Redspencer's Track-Tuned IS350 w/ OS Giken LSD Build Thread
07-19-19, 05:49 AM
#661
Lwerewolf you should post that in the brake section. I don't intend to track the car so I'm more apt to find one product and stick with it.
That said, when the brakes were apart a couple of weeks ago all 10 pistons pushed by hand so the fluid swap I did a year ago is not sticking pistons.
That said, when the brakes were apart a couple of weeks ago all 10 pistons pushed by hand so the fluid swap I did a year ago is not sticking pistons.
07-19-19, 06:45 PM
#663
By the way, with regards to the brake fluid, take a look at this:
https://www.industryweek.com/compani...ake-fluid-leak
Quite likely not the best link. At any rate, from what I've read so far, back in 2010 Honda and Toyota both recalled a number of models for a change of rubber seal material in their braking systems, due to incompatibility with, well... non-OEM brake fluids, "due to a lack of polymer lubricants" or whatever. It also turns out that Toyota/Honda OEM fluids (at least the dot3 variety) swell the rubber seals the least amount out of all (not exaggerating too much here) DOT fluids available. Brake issues due to seal swell are sometimes not very intuitive to diagnose apparently, and in my case, I REALLY don't want to damage the electric vacuum booster (hybrids, gs430/460/ls460 have those - no clue why they'd put it on anything other than the hybrids, to be honest).
I haven't found any solid details yet on what's OK and not OK and why. Turns out (no, don't quote me on it, research) most (NOT all - Shell ESC, Castrol LMA... etc) higher performance fluids have high seal swell characteristics.
https://www.industryweek.com/compani...ake-fluid-leak
Quite likely not the best link. At any rate, from what I've read so far, back in 2010 Honda and Toyota both recalled a number of models for a change of rubber seal material in their braking systems, due to incompatibility with, well... non-OEM brake fluids, "due to a lack of polymer lubricants" or whatever. It also turns out that Toyota/Honda OEM fluids (at least the dot3 variety) swell the rubber seals the least amount out of all (not exaggerating too much here) DOT fluids available. Brake issues due to seal swell are sometimes not very intuitive to diagnose apparently, and in my case, I REALLY don't want to damage the electric vacuum booster (hybrids, gs430/460/ls460 have those - no clue why they'd put it on anything other than the hybrids, to be honest).
I haven't found any solid details yet on what's OK and not OK and why. Turns out (no, don't quote me on it, research) most (NOT all - Shell ESC, Castrol LMA... etc) higher performance fluids have high seal swell characteristics.
I hope so too. In fact, today was the day I was scheduled to have a mobile wheel repair specialist come to the house to fix all four wheels but something came up to where I had to cancel the appointment which I'll elaborate on below...
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Today is a day of sadness and regret
. A day I would never have thought would be possible after all these years but never say never 
. I've decided to relinquish my adrenaline-fueled track day habits and to take things nice and slow from now on like the stereotypical Lexus owner.After 13 years of putting so much labor and love into my track-tuned IS350, I've decided to donate the Redspencer IS350 to the Driving School for the Blind. It's been great being a part of this community and helping others with their builds. I've decided to replace the car with another Lexus IS350, this time a convertible. Behold my new acquisition, the 2014 IS350C!
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Okay...Okay...I was kidding about getting rid of the Redspencer IS350.
I did add another Lexus to the stable which is this low mileage, single owner, 2014 IS350C.
On the days when I want to take my drives nice and mellow, I'll break out the IS350C and will drop the top down. Comparing this car to the other IS350, I forgot how whisper quiet Lexus makes their engines. I'll take care of that by installing another F-Sport Lower Intake Box and 3IS F-Sport Intake Tube w/ Sound Generator. 
The following users liked this post:
2013FSport (07-20-19)
07-20-19, 03:12 PM
#664
I have this local place you can donate too - Blind Dogs make Bad Guides! 
Wow - a nice play! Do enjoy! How many miles? I like the nose, a little different!
As for the old side kicks hard pedal after sitting, pull the MC and replace the grommet. Use a suitable brake grease on the pushrod through the rubber and you should be set. If the lines will flex far enough it could be 15min fix for $6.00!
Congratulations!
Wow - a nice play! Do enjoy! How many miles? I like the nose, a little different!
As for the old side kicks hard pedal after sitting, pull the MC and replace the grommet. Use a suitable brake grease on the pushrod through the rubber and you should be set. If the lines will flex far enough it could be 15min fix for $6.00!
Congratulations!
07-20-19, 07:59 PM
#666
Instructor
I like it. Nondescript silver for stealth performance duties (nevermind the exhaust note) and black coupe for everyday.
I can see you ordering RC-F/GS-F LCA bushings very soon, if you haven't done so already. Possibly sway bars as well
I can see you ordering RC-F/GS-F LCA bushings very soon, if you haven't done so already. Possibly sway bars as well
07-21-19, 04:51 AM
#667
I have this local place you can donate too - Blind Dogs make Bad Guides!
Wow - a nice play! Do enjoy! How many miles? I like the nose, a little different!
As for the old side kicks hard pedal after sitting, pull the MC and replace the grommet. Use a suitable brake grease on the pushrod through the rubber and you should be set. If the lines will flex far enough it could be 15min fix for $6.00!
Congratulations!
Wow - a nice play! Do enjoy! How many miles? I like the nose, a little different!
As for the old side kicks hard pedal after sitting, pull the MC and replace the grommet. Use a suitable brake grease on the pushrod through the rubber and you should be set. If the lines will flex far enough it could be 15min fix for $6.00!
Congratulations!
Thanks for the tip on replacing the grommet on the master cylinder. I'll give that a shot in the future to see if it resolves the stiff brake issue as replacing the booster check valve with grommet didn't have an impact.
Hmm...since I still have the RR Racing OBD Unit, I'll have to ping the shop to see how much extra it would cost to add a IS350C vehicle profile (as the OBD units are supposedly tied to a single vehicle VIN)...
You've already read my mind.
Knowing what we know with the front tires prematurely wearing out every 15,000 miles on the inner treads, I'll most certainly look into getting new front LCA bushings installed as a long-term investment to reducing tire wear. Sway bars are a great way to improve handling without sacrificing ride height (I definitely want to keep the ride height higher on the IS350C compared to the silver IS350) and is another future mod to consider. I'll first have to get more seat time to see if the stock suspension setup on the IS350C becomes a nuisance to me.The Florida summer heat wave needs to go away so I can go back to doing HPDE and AutoX events as well as going back to making more videos. When the weather cools down enough in Nov/Dec, I'll take the FBO IS350 to the drag strip to see what this setup can do in the 1/4 mile.
Last edited by redspencer; 07-21-19 at 09:01 AM.
07-21-19, 10:00 AM
#668
@redspencer Quick question I've been following your build for a couple of years now and your car is awesome, I have the same car and it's the same color too..lol but, unfortunately it's a 250 with a 6sp gearbox but, don't get me wrong it's still a blast to drive. Since the F sport springs and shocks are no longer available new. I opted for BC racing coil overs. I plan to auto cross my 250 I already have the F sport front and rear sway bar I plan on joining a club soon but, the only one here in South Florida only holds events in West Palm Beach for now since they re paved the BB&T center parking lot. The track is an hour away but, I'm cool with that. Hell I drive 3 1/2 hrs to take the kids to see Mickey Mouse every other summer..lol Anyways according to BC racing website, the minimum you can lower the coils are 2' inches. I know right now I can fit three fingers in the front and two in the back with the stock height. Will two inches be good for autocross ? I will be running ESR Sr11's +30 18x 8.5 in the front and +35 18x9.5 in the rear.
07-21-19, 11:16 AM
#669
@redspencer Quick question I've been following your build for a couple of years now and your car is awesome, I have the same car and it's the same color too..lol but, unfortunately it's a 250 with a 6sp gearbox but, don't get me wrong it's still a blast to drive. Since the F sport springs and shocks are no longer available new. I opted for BC racing coil overs. I plan to auto cross my 250 I already have the F sport front and rear sway bar I plan on joining a club soon but, the only one here in South Florida only holds events in West Palm Beach for now since they re paved the BB&T center parking lot. The track is an hour away but, I'm cool with that. Hell I drive 3 1/2 hrs to take the kids to see Mickey Mouse every other summer..lol Anyways according to BC racing website, the minimum you can lower the coils are 2' inches. I know right now I can fit three fingers in the front and two in the back with the stock height. Will two inches be good for autocross ? I will be running ESR Sr11's +30 18x 8.5 in the front and +35 18x9.5 in the rear.
FYI, you can look into attending a Tire Rack Track Night in America HPDE event. It's open to all levels of driving (Beginner to Seasoned) and they regularly host events at PBIR in West Palm Beach (next one is on August 20): https://www.tracknightinamerica.com/
07-21-19, 12:58 PM
#670
Changing the ride height will alter multiple suspension geometries: roll center, roll couple, roll axis, camber curves, etc. Based on the info I gathered from the IS-F subforums, reducing the height by 1.0-1.5" is optimal for our platform. Without having the engineering data to verify the exact changes being done to the tire contact patch when further reducing ride height, it's difficult to predict if there would be further gains to be had or not. This is a great website to further understanding the science of suspension tuning: http://farnorthracing.com/autocross_secrets5.html
FYI, you can look into attending a Tire Rack Track Night in America HPDE event. It's open to all levels of driving (Beginner to Seasoned) and they regularly host events at PBIR in West Palm Beach (next one is on August 20): https://www.tracknightinamerica.com/
FYI, you can look into attending a Tire Rack Track Night in America HPDE event. It's open to all levels of driving (Beginner to Seasoned) and they regularly host events at PBIR in West Palm Beach (next one is on August 20): https://www.tracknightinamerica.com/
Good info in the far north link. Makes me wonder how much they improved the F-sport/IS-F suspension over the base models? In the front its springs, shocks, lower A-Arm, sway bars, and LCA.
The rear has the springs, shocks, spindle, toe links, and a couple of different arms. I would guess to reduce camber roll associated with body roll.
That said I can't imagine trying to measure everything in the rear and get it close enough to right to gather good data in that modeling tool.
07-22-19, 11:16 AM
#671
Good info in the far north link. Makes me wonder how much they improved the F-sport/IS-F suspension over the base models? In the front its springs, shocks, lower A-Arm, sway bars, and LCA.
The rear has the springs, shocks, spindle, toe links, and a couple of different arms. I would guess to reduce camber roll associated with body roll.
That said I can't imagine trying to measure everything in the rear and get it close enough to right to gather good data in that modeling tool.
The rear has the springs, shocks, spindle, toe links, and a couple of different arms. I would guess to reduce camber roll associated with body roll.
That said I can't imagine trying to measure everything in the rear and get it close enough to right to gather good data in that modeling tool.
07-22-19, 04:14 PM
#673
Over the weekend, I had the opportunity to do some spirited driving to test out the new Ultra Racing front tower brace in order to see if there is a noticeable difference. As noted on my post above, I had been reluctant for years to add this mod as the Lexus IS does not have struts up front and instead has a double-wishbone suspension. The design of the majority of available tower bars (three-piece pivot-type) also does not add confidence to the functionality of this type of upgrade.
Suffice to say, after finding an available one-piece solid steel tower brace and installing it, I’m happy to report that there is a tactile difference with how the chassis responds to steering inputs. Much like when I previously installed the F-Sport rear chassis brace and four-point GT Spec front lower brace, I noticed a difference in chassis responsiveness with sudden steering inputs at mid-speeds (30+ mph). It feels like a subtle change with how the lateral load is distributed as there is another path for the chassis to resist the stress of the g-forces through added chassis stiffness and rigidity. I don’t have any metrics showing that this mod will minimize deflection of the suspension geometry or will improve lap times but the solid tower brace does subtlety change the behavior of how the chassis responds to steering inputs and provides a bit more connectivity between driver and machine via an even more rigid chassis which should benefit the rest of the mods on this car.
Suffice to say, after finding an available one-piece solid steel tower brace and installing it, I’m happy to report that there is a tactile difference with how the chassis responds to steering inputs. Much like when I previously installed the F-Sport rear chassis brace and four-point GT Spec front lower brace, I noticed a difference in chassis responsiveness with sudden steering inputs at mid-speeds (30+ mph). It feels like a subtle change with how the lateral load is distributed as there is another path for the chassis to resist the stress of the g-forces through added chassis stiffness and rigidity. I don’t have any metrics showing that this mod will minimize deflection of the suspension geometry or will improve lap times but the solid tower brace does subtlety change the behavior of how the chassis responds to steering inputs and provides a bit more connectivity between driver and machine via an even more rigid chassis which should benefit the rest of the mods on this car.
https://www.rr-racing.com/RR-Racing-...isfchbrc01.htm
07-22-19, 06:15 PM
#674
When I was recently searching for available solid front tower braces for the IS350, RR-Racing originally didn't have this IS-F specific brace listed as being compatible with the IS250/IS350. I guess they changed that if they had an opportunity to test fit it on an IS250 or IS350.
It also sounds like it's a tight fit if they suggest jacking the front end of the car to properly align the brace. Who's going to be the first among us to purchase one?
It also sounds like it's a tight fit if they suggest jacking the front end of the car to properly align the brace. Who's going to be the first among us to purchase one?
07-23-19, 07:42 AM
#675
When I was recently searching for available solid front tower braces for the IS350, RR-Racing originally didn't have this IS-F specific brace listed as being compatible with the IS250/IS350. I guess they changed that if they had an opportunity to test fit it on an IS250 or IS350.
It also sounds like it's a tight fit if they suggest jacking the front end of the car to properly align the brace. Who's going to be the first among us to purchase one?
It also sounds like it's a tight fit if they suggest jacking the front end of the car to properly align the brace. Who's going to be the first among us to purchase one?