Suspension Thoughts after 2000 Kilometer Alpine Tour + 10 hrs of intense twisties

[Roadway 5.0]

I think your ability to break the tires loose and throttle steer is as much to do with the ability to make the differential work better as anything. Your torsen will not be able to bias torque well or at all if the inside tire gets light, and softening the rear bar allows it to do that. Big spring/soft bar is best on the back of these cars for getting the power down. Having the midcorner balance be a little less oversteery helps too.

The Torsen not getting the juice to each wheel appropriately makes a whole lot of sense. There were times I pushed to get the back end to slide out and was denied; something that never occurred prior to stiffening the rear bar.

Sponsored

 

[Roadway 5.0]

Update: I found the reason why I can slide the rear a bit better these days, even after loosening my rear swaybar...

The photo below doesn’t do the lack of tire-tread justice; there are only a few millimeters remaining I guess an intense roadtrip will do this, even if the tires have only 10,000 miles or so

 

[Norm Peterson]

I'm thinking that the number of heat cycles the tire went through on the way to get worn that far has more to do with this than the amount of wear itself.


Norm

 

[Roadway 5.0]

I'm thinking that the number of heat cycles the tire went through on the way to get worn that far has more to do with this than the amount of wear itself.


Norm

Interesting. So cold-hot-cold cycles basically alter tire composition over time? Is this Pirelli notorious or does this effect all tires?

 

[BmacIL]

Interesting. So cold-hot-cold cycles basically alter tire composition over time? Is this Pirelli notorious or does this effect all tires?

Yes and it affects all tires, particularly summer tires. Pirellis have a high operating temp range compared with its competitors, so unless they're on track they don't get hot enough to work well.

 

[TheLion]

Yes and it affects all tires, particularly summer tires. Pirellis have a high operating temp range compared with its competitors, so unless they're on track they don't get hot enough to work well.

I can confirm the Pirellies definitely don't like to operate when cool or cold. Throw in rain and forget it, their traction is horrible. However once you start pushing the car repeatedly on warmer days and they heat up they do start to stick quite well. I think honestly they are a better track tire than a street tire. Most people say they suck and while that's true as a street tire due to temperature fluctuations and rain, I'm starting to realize they were designed more as a track tire at heart even though they come as an OE tire option for the street.

Ford marketed the PP GT's as "track ready" and they actually put a decent track tire on the car. Problem is they don't perform well in street applications, wear very quickly (I have a little over 7,500 miles on my rear Pirellies which were BRAND new when I bought the car, original owner worn then previous rears bald in 5,600 miles, my guess, drag racing or auto x, no signs of burnouts as there wasn't any rubber in the fender well).

They wear very quickly. My Pirellies in the back have maybe about 2k miles left on the tread already. So they are a 7k~10k tire for street use. However that does not mean there aren't better track tires with greater lateral grip and better tread life, but I don't think they would actually be a bad track tire even if not so great a street tire.

 

[Roadway 5.0]

I can confirm the Pirellies definitely don't like to operate when cool or cold. Throw in rain and forget it, their traction is horrible. However once you start pushing the car repeatedly on warmer days and they heat up they do start to stick quite well. I think honestly they are a better track tire than a street tire. Most people say they suck and while that's true as a street tire due to temperature fluctuations and rain, I'm starting to realize they were designed more as a track tire at heart even though they come as an OE tire option for the street.

Ford marketed the PP GT's as "track ready" and they actually put a decent track tire on the car. Problem is they don't perform well in street applications, wear very quickly (I have a little over 7,500 miles on my rear Pirellies which were BRAND new when I bought the car, original owner worn then previous rears bald in 5,600 miles, my guess, drag racing or auto x, no signs of burnouts as there wasn't any rubber in the fender well).

They wear very quickly. My Pirellies in the back have maybe about 2k miles left on the tread already. So they are a 7k~10k tire for street use. However that does not mean there aren't better track tires with greater lateral grip and better tread life, but I don't think they would actually be a bad track tire even if not so great a street tire.

I totally agree. The Pirellis really stick well when hot, and the feedback is equally as good when toasty. The problem is that they just take too long to get to maximum grip.

My plans for spring are either P4Ses, Continental Extremes, or some unknown tire that gives maximum feedback for a great price (I’ll sacrifice some grip for feel).

@TheLion What will you go to after your Pirellis wear out?

 

[TheLion]

I totally agree. The Pirellis really stick well when hot, and the feedback is equally as good when toasty. The problem is that they just take too long to get to maximum grip.

My plans for spring are either P4Ses, Continental Extremes, or some unknown tire that gives maximum feedback for a great price (I’ll sacrifice some grip for feel).

@TheLion What will you go to after your Pirellis wear out?

I'm planning on running Pilot Spot AS3+'s on my stock PP wheels for the winter (don't drive in the snow much as our Prius with snow tires work well in the winter, low torque + snow tires = awesome traction), but I do drive it on the "dry" winter days, so Pilot Sports will work well through the later fall, winter and early spring in lower temps that still permit some fun (alibiet more conservatively).

On my RTR Tech 7's I'm planning on running Pilot Sport 4S's. They are 23 lbs per wheel in a 4 square setup. So it will be a really nice street / light duty track setup. The car is mostly a performance street car right now. Maybe in a couple of years that will change, but right now I enjoy "sporty touring" of new back country roads which there are literally thousands of miles worth in this whole region. So it's endless exploration! Lots of fun and beautiful scenery.

Slowly I'm tweaking the car for occasional HPDE little by little. I also just got my alignment done FINALLY and did the installation of the Steeda Roll Center Correction and Bumpsteer Kit (did both at the same time).

So I'm now running the following:

1. BMR SP080's on stock PP struts
2. MaximumMotorsports Caster / Camber Plates
3. BMR CB05 IRS Lockout
4. FP M-5A460-M Toe Link Spherical Bearings
5. Steeda Roll Center and Bumpsteer Correction Kit
5. Ford Performance Power Pack 2 (dealer installed with warranty paperwork)
6. JLT 3.0 Catch Can (modified with an anti-slosh baffle)
7. TriboTEX MSH based DLC friction modifier (look over at the issues thread on the BBQ Tick threads or on the Ford Performance Power Pack threads for the MASSIVe amount of standardised testing and data I provided on this, most additives are indeed snake oil as they say, but this one is not and it's based on extensive R&D to address boundary, mixed and elastohydrodynamtic lubrication short comings of existing motor oils that rely heavily on ZDDP). For oil I'm running Mobil 1 5W-20 Advanced Full Synthetic with an OE FL500-S filter, change at 5k mile intervals.
8. Corsa Sport cat back exhaust
9. Steeda Tri-Axes Short throw + Ford Performance Aluminum shifter arm bushings (had them left over from the FP Short Throw kit I installed in my Ecoboost but never used the bushings, holy crap did they help shifting during power down on my GT, not sure why FP is the only one replacing the rubber shifter arm bushings...but hey it works!)
10. Ravenol MTF-2 75W-80 Manual Transmission oil. I was still having issues with 2nd gear nibbling and completely failing to synchronize on occasion even with the BGSyncroShiftII fluid. After digging I realized BG was actually Manual Transaxle fluid and not intended for the high loads of a RWD manual transmission. Ravenol meets both Ford and GM specs as well as BMW's, Audi's and several others for MTF. Motul DCTF is another great option. BG is not so much...it only reduced the "grittyness" a little but did nothing to resolve actual shifting issues. Ravenol completely changed the shifting, it's very smooth, consistent, no nibble or kick so far in any gear, especially 2nd, cold or hot. It almost has a bit of "heft" or "weighted" feel to it now which I actually really like.

Alignment specs: -1.4 camber on both sides in front (with in BMR's spec that is -1.5 +/- 0.3), -1.25 in the rear on the dot, also within BMR's spec. Bumpsteer I actually set correctly in my garage following Steeda's instructions according to the shop, i'm running all the spacers above the ball joint except the smallest one and one of the 3 smallish ones. The shop I used is a specialty shop that focuses on performance car alignments, they service a lot of auto x and HPDE cars in our area, so it's not your typical dealer alignment where unless it's out of spec they won't touch it.

0.20 total toe in the rear (BMR's spec). I am running a small amount of Toe Out in the front however, 0.03 ish if I remember correctly, about what the GT350R runs. The tech suggested a small amount of toe out with my setup to really enhance response in corners, so far I'm really liking it. Also the caster and toe out add a little more "heft" to the steering. I can also throttle steer the car now where I couldn't before. And holy crap does the car feel more planted in corners, it's far more communicative and planted than it was. I'm REALLY liking that, kinda like a big fat MX-5 M-edition (had a 97 back in college, mostly stock) in terms of feeling well planted in corners.

He did note however, that despite the fact that the caster / camber plates allowed a lot more camber than we ended up with as far as adjustment range, adding more than -1.4 camber with the 7.21 caster setting started to really throw the toe angles out of whack (couldn't adjust it to get it right) and since -1.4 was still within BMR's spec, that's as far as he recommended going with the car as is. Nn the up side, the front has more camber gain than it did, I gained -0.2 degrees just by having a single 180 lb passenger sit in the front of the car during the alignment up on the rack. So there's more camber gain with a corrected roll center than there was previously. When your running a lowered (than factory) roll center you need more static camber as your outside the greatest gain region in the arch of movement, while that's ok for a track only car, it's not so good for a car that also sees a fair amount of street use.

So the effect of raising the roll center back up closer to where it "should be" reduced the maximum static camber I could run (well maybe it's more a combination of that and the bump steer settings) without throwing toe angles into the weeds, however on the flip side the car now has more camber gain as the suspension compressed then without them so it compensates, so I don't need as much static camber. That will have a positive effect on steering response as well (roll center correction). The rear camber is all the way out to it's minimum setting to hit -1.25 degrees on the SP080 springs. So going much lower in the rear than 0.5" will limit your camber range even further and screw with the rear roll center / camber gain curves.

The combination of the alignment and the steeda bumpsteer / roll center correction kit reduced body roll a bit, but by no means eliminated it. However it completely eliminated that "tipping sensation" where the car feels like suddenly starts to roll a lot more. It's now linear and progressive, making the car far more predictable. The car's suspension is simply working more optimally and it's really good for a street car. I'm starting to wonder if I'd even need bars with SP083's and FP Track dampers.

I may also run 1/8 rear spacers with the SP083's to preserve the rear end geometry, giving it a nearly identical ride height to the GT350R (0.33 lower than GT, 1/8" spacer with SP083's would give me 0.5" lower than a regular GT). Or I may be able to get some serious handling out of the SP080's with a set of GT350 bars. BMR said that very thing, run a set of stiffer bars and give the car a more aggressive alignment and you'll be fairly close to the SP083 / FP Track damper setup but with a more street friendly ride.

Obviously a more purely track focused spring and damper setup is going to be faster, but how much and does it really matter for a fun car that mostly street with occasional track? Jurry is still out, but I may try the GT350R bars next spring. Then if I need more I now have bar tuning options to pair with the SP083's / FT Track dampers as I can mix and match front and rear bars. Right now with my current alignment settings I'm not sure the car needs more bar up front or out back, but it's going to take some time to get used to it and see where it's at as it's a completely different animal after the alignment + Roll Center / Bumpsteer kit.

Combine that with the fact that the Power Pack 2, 93 octane, catch can and TriboTEX the car is making some pretty good power, definitely in the 420~430 whp range.

 

[Roadway 5.0]

I'm planning on running Pilot Spot AS3+'s on my stock PP wheels for the winter (don't drive in the snow much as our Prius with snow tires work well in the winter, low torque + snow tires = awesome traction), but I do drive it on the "dry" winter days, so Pilot Sports will work well through the later fall, winter and early spring in lower temps that still permit some fun (alibiet more conservatively).

On my RTR Tech 7's I'm planning on running Pilot Sport 4S's. They are 23 lbs per wheel in a 4 square setup. So it will be a really nice street / light duty track setup. The car is mostly a performance street car right now. Maybe in a couple of years that will change, but right now I enjoy "sporty touring" of new back country roads which there are literally thousands of miles worth in this whole region. So it's endless exploration! Lots of fun and beautiful scenery.

Slowly I'm tweaking the car for occasional HPDE little by little. I also just got my alignment done FINALLY and did the installation of the Steeda Roll Center Correction and Bumpsteer Kit (did both at the same time).

So I'm now running the following:

1. BMR SP080's on stock PP struts
2. MaximumMotorsports Caster / Camber Plates
3. BMR CB05 IRS Lockout
4. FP M-5A460-M Toe Link Spherical Bearings
5. Steeda Roll Center and Bumpsteer Correction Kit
5. Ford Performance Power Pack 2 (dealer installed with warranty paperwork)
6. JLT 3.0 Catch Can (modified with an anti-slosh baffle)
7. TriboTEX MSH based DLC friction modifier (look over at the issues thread on the BBQ Tick threads or on the Ford Performance Power Pack threads for the MASSIVe amount of standardised testing and data I provided on this, most additives are indeed snake oil as they say, but this one is not and it's based on extensive R&D to address boundary, mixed and elastohydrodynamtic lubrication short comings of existing motor oils that rely heavily on ZDDP). For oil I'm running Mobil 1 5W-20 Advanced Full Synthetic with an OE FL500-S filter, change at 5k mile intervals.
8. Corsa Sport cat back exhaust
9. Steeda Tri-Axes Short throw + Ford Performance Aluminum shifter arm bushings (had them left over from the FP Short Throw kit I installed in my Ecoboost but never used the bushings, holy crap did they help shifting during power down on my GT, not sure why FP is the only one replacing the rubber shifter arm bushings...but hey it works!)
10. Ravenol MTF-2 75W-80 Manual Transmission oil. I was still having issues with 2nd gear nibbling and completely failing to synchronize on occasion even with the BGSyncroShiftII fluid. After digging I realized BG was actually Manual Transaxle fluid and not intended for the high loads of a RWD manual transmission. Ravenol meets both Ford and GM specs as well as BMW's, Audi's and several others for MTF. Motul DCTF is another great option. BG is not so much...it only reduced the "grittyness" a little but did nothing to resolve actual shifting issues. Ravenol completely changed the shifting, it's very smooth, consistent, no nibble or kick so far in any gear, especially 2nd, cold or hot. It almost has a bit of "heft" or "weighted" feel to it now which I actually really like.

Alignment specs: -1.4 camber on both sides in front (with in BMR's spec that is -1.5 +/- 0.3), -1.25 in the rear on the dot, also within BMR's spec. Bumpsteer I actually set correctly in my garage following Steeda's instructions according to the shop, i'm running all the spacers above the ball joint except the smallest one and one of the 3 smallish ones. The shop I used is a specialty shop that focuses on performance car alignments, they service a lot of auto x and HPDE cars in our area, so it's not your typical dealer alignment where unless it's out of spec they won't touch it.

0.20 total toe in the rear (BMR's spec). I am running a small amount of Toe Out in the front however, 0.03 ish if I remember correctly, about what the GT350R runs. The tech suggested a small amount of toe out with my setup to really enhance response in corners, so far I'm really liking it. Also the caster and toe out add a little more "heft" to the steering. I can also throttle steer the car now where I couldn't before. And holy crap does the car feel more planted in corners, it's far more communicative and planted than it was. I'm REALLY liking that, kinda like a big fat MX-5 M-edition (had a 97 back in college, mostly stock) in terms of feeling well planted in corners.

He did note however, that despite the fact that the caster / camber plates allowed a lot more camber than we ended up with as far as adjustment range, adding more than -1.4 camber with the 7.21 caster setting started to really throw the toe angles out of whack (couldn't adjust it to get it right) and since -1.4 was still within BMR's spec, that's as far as he recommended going with the car as is. Nn the up side, the front has more camber gain than it did, I gained -0.2 degrees just by having a single 180 lb passenger sit in the front of the car during the alignment up on the rack. So there's more camber gain with a corrected roll center than there was previously. When your running a lowered (than factory) roll center you need more static camber as your outside the greatest gain region in the arch of movement, while that's ok for a track only car, it's not so good for a car that also sees a fair amount of street use.

So the effect of raising the roll center back up closer to where it "should be" reduced the maximum static camber I could run (well maybe it's more a combination of that and the bump steer settings) without throwing toe angles into the weeds, however on the flip side the car now has more camber gain as the suspension compressed then without them so it compensates, so I don't need as much static camber. That will have a positive effect on steering response as well (roll center correction). The rear camber is all the way out to it's minimum setting to hit -1.25 degrees on the SP080 springs. So going much lower in the rear than 0.5" will limit your camber range even further and screw with the rear roll center / camber gain curves.

The combination of the alignment and the steeda bumpsteer / roll center correction kit reduced body roll a bit, but by no means eliminated it. However it completely eliminated that "tipping sensation" where the car feels like suddenly starts to roll a lot more. It's now linear and progressive, making the car far more predictable. The car's suspension is simply working more optimally and it's really good for a street car. I'm starting to wonder if I'd even need bars with SP083's and FP Track dampers.

I may also run 1/8 rear spacers with the SP083's to preserve the rear end geometry, giving it a nearly identical ride height to the GT350R (0.33 lower than GT, 1/8" spacer with SP083's would give me 0.5" lower than a regular GT). Or I may be able to get some serious handling out of the SP080's with a set of GT350 bars. BMR said that very thing, run a set of stiffer bars and give the car a more aggressive alignment and you'll be fairly close to the SP083 / FP Track damper setup but with a more street friendly ride.

Obviously a more purely track focused spring and damper setup is going to be faster, but how much and does it really matter for a fun car that mostly street with occasional track? Jurry is still out, but I may try the GT350R bars next spring. Then if I need more I now have bar tuning options to pair with the SP083's / FT Track dampers as I can mix and match front and rear bars. Right now with my current alignment settings I'm not sure the car needs more bar up front or out back, but it's going to take some time to get used to it and see where it's at as it's a completely different animal after the alignment + Roll Center / Bumpsteer kit.

Combine that with the fact that the Power Pack 2, 93 octane, catch can and TriboTEX the car is making some pretty good power, definitely in the 420~430 whp range.

@TheLion Looks like your build is coming together well

It seems like the P4Ses you’ll go to are the gold standard, and for good reason. I had PSSes on my BMW and they were great when ran a few psi lower than the door’s placard recommendation. The only flaw was that they were crashy on larger road flaws.

Oddly though, as I now run my winter tires (Bridgestone Blizzak), I long for a summer tire that has the “feelsome” sidewall compliance and immediate steering response that the Blizzaks have. Maybe the P4Ses are the ones, maybe not. I forsee a good deal of research coming over the next few months.

 

[TheLion]

I suspect the PS4S will fit your needs. Everything I've read on them suggests they have very good street manners but also that perfect increasing weightiness to response as you start to push them, very linear. So for high performance street tire there is nothing on the market that bests the PS4S in either feel / feedback / linearity or outright grip levels. Tread life is also top notch for a tire of that type with many people getting 25k~30k+ miles out of them which is phenomenal for a tire with that kind of grip level. They also tend to not be harsh over bumps, which is a criticism of the Pilot Sport AS3+'s I'll be replacing my pirellies with (I ran them on my Ecoboost, a truly awesome tire for an all season with higher outright grip than the P Zero's that are on the car now).

And no, the RE-71R's are not a true street tire. They are a racing slick that's DOT legal. They last all of about 5k~7k miles on the road, don't perform well in standing water (but do grip well on damp roads). They are an awesome auto x tire, in fact THE tire to get. But their noise is horrendous as well. Just not something you'd want to drive any great distance on the street unless your only hooning around. They have incredibly good feedback as well, so all of their attributes are first and fore most on maximum outright grip and feel all else be damned. In that they do well.

I love to tour and explore as well as push the car hard though, so I look for tire setups that are more LeMans type focus or HPDE type focus. Something that will hold up under repeated abuse over and over and over again. BTW any recommendations on brake pads? At 22,000 miles my front pads are down to about 1/4 inch already...I suppose hitting 110~120 on a regular basis will wear them down fast. Upside is those big meaty brembos have held up like champs. My only complaint about the stock pads is glazing and the resulting "squeal" during normal driving. Although they've worn down enough now that the glaze is gone and they no longer squeal, but I suspect in about another 8k~12k miles I'll need new pads up front.

But I can say that after finally really being able to push the car in a few turns (90+ full throttle in mid corner / exit on a high speed sweeper topping out at 120 on the straight and enter the next corner at around 90ish) the car has much more steering, but it doesn't seem to over steer which is really good. It has just a hint of under-steering until you hit the throttle then the car nearly steers itself through the corner. Very good balance now and if I add any front bar I'm going to have to add rear bar to keep the balance f / r. There is some roll, but it's reasonably well managed by the stock PP sway bars.

The car actually feels well planted now instead of floaty and disconnected like it's going to keep going despite my turning the wheel and slide right off the road, giving me confidence to push much harder in corners. I can actually steer into a corner well now and power through it. I really like the balance it has. There's no "tipping sensation" that I used to get from a lowered roll center and it definitely seems that there is some camber gain based on how the steering firms up and "digs in" on corner entry and mid-corner. It's just a completely different car and now there's a really good balance of power vs. handling. Still not exactly where I want it, but it's getting pretty close and really brings out the fun or "road race" type driving. It encourages me to drive the car hard instead of always slowing way down and being overly cautious, like it wants to be driven hard, begging me to push more.

If anything, I wonder if running my 4-square setup will upset the balance I currently have? Right now i'm burning up the stock staggered P Zeros on the PP wheels (also still get vibration around 110~120, but I suspect the PP wheels, one may even be bent slightly as I hit a pretty big pot hole about 3 months ago). If so I may add just a little more rear bar to compensate, but I'm hoping 2 cm wider front tires won't have that much impact on F / R balance. At least I hope not as I really like the current balance.

So next spring I'll try both 34 mm and 24 mm GT350R front and rear bars with my existing setup to try and preserve that F / R balance but give just a little more bar. I honestly think that is the ultimate "street performance touring" setup, something that can really handle but doesn't give up all of it's touring enjoyment. The car is still pretty comfortable to tour in. It doesn't need much more bar, but a small amount more would allow me to push just a little more. But for stock PP bars it's pretty good. I am now reaping the benefits of a lowered CG (less weight transfer) but without the negatives of reduced steering response and increased roll due to a lowered roll center. We'll see how the front tires wear but I was also having issues with severe inside shoulder wear, as in there's almost no tread on the inside shoulders but the rest of the tire has 5/32 or more tread left. I'm thinking the alignment + the geometry correction will fix that.

I am running a small amount of toe out, so I do get just a hint of "pull" under certain road conditions, but it's very linear and not "sudden" like tram lining is. It's just a tad more sensitive to drifting left or right under normal driving. Pushing it hard it's super planted, it actually feels like the whole grip increases as you push it but "loosens up" once you go back to normal driving. I really like it and would recommend this setup to anyone who uses their car for dual purpose but with greater use as a street car. Maybe as I mentioned add the GT350R front and rear bars with it for a true street performance setup.

And I'm REALLY liking the Ravenol MTF-2 fluid as well. I've had a very picky MT-82 since the get go. Tried BGSyncroShiftII that in my opinion is the most over hyped fluid and while it was decent at first in terms of feel (reduces grittiness / notchy feeling) it didn't resolve the 2nd gear issues with the syncros kicking, nibbling or even failing to engage. 2nd gear was still very picky, just less gritty with the BG. My only reason for switching again was trying to get 2nd gear to actually function well. Sure, it worked ok when under power, but for daily driving it did not always want to sync even though it felt like it was in gear and it still felt too "lightweight" or "cheap", like I was driving a FWD manual trans-axle car, not a 465 hp V8. Ravenol fixed 95% of that and it's plenty good enough now, in fact it went from the worst to the best manual I've ever driven after the Ravenol MTF-2, Ford Performance aluminum shifter arm bushings and Steeda Tri-axes short throw. Super smooth, weighted feel and now easy to find and precise gates. Before those three it was gritty, kicked like a mule at times and difficult to find the gates under power causing occasional missed gears. It really does shift well now and no MGW was necessary.

So for the MT-82 I would highly recommend the Ford Performance short throw so you can get their aluminum arm bushings that it comes with and then using Ravenol MTF-2 75W-80 manual transmission oil or Motul DCTF fluid (also another good option with similar characteristics). It's cheap, it works and it should perform quite well. Sorry BG, but Manual Transaxle fluid just is not well suited for a high HP V8 manual transmission. Ravenol also exceeds Ford's and GM's OE specs for MTF/DCTF fluids in that viscosity.

 

[BmacIL]

Agree to disagree on the improvement with BG fluid but I'm glad to hear your feedback on the roll center changes!

 

[Norm Peterson]

If anything, I wonder if running my 4-square setup will upset the balance I currently have? Right now i'm burning up the stock staggered P Zeros on the PP wheels (also still get vibration around 110~120, but I suspect the PP wheels, one may even be bent slightly as I hit a pretty big pot hole about 3 months ago). If so I may add just a little more rear bar to compensate, but I'm hoping 2 cm wider front tires won't have that much impact on F / R balance. At least I hope not as I really like the current balance.

Are those 20 mm wider tires going to go on wider wheels than 9's?

I would expect squaring up a staggered wheel/tire situation to call for less rear bar rather than more, or more front bar with the rear bar left as is.


Norm

 

[Roadway 5.0]

I suspect the PS4S will fit your needs. Everything I've read on them suggests they have very good street manners but also that perfect increasing weightiness to response as you start to push them, very linear. So for high performance street tire there is nothing on the market that bests the PS4S in either feel / feedback / linearity or outright grip levels. Tread life is also top notch for a tire of that type with many people getting 25k~30k+ miles out of them which is phenomenal for a tire with that kind of grip level. They also tend to not be harsh over bumps, which is a criticism of the Pilot Sport AS3+'s I'll be replacing my pirellies with (I ran them on my Ecoboost, a truly awesome tire for an all season with higher outright grip than the P Zero's that are on the car now).

And no, the RE-71R's are not a true street tire. They are a racing slick that's DOT legal. They last all of about 5k~7k miles on the road, don't perform well in standing water (but do grip well on damp roads). They are an awesome auto x tire, in fact THE tire to get. But their noise is horrendous as well. Just not something you'd want to drive any great distance on the street unless your only hooning around. They have incredibly good feedback as well, so all of their attributes are first and fore most on maximum outright grip and feel all else be damned. In that they do well.

I love to tour and explore as well as push the car hard though, so I look for tire setups that are more LeMans type focus or HPDE type focus. Something that will hold up under repeated abuse over and over and over again. BTW any recommendations on brake pads? At 22,000 miles my front pads are down to about 1/4 inch already...I suppose hitting 110~120 on a regular basis will wear them down fast. Upside is those big meaty brembos have held up like champs. My only complaint about the stock pads is glazing and the resulting "squeal" during normal driving. Although they've worn down enough now that the glaze is gone and they no longer squeal, but I suspect in about another 8k~12k miles I'll need new pads up front.

But I can say that after finally really being able to push the car in a few turns (90+ full throttle in mid corner / exit on a high speed sweeper topping out at 120 on the straight and enter the next corner at around 90ish) the car has much more steering, but it doesn't seem to over steer which is really good. It has just a hint of under-steering until you hit the throttle then the car nearly steers itself through the corner. Very good balance now and if I add any front bar I'm going to have to add rear bar to keep the balance f / r. There is some roll, but it's reasonably well managed by the stock PP sway bars.

The car actually feels well planted now instead of floaty and disconnected like it's going to keep going despite my turning the wheel and slide right off the road, giving me confidence to push much harder in corners. I can actually steer into a corner well now and power through it. I really like the balance it has. There's no "tipping sensation" that I used to get from a lowered roll center and it definitely seems that there is some camber gain based on how the steering firms up and "digs in" on corner entry and mid-corner. It's just a completely different car and now there's a really good balance of power vs. handling. Still not exactly where I want it, but it's getting pretty close and really brings out the fun or "road race" type driving. It encourages me to drive the car hard instead of always slowing way down and being overly cautious, like it wants to be driven hard, begging me to push more.

If anything, I wonder if running my 4-square setup will upset the balance I currently have? Right now i'm burning up the stock staggered P Zeros on the PP wheels (also still get vibration around 110~120, but I suspect the PP wheels, one may even be bent slightly as I hit a pretty big pot hole about 3 months ago). If so I may add just a little more rear bar to compensate, but I'm hoping 2 cm wider front tires won't have that much impact on F / R balance. At least I hope not as I really like the current balance.

So next spring I'll try both 34 mm and 24 mm GT350R front and rear bars with my existing setup to try and preserve that F / R balance but give just a little more bar. I honestly think that is the ultimate "street performance touring" setup, something that can really handle but doesn't give up all of it's touring enjoyment. The car is still pretty comfortable to tour in. It doesn't need much more bar, but a small amount more would allow me to push just a little more. But for stock PP bars it's pretty good. I am now reaping the benefits of a lowered CG (less weight transfer) but without the negatives of reduced steering response and increased roll due to a lowered roll center. We'll see how the front tires wear but I was also having issues with severe inside shoulder wear, as in there's almost no tread on the inside shoulders but the rest of the tire has 5/32 or more tread left. I'm thinking the alignment + the geometry correction will fix that.

I am running a small amount of toe out, so I do get just a hint of "pull" under certain road conditions, but it's very linear and not "sudden" like tram lining is. It's just a tad more sensitive to drifting left or right under normal driving. Pushing it hard it's super planted, it actually feels like the whole grip increases as you push it but "loosens up" once you go back to normal driving. I really like it and would recommend this setup to anyone who uses their car for dual purpose but with greater use as a street car. Maybe as I mentioned add the GT350R front and rear bars with it for a true street performance setup.

And I'm REALLY liking the Ravenol MTF-2 fluid as well. I've had a very picky MT-82 since the get go. Tried BGSyncroShiftII that in my opinion is the most over hyped fluid and while it was decent at first in terms of feel (reduces grittiness / notchy feeling) it didn't resolve the 2nd gear issues with the syncros kicking, nibbling or even failing to engage. 2nd gear was still very picky, just less gritty with the BG. My only reason for switching again was trying to get 2nd gear to actually function well. Sure, it worked ok when under power, but for daily driving it did not always want to sync even though it felt like it was in gear and it still felt too "lightweight" or "cheap", like I was driving a FWD manual trans-axle car, not a 465 hp V8. Ravenol fixed 95% of that and it's plenty good enough now, in fact it went from the worst to the best manual I've ever driven after the Ravenol MTF-2, Ford Performance aluminum shifter arm bushings and Steeda Tri-axes short throw. Super smooth, weighted feel and now easy to find and precise gates. Before those three it was gritty, kicked like a mule at times and difficult to find the gates under power causing occasional missed gears. It really does shift well now and no MGW was necessary.

So for the MT-82 I would highly recommend the Ford Performance short throw so you can get their aluminum arm bushings that it comes with and then using Ravenol MTF-2 75W-80 manual transmission oil or Motul DCTF fluid (also another good option with similar characteristics). It's cheap, it works and it should perform quite well. Sorry BG, but Manual Transaxle fluid just is not well suited for a high HP V8 manual transmission. Ravenol also exceeds Ford's and GM's OE specs for MTF/DCTF fluids in that viscosity.

You’re the third person, including myself, that has a vibration issue with the PP wheels at around 120mph. Seems like more than a theorized trouble at this point.

As far as pads, I’ll likely go to a ceramic pad when due. I don’t track the car (and thus don’t need anything intense) and I like the low dust/silent operation. I had PosiQuiets on my BMW and they were great.

On to sway bars: have you considered adjustable units? More expensive, yes, but the ultimate 20 minute dynamic change as opposed to ripping bars out.

As far as tires, thanks for the data. It looks like P4Ses will win the war unless something far less expensive can muster competition. I’ll also take a look into that trans fluid.

 

[TheLion]

@BmacIL dont get me wrong I have nothing against BG. It is a big improvement over stock in terms of smooth shifting in general. But my MT-82 still nibbled in 2nd gear often, even kicked hard on occasion and when cold would some times fail to sync so id let the clutch out and griiinnd...so I got a lucky MT-82 BG was my first attempt to.resolve functional issues where yours appears to working properly from the start amd only looking to improve shift quality as opposed to actually correct a functional problem which BG did not do for me but Ravenol did. Others have also tried BG to resolve some actual issues with varying degrees of success but so far all that have gone to Motul DCTF or Ravenal MTF-2 have had success.

So for me BG is not the best solution even if it is an improvement over stock. If it works for you particular MT-82 and meets your requirements theres no need to change.

But getting back to suspension I absolutely love the setup after correcting roll center and bump steer. You may not notice it as much as me but id be surprised if your car didnt still see a decent measurable improvement. Steeda claims correcting the roll.center took off over a second on their auto x car they compete with and ild back that up. Given my setup is likely more sensitive to roll center than yours my results are more pronounced but the ultimate setup.id imagine is the 083s, track Dampers with irs bits and a correctex geometry with maybe a gt350 bar up front depending on tire / wheel combo and driver preferences.

 

[BmacIL]

@BmacIL dont get me wrong I have nothing against BG. It is a big improvement over stock in terms of smooth shifting in general. But my MT-82 still nibbled in 2nd gear often, even kicked hard on occasion and when cold would some times fail to sync so id let the clutch out and griiinnd...so I got a lucky MT-82 BG was my first attempt to.resolve functional issues where yours appears to working properly from the start amd only looking to improve shift quality as opposed to actually correct a functional problem which BG did not do for me but Ravenol did. Others have also tried BG to resolve some actual issues with varying degrees of success but so far all that have gone to Motul DCTF or Ravenal MTF-2 have had success.

So for me BG is not the best solution even if it is an improvement over stock. If it works for you particular MT-82 and meets your requirements theres no need to change.

But getting back to suspension I absolutely love the setup after correcting roll center and bump steer. You may not notice it as much as me but id be surprised if your car didnt still see a decent measurable improvement. Steeda claims correcting the roll.center took off over a second on their auto x car they compete with and ild back that up. Given my setup is likely more sensitive to roll center than yours my results are more pronounced but the ultimate setup.id imagine is the 083s, track Dampers with irs bits and a correctex geometry with maybe a gt350 bar up front depending on tire / wheel combo and driver preferences.

The Ravenol may be worth a try. I've had the BG in for about 30k miles so it'll be due in the future.

I may try those links too.

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