SeeeeeYa

Seeeya, there are NO LCA is in the rear. Please use correct term, it's confusing. The rear suspenction has trailing arms. LCA = lower control arm and is part of the front suspension.

Whatever. NP. Just so everyone is on the same page . I know what it is, where it is, and what it does. Various people have had trouble labelling it... like now .

In the Vac Pics it is called "Rear Arm." All those pieces that have "link" attached to them are NOT the device with the bushings I'm referencing. In fact, in the Vac Pics, there is no mention of "trailing arms."

I have attached the .pdf. The arm we are discussing is item "#11, Rear arm." The bushing I speak about is "#13, Rear arm front bushing."

I hope this removes any ambiguity.

I will put this simply, cause I don't have time (all due respect, and you know that).

 

I am fairly certain that my diff inserts are still more effective then your plastic inserts held in place with the 3M stuff.

 

I DID THE SAME THING ABOUT 1 YEAR AGO!!!!

 

Of course I did it after your write-up, thank-you.

 

That being said, I don't think it matters.

 

 

I would be willing to bet serious money that your car would do it too in the cold.

 

I have the Beatrush piece on order (pics earlier in this thread), but I don't think that will do it too.

 

 

The thing is in the winter it is soo ridiculously loud, and it happens so easy, it makes sense that the problem is what I described above. It sounds like someone is back there with a mini-jack hammer.

 

Long story short (I am sure you will reply, and I will have to explain further) you are likely incorrect in your analysis.

We both know it isn't about me being "right," it is about solving a problem. It is a problem for our senses and peace of mind. But worse, it can break things.

Now, regardless of which diff solution is better, you still have not said, definitively, that you have addressed the forward bushings in the rear LCA/trailing link/whatever!

The diff bushings are crap and have been taken care of satisfactorily.

The transmission(s) have their mountings addressed satisfactorily.

But on our cars the number ONE area anyone with a drag race history or understanding will look to FIRST is the same one on ANY car..... the rear lower control arm bushings!! Just look at these bushings, they are exactly like the diff bushings, full of air and progressively more squishy as they age. As I have said before, on my/any race car the entire arm was replaced with a box section piece with steel bushings, NO RUBBER. The reason why is the wheels try to outrun each other and that back and forth causes all the floppily LGT suspension to wind up/wind down, making the floppily drive shaft assy to flop around, the various bits in the rear to load and unload, ad f'ing nauseum!!

AGAIN: Did you modify your rear LCA forward bushings?? (And if yes, HOW did you modify them.)

(If you answer yes I'm just glad I don't live where it gets that cold... no, I'm already glad of that. )

I have broken a rear diff and a rear axel. I am fully aware of the "PROBLEM" that we are discussing. It has cost me a lot of money and grief. Therefore, I set out to fix it. One by one the things I did reduced the problem. But it was not until my car sat on a rack for a couple weeks waiting on my IPT 5EAT that I had the wherewithall to really get to those rear LCA bushings, they are almost hidden. However, once I had them inserted and 3M polyed, and it sat there and hardened on the rack, the noise was gone. Once or twice, on a 0-60 timed run with a high brake torque launch there was an instantaneous thump along with the normal little squeal from the tires. That is all, and understandable since I don't intend to put steel inserts there for that Nth degree of traction. Excepting that extreme condition, not once, in any temperature, under any power or conditions have I had a suspension noise since the car came off the rack. (Other than when the rear axel went, of course.)

Trust me here. You don't have a different problem.

I think if you were living in a cold environment you would still have that problem. What have you done that I haven't done?

 

I know you filled in your upper rear diff bushings with that 3M stuff. Well I have the WL poly rear diff inserts, and I can pretty much gaurantee that they allow less movement and are stiffer then the 3M stuff.

 

I have stiffer engine mounts, STI trans mount, Ralitek poly bushings holding the trans mount (can't remember the exact name right now).

 

My suspension sags very little (KW2s) on accel.

 

I only get it when it is about 20F or less outside, but I still get it.

 

 

FWIW my Beatrush front diff support bar is on the boat from Japan as we speak.

 

 

Maybe it is the rear suspension subframe. Maybe the rubber shrinks when it is colder, just enough to cause some contact somewhere?

The one I have done that you don't list as having done, is what made the final difference for me.

As for your inserts in the rear diff upper bushings, I can imagine they are a great product. I wish they had been there, or I had known about them, when I started trying to eliminate "The Noise." However, I don't have just 3M poly in those openings, I have cut-to-fit plastic inserts in them... the 3M poly just cements them in and fills in every iota of space the inserts don't. The inserts you have are a nice easy fix, I had to work for mine and I'm sure they are, at the least, as effective. They made a huge difference.

The Rallitek poly insert for my 5EAT mount made a difference, too.

I've had my Teins so long I don't remember any correlations, but it doesn't squat or dive either.

The thing I did that you didn't do must make a difference. Odd that no one, that I can remember at least, has also done it. Yet everyone still says there isn't any "fix" .... even though they don't fix all the things I have said numerous times fixed it for me, especially what may be the biggest problem of all.

I cannot replicate the kind of temps you have to deal with up there in the Frigid North, although from my thirty years in NE I can appreciate it. But until someone does ALL the mods I have, AND lives where it gets really cold, the final word on my fix is not in. Why doesn't someone (like you Mr. LBGT ) complete the job and fix the remaining bushings. Then we will know.

Until then I am going to continue to listen to people piss and moan over something I believe a little time, a little work, and very little money can eliminate.

Now, if you finish the job and do the same thing for your rear forward lower link/control arm bushings that you did for the upper rear diff bushings.... or what I did as outlined somewhere in this thread, maybe we could put to rest whether or not there is the fix I contend there is. Oh, I think that new support you're waiting on will help as well. Linky?

Think about it. All this big thread is about is wheel hop. Nothing more. The complexity of our suspension, however, makes our solution more complex. And, being wheel hop, until every piece of rubber has been replaced by steel there will be traces for anyone who wants to abuse their daily driver. For everyone else I think there is a realistic solution.

We await your final report . My preliminary report says I'm done.

This is where I point out that I don't have that "problem" anymore.

I figured out what caused it. I addressed every element of that causation. The problem went away. It's not complicated. But it does take some work that you cannot get done at..... THE DEALER . You have to get dirty.

It is able to do pretty much what the Tactrix cable does. You can log and you can flash images. Getting it to work is not always a straight-forward process and that's where the Tactrix cable is better. If you are on a tight budget and you're willing to work out the problems, the VAG-COM is a good alternative.

If you're on that tight a budget, doing reflashes may not be for you .

this issue has nothing to do with the tranny. it's a DBW ISSUE. (talking about the revs hanging in sport#)[/quote

 

Mr. Pumpkin, you don't know what you are talking about.

 

It is absolutely amazing that after more than four years some people still don't know how the 5EAT works.

 

I had the car at 3/4 throttle today (sport mode) and got it up to 5k RPMs (probably doing 75mph - not sure what gear) when I let off the gas and it didn't shift to a higher gear. It stayed at 5k and slowed to 4.5k RPMs before it finally up-shifted, which lasted for maybe 4 seconds.

 

This is exactly how the 5EAT works. As said, it holds gears much longer in Sport mode.... both accelerating AND decelerating. If instead of keeping your foot off the pedal you had given it enough gas to resume speed instead of keeping it in negative acceleration/deceleration, it would have shifted. Instead, it was keeping you in the 'right' gear for performance driving, i.e., Sport Mode.

 

Next time just give the stick a quick flick to the right and back. That'll cancel whatever is going on in Sport, returning it to Sport will start it 'learning' what to do all over again.

 

It is a 'smart' transmission, with G sensors and a TCU, and adjusts a number of performance characteristics appropriate for conditions. Learning how it works under all those conditions will increase your ability to use it to your advantage.

There are some that are running rear adjustable lower control arms, which enables a lot of negative camber dial-in, at the expense of torquing the rear LCA bushing. Hardening (removing the air space) the rear front LCA bushing would prohibit this for those going this route.

Off topic, but could you point me to some links... for both that adjustable arm as well as words by those using it? I'm curious, as I don't see how that bushing could possibly influence camber one way or the other. That is one heck of a component to be replacing, it looks like a forged piece and holds the entire rear wheel/brakes/etc. One would think such a performance piece would come with significantly better bushings than the POS (performance wise, not NVH) stock ones.

^ And if you do install a hard front bush in the rear LCA say goodbye to any significant camber back there as that is where most would be getting it. Short of installing top camber plates.

 

As Uncle Mat says, camber via the rear LCA is hack.

The idea isn't to install a hard bushing in the rear arm, but to eliminate the "air pockets" just as is done for the diff bushings. Actually removing and replacing that bushing would take effort significantly greater than the worth.

I have eliminated the "air pockets" in those bushings just as I did in the diff bushings, with PCV inserts and 3M Poly goop. It would be difficult to apply a fix similar to the WL inserts for the rear diff bushings. That is, if there are any inserts that would fit. But it is necessary to address them somehow, in a similar manner, if control of the rear tires is desired.

With all the bushing modifications plus the transmission insert/bushing I have NO NOISE under almost all conditions. Once, on a bad surface, with torque brakeing to 3200rpm I had one event.... once. Otherwise I can take off at 4.2 to 4.5 0-60 times all day long without any noises whatsoever. ALL the car does is leap forward.

As for alignment, camber or otherwise, that rear arm bushing doesn't control it, nor is the rear alignment adjustable. By centering the bolt/bushing in the rubber bushing with inserts, then solidifying them in with the 3M poly, the rear tires stop having the ability to try and outrun each other, back and forth. Also, after coilovers and lowering, plus firming all the aforementioned bushings as well as installing the poly front LCA bushing (an almost necessary mod IMHO), my tire wear has been perfect through two sets of tires. I added a little front camber on purpose. with the adjustment bolt.

FWIW I put in my WhiteLine Diff insert.

 

I still get the noise.

What is the complete list of your mods addressing this issue now? In reading over these past posts I do not see anything about the REAR LCA FRONT bushing. While I sure wish that WL diff insert were around a couple years ago when I was working on this, making light of what was a messy job however effective.... without a similar modification to the REAR LCA front bushing you're only removing flex in HALF the equation in the rear.

I'll say it again, anyone who drag raced one of the muscle cars in the past knows that one of the FIRST things you did was replace/modify/augment or otherwise FIX the lower control arms that located the rear axel. While the modern independent rear suspensions introduce a lot more areas of flex compared to a solid rear axel, the fact remains that without an almost solid lock on the positioning of the two rear wheels relative to themselves and the chassis.... you are going to have the two rear wheels acting independently under power! This breaks things. It also makes noise, your alert that 1) you're losing traction, and 2) keep it up and you will break something.

In the end, even with each and every little rubber bit tightened with kits and inserts and rubber, depending on horsepower and the violence of the launch, there will still be the "noise" everyone is trying to get rid of. Get over it. There is only ONE way to end it, solid metal bushings. But since these are street cars no one wants that.

Therefore, address ALL the bushings to the degree you can tolerate and live with the remaining flex. In doing so you will have moved the "problem" (one you created by giving your LGT more power than it was designed for, and operated in a manner it was not designed for ) high enough up the scale that it won't be a problem except in extreme abuse.

Oh, I wasn't arguing with you, I totally agree. My intent was to provide you the opportunity to say what you just did .

There is far too little emphasis put on what you are highlighting here. People are tuning up a storm everywhere with ST, Enginuity, Romraider, cable this and cable that, and are largely unaware of how disastrous their actions can be. Familiarity is breeding contempt for the repercussions.

You may save a bunch of engines if people read and take this seriously.

Good thread as usual LBGT.

But if there is such a thing as DA, FBKC, and all the rest of Subaru's knock handling ability, for which it is much praised, then why the concern? There are even special maps for when knock gets so bad all the normal maps don't work anymore. Given the variability in fuels these days, added to all the environmental variables, it would seem impossible for any car to be det free all the time.

Back when I got my AP the Cobb maps almost always had some pulled timing. Later, on TDC eTunes the same pattern was there. No one ever said a couple of degrees of DA being pulled was terrible. The only warning was to make sure it never went into MINUS DA.

Is the point of this thread to assist in the development of a well rounded tune? Or is it pointing out that having anything other than perfect DA is a motor killer.

If this motor is that sensitive and that fragile then a) Subaru's knock control is a joke, and b) abandon all hope for a long lasting turbo motor because perfect DA all the time ain't gonna happen.

Do's anyone one know if my car is top feed or side feed going to by delets

You might want to research a little more before jumping into deletes..... but your 06 LGT has side feed injectors, to answer your (I think) question directly.

My latest avo380 tune with some unique tuning you might all appreciate.

 

The actuator is "lazy", at the moment it seems to me that the avo (among others) actuator has a different internal design than the OEM actuators that really makes them unsuitable for highly responsive ECU control. There's a very large delay in changing the pressure in the actuator which delays movement of the door, which means boost is slow to change in either direction. With my turbo this becomes an issue over 4000rpms where boost rises very quickly, even with no WGDC the actuator will not respond quickly enough to prevent a boost spike due to the internal volume. Based on this theory I've done the following to my tune, and it works incredibly well for "normal" driving - going WOT after a shift. Boost gauge needle looks like it hits a brick wall, and stays there. On a dyno it may be disappointing because you may never hit the WGDC plateau (look at TD proportional at 0 psi!!!). Spool in 3rd+ from a digg may be slow too, but no one does this outside of a dyno pull. The OEM actuators seemed to be designed around this but I simply haven't had the time to take one and modify it to fit the avo.. It will require a lot of welding a cutting that I don't have the time to do right now. If anyone can source me one, especially on that has a flat mounting plate attached (VF34's I think) feel free to let me know. TD integral is also set with maximum response values across the board - this is again mostly a function of the actuator volume. Pretty much sucks imho.

 

The other thing to notice is the primary fuel map, it's been modified to have stable cold start idle when you have TGV's deleted. The number you have to beat is 14.41, I turned mine up a bit to save fuel on cold start, but you could easily make this lower for better cold starts if necessary. Pay attention to the load columns. If this doesn't make your cold starts rock solid - replace your front O2 sensor.

And then there is...

Hey guys - Whiteline has released an insert kit for the 08 Impreza that fills the voids. We're wondering if it would also fit the leggy. Anyone want to swing by the shop so we can take a look?

And while you're at it (assuming you are referencing the rear diff's top two mounts), see if they fit the rear LCA forward bushings as well. If so, this insert would be most of the answer.

Recall on the wheel bearings????? More info or link?

You haven't heard about this?

I hadn't either but Subaru sent me some paperwork and later paid me every cent I paid, about two years ago!, to get one of my rear wheel bearings replaced. I'd decided to get someone I trusted to replace it instead of the local "dealership," who had demonstrated their incompetence. I willingly paid out of pocket for it. All I had to do to get reimbursed was provide copies of my receipts along with Subaru's paperwork. Amazed me.

There isn't any TSB # on the letter they sent me. As a registered owner of a "2005 or 2006" I was being notified that either one or both of my rear wheel bearings could be bad........etc. They advised that the warranty coverage for my rear wheel bearings was being extended to "8 years (96 months) or 100,000 miles, whichever occurs first."

"Subaru of America, Inc

Attention: Legacy/Outback Rear Wheel Bearing Extended Warranty Program

P.O. Box 6000

Cherry Hill, NJ 08034-6000"

what exactly does the restrictor pill do? If im going to get a pro-tune stage 1, should I have my pill changed so I can have more aggressive boost?

The answer to your first question.

http://www.cobbforums.com/forums/images/HowSubaruFactoryBoostControlSystemWorksv109.pdf

The answer to your second question is NO.

Here are the ones I have from my notes for RomRaider. Not sure if you can see them all from ST (don't have it).

 

P2004 - TGV - INTAKE MANIFOLD RUNNER CONTROL STUCK OPEN (BANK 1).

P2005 - TGV - INTAKE MANIFOLD RUNNER CONTROL STUCK OPEN (BANK 2).

P2006 - TGV - INTAKE MANIFOLD RUNNER CONTROL STUCK CLOSED (BANK 1).

P2007 - TGV - INTAKE MANIFOLD RUNNER CONTROL STUCK CLOSED (BANK 2).

P2008 - TGV - INTAKE MANIFOLD RUNNER CONTROL CIRCUIT / OPEN (BANK 1).

P2009 - TGV - INTAKE MANIFOLD RUNNER CONTROL CIRCUIT LOW (BANK 1).

P2011 - TGV - INTAKE MANIFOLD RUNNER CONTROL CIRCUIT / OPEN (BANK 2).

P2012 - TGV - INTAKE MANIFOLD RUNNER CONTROL CIRCUIT LOW (BANK 2).

P2016 - TGV - INTAKE MANIFOLD RUNNER POSITION SENSOR/ SWITCH CIRCUIT LOW (BANK 1).

P2017 - TGV - INTAKE MANIFOLD RUNNER POSITION SENSOR/ SWITCH CIRCUIT HIGH (BANK 1).

P2021 - TGV - INTAKE MANIFOLD RUNNER POSITION SENSOR/ SWITCH CIRCUIT LOW (BANK 2).

P2022 - TGV - INTAKE MANIFOLD RUNNER POSITION SENSOR/ SWITCH CIRCUIT HIGH (BANK 2).[/quote

 

Of course ST can address them. Your list is correct.

Man.... I dread doing that work.

Bushing work sucks!

Word!

Nothing about it is easy. But the rewards are worth it...... or were for me.

And I do not make the noise anymore, in any temperature or under any circumstance......

Where once the wheel hop and driveline flailing, directly or indirectly, caused failure of a rear diff and a rear axel, the car now does what it's asked without complaint. Most was eliminated by my rear diff bushing mods. The rest went after I modified the rear lower control arms' front bushings, and installed the Rallitek transmission support insert.

I was not able to rescale any maps and keep it within the size limitation. I did only tip in and any necessary base map changes and left everything else in the rt

Unfortunately, without changing, at a minimum, Primary Fuel and Timing and DA scale values one cannot tune for a larger turbo, nor a highly tuned VF40 for that matter. Scale values are only saved in the base map.

As I developed my tune I found some things were mandatory in a Base Map and some things were not. Scale values are. Tip in is another as well as FIBET. Luckily, Cobb's 1.16 starts with many of the base map values I could live with. Over time I would attempt to change a value just to see how it affected memory restraints, learning what could be changed after the mandatory items were attended to.

I found it best, though time consuming, to start with a fresh copy of my Cobb ST format 1.16, address load scales, CEL toggles, and other must-have base map changes.... then experiment with what other changes I'd LIKE to have one by one, saving the map incrementally so I'd know how close to the edge I was getting. Not everything affects memory the same.

Yup, I plan to re-install the stock intake. I have the flow test page from DW and a calculated base number for the injector scaling(3563-ish) and they are modified stockers so the latency should remain the same as or close to stock. I guess I'll just have to get up early tomorrow and just do it. Hopefully, it will let me change that injector scaler number upfront without too much hassle. Other than that, I think I have the rest covered for the moment.

FWIW, my DW740's are scaled to 3654.

Only Tip In and FIBET are base map only tables, that you can deal with later. You can adjust scale, etc., in the RT tables and install your RT, revised separately from the Base Map, after the Base Map is first installed. You never need start the car of course until both maps are loaded.

To keep within the memory restrictions of my APv1 I have had to keep the changes in the Base Map to the barest minimum. Things like rescaling your fuel and timing maps are necessary, but actual fuel or timing data is not. And so forth.

The Cobb directions are pretty clear...I believe it's (just download the pdf): unmarry the AP, load ST on computer, load ST on AP (it MUST be unmarried...ask me how I know...), load an ST base map using map manager, marry AP (with ST) to vehicle using ST base map. Go forth and tune.

If you have other than stock injectors or an aftermarket BCS, for example, I suggest that after all the unmarrying and remarrying is done, that the base map you first install have those items tuned for. I used Cobb's Stage2 93 1.16 as a base and modified its BASE MAP tables for those parts. Since I have TGV deletes, and CEL codes can only be turned off or on in the base map, I had to accommodate those as well.

In addition, review each and every BM table. Some will need a tweak, most will be fine. Because flashing a base map is more complicated and time consuming (as well as potentially dangerous), I try to make sure my base map is as complete as possible.

Almost all the 'tuning' you'll do will be done using Real Time maps, wonderfully accomplished with Cobb's real time tuning. You will almost certainly have to have, therefore, a Real Time map to accompany that Base Map you first install. Thereafter each tuning session with ST will end with the RT map that is in ST on your laptop, in your car's ECU as well. I tend to save these day-to-day changes in uniquely named RT maps so I don't inadvertantly lose them (I have countless maps saved in folders after a year now )

Take your time, get the Base Map right, and you'll find tuning fun, addictive, and a satisfying last step in your control over your car.

Get familiar with all the different sites with tuning forums. Cobbforums, Nasioc tuning section and even RomRaider. This will help you greatly when starting off and even later on.

^^^ in a nutshell.

Plus, be very cautious. Do everything in small, measured, steps.... then log log log.

Turn in Concept's 08 STI is one sexy ride. I saw it out on track at Autobahn Country Club the end of last month.

 

I've got my bushings filled with the poly goo and 70% or more of the NVH is gone with this fix. I'm actually considering removing the rear suspension and subframe (if this can be done with all bolts) and having a local machine shop create some solid aluminum or delrin bushings for the rear diff carrier and control arm bushings.

While the 'poly goo' is some really great stuff and makes this mod possible, in my experience it isn't enough alone to do the job here. I tried a variety of things before coming up with what worked best for me; the PVC inserts I described earlier, all then molded together with the poly goo. Because of how well the poly really works, however, once you have it firmly in there removing it to do something else, like put some solid inserts in, may prove VERY difficult to impossible. Therefore, think hard about what to do.

The PVC inserts I used are incredibly easy to fashion, requiring but minutes with a hacksaw to cut. It is that messy goo that's the pain , requiring one's fingers to properly fill, shape and mold things properly. And, DO NOT MOVE THE CAR FOR ONE FULL DAY AFTERWARD. It takes longer for the poly to harden, but you can drive it, CAREFULLY, after a day. Two days is even better. If you rush it, and drive before the poly has hardened enough, the mod will not be wholly effective. For me, that was a tough thing to do.... modify the car and let it sit for a couple of days, but I did.

Later I did the same thing to my rear LCA front bushings. They are a lot harder to do and get to, but are a necessity to do. Finally, I installed Rallitek's original (large!!), hard, transmission support insert (for my 5EAT).

I no longer have the driveline noises that plagued me for over two years, and I have a lot more horsepower now. (Those "noises" were the result of driveline movement I am convinced broke my rear diff and, possibly, rear axel.) No need to rip things out (although I did a lot of ripping out along the way )

On that subject of removing the rear subframe so aftermarket bushings can be installed: any manufacturer who is silly enough to market one will lose money. If you've ever replaced such a bushing, like I did with the front LCA bushings, you know the degree of difficulty involved. If people think a little PVC and 3M WS Poly is tough..... try multiplying that a few dozen times. Furthermore, the rear diff bushings are but PART of the solution, you'ld need ones for the rear LCA's front bushings as well.... etc.

As far as solid bushings, I don't think anyone wants to do that. Unless one has a track only vehicle, totally modified for the purpose, solid bushings would be too punishing. As it is, these more firm bushings changed the nature of my car, NVH wise. Just having a car that works without protesting, however, makes it well worth it to me.

Finally, if an aftermarket insert, like the one for the transmission mount, could be crafted of a hard enough material and filled the spaces in the bushing(s) (remember the LCA) it might work. But then, so does a little PVC and some goo .

You fixed your car. You found something that works for your situation. Good for you and thanks for sharing.

You're welcome...... but after 33 pages and almost 500 posts on the subject of

Growling noise in rear while accelerating hard in 1st or 2nd ??

I don't think my "situation" is unique. With some relatively small variations on the theme our car's suspensions are about like human bodies, different by far smaller degrees than they are the same.

Similarly, it doesn't take a rocket scientist to suspect that a cure for one just might be a cure for others with the same problem. Thirty three pages. Nearly five hundred posts. Most who post have not addressed their cars in the manner of the few who report successful treatment of the problem. Talking about it and wishing for some gadget magic won't get it fixed.

Sarcasm aside, the source of the "Growling noise in rear while accelerating hard in 1st or 2nd ??" isn't some anthropomorphic bolt back there taunting people. What it is is what I said it is . Take the slop out of YOUR driveline and suspension and YOUR noise will go away, too.

It would be nice if a trusted vendor suddenly announced a package full of goodies guaranteed to end the Growling noise in rear while accelerating hard in 1st or 2nd ??. I'll say it again, ain't gonna happen. Too hard to fix that way, for too few people. No money to be made. Which leaves people to continue to wring their hands and pound the keyboards in vain.... or get under their car, get dirty , and do something that makes sense to correct it.

Did I mention I fixed mine?