probably also doesn't help that my baseline was on the low side. Had it been higher, I'm sure my final numbers would of also reflected it.

Others members also make more boost and power than I did with the use of higher octane fuel and both upper and lower pulley, such as 2.55/8.6 combination. I figure if I add a 2.85 upper to my 9.55 lower then I should hopefully be around a similar 13-14 psi, which should hopefully net me in the 650+ range on 91 octane.

I'll definitely look into the by pass adjustment, boost leaks and cam overlap to make sure I'm not losing any boost.

No, you're definitely not going from 13 PSI down to 8-9 because of a Cam and Headers.

2.55" or 9.17" lower is 18% overdrive.

You however have a 9.55" which is 22.5% overdrive, and therefore should make more power and boost than a 2.55" upper which is, again, 18%.

As mentioned by me and Ted, your power is definitely pretty low, and though you could blame it on a dyno, the other red flag is the boost, again really low. A 18% pulley, intake, headers, and ported blower should make that much power on 93.

Adding a 2.75" or 2.85" upper pulley with a 9.55" is a wonkey setup, I'd recommend listening to Ted and sticking with the 9.55" only or switching that 9.55" for a 10" or switching the 9.55" out for a 9.17" and adding a 2.55" upper.

Again, you shouldn't need any more supercharger over drive than 22.5% to hit 650 RWHP. Your setup should be making around there. If you were to add more pulley and porting you should nearly hit 700, or just under. As you push beyond 650 RWHP, you're going to be hitting the limits of 93 octane and you'll need to look at Meth or E85, or running on Torco.

[incon3037r]

Originally Posted by JANNETTYRACING

This.




18% should produce exactly the same boost weather it is upper or lower.

Headers only decrease boost between .5 and 1 psi

Air intakes increase boost by same amount so it becomes a wash.

Cams will lower boost about 1-2 psi.

Belt slip is very common with upper pulley changes.

I never change the upper in any of our power upgrade packages.

Upper pulley changes are a last resort change when maxing out the blower.

Ted

Originally Posted by Can'tHave2MuchHP

No, you're definitely not going from 13 PSI down to 8-9 because of a Cam and Headers.

2.55" or 9.17" lower is 18% overdrive.

You however have a 9.55" which is 22.5% overdrive, and therefore should make more power and boost than a 2.55" upper which is, again, 18%.

As mentioned by me and Ted, your power is definitely pretty low, and though you could blame it on a dyno, the other red flag is the boost, again really low. A 18% pulley, intake, headers, and ported blower should make that much power on 93.

Adding a 2.75" or 2.85" upper pulley with a 9.55" is a wonkey setup, I'd recommend listening to Ted and sticking with the 9.55" only or switching that 9.55" for a 10" or switching the 9.55" out for a 9.17" and adding a 2.55" upper.

Again, you shouldn't need any more supercharger over drive than 22.5% to hit 650 RWHP. Your setup should be making around there. If you were to add more pulley and porting you should nearly hit 700, or just under. As you push beyond 650 RWHP, you're going to be hitting the limits of 93 octane and you'll need to look at Meth or E85, or running on Torco.

I appreciate the help guys and trust what you're telling me. Ted's post are the reason I chose to go with the 9.55" in the first place. I'm definitely going to address the issue and figure out whats going on, since my low 91 octane and elevation aren't the issue. Other than the by pass adjustment and possible supercharger leakage, is there anything else I should look for ie; belt slip too much overlap?