When you are boosting....

by **swimshady906** » Sun Feb 22, 2004 8:57 am

Do you guys make full 4 or 6 or 7 ( or whichever you are running) psi under full throttle? Mine will only make 4 psi right before i shift, otherwise it will sit comfortably at 3, and then around 1.5 under 3300 rpms.... Is this right ? And can i change it?

by **SC V6** » Sun Feb 22, 2004 9:28 am

just because of the pressure of running high boost.. sometimes when im all over it I could see 8.5 pounds at the top of my gear.. and I have the low compression heads, and full exhaust..
later
Scott

by **Mole** » Sun Feb 22, 2004 10:08 am

just like before, boost needs time to build. 4psi is only seen or used in really hammering the gas.

if you're auto, crank it out in 2nd gear.

if manual crank it out in 3rd gear.

by **JoeB** » Mon Feb 23, 2004 7:24 am

I have a 6psi pulley on an auto and will hit about 8.5 peak. With the stock setup (+6psi pulley), I would only run mild (~1psi) boost up to 3600 RPM then only to 6psi peak, after the modifications Gadget made, the boost seems to build very quick even at lower RPMs. -JoeB

by **swimshady906** » Wed Feb 25, 2004 12:21 pm

Thanks guys

by **Mole** » Wed Feb 25, 2004 6:22 pm

JoeB wrote:I have a 6psi pulley on an auto and will hit about 8.5 peak. With the stock setup (+6psi pulley), I would only run mild (~1psi) boost up to 3600 RPM then only to 6psi peak, after the modifications Gadget made, the boost seems to build very quick even at lower RPMs. -JoeB

how in the world can you max out @ 8.5psi when your pulley is only limited @ 6psi??

i'd understand if it goes a little above like .5psi, but all the way to 8.5????

by **shidosha01** » Wed Feb 25, 2004 6:57 pm

JoeB wrote:I have a 6psi pulley on an auto and will hit about 8.5 peak. With the stock setup (+6psi pulley), I would only run mild (~1psi) boost up to 3600 RPM then only to 6psi peak, after the modifications Gadget made, the boost seems to build very quick even at lower RPMs. -JoeB

I get the same experience too. Might be the cooler weather we're getting here.

by **SC V6** » Wed Feb 25, 2004 7:04 pm

its the pressure that still is inside of the cylinders because of the exhaust lag and crap.. its still boosting the 6psi,

by **cdssolara** » Wed Feb 25, 2004 8:12 pm

I have a 7 psi pulley, and I can get to that very quickly. It usually tops out at 7, but it hit 7.5 once on the dyno. I have a manual, and I don't seem to get any boost in 1st gear. In second gear I have to hit it pretty hard, and boost will than register above 3500 rpm, maxing out between 4 and 5 psi. In 3rd through 5th gears, boost comes on at 2500 rpm, or even a little below, and will spin up to 7 instantly. I have a light flywheel, so my engine may rev a little quicker than stock.

by **cdssolara** » Wed Feb 25, 2004 8:16 pm

TRDMole177 wrote:
JoeB wrote:I have a 6psi pulley on an auto and will hit about 8.5 peak. With the stock setup (+6psi pulley), I would only run mild (~1psi) boost up to 3600 RPM then only to 6psi peak, after the modifications Gadget made, the boost seems to build very quick even at lower RPMs. -JoeB

how in the world can you max out @ 8.5psi when your pulley is only limited @ 6psi??

i'd understand if it goes a little above like .5psi, but all the way to 8.5????

I agree with this. The boost pressure might spike well above the expected psi if there is a lot of back pressure. If the exhaust is free flowing, like with the JP Performance headers and exhaust, there shouldn't be that kind of back pressure. I know that with mine, I noticed right away that there was less back pressure.

by **swimshady906** » Wed Feb 25, 2004 10:51 pm

My boost spikes to 4.5

But does anyone know why it doesnt boost to the pully amount when you floor it under 3500? There is no lag or boost build up time with a roots blower just closing the wastegate but thats <1 sec

by **JoeB** » Thu Feb 26, 2004 9:19 am

I'm not sure how it can go up to 8.5psi, I only know that it does. I too have the full JP Performance exhaust (headers, y-pipe and exhaust) so that's not the issue. Rizal's setup is just like mine including JPP exhaust except his is manual and mine is auto. He gets the same boost numbers. -JoeB

by **esculatus** » Fri Mar 26, 2004 12:20 pm

man... how come my stock 4 psi pulley can never get me to 4... max I get is like 3.2-3.5...

by **JoeB** » Fri Mar 26, 2004 4:19 pm

esculatus wrote:man... how come my stock 4 psi pulley can never get me to 4... max I get is like 3.2-3.5...

I'm not sure, that's odd. My stock pulley would go to 4psi exactly. Maybe it's the valve or a leak or something. I wish I knew more to help. -JoeB

by **Mole** » Fri Mar 26, 2004 8:00 pm

boost can also depend on load conditions.

When you are boosting....

When you are boosting....

Who is online