Boost Characteristics of A Large Turbo
I thought i remembered you posting in the other threads, but i was too lazy to go back and verify my instinct.
these are my mods
Buschur 3” turbo back with test pipe
Aem intake
Forge diverter valve
Hallman mbc
255 walbro fuel pump
Megan o2 housing
Megan exhaust manifold
Custom dynoflash
NGK BR8ES or 7
780 cc Buschur injectors
20g-9-5 Buschur turbo w/10.5 hotside
Buschur deluxe FMIC with lower piping
HKS 272 Intake and Exhaust cams
ACT MB7-HDSS clutch and pressure plate
10.45lb steel Prostreet online flywheel
im adding the ATP kit.
Buschur 3” turbo back with test pipe
Aem intake
Forge diverter valve
Hallman mbc
255 walbro fuel pump
Megan o2 housing
Megan exhaust manifold
Custom dynoflash
NGK BR8ES or 7
780 cc Buschur injectors
20g-9-5 Buschur turbo w/10.5 hotside
Buschur deluxe FMIC with lower piping
HKS 272 Intake and Exhaust cams
ACT MB7-HDSS clutch and pressure plate
10.45lb steel Prostreet online flywheel
im adding the ATP kit.
as for more mods, we will get a good idea. who is tuning u?
Jestr remote tuning. I have a wideband and EcuFlash + EvoScan... I already have the first base map, and it actually looks very good so far. Maybe alittle rich, but he hit the spool-up spot in the RPM range, almost perfect. Which is amazing for this being a not-so-popular turbo combo....
i have a peak boost 3076 kit and it did the same thing when i put the kit on with a ball and spring (hallman) type controller. so i called tim and PB and he told me that this controller wont work. it will NOT control the boost from a big turbo.
i used this controller on my stock turbo and it worked great! in my case i have an aem ems so i hook up a GM boost sol. and run it with the ems. NO more problems!
if you dont have an electronic controller then you can use a bleed style controller like turbonetics. i dont like them but they work. BUT, it needs to be hooked up differently than your hallman. do the following....
1- run a boost line straight from the lower ic pipe to the bottom on the wastegate.
2- put a tee fitting somewhere in that line.
3- run the line off of the tee fitting to the inlet side of your bleed style controller.
4- then run a line from the outlet side of the controller to the top of the wastegate.
now, turn the contoller knob all the way out till you cant blow through it.
note: you will always be able to blow through the outlet side of the controller. this is normal. but you should not be able to blow through the inlet side!
then all you got to do is turn the knob in and it will add boost.
only turn it a little bit at a time to keep from having and accident!!
this setup works on a different principal than the way you have yours hooked up.
your way, the spring holds pressure till it overcomes the spring.
this way it is like putting a stiffer spring in the WG as this way the boost bleeds onto the top of the WG and holds the valve down. and you can vary this amount by bleeding more pressure to the top of the WG.
hope this helps.... i have already been there scratching my head too !!
-derek
i used this controller on my stock turbo and it worked great! in my case i have an aem ems so i hook up a GM boost sol. and run it with the ems. NO more problems!
if you dont have an electronic controller then you can use a bleed style controller like turbonetics. i dont like them but they work. BUT, it needs to be hooked up differently than your hallman. do the following....
1- run a boost line straight from the lower ic pipe to the bottom on the wastegate.
2- put a tee fitting somewhere in that line.
3- run the line off of the tee fitting to the inlet side of your bleed style controller.
4- then run a line from the outlet side of the controller to the top of the wastegate.
now, turn the contoller knob all the way out till you cant blow through it.
note: you will always be able to blow through the outlet side of the controller. this is normal. but you should not be able to blow through the inlet side!
then all you got to do is turn the knob in and it will add boost.
only turn it a little bit at a time to keep from having and accident!!
this setup works on a different principal than the way you have yours hooked up.
your way, the spring holds pressure till it overcomes the spring.
this way it is like putting a stiffer spring in the WG as this way the boost bleeds onto the top of the WG and holds the valve down. and you can vary this amount by bleeding more pressure to the top of the WG.
hope this helps.... i have already been there scratching my head too !!
-derek
yep, that will do it. electronic controllers are the chit. like i said, i dont like that turbonetics one. the adjustment sucks. but when you get a new controller i think you should hook it up this way. unless the one you buy tells you not to.
in my aem ems instructions it show this setup as the way you are suppesed to hook up an external wastegate. it shows your setup hooked to an internal gate.
also, as a tip to save you some trouble.... just in case!
with the setup i got you can only use a 3way boost solonoid like the GM one...
if you use a 2way like the stock one then you WILL have problems. i asume that most aftermarket controllers use a 3way. the way you can tell is, if you can blow through one side of the solinoid with it closed the its a 3way. if you cant like the stock solinoid then its a 2way. hope this helps...
-derek
in my aem ems instructions it show this setup as the way you are suppesed to hook up an external wastegate. it shows your setup hooked to an internal gate.also, as a tip to save you some trouble.... just in case!
with the setup i got you can only use a 3way boost solonoid like the GM one...
if you use a 2way like the stock one then you WILL have problems. i asume that most aftermarket controllers use a 3way. the way you can tell is, if you can blow through one side of the solinoid with it closed the its a 3way. if you cant like the stock solinoid then its a 2way. hope this helps...
-derek
Your MBC seems to be acting funny.
With my GT-35 R I get up to wastegate spring pressure, and then have slight boost creep as RPM's rise. this is because I have a small external WG (38mm).
If I have my Halman RX MBC set to 24 psi or above then my boost pressure rises to the set point and stay steady as a rock up to redline. No reaching WG spring pressure and then jumping up to MBC set pressure like you are talking about.
Keith
PS: Yes, a MBC works great on a big turbo... anyone telling you different is trying to sell you a EBC for the $$$
With my GT-35 R I get up to wastegate spring pressure, and then have slight boost creep as RPM's rise. this is because I have a small external WG (38mm).
If I have my Halman RX MBC set to 24 psi or above then my boost pressure rises to the set point and stay steady as a rock up to redline. No reaching WG spring pressure and then jumping up to MBC set pressure like you are talking about.
Keith
PS: Yes, a MBC works great on a big turbo... anyone telling you different is trying to sell you a EBC for the $$$
Last edited by Fourdoor; Feb 5, 2007 at 07:03 PM.
Your MBC seems to be acting funny.
With my GT-35 R I get up to wastegate spring pressure, and then have slight boost creep as RPM's rise. this is because I have a small external WG (38mm).
If I have my Halman RX MBC set to 24 psi or above then my boost pressure rises to the set point and stay steady as a rock up to redline. No reaching WG spring pressure and then jumping up to MBC set pressure like you are talking about.
Keith
PS: Yes, a MBC works great on a big turbo... anyone telling you different is trying to sell you a EBC for the $$$
With my GT-35 R I get up to wastegate spring pressure, and then have slight boost creep as RPM's rise. this is because I have a small external WG (38mm).
If I have my Halman RX MBC set to 24 psi or above then my boost pressure rises to the set point and stay steady as a rock up to redline. No reaching WG spring pressure and then jumping up to MBC set pressure like you are talking about.
Keith
PS: Yes, a MBC works great on a big turbo... anyone telling you different is trying to sell you a EBC for the $$$
Your MBC seems to be acting funny.
With my GT-35 R I get up to wastegate spring pressure, and then have slight boost creep as RPM's rise. this is because I have a small external WG (38mm).
If I have my Halman RX MBC set to 24 psi or above then my boost pressure rises to the set point and stay steady as a rock up to redline. No reaching WG spring pressure and then jumping up to MBC set pressure like you are talking about.
Keith
PS: Yes, a MBC works great on a big turbo... anyone telling you different is trying to sell you a EBC for the $$$
With my GT-35 R I get up to wastegate spring pressure, and then have slight boost creep as RPM's rise. this is because I have a small external WG (38mm).
If I have my Halman RX MBC set to 24 psi or above then my boost pressure rises to the set point and stay steady as a rock up to redline. No reaching WG spring pressure and then jumping up to MBC set pressure like you are talking about.
Keith
PS: Yes, a MBC works great on a big turbo... anyone telling you different is trying to sell you a EBC for the $$$
I'll have to try the higher psi thing when i get some race gas in it, and see what happens.



