boosting late?
1st Gear
Joined: Oct 2006
Posts: 443
From: Newfieland
RE: boosting late?
I'd vote for the n75 starting to crap out on you too. Personally I'd vote for just unplugging it and running a mbc, but its risky depending on how well your self control is when it comes to boost
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2nd Gear
Joined: Mar 2006
Posts: 1,358
From: Sauga
RE: boosting late?
auditech79
Date 6/30/2007 11:18:57 PM
If your getting strange boost like this i would be looking at the N75 valve.
A malfunctionng N75 can cause anything from strange boost spikes to under boost at all rpm's ect.
I've seen all kinds of wacked out things caused by the valve, this is assuming you ARE reaching full boost consistantly and you know what FULL boost is, if your idea of full boost is 5 psi at 5000 rpms then your turbo is probably toast, you didn't specify what your boost levels were.
1st Gear
Joined: May 2007
Posts: 14
From:
RE: boosting late?
I'm having similar problems and what I noticed was two things. The gasket between my turbo and exhaust was sticking out more than the usual amount and after taking a closer look, I noticed that I was missing a bolt and have a major loss of back preasure.
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2nd Gear
Joined: Mar 2006
Posts: 1,358
From: Sauga
RE: boosting late?
[quote
CALI KID
Date 7/1/2007 3:24:52 PM
I'm having similar problems and what I noticed was two things. The gasket between my turbo and exhaust was sticking out more than the usual amount and after taking a closer look, I noticed that I was missing a bolt and have a major loss of back preasure.
][/quote]
I have checked all that, all bolts around my exhaust,turbo and manifold are at proper torque specs. nothing is loose, no cracks that i can see. i think that it is my n75 but wont be able to tell till my neighboor gets home.
CALI KID
Date 7/1/2007 3:24:52 PM
I'm having similar problems and what I noticed was two things. The gasket between my turbo and exhaust was sticking out more than the usual amount and after taking a closer look, I noticed that I was missing a bolt and have a major loss of back preasure.
][/quote]
I have checked all that, all bolts around my exhaust,turbo and manifold are at proper torque specs. nothing is loose, no cracks that i can see. i think that it is my n75 but wont be able to tell till my neighboor gets home.
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Joined: Sep 2005
Posts: 13,664
RE: boosting late?
ORIGINAL: Andyrew
I noticed when I open my exhaust up (I have a cutout) that, for some freak reason, I boost later....
Roughly .2k rpms for full (17psi), or till it starts to kick.
I noticed when I open my exhaust up (I have a cutout) that, for some freak reason, I boost later....
Roughly .2k rpms for full (17psi), or till it starts to kick.
TeeterTawter:
If your buddies N75 solves your problem, and you have to buy a new one, justbypass the n75 altogether andgo with a mbc. My n75 was putting me in limp mode, so I just decided to get a mbc. They can be had a lot cheaper and do a great job. A bleeder/gated type is probably best for the k03 because it provides a smoother boost delivery. A ball/spring type is what youd want with a BT/more aggressive tuning.
CincyTT recomended an ebaymbc to me that his bro uses on his passat, which is what I got. PM me if you want the link to where I got it from. $22 shipped!
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2nd Gear
Joined: Mar 2006
Posts: 1,358
From: Sauga
RE: boosting late?
so i replaced my n75 with my buddies, car hits full boost(spike 20 psi)at 3800 rpm and tappers off around 5500. seems about right but a lil laggy still. so i am thinking it is the n75 valve and the reason its laggy isthe n75 i tried isoff of a 2001 jetta and not an audi.
onepoint8tee:
i am goin to send you a pm about your mbc, so im assuming you have the bleeder/gated type mbc. easy install?
onepoint8tee:
i am goin to send you a pm about your mbc, so im assuming you have the bleeder/gated type mbc. easy install?
Site Moderator
Joined: Sep 2005
Posts: 13,664
RE: boosting late?
Here are instructions: http://www.turbosmartusa.com/index.p...oad&id=139
Pretty easy. Youll like it A LOT. Full boost for me (set at 18/19 psi now with no spiking)is reached at or a little bellow 3k rpms. I had it set to 20/21 psi and ran into throtle cut on the highway a few times. Since I turned it down to 18ish,its perfect and is probably where it should be at for a 1.3 bar chip.
Pretty easy. Youll like it A LOT. Full boost for me (set at 18/19 psi now with no spiking)is reached at or a little bellow 3k rpms. I had it set to 20/21 psi and ran into throtle cut on the highway a few times. Since I turned it down to 18ish,its perfect and is probably where it should be at for a 1.3 bar chip.
I'm make believe
Joined: Dec 2006
Posts: 17,587
From: In my head
RE: boosting late?
ORIGINAL: onepoint8tee
You are losing lots of backpressure when the cut out is open. The turbo causes all the backpressure the enigne needs and the turbo doesnt need any (bigger is better, but has deminishing returns so 2.5 or 3" is about all you need, but larger exhaust, faster spool but lose some torque before spool up) Manual cutouts make no sense on a turbo charged engine imo.If anything, youdwant an electric/remotecutoutso you can open it up at the right times, depending on when your turbostarts to spool. The turbo needs a certain amount of back pressure to be efficient. ATP VES isa wastegate operated cutout, opens at 5psi and with a mbc you can set it to open later if desired.
TeeterTawter:
If your buddies N75 solves your problem, and you have to buy a new one, justbypass the n75 altogether andgo with a mbc. My n75 was putting me in limp mode, so I just decided to get a mbc. They can be had a lot cheaper and do a great job. A bleeder/gated type is probably best for the k03 because it provides a smoother boost delivery. A ball/spring type is what youd want with a BT/more aggressive tuning.
CincyTT recomended an ebaymbc to me that his bro uses on his passat, which is what I got. PM me if you want the link to where I got it from. $22 shipped!
N75's suck and a good mbc is far better. People spending ~$75 on a N75 is just silly
You are losing lots of backpressure when the cut out is open. The turbo causes all the backpressure the enigne needs and the turbo doesnt need any (bigger is better, but has deminishing returns so 2.5 or 3" is about all you need, but larger exhaust, faster spool but lose some torque before spool up) Manual cutouts make no sense on a turbo charged engine imo.If anything, youdwant an electric/remotecutoutso you can open it up at the right times, depending on when your turbostarts to spool. The turbo needs a certain amount of back pressure to be efficient. ATP VES isa wastegate operated cutout, opens at 5psi and with a mbc you can set it to open later if desired.
TeeterTawter:
If your buddies N75 solves your problem, and you have to buy a new one, justbypass the n75 altogether andgo with a mbc. My n75 was putting me in limp mode, so I just decided to get a mbc. They can be had a lot cheaper and do a great job. A bleeder/gated type is probably best for the k03 because it provides a smoother boost delivery. A ball/spring type is what youd want with a BT/more aggressive tuning.
CincyTT recomended an ebaymbc to me that his bro uses on his passat, which is what I got. PM me if you want the link to where I got it from. $22 shipped!
N75's suck and a good mbc is far better. People spending ~$75 on a N75 is just silly
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