Forge MBC tapering...
Originally Posted by qazsz
I have IX with k&n drop in filter. i just put in the forge mbc with soft spring. i was wondering if it was normal to spike at 20 psi and then taper to 15 (this was after ~25 clicks). i will be putting on a tbe pretty soon and then i will do the mail in flash from dynoflash. do you think it would be able to spike 21psi and have less taper than what im getting now? or should i try changing the spring? I have the mbc connected to the wastegate and the turbo outlet.
edit: i jsut found out that i still that little pill in the stock turbo outlet tubing. could this be why its tapering so much. the instructions i read in the how-to section didnt say anything about that little pill. i just used the new tubing that came with the mbc. should i put it back onto the new tubing?
edit: i jsut found out that i still that little pill in the stock turbo outlet tubing. could this be why its tapering so much. the instructions i read in the how-to section didnt say anything about that little pill. i just used the new tubing that came with the mbc. should i put it back onto the new tubing?
oh ok. what do you think about my tapering issue. do you think its normal. i was doing some pulls in third gear up to ~6k rpm. im using the stock mr guages and its spiking at 1.4bar and then tapers to 1.1. what do you think?
Originally Posted by qazsz
oh ok. what do you think about my tapering issue. do you think its normal. i was doing some pulls in third gear up to ~6k rpm. im using the stock mr guages and its spiking at 1.4bar and then tapers to 1.1. what do you think?
Tom
No, it doesn't need an upgraded wastegate, because it's not tapering because of the wastegate - the turbo is unable to keep pace with the head. You can force the boost to not drop as much with a Forge IX WGA or with an EBC with tweaked settings, but then you're just forcing it to blow hot air unless you use something to cool the intake charge (e.g. alky).
People need worry less about their perceived "boost taper" and focus MORE on their performance. I think it has become a stigma where people don't know anything else about their car, but they sure can watch that boost gauge, so if their boost tapers, then it must be bad!! It's not necessarily bad. Go see if it loses power on the dyno or runs crappy at the track.
People need worry less about their perceived "boost taper" and focus MORE on their performance. I think it has become a stigma where people don't know anything else about their car, but they sure can watch that boost gauge, so if their boost tapers, then it must be bad!! It's not necessarily bad. Go see if it loses power on the dyno or runs crappy at the track.
Originally Posted by Warrtalon
People need worry less about their perceived "boost taper" and focus MORE on their performance. I think it has become a stigma where people don't know anything else about their car, but they sure can watch that boost gauge, so if their boost tapers, then it must be bad!! It's not necessarily bad. Go see if it loses power on the dyno or runs crappy at the track.
Edit: Just checked my log, and it does not taper to 15psi, it tapers to 17psi at 7400rpm. The taper really begins at 5700rpm.
Last edited by steevo; Nov 13, 2006 at 12:26 PM.
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Originally Posted by Warrtalon
Well, why did you change to a Hallman if your Forge was doing so well? If it held more boost as proven by a MAP sensor, then put it back on...
+1
Originally Posted by Warrtalon
Well, why did you change to a Hallman if your Forge was doing so well? If it held more boost as proven by a MAP sensor, then put it back on...
Originally Posted by 2theMAX
So what determines if you run the stiffer spring or not?
Edit: This is answered in the other thread.
Edit: This is answered in the other thread.
Thread Starter
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From: Irvine California
Originally Posted by 2theMAX
So what determines if you run the stiffer spring or not?
Edit: This is answered in the other thread.
Edit: This is answered in the other thread.
Just remember to start low and bring boost up a few clicks at a time to prevent possible overboost conditions.
i dont want to cause a problem here but my forge parts are great.
stock i was boosting 19psi tappering to almost 16psi. i put the mbc on and i set it to boost at 21psi and it tappers to just a lil over 18 psi. i then put my wga in and a tune and i spike 24 hood 22 and im holding HOLDING 20 at redline in 3and 4 gears. 5th i dont hit redline offen but say at 6100 rpm im holding 21 ish. id say at redline i would be at 20.
i tested my boost gauge and i tested the gauge i regulate how much psi it is showing. there bouth dead on. tapper will always happen yes but some do see more then others.
stock i was boosting 19psi tappering to almost 16psi. i put the mbc on and i set it to boost at 21psi and it tappers to just a lil over 18 psi. i then put my wga in and a tune and i spike 24 hood 22 and im holding HOLDING 20 at redline in 3and 4 gears. 5th i dont hit redline offen but say at 6100 rpm im holding 21 ish. id say at redline i would be at 20.
i tested my boost gauge and i tested the gauge i regulate how much psi it is showing. there bouth dead on. tapper will always happen yes but some do see more then others.