cjmatt
08-23-2007, 08:54 PM
Hey everyone, Ive got a 355ci 9.1:1 lt1 with a vortech Ysi on it, as well as a 26/68 cog setup. So a slipping belt isnt the problem. Ive wound the car up a few times and havent seen more than 6psi. at 4500 rpms im seeing like 4. With this cog setup on a t-trim I should be making 15. On the ysi it should be more like 18...
My only conclusion so far is that the Mondo bypass either isnt closing fast enough, or is getting forced back open. Ive got alot of things running off of the vacuum line on the drivers side of the intake(bypass, boost gauge, and timing retard control). Does that port even see boost or is it somehow linked to the pcv? Also, on the passenger side there are two other vacuum ports. one goes to the fuel pressure regulator, and one goes into the harness somewhere, anyone know where? would it be smarter to "t" into one of these?
My only other thought is that possibly the ebay intercooler ive got is leaking somehow under boost and i just havent noticed due to having the maf right before the throttle body.
Anyone got any other ideas?
Schurters LT1
08-24-2007, 08:25 AM
put a vac gauge on the piping and see where the boost is going....
who did you brackets for the ysi?
cjmatt
08-24-2007, 09:49 AM
put a vac gauge on the piping and see where the boost is going....
who did you brackets for the ysi?Wouldnt the piping have the same overall boost as the motor? Im not quite sure I understand what you mean. If there is a leak somewhere, then its not going to pressurize anyway. Todays plan is to pull the bumper offand check for leaks in the intercooler as well as checking the bypass valve functionality. Im going to run a direct line from the intake to only a spare boost gauge and the bypass to see if it improves.
The brackets/standoff/tensioner was designed/made between me and Victory Racing. Its a pretty slick setup. There were some issues initially where it wanted to pull the bolts right out of the vortech standoff bracket on the head, but we retapped it deeper and used a turnbuckle to a header bolt to keep the blower from flexing forward...these ysi's are damn violent when they spin up
Schurters LT1
08-24-2007, 10:21 AM
put a vac gauge on the out let of the blower and see what kind of boost you have so you reallly no
cjmatt
08-24-2007, 11:12 AM
put a vac gauge on the out let of the blower and see what kind of boost you have so you reallly no
Alright, ill check that, but like I said, if there is a leak in the system, it would be like not having a pipe on the end of the the blower. without any restriction, there will be no boost.
I think I'm going to pull the intercooler off and toss in a straight piece of pipe temporarily to see if it spools any quicker. Probably ice it down as well to try and keep IATS down somewhat. At least it would eliminate one possibility. If it creeps above above 6psi at lower rpms at least I would know that the problem lies in the piping somewhere and not the bypass.
JZ28Max
08-24-2007, 11:47 AM
the small nipple port on the drivers side should work fine for you even with the other items you said you have tee'd to that port. i have my mondo hooked up there with several other items also with no problems. have you tried adjusting the valve?
cjmatt
08-24-2007, 01:26 PM
the small nipple port on the drivers side should work fine for you even with the other items you said you have tee'd to that port. i have my mondo hooked up there with several other items also with no problems. have you tried adjusting the valve?
No not yet. I got it used and I think its already been turned in a little bit. When I hooked it up to my mity-vac before installing it, itd begin to open around 4 psi of vacuum
97WS6Pilot
08-24-2007, 08:19 PM
Are you making good power? Maybe your boost guage is leaking. It would be very unlikely your intercooler is leaking. They pressure test those. Also that Mondo could be leaking.:)
ulakovic22
08-24-2007, 08:33 PM
How easy is it to just bypass your blow off valve? Seems a lot easier than pulling the intercooler.
cjmatt
08-31-2007, 10:24 PM
Could it possibly be partially related to the fact that im still only using the stock throttle body? is there a maximum it will flow even boosted?
97WS6Pilot
09-01-2007, 09:28 AM
Could it possibly be partially related to the fact that im still only using the stock throttle body? is there a maximum it will flow even boosted?
No, It doesn't affect boost that much.:)
robvas
09-05-2007, 10:46 AM
Could it possibly be partially related to the fact that im still only using the stock throttle body? is there a maximum it will flow even boosted?
If anything it'd create more boost because of it being a restriction