[JasW]

Any idea why my peak boost would drop a full 1.0 psi after replacing the stock charge pipe? I'd hit 19.8 psi using the stock CP while waiting for the aftermarket CP to come in:

http://www.datazap.me/u/jasw/wedge-m...=0&data=4-6-20

Now after replacing the CP, the peak boost now hits 18.8 psi:

http://www.datazap.me/u/jasw/3rd-and...og=0&data=4-20

Completely stock except for the CP, boost target is always 18.2, running a Wedge custom tune, and the only other difference is that I've been running an E25 mix to smooth out the negative timing corrections that can be seen in the earlier pull.

[alexg212]

Did you install an o-ring on the throttle body connection?

[E30 Racer]

Boost target is 18.2 at 6.5k ROM, and requested load is pretty high. Not sure hitting 19.x was realistic since the car had a pretty significant throttle closure at nearly the same time. Seems much happier in the second log....does it feel different on the road?

Either way, targeting that kind of boost at high RPM on a stock car seems pretty aggressive.

[LMB335IS]

You're second log looks much better overall but your IAT is heading through the roof. You need a ATM stepped IC badly. Could just be the heat.

[whosdady]

Originally Posted by JasW

Any idea why my peak boost would drop a full 1.0 psi after replacing the stock charge pipe? I'd hit 19.8 psi using the stock CP while waiting for the aftermarket CP to come in:

http://www.datazap.me/u/jasw/wedge-m...=0&data=4-6-20

Now after replacing the CP, the peak boost now hits 18.8 psi:

http://www.datazap.me/u/jasw/3rd-and...og=0&data=4-20

Completely stock except for the CP, boost target is always 18.2, running a Wedge custom tune, and the only other difference is that I've been running an E25 mix to smooth out the negative timing corrections that can be seen in the earlier pull.

Check connections for potential boost leaks. It seems obvious but you might be surprised how leaks can spring up.

[E30 Racer]

Originally Posted by whosdady

Check connections for potential boost leaks. It seems obvious but you might be surprised how leaks can spring up.

What evidence do you see to indicate a boost leak? I'm not seeing it.

[Tiago@VRSF]

Check the o-ring at the throttle body and the o-ring at the tmap sensor. Also make sure your t-bolts/couplers are tight and correctly placed. If your CP has a meth bung make sure that's tight as well.

[JasW]

Originally Posted by alexg212

Did you install an o-ring on the throttle body connection?

Originally Posted by Tiago@VRSF

Check the o-ring at the throttle body and the o-ring at the tmap sensor. Also make sure your t-bolts/couplers are tight and correctly placed. If your CP has a meth bung make sure that's tight as well.

O-ring from the stock CP was installed. The new CP is pretty much a straight up replacement for the stock pipe. Oddly, a day or so after the CP change, I got a charge air temp sensor fault, which led to checking the CP connections again -- all good and tight -- and finding the TMAP sensor was indeed going bad. I took it to the (mod-friendly) dealer under warranty and had the sensor replaced. So all connections on the CP have essentially been triple checked.

Originally Posted by E30 Racer

Boost target is 18.2 at 6.5k ROM, and requested load is pretty high. Not sure hitting 19.x was realistic since the car had a pretty significant throttle closure at nearly the same time. Seems much happier in the second log....does it feel different on the road?

Either way, targeting that kind of boost at high RPM on a stock car seems pretty aggressive.

Yep, lol, welcome to the world of Wedge Performance. Ken made me a very aggressive map -- and me likey. That throttle closure was my fault -- forgot to turn traction control off on that earlier run. But you make a key point -- the car doesn't really feel different, it's still crazy fast with a rush of boost. The difference between 18.8 psi and 19.8 psi peak boost is something I can of course see in the log, but not feel/sense on the road.

Originally Posted by LMB335IS

You're second log looks much better overall but your IAT is heading through the roof. You need a ATM stepped IC badly. Could just be the heat.

I'd been going into the low 160s with 3rd gear pulls here and there, but continuing on with the pull in 4th got things up to 180 (not to mention 130 mph in a 45 zone!). Yikes. That is the one remaining problem and of course Ken really can't do much about it on his end. The heat is oppressive down here. Of course, I don't drive WOT all of the time -- who does? -- so it's really only a problem on these pulls. Still, an FMIC is likely the next step. Along with DPs!

[Tiago@VRSF]

What brand chargepipe is it?

We have had few customers purchase our CP due to issues with improperly machined throttle body flanges.

[LMB335IS]

Originally Posted by JasW

O-ring from the stock CP was installed. The new CP is pretty much a straight up replacement for the stock pipe. Oddly, a day or so after the CP change, I got a charge air temp sensor fault, which led to checking the CP connections again -- all good and tight -- and finding the TMAP sensor was indeed going bad. I took it to the (mod-friendly) dealer under warranty and had the sensor replaced. So all connections on the CP have essentially been triple checked.



Yep, lol, welcome to the world of Wedge Performance. Ken made me a very aggressive map -- and me likey. That throttle closure was my fault -- forgot to turn traction control off on that earlier run. But you make a key point -- the car doesn't really feel different, it's still crazy fast with a rush of boost. The difference between 18.8 psi and 19.8 psi peak boost is something I can of course see in the log, but not feel/sense on the road.



I'd been going into the low 160s with 3rd gear pulls here and there, but continuing on with the pull in 4th got things up to 180 (not to mention 130 mph in a 45 zone!). Yikes. That is the one remaining problem and of course Ken really can't do much about it on his end. The heat is oppressive down here. Of course, I don't drive WOT all of the time -- who does? -- so it's really only a problem on these pulls. Still, an FMIC is likely the next step. Along with DPs!

I live in St Pete so I'm right there with ya. This illustrates what a difference maker it is. Full 3rd-4th pull, middle of the day 90+ degrees, hitting the on ramp. Zero post shift timing drop, zero cyl. corrections and peaking at about 21 psi on E60. IAT hits 128F.
http://www.datazap.me/u/veloman62/lo...4&zoom=118-200

[JasW]

Originally Posted by Tiago@VRSF

What brand chargepipe is it?

We have had few customers purchase our CP due to issues with improperly machined throttle body flanges.

Miami Performance Inc. (MPI). AA is the top dog here in Miami, but they get their stuff from China -- MPI has their stuff machined to their specs here in the US. They have an excellent local rep, which in Miami means a lot. What issues with CPs are you talking about? I don't really have an issue with the MPI CP -- the connections are tight, the stock o-ring and c-clip were used, what more can I look for? But in the end, given the choice between a high risk of blowing the stock CP off or getting 1.0 psi lower peak boost with an aftermarket CP, I'll take the latter. I'd still like to know why the boost would be a bit lower, though.

Originally Posted by LMB335IS

I live in St Pete so I'm right there with ya. This illustrates what a difference maker it is. Full 3rd-4th pull, middle of the day 90+ degrees, hitting the on ramp. Zero post shift timing drop, zero cyl. corrections and peaking at about 21 psi on E60. IAT hits 128F.
http://www.datazap.me/u/veloman62/lo...4&zoom=118-200

Whose intercooler are you using? I'd been intending to stick with MPI, even though the AA 5" is $150 cheaper, but I'm open minded.

Why is the 18.2 boost target line on your log below the 20+ boost line? I don't get that.

[TheYuriPanda]

Originally Posted by Tiago@VRSF

Check the o-ring at the throttle body and the o-ring at the tmap sensor. Also make sure your t-bolts/couplers are tight and correctly placed. If your CP has a meth bung make sure that's tight as well.

IMPORTANT. Make sure all installs on chargepipes DO NOT forget the o-ring to the throttle body. I did, caused an over boost and my turbo turbine shattered.

[LMB335IS]

Originally Posted by JasW

Miami Performance Inc. (MPI). AA is the top dog here in Miami, but they get their stuff from China -- MPI has their stuff machined to their specs here in the US. They have an excellent local rep, which in Miami means a lot. What issues with CPs are you talking about? I don't really have an issue with the MPI CP -- the connections are tight, the stock o-ring and c-clip were used, what more can I look for? But in the end, given the choice between a high risk of blowing the stock CP off or getting 1.0 psi lower peak boost with an aftermarket CP, I'll take the latter. I'd still like to know why the boost would be a bit lower, though.



Whose intercooler are you using? I'd been intending to stick with MPI, even though the AA 5" is $150 cheaper, but I'm open minded.

Why is the 18.2 boost target line on your log below the 20+ boost line? I don't get that.

I use a VRSF 7" but it requires cutting. If you're not keen on some hacking a 5" stepped design (ATM, VRSF come to mind) will slide right in.

MHD's max target without MBoost is about 18.3. I get around that with the PID tuning done by BuraQ on my Cobb maps. I switched it all over via TunerPro and I had the mods to run it. I've since added the N20 sensor and incorporated it into my flash, skipping the N20 option on the flash install for more accurate reading. It will come in handy down the road.

[Tiago@VRSF]

An improperly machined throttle body flange will cause a leak, especially if the flange is warped. The tolerances have to be really tight in order for the o-ring to seal properly.

[whosdady]

Originally Posted by E30 Racer

What evidence do you see to indicate a boost leak? I'm not seeing it.

I didn't say he had a boost leak. I simply suggested making sure there aren't any. Even when adding something as simple as a charge pipe, a boost leak COULD pop up. Loose clamps, maybe a lower pipe was bumped while maneuvering the old pipe out, the diverter valves/bov may not be connected properly to the new pipe, etc...It happens A boost leak will cause him to run lower boost which is the problem he's having.

[Real Nice Guy]

Originally Posted by Tiago@VRSF

An improperly machined throttle body flange will cause a leak, especially if the flange is warped. The tolerances have to be really tight in order for the o-ring to seal properly.

I recently installed your charge pipe, the included o-ring was too fat... had to reuse the stock one.

[alexg212]

Originally Posted by Real Nice Guy

I recently installed your charge pipe, the included o-ring was too fat... had to reuse the stock one.

Vrsf uses a larger one intentionally. Once you get it on there, it creates a better seal.

[Tiago@VRSF]

Originally Posted by alexg212

Vrsf uses a larger one intentionally. Once you get it on there, it creates a better seal.

Originally Posted by Real Nice Guy

I recently installed your charge pipe, the included o-ring was too fat... had to reuse the stock one.

Just rub a bit of oil on the o-ring and it'll slip right onto the TB with a bit of force

[E30 Racer]

Originally Posted by whosdady

I didn't say he had a boost leak. I simply suggested making sure there aren't any. Even when adding something as simple as a charge pipe, a boost leak COULD pop up. Loose clamps, maybe a lower pipe was bumped while maneuvering the old pipe out, the diverter valves/bov may not be connected properly to the new pipe, etc...It happens A boost leak will cause him to run lower boost which is the problem he's having.

Right, but his actual boost is exceeding the target. It's only in this area he "lost" boost after the CP install. If the car was set up correctly, the target wouldn't have been exceeded in the first place, right?

[JasW]

Originally Posted by E30 Racer

Right, but his actual boost is exceeding the target. It's only in this area he "lost" boost after the CP install. If the car was set up correctly, the target wouldn't have been exceeded in the first place, right?

Not sure what you're getting at -- true, the post-new CP loss of boost was in the area exceeding target, but it was exceeding target before with the stock CP. How could the car not have been set up correctly when it was stock?

[JasW]

Originally Posted by Tiago@VRSF

An improperly machined throttle body flange will cause a leak, especially if the flange is warped. The tolerances have to be really tight in order for the o-ring to seal properly.

So are you saying that this is the most likely reason for the 1.0 psi loss at peak boost? I certainly can't tell if the throttle body flange on the new CP is warped or otherwise improperly machined -- it goes on and is tight. I'm not sure how I can tell the company this -- I brought the car to their shop after noticing this slight drop and they said everything was fine with the CP.

[E30 Racer]

Originally Posted by JasW

Not sure what you're getting at -- true, the post-new CP loss of boost was in the area exceeding target, but it was exceeding target before with the stock CP. How could the car not have been set up correctly when it was stock?

I'm not referring to the hardware, I'm referring to the tune. Ideally, you should not exceed the boost target. At least the mild throttle closure indicates the car still has the ability to compensate for it.

Having said all that, are you sure you're comparing apples to apples? The two individual logs you posted were collected over two weeks apart, are using different fuel mixtures, and appear to be using different tune revisions. Seems plausible an attempt to reduce the boost overshoot may have been made between your v1.1 and v3 iterations.