CovertRussian's 2000 Infiniti G20 - SR20DE+T & 6 Speed

[covertrussian]

Finally got to autocross the car with the panhard bar. The results were amazing, the car was rotating really well, and this is with 8k rear springs, no rear swaybar, 32f/38r psi's, and crappy front left alignment. If your gonna race any beamed Nissan this mod is a must, I would argue it should be the second mod you do (with first being coilovers), the difference is that drastic!

 

Usually a mod to this car will make the car handle better on the street, but when I would go autocrossing I would fairly disappointed. This setup was not as impressive on the street, but surprised me with how well it rotated while autocrossing.

 

Some pics from yesterday:

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Pics/Racing/AutoX/2017-0521_001.jpg~original

 

New profile pic time!

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Pics/Racing/AutoX/2017-0521_002.jpg~original

 

Get some camber adjustability in there? Top hats?

 

Sadly it's not that easy on these cars. Since it doesn't have a McPherson Strut, you can't just get new top hats or slot the shock mount to gain camber. You have to get shorter upper control arms

 

Here is what the suspension look like:

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/Cusco%20UCA/CuscoUCA_02.jpg~original

 

I used to run those Cusco control arms, which are 10mm shorter then stock arms (gaining about -1* of camber). But the bearings went shot in them and I went back to running the stock arms, but with a modified rear bracket to raise the roll center back up.

 

Now that my rear end has been fixed, I'm still rolling over the front tires, so it's time to add camber with those Cusco's.

 

Perhaps I missed it; is there a dyno plot with the tune/turbo?

 

You know I haven't gotten around to posting a turbo one. She's making too much power for autocross, so I haven't been worried about it. Infact I've been considering detuning it a bit

[covertrussian]

Speaking of gaining camber and upper control arms, here is the mods that I did to help this car gain more dynamic camber. Shorter arms do help with some static camber, but not quite enough.

 

Measured the camber curves of couple different setups, Stock UCA's, Cusco UCA's, and lower mounting points. I measured these at the hub, the angle gauge was set to 0 at stock height then I moved the suspension from 50mm (2") rebound and compression. Car is about 1" lower then stock, these measurements treated that height as the static height. The reason I stopped at 2" compression is because the suspension was topping out with tires on and the third link would rub against the inside fenderwell.

 

Before we begin, I encourage you to read this page, to understand how to read this kind of a graph properly.

 

Lets start with Stock UCA vs the 10mm shorter Cusco UCA, which gain us about -1* of static camber:

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/UCA%20Mounts/P11CamberCurve_StockvsCusco_StockMount.png~original

 

Not only do the shorter UCA's gain more static camber, the camber curve also becomes more aggressive. Stock arms stay at 0* camber for quite a while, you have to compress the suspension almost 0.5" before any camber is gained. For stock soft suspension this might be fine, but not for stiffer spring setups.

 

Next I lowered the UCA mounting points, the new holes should be about 15mm lower and 5mm back. This is called the Guldstrand Mod.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/UCA%20Mounts/RearMount_15mm_01.jpg~original

 

Not only do the attachment points raise the roll center, they also alter the camber curve. The new location made the camber curve be a much straighter line. What's interesting is, the longer stock arms and the shorter Cusco's have a very similar camber curve.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/UCA%20Mounts/P11CamberCurve_StockvsCusco_15mmLower_5mmBack.png~original

 

 

Finally lets compare each UCA's stock location vs lower mounting point.

 

Stock UCA's show a tremendous improvement from being mounted lower and gain camber much faster:

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/UCA%20Mounts/P11CamberCurve_StockUCA_Lower.png~original

 

Shorter UCA's also saw a very good improvement over stock mounting holes, I drove on this setup for a while and it simply transformed this car into something else. Front end had a lot more grip vs stock mounting location.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/UCA%20Mounts/P11CamberCurve_CuscoUCA_Lower.png~original

[fedaykin]

Ahhh, my R32 GT-R has similar design front suspension (wow I'm surprised they put that in a G20/Primera and not MacPherson struts). I have adjustable upper arms, similar to yours. Mine is able to rotate so it doesn't destroy the bushes in a week. I run -2.5°/-1.5° (f/r), but of course my car is totally different to yours.

[covertrussian]

Ahhh, my R32 GT-R has similar design front suspension (wow I'm surprised they put that in a G20/Primera and not MacPherson struts). I have adjustable upper arms, similar to yours. Mine is able to rotate so it doesn't destroy the bushes in a week. I run -2.5°/-1.5° (f/r), but of course my car is totally different to yours.

 

You know I wish the Primera's would have just came with McPherson struts stock. A well setup strut is not only simpler, but can be setup to be much better then our complex binding multi-links.

 

Which UCA are you running, I've seen prototype one that rotate, but not production models? Sadly P10/P11 UCA's are a bit different the R32/Z32 ones, and there is no real aftermarket to make a rotating UCA. Here is what our arms look like:

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/Cusco%20UCA/UCA_Stock-Cusco.jpg~original

 

How much shorter did you make your UCA's then stock to gain -2.5*? Or are you pretty low? Cusco -10mm arms got me -1* of camber tops, and being 1* lower gained me another -0.5* camber, I would love to get -2.0-2.5...

[fedaykin]

This style (just a cheapie with spherical bearings).

http://pics.driftworks.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/r/3/r32-camber-arms.jpg

I actually left the two rings slightly loose so it moved (no issue after almost 5 years), not "proper" pivoting arm like UAS's design

 

Sadly it looks like P10 mounting points are too much offset so you'd need fancy pivoting arms. But hey, looks like your drilling mod works.

[covertrussian]

Keeping those rings loose is probably why they haven't broken on you yet!

 

I remember seeing these guys, they look awesome.

[covertrussian]

Dug around found the dyno run logs from when the motor was stock (just with 3" catback, with 3" OEM STI muffler, all from the turbo days before stock motor went back in).

 

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Dyno/G20%20RR%20Stock%203in%20Catback%20vs%20GT28r%209psi.png~original

[fedaykin]

Keeping those rings loose is probably why they haven't broken on you yet!

 

I remember seeing these guys, they look awesome.

Haha yeah I got lucky and unintentionally left them a little loose.

I even bought a pair of Hardrace (rubber bushes) upper arms in anticipation of replacement (sold them as I didn't need it).

There's also GKTech's design:

https://www.sau.com.au/forums/topic/450923-gktech-r32-gtrz32-front-upper-control-arms/

Maybe you can get him to modify his design for your application and do a group-buy run?

[covertrussian]

I saw those before too, they look nifty, just not sure it's worth the complexity. I found replacement bearings for my Cusco's, and cheap at that. I'm not sure I want to go all that much shorter then -15mm from stock, since our arms are relatively short compared to other SLA suspensions, you run the risk of instant center changing too drastically.

[covertrussian]

After about a year my Cusco UCA bearings were shot. After they set on my shelf for about a year I finally decided to find replacement bushings. Turns out Cusco uses what's called shielded bearings (part number: 6203Z), but they are not sealed, aka shielding doesn't do anything to prevent water or dust from getting in.

 

After doing some research I found sealed bearings that fit perfectly, and only cost $1.50 a bearing on Amazon!

 

Sealed bearing part number: 6203-2RS

Bearing Dimensions:

OD: 40mm

ID: 17mm

W: 12mm

 

These new bearings fit perfectly. Old bearings are on the ground on the right.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/Cusco%20UCA/20170524_175716.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/Cusco%20UCA/20170524_175819.jpg~original

 

Removing the old ones is real easy, just take a long screw driver and stick it inside one of the bearings and tap the other side's bearing out. I easily pressed mine in with a shop press, but I bet you can do it with a hammer or shop vise too.

 

Installation

 

Last time I installed these I noticed that I had to keep on tightening the bolts for longer then usual. What I didn't realize is it was bending the 3rd link in. This became a big problem when I went to install stock UCA's, they wouldn't fit, so I had to bend it back out. It still wouldn't fit the SuperPro bushings that I just installed, which is why I decided to rebuild the Cusco's instead.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/Cusco%20UCA/CuscoUCA_04.jpg~original

 

This time around I used a washer to make up for the arm being narrower.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/Cusco%20UCA/CuscoUCA_05.jpg~original

 

Arm is installed and here is what it looks like at full compression.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/Cusco%20UCA/CuscoUCA_06.jpg~original

 

Driving Impressions

This should get me about -1.7* of camber and with how this suspension design works, should gain some caster. I'm not sure I'm curious enough to pay $30 to find out how much caster the shorter UCA's might have gained.

 

With lowered UCA rear mounts (raised front roll center) and lowered rear roll center, these shorter upper control arms made a HUGE difference. I don't recall it making such a big difference when I first installed the UCA's. With my current tires (which are wearing badly on outside shoulders by now), I was able to push the car above my limits in some turns.

 

I think these tires could use a bit more camber, but there isn’t much that I can do (out of the box) to gain more camber (besides slamming the car, which I refuse to do). Thus I'm starting to look into maybe doing offset front LCA bushings.

[covertrussian]

My current summer tires are almost gone, so it was time to start shopping for new tires. I was also looking for something wider then 7.5", but with 4x114.3 bolt pattern the options are non-existent. Thus I was pretty happy to find these wheels in 17x9" with 17mm offset.

 

Normally I wouldn't want to go with that low of an offset due to scrub radius issues, but my car has SAI of 17* with stock UCA's, probably almost 20* with shorter upper control arms. Thus moving the wheels out should actually put my scrub radius into a more favorable point (should still be negative like FWD cars like).

 

Old tires are Cooper RS3-S (on the left), new tires Yakohoma AD08r (right). Even though new tires are only 10mm wider in the section width, AD08's tend to run wider tread width then most tires so in reality these tires are 20mm wider.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170602_183018.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170602_182945.jpg~original

 

 

225/45/17 on 7.5" with 40mm offset is about the max you can run without hitting the suspension components.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/Cooper%20RS3-S/20170602_082312.jpg~original

 

Going with 17mm offset gave enough clearance for 9" wide wheels and might actually fit 255's.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170602_183607.jpg~original

 

Plus new wheels/tires are no longer rubbing against the body/transmission.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170602_184020.jpg~original

 

 

So we got suspension clearance, but that came at the cost of more poke and fender clearance.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170602_181717.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170602_181741.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170602_181646.jpg~original

 

 

Rear is also having fitment issues, saggy butt fenders also reduce the clearance, looks like I'll be running negative rake.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170602_185731.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170602_185725.jpg~original

 

 

Removed the front shock and checked if it would clear the fender under compression. Even with -1.7* static camber and with SLA suspension I was still hitting the fender after 1" compression.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170608_190730.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170608_190748.jpg~original

 

Checking clearance with the wheel being compressed, These tires are wide!

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170608_191340.jpg~original

 

After more fender rolling and lots of pulling (will post pics later) got the wheels to fit. Front fits good with no rubbing now, had to raise the rear 10mm to get it to stop rubbing against the inner fender wheel (it's double walled). On the flip side, these tires increased my track width by about 3" (don't know for since I didn't measure with with the shorter upper control arms).

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170610_174945.jpg~original

 

All done for today, personally I like the wider stance that these wheels provide, looks beefy.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Wheels/Drag%20DR48/20170610_174956.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Wheels/Drag%20DR48/20170610_175722.jpg~original

 

 

Impressions: Tires are still new and greasy, once I break them in will have better data, but so far they are holding real well. They didn't break loose in first gear until 6k rpm, no torque steer or wandering, which is common for wider tires. When I finally got the front tires to break loose in a turn, the rear was breaking loose right behind it, so it's becoming a much more neutral car.

[fedaykin]

Time for some flares, or wide body

[covertrussian]

Yup that's the end goal, thats why I didn't mind trying to pull them, if all else fails there is flares option.

 

The only downside is, flares and my other wheels will look silly. Might need to run some wheel spacers.

[whitetiger]

time for flares, Penskes, and 285wide Hoosier A7's. that way you can show SMF a good showing.

[covertrussian]

New tires and low offset wheels were not happy with even my rolled fenders and slightly pulled fenders. I needed to pull them more.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170608_190826.jpg~original

 

Here is what the fenders looked liked after I rolled and pulled them last year, as you can see the fender is beveling out compared to the bumper (where before it was more flush with the bumper). I've been wanting to pull the bumper mount part out to make it more even.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170610_122710.jpg~original

 

This time around instead of a bat and phone book, I actually got a fender roller (which are stupid cheap nowdays at around $50). Started rolling and pulling the lip out.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170609_195223.jpg~original

 

As expected, it started buckling around the lip, even with good heat, the metal is just getting too old.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170610_104740.jpg~original

 

To pull the bumper mount out I used the roller and another high tech tool....

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170610_134755.jpg~original

 

While working on it, you don't really see the difference, but after I installed the plastic weather guard, I was pleased with how much it actually pulled out, bearing in mind that around 1/2" of the plastic goes inside the bumper, I would say I pulled almost 1".

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170609_202045.jpg~original

 

Here is how much pulling the lip out gave:

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170609_202052.jpg~original

 

Test fitting the wheel, yay it finally clears.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170609_202458.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170609_202509.jpg~original

 

Up close of how much the fender pulled out, and of course the buckling (which actually is not as noticeable in person)

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170610_104749.jpg~original

 

 

Moving on to the rear... The rear is more painful to deal with, for one there is an inner fender that will prevent you from being able to pull out the outer fender. Rear also has less droop, thus I couldn't really get the roller into angles that I wanted, and when I did the head would turn, thus I had to add another high tech solution to keep it form moving down.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170610_115608.jpg~original

 

After fighting with it for a while I finally got the rear outer lipped out to clear the wheel, actually turned out good. I jumped on the trunk and rear door frames, and didn't hear it contacting or anything.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170610_122009.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170610_122013.jpg~original

 

Went for a test drive and heard the dreaded rubbing sound. This time it was rubbing against the inner fender well, which is V shaped.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170610_164920.jpg~original

 

Resorted to some body hammer persuasion, that and raised the rear 10mm (which is now about 1/2" lower then stock). This reduced most of the rubbing, but heavy bumps it still rubs. Sadly all this tire contact made the rear fender buckle a little too, so it no longer looks as nice as in above pics.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170610_165455.jpg~original

 

 

 

Finally the side by side shots...

Here is what the fender looked like after rolling and very slight pulling 2 years ago on 225/45/17 on 17x7.5" ET40's.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Rolling/FenderRolled_001.jpg~original

 

Here is what it looks like with the 0.9" wider 235/45/17 on 17x9" ET17's. Now this side is facing downhill, thus has less camber.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Tires/AD08r%20235-45-17/20170602_181717.jpg~original

 

Finally, what it looks like after all the fender pulling.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Exterior/Fender/Pulling/20170610_174945.jpg~original

[fedaykin]

Bloody hell you're a brave man on those fenders haha. Also, clear up your headlights.

[covertrussian]

Too busy making the damn thing handle well . I'm cleaning the headlights almost once a year using headlight cleaners, trying to find a more permanent solution...

[BarManBean]

Too busy making the damn thing handle well . I'm cleaning the headlights almost once a year using headlight cleaners, trying to find a more permanent solution...

 

You ever try thinned urethane? I think that's one method, would have to double check for sure tho!

[covertrussian]

I haven't, but it sounds interesting for sure, found this how to.

 

I've tried using spray clear coat, that worked horribly so had to remove all of that... Urethane method sounds much better.

[covertrussian]

While I was testing the new wheel fitment, I measured the camber curve and got an idea to measure the caster curve. Since our upper control arm is mounted to the back of the car, it gains camber (lazily) and caster during compression, thus I was curious how much caster it would gain.

 

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/UCA%20Mounts/RearBracket_Lower_and_back_Caster%20Gain.jpg~original

 

This curve is with 10mm shorter Cusco UCA's which should have a more aggressive caster curve. Unlike camber curve, where negative gain is good, with caster positive gain is what you want.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Upper/Cusco%20UCA/Caster%20Curve%20-%20Cusco%20UCA.png~original

 

Raw data in case image goes away:

Travel	Change	Total Caster
-1.97	-0.4	4.1
-1.57	-0.4	4.1
-1.22	-0.4	4.1
-0.83	-0.2	4.3
-0.39	0.00	4.5
0.00	0.00	4.5
0.43	0.20	4.7
0.83	0.40	4.9
1.18	0.55	5.05
1.57	0.95	5.45
1.97	1.40	5.9

 

Starting caster is 4.5*, at least it is with stock UCA's, haven't measured new caster with shorter Cusco UCA's yet.

 

At 1" compression the suspension gains 0.5* of caster, giving me about 5* total caster, by 2" of compression I'm almost at 6* of caster, which is RWD caster territory. This much caster would start causing torque steer issues on a FWD car, but since it only comes dynamically downsides of caster are not as noticeable.

[covertrussian]

I've been curious about what alignment changes Cusco front UCA's would bring. Obviously they add camber, but it also should change the SAI and Caster due to the angle that the upper arms are mounted at.

 

I put on my old 17x7.5 et40 wheels for this, but didn't get a chance to lower the rear back down, toe was adjusted between these too, besides that the main change was the 10mm shorter Cusco UCA's.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Alighnment/G20%20-%20Cusco%20FUCA%20and%20Positive%20Rake.jpg~original

 

For comparison sake, here is the stock UCA alignment numbers.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Alighnment/G20%20Alighment%20-%2005-19-2017.jpg~original

 

 

Take aways:

• Cusco 10mm Shorter UCA's gained me an impressive -1.5* on both sides. This is definitely thanks to the Guldstrand mod, putting the arms into a more aggressive camber curve.
  
• Shorting the arms by 10mm also increased the Steering Axis Inclination. By 0.8* on left side and only 0.2* on right side. Looks like SAI increase is not linear to increase in camber (which is good!)
  
• I lost caster! This doesn't make sense, since the shorter arms should have gained me caster, it's possible that cusco's angle the arms slightly differently. Adding positive rake (raising rear up 10mm) does reduce caster, but I wouldn't think it would be as much as 1* though (and negating the arm gains too).
  
• Included Angle was reduced more then SAI was added, which is a good thing (less SAI = less positive camber gain when you turn the wheel).
  
• Raising the rear 10mm set the thrust angle to 0*. My panhard bar was also 5mm lower on axle side then body side, raising the rear 10mm made it be perfectly level.
  

 

My left is still not happy. Couple ideas on what it might be, my subframe could be shifted, my LCA could have shifted inward, shot LCA front bushing, or the alignment rack is off (which I highly doubt).

 

I walked around the car and pushed on each wheel attachment to make sure it was fully in, and at best camber would change 0.1* What was interesting is, when I got into the driver seat, passenger wheel gained camber, when I got into the passenger seat, drive wheel gained camber, does that make sense?

[covertrussian]

I used to run ES LCA bushings, but I really hated how rough it made the car be (was a daily at that time). I ended up pulling the ES bushings and installing OEM style bushings instead. While this helped the comfort, but there is definitely plenty of flex in those bushings.

Here is the OE bushing before I installed them last time:

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Lower/Nolathane%20Forward/LCA%20Front%20Moog%20Bushing.jpg~original

 

Before removing the oe style bushings, I tested the amount of slop they had by moving the lower mount by hand, and it would move quite a bit, contributing to camber loss in a turn. The fix is stiffer poly bushings...

 

I didn't really want to use ES bushings again, since they were so rough and ferrari21 noticed that ES Maxima bushings are actually too short for our cars. I started researching other bushings, I'm a fan of SuperPro's, but sadly they are also are shorter like ES ones. But Whiteline and Nolathane were a few mm longer. It also seems like Nolathane is the same as Whiteline, just rebadged (and cheaper).

 

Part number for Nolathane bushings that I got: REV028.0080

 

ES vs Nolathane: You can see how the Nolathane one is slightly longer and has a thicker bushing.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Lower/Nolathane%20Forward/G20%20LCA%20Front%20-%20Nolathane%20vs%20ES%20001.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Lower/Nolathane%20Forward/G20%20LCA%20Front%20-%20Nolathane%20vs%20ES%20002.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Lower/Nolathane%20Forward/G20%20LCA%20Front%20-%20Nolathane%20vs%20ES%20003.jpg~original

 

I extracted the OE style bushings with my die grinder (saved me the trouble of removing the arms). Afterwards these just pressed right in. The nice thing about these bushings is the knurling inside (Whiteline and SuperPro also has this). This helps reduce friction, retains grease, and probably increases comfort.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Lower/Nolathane%20Forward/LCA%20Nolathane%20Install%20001.jpg~original

 

Instructions call for reusing the OEM outside washer, but I didn't like that it didn't fully cover the bushing, so used a spare washers I had laying around.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Lower/Nolathane%20Forward/LCA%20Nolathane%20Install%20002.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Lower/Nolathane%20Forward/LCA%20Nolathane%20Install%20003.jpg~original

 

Everything tightened and plenty of threads left (bigger washers can interfere with this sometimes).

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Lower/Nolathane%20Forward/LCA%20Nolathane%20Install%20004.jpg~original

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Suspension/Control%20Arm%20Lower/Nolathane%20Forward/LCA%20Nolathane%20Install%20005.jpg~original

 

Testing

It feels like it helped reduce some slop, but not a night and day difference (probably because my other tires are getting too bald). The best part of all, it doesn't feel like NVH went up at all, which is a really a pleasant surprise.

[covertrussian]

I've been getting the car ready for track day, down at NCCAR, coming up this Sunday. Finally reinstalled the new wheels/tires, had to roll and pull the rear fenders more (due to rubbing).

 

One thing that I noticed again with this wheel/tire combo, is the car being unstable over bad roads, kind of bump-steery, I wrote it off as a typical big offset/wide tire syndrome. Since the car was professionally aligned in June and since wheels/tires shouldn't effect alignment I didn't bother checking the alignment after installing the new tires. Also I did verify the pro-alignment with my toe plates, and it was the same as the specs on paper.

 

Well I checked the front toe last night, and it was toeing out by 1/8"! The tie rods were guerilla tightened, so it didn't shift post pro-alignment. How on earth right, that shouldn't happen with just a wheel/tire change? Best I cam muster is, higher offset wheels change the leverage on the springs, so the springs are now compressing more, thus the car is sitting lower then it would be on the other tires. The car is much more stable now,

 

Has anyone seen their toe change with higher offset wheels?

 

EDIT: Just ran through some numbers, confirming that the suspension is lowered more on new wheel/tire combo.

Previous tires were 24.96" tall new, 24.84" at ~4/32's tread life left, New tires are 25.2" tall with brand new tread. SO new tires are 0.36" taller diameter, but we only care about the radius, which is 0.18", I like metric so 4.6mm. That's how much taller the new tires should make the car uniformly.

 

Old tires measured the jack points being 210mm off the ground. You would expect the new tires to be measured around ~215mm, but in reality the new tires measured in at 210mm too. Which means, while the car stayed the same height, suspension compressed 4.6mm. I don't have my bump steer mapped out, but 1/8" toe change doesn't seem so crazy now.

[covertrussian]

I've been wanting to rebuild the exhaust for years now. For one my axle back vband portion would hit the body, freaking people out on turns, while Autocross doesn't care, I needed keep those kind of noises to the minimum in preparation for an HPDE track day. The other issue I had was the slip in portion of the exhaust would walk out every couple months, even with the U bolt super tight. Combined all that with me needing the 5" resonator for the Legacy, it was time to cut it all up and rebuild. I'm glad I did because my 400 cel ceramic cat was cracked and starting to fall apart.

 

Being more scientific, I measured the before and after back pressures. Even with a restrictive bad cat, this setup only had 3.5psi of backpressure pre-cat. Curious about how much backpressure the muffler was doing, I removed it and that registered 2.5psi.

 

 

Started the build with the flange that bolts to downpipe, after welding the pipe inside the flange, I noticed some dead space between the pipe and the flange. To improve flow I used a hammer to flatten the inside portion and get it to be more flush with the flange. Then welded onto the resonator.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Engine/Exhaust/Catback/Exhaust%202017_001.jpg~original

 

 

Here I have the resonator, Dynomax 17296, and a metalic 300cel cat, Thunderbolt 415300. Since the new resonator, is a huge 6" can, it wouldn't fit behind the cat without hitting the body. Thus I had to make a quick judgement call and just install it pre-cat. If this causes any issues I'll redo it later.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Engine/Exhaust/Catback/Exhaust%202017_002.jpg~original

 

Then I had the fun time figuring out how to prevent body contact and still provide enough room for rear swaybar. Tacked it all up and welded it together. Here is the cat to axle portion.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Engine/Exhaust/Catback/Exhaust%202017_003.jpg~original

 

Installed on the car, here is the resonator and cat portion

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Engine/Exhaust/Catback/Exhaust%202017_004.jpg~original

 

This version of the exhaust now sits higher, which means I can finally use the little plate again, I may rebuild it and make it into a chassis reinforcement plate (it's too thin stock to do that).

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Engine/Exhaust/Catback/Exhaust%202017_005.jpg~original

 

Final modification was the the STI muffler. Years ago I drilled out the stock pipe and stuck in a 3" pipe all the way down. This made the car be a little too quiet from a distance, at idle it sounds deep and mean, but at full throttle it would get quiet (it sounds like a stock car when autocrossing). The perforated pipe on the right is the muffler exit

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Engine/Exhaust/Catback/Exhaust%202017_006.jpg~original

 

Here is the flow diagram of the stock muffler and the new modified version.

http://i160.photobucket.com/albums/t188/covertrussian/Cars/00%20G20t%20KH3/Engine/Exhaust/Catback/Exhaust%202017_STIMuffler_Modified%20Flow.jpg~original

 

 

Results

Now for the results that matter... it's a tad bit louder but you can barely tell from the cabin.

 

Back Pressure: This setup with muffler measured ~2psi of backpressure! This flow increase had an interesting result, the car stared missfiring/hesitating when doing the tests. At first I figured it was the ECU not being happy without the wideband (where I would put the EGBP probe). Seat of the pants power levels were about the same if not worse (didn't do any virtual dyno tests with it missing), This was confusing because spark plugs were brand new iridiums, though I did gap them to 0.035". I gapped them down to 0.030", went for a test drive and the car was a whole new beat. With my new sticky tires, second gear would cause major torque steer. Afterwards did some virtual dyno logs and the car was up by 10whp a very pleasant surprise, now at 250whp.

 

Next fun part is gas mileage: With old catback and 0.035" gaped iridiums I got 32mpg highway with my old 225/45/17 tires, which was down from even last year. After exhaust rebuild, new plug gap, and new sticky low offset tires (235/45/17), on the way to the race track I got 27mpg. I chucked it at tires being the issue, but I noticed the car did have too much power while cruising.

 

I'm already running a very minimal 23* of peak cruise timing at 2,700rpm (70mph), I can't imagine it wanting less. Figured I would try reducing the timing by two more degrees though, making it be 21* of peak cruise timing. Also, I noticed that telling NEMU to target 14.7 closed loop meant the ECU was swinging 14.2-14.9 AFR mostly, I raised the target AFR to be 15.0, which started keeping the AFR's closer to 14.4-15.3 range (more like other stock cars).

 

With these two tuning changes, on my trip back from the race track (I filled up after racing), I got a really impressive 39mpg! This further proves that doing power mods can also help gas mileage, but only after you tune for them.