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Hope everyone is doing well with the current pandemic situation. With a shelter-in-place order in FL, things have been a bit idle for me. Perhaps it's a good time for a new mod for the IS350 (in the form of a racing seat)? What do you think?
On another note, I spent some time today washing and waxing the IS350C. I was quite impressed with how reflective the Obsidian Black was in the sunlight. It almost has a chameleon-like appearance. I hope to make time for the F-Sport sway bars install sometime soon.
On a final note, I didn't really get a new racing seat for the IS350. It's actually a gaming chair that I bought for my son but it did look the part when I placed it over my driver seat. Lol. Is it too late for April Fools?
It's been a while since I last posted but being sheltered-in-place makes for fewer opportunities to go to an autocross or meet with other car enthusiasts. I did, however, get a chance to install the front and rear F-Sport sway bars on the other IS350 (the black IS350C) and that project took significantly longer than I expected (especially with previous experience on the F-Sport sway bars swap being a piece of cake on the IS350 sedan). On the plus side, I did marvel at what I had found underneath the chassis of the IS350C as I spent many long hours underneath the car.
Below is my experience on the ISC F-Sport sway bars install and what I noted on the differences between the IS350 sedan and convertible models.
- First thing first was raising the front end of the IS350C:
- Here are the two new F-Sport sway bars on standby (nice and clean):
- What I immediately noticed when I first looked underneath the IS350C were the number of aero panels and additional bracing which were used to increase the rigidity of the convertible model. In fact, a lot of the bracing and aero panels on the IS350C reminds me of the under chassis bracing and panels found on the 3rd Gen IS models.
- I recall an interview from a Lexus rep when the 3rd Gen IS was making its debut and it was touted that the fins implemented on the aero panels were derived from Formula One technology (which greatly increase stability at high speeds). It looks like these aero panels with fins also exist on the 2nd Gen IS Convertible model (at least for the 2014MY).
- Besides having to pull out all of the screws and fasteners on the large panel up front (in order to access the front sway bar), I did notice two additional side panels that I don't recall having on my IS350 sedan. It also looks like it is used for aero purposes.
- After an hour or so from beginning the project, all three front panels were removed and put to the side:
- Removing the original sway bar up front was an easy task. Here are the old and new front sway bars next to one another. Though I didn't get to measure the diameter of both front sway bars, there is a very noticeable weight difference between the two as the F-Sport front sway bar is much heavier than the stock front sway bar (Lexus F-Sport brochure states the F-Sport front sway bar for the IS350 Convertible is 30mm and increases stiffness by 100% over the original front sway bar.
- Here is the front F-Sport sway bar on the IS350C before I reattach the three front panels.
- When I began working on the rear of the IS350C, the instructions informed me that multiple braces had to be removed and/or loosened before the rear sway bar can be removed. Here is a pic of some of the bracing used in the rear of the IS Convertible which stretches across the rear subframe.
- The instructions also mandated that you use a jack or transmission lift on the rear suspension in order to keep the suspension components secured as critical bracings are removed from both the left and right sides of the rear. The diagram provided on the instructions were not well drawn which took me longer than I wanted to determine where exactly I had to secure the rear suspension. I finally figured out the exact spot after reviewing what rear suspension section could lose alignment as I removed a few of the chassis bracing on the car.
- After another hour or two, the rear braces and panels that needed to be removed were off of the car.
- As you can see, the stock rear sway bar on the IS350C is quite narrow compared to the rear F-Sport sway bar. Lexus states that the F-Sport rear sway bar used for the IS350C is 19mm and will increase stiffness by a substantial 300% over stock. Based on how scrawny and lightweight the stock rear sway bar was compared to the heft and thickness of the rear F-Sport sway bar, I wouldn't doubt it (especially with my observation that the stock IS350C is noticeably more prone to roll than a stock IS350 sedan).
- Another challenge I had with the removal and install of the rear sway bars on the IS350C compared to the IS350 sedan was how tight the clearances were to getting the old sway bar off and the new sway bar on. It required the loosening of the exhaust hangers on the driver side as well as loosening other under chassis braces in order to finally swap out the rear sway bars. Nonetheless, there was a light at the end of the tunnel and the rear F-Sport sway bar was finally installed (though it did receive a few scrapes as it was a pain to get it across the under chassis of the ISC.
That was one experience I don't ever want to go through again (at least with the convertible model). On the plus side, the handling characteristics of the IS350C with the F-Sport sway bars are immediately noticeable and significantly more confidence-inspiring when engaging in the corners. With the stock sway bars, not only was there a lot of roll and front plow understeer, when you tried to return back to neutral, the convertible felt very unstable. With the new sway bars, the IS350 Convertible has substantially less body roll and helps to maintain traction and suspension geometry with the tires under load. Though the install process was much more of a challenge than what I originally expected, the end results were worth it.
On a side note, I do wonder if the aero panels on the IS350C are compatible with the IS350 sedan. If so, that would be a great breakthrough as I believe aero panels on the USDM 2IS350s are non-existent (they do exist on the JDM versions though). The braces used on the IS350C would also be a great addition to an IS350 sedan but it would likely require body work in order to properly secure these braces underneath the chassis of the sedan model.
It's been a while since I last posted but being sheltered-in-place makes for fewer opportunities to go to an autocross or meet with other car enthusiasts. I did, however, get a chance to install the front and rear F-Sport sway bars on the other IS350 (the black IS350C) and that project took significantly longer than I expected (especially with previous experience on the F-Sport sway bars swap being a piece of cake on the IS350 sedan). On the plus side, I did marvel at what I had found underneath the chassis of the IS350C as I spent many long hours underneath the car.
Below is my experience on the ISC F-Sport sway bars install and what I noted on the differences between the IS350 sedan and convertible models.
- First thing first was raising the front end of the IS350C:
- Here are the two new F-Sport sway bars on standby (nice and clean):
- What I immediately noticed when I first looked underneath the IS350C were the number of aero panels and additional bracing which were used to increase the rigidity of the convertible model. In fact, a lot of the bracing and aero panels on the IS350C reminds me of the under chassis bracing and panels found on the 3rd Gen IS models.
- I recall an interview from a Lexus rep when the 3rd Gen IS was making its debut and it was touted that the fins implemented on the aero panels were derived from Formula One technology (which greatly increase stability at high speeds). It looks like these aero panels with fins also exist on the 2nd Gen IS Convertible model (at least for the 2014MY).
- Besides having to pull out all of the screws and fasteners on the large panel up front (in order to access the front sway bar), I did notice two additional side panels that I don't recall having on my IS350 sedan. It also looks like it is used for aero purposes.
- After an hour or so from beginning the project, all three front panels were removed and put to the side:
- Removing the original sway bar up front was an easy task. Here are the old and new front sway bars next to one another. Though I didn't get to measure the diameter of both front sway bars, there is a very noticeable weight difference between the two as the F-Sport front sway bar is much heavier than the stock front sway bar (Lexus F-Sport brochure states the F-Sport front sway bar for the IS350 Convertible is 30mm and increases stiffness by 100% over the original front sway bar.
- Here is the front F-Sport sway bar on the IS350C before I reattach the three front panels.
- When I began working on the rear of the IS350C, the instructions informed me that multiple braces had to be removed and/or loosened before the rear sway bar can be removed. Here is a pic of some of the bracing used in the rear of the IS Convertible which stretches across the rear subframe.
- The instructions also mandated that you use a jack or transmission lift on the rear suspension in order to keep the suspension components secured as critical bracings are removed from both the left and right sides of the rear. The diagram provided on the instructions were not well drawn which took me longer than I wanted to determine where exactly I had to secure the rear suspension. I finally figured out the exact spot after reviewing what rear suspension section could lose alignment as I removed a few of the chassis bracing on the car.
- After another hour or two, the rear braces and panels that needed to be removed were off of the car.
- As you can see, the stock rear sway bar on the IS350C is quite narrow compared to the rear F-Sport sway bar. Lexus states that the F-Sport rear sway bar used for the IS350C is 19mm and will increase stiffness by a substantial 300% over stock. Based on how scrawny and lightweight the stock rear sway bar was compared to the heft and thickness of the rear F-Sport sway bar, I wouldn't doubt it (especially with my observation that the stock IS350C is noticeably more prone to roll than a stock IS350 sedan).
- Another challenge I had with the removal and install of the rear sway bars on the IS350C compared to the IS350 sedan was how tight the clearances were to getting the old sway bar off and the new sway bar on. It required the loosening of the exhaust hangers on the driver side as well as loosening other under chassis braces in order to finally swap out the rear sway bars. Nonetheless, there was a light at the end of the tunnel and the rear F-Sport sway bar was finally installed (though it did receive a few scrapes as it was a pain to get it across the under chassis of the ISC.
That was one experience I don't ever want to go through again (at least with the convertible model). On the plus side, the handling characteristics of the IS350C with the F-Sport sway bars are immediately noticeable and significantly more confidence-inspiring when engaging in the corners. With the stock sway bars, not only was there a lot of roll and front plow understeer, when you tried to return back to neutral, the convertible felt very unstable. With the new sway bars, the IS350 Convertible has substantially less body roll and helps to maintain traction and suspension geometry with the tires under load. Though the install process was much more of a challenge than what I originally expected, the end results were worth it.
On a side note, I do wonder if the aero panels on the IS350C are compatible with the IS350 sedan. If so, that would be a great breakthrough as I believe aero panels on the USDM 2IS350s are non-existent (they do exist on the JDM versions though). The braces used on the IS350C would also be a great addition to an IS350 sedan but it would likely require body work in order to properly secure these braces underneath the chassis of the sedan model.
Great job man. Awesome detailed breakdown and info on your work.👍
Great job man. Awesome detailed breakdown and info on your work.👍
Thanks . I figure I would do a mini documentary of the process as I couldn't find a similar writeup on the ISC subforums and it would make for a unique experience being that the sedan and convertible IS models are similar yet different.
Though the car is no longer on jack stands, I took a few extra shots of the underbody to see what unique braces I could find on the convertible that are not present or the same as the sedan model. I don't know the exact terminology for each specific brace but here's their locations:
Front cross brace:
Center/Rear cross brace:
Rear subframe braces:
There is one more long brace bar (passenger side) not seen on the above pic as its removal wasn't required.
Originally Posted by Gville350
Great work!
Let us know if you end up checking to see if the under-body panels from the convert align with the sedan!
Interesting enough, another CL member mentioned that some of the 3rd Gen GS350 underbody panels are compatible with the 2IS350 (only requires some trimming to fit). These would be more easily available to obtain.
I've looked at parts diagrams and looks like the front chassis brace from the 3is will be a bolt on to the 2is. engine cradle/ k member are the same. there a few bits besides the braces themselves that will be required but again they're bolt on pieces
Interesting enough, another CL member mentioned that some of the 3rd Gen GS350 underbody panels are compatible with the 2IS350 (only requires some trimming to fit). These would be more easily available to obtain.
Man, over the past few weeks or so I have been researching different cars as a replacement for my 240sx as a daily (cause I refuse to daily my Evo...and it can't right now) when a friend of mine recommended the IS350 because I had been looking at v6 .... Camrys :/ Anyway, I stumbled upon your exhaust videos and subsequently this thread. I've been reading through it, more and more impressed with how long you've had the car, what you've done with it, and that theres a luxury car that will handle and accelerate like nothing I've seen for the price/reliability/comfortableness. I am sold on it as my next car, if for nothing else than the reliability and the exhaust note haha.
Anyway, the purpose of my post was to say thank you for doing what you've done and documenting it where someone like me could find it. Its extremely valuable information in here and I hope soon I can start on my own.
p.s. the best info I've seen was to not get a 2006 haha I don't want to have to do that pedal dance.
Man, over the past few weeks or so I have been researching different cars as a replacement for my 240sx as a daily (cause I refuse to daily my Evo...and it can't right now) when a friend of mine recommended the IS350 because I had been looking at v6 .... Camrys :/ Anyway, I stumbled upon your exhaust videos and subsequently this thread. I've been reading through it, more and more impressed with how long you've had the car, what you've done with it, and that theres a luxury car that will handle and accelerate like nothing I've seen for the price/reliability/comfortableness. I am sold on it as my next car, if for nothing else than the reliability and the exhaust note haha.
Anyway, the purpose of my post was to say thank you for doing what you've done and documenting it where someone like me could find it. Its extremely valuable information in here and I hope soon I can start on my own.
p.s. the best info I've seen was to not get a 2006 haha I don't want to have to do that pedal dance.
Thanks for the kind words. This build thread was originally intended to be a source for performance knowledge on the sleeper-status of the 2nd Gen IS350 and throughout the years, it's grown to be one of the largest build threads on Club Lexus. There have been lots of great contributions from other CL members on this thread which has had helped to further evolve this build and to break new boundaries on the capabilities of this IS platform. The 2GR-FSE was a benchmark engine back in terms of performance and technology in 2005 and while it doesn't get the proper attention like a Nissan/Infiniti VQ motor, a tuned 2GR-FSE does provide a phenomenal powerband throughout the entire RPM range and is a buttery smooth engine with an attention-grabbing exhaust note when paired with the proper aftermarket parts (my IS350 constantly receives compliments on its sounds at track days from other drivers with much higher-end cars and engines). The curb weight, wheelbase, weight distribution, gearing, and other specs of the 2nd Gen IS350 make it a great platform to build upon as newer generation models continue to become heavier and larger.
Besides my headlights looking faded and some rock chips on the bumper, the exterior, interior, and mechanical bits have been rock solid for nearly 14 years and the IS350 has been a blast to drive as a daily driver. My philosophy as a car enthusiast is that a vehicle should stir the emotions on a daily basis and create a strong positive bond between man and machine.
On a side note, I was going through some old pics of mine and thought I'd post some other vehicles that had been in my stable which were also fun to drive (some more than others). As you can see, I'm a passionate Lexus/Toyota owner :
Previous Vehicles:
Toyota Supra/ Lexus SC300 (2JZ siblings):
Lexus SC430 (with my mostly stock IS350):
Current Vehicles:
Lexus IS350 and IS350C (double the 2GR-FSE goodness):
Lexus GX470 (surprisingly fun to drive off-road in the Tennessee/Carolina mountains):
Future Vehicle??
A91 Edition Toyota Supra (this limited-edition spec has been a challenge to secure an allocation on. I'm hoping to acquire one in August)
Thank you so much @redspencer for this goldmine of information and your experiences. I have a '11 IS350 AWD stock, and have my first High Performance Driving class to get into tracking next week. If I end up wanting to track my IS350 (hesitating because I don't know if I want to track my daily), I'll take your advice of upgrading these to make it more track oriented: a set of BC Racing coilovers (or F-Sport shocks and springs), front and rear F-Sport Sway Bars, the F-Sport Chassis brace, and the 2011+ IS-F Steering ECU.
Do any of these recommendations change given my car is AWD? Is it better to have a dedicated track car or would you recommend dailying and tracking this car? Seems like a pretty reliable car where this is doable.
Thank you so much @redspencer for this goldmine of information and your experiences. I have a '11 IS350 AWD stock, and have my first High Performance Driving class to get into tracking next week. If I end up wanting to track my IS350 (hesitating because I don't know if I want to track my daily), I'll take your advice of upgrading these to make it more track oriented: a set of BC Racing coilovers (or F-Sport shocks and springs), front and rear F-Sport Sway Bars, the F-Sport Chassis brace, and the 2011+ IS-F Steering ECU.
Do any of these recommendations change given my car is AWD? Is it better to have a dedicated track car or would you recommend dailying and tracking this car? Seems like a pretty reliable car where this is doable.
Thanks again!
That's awesome to hear. There's definitely a lot of great information buried within the hundreds of posts on this thread (discussions about datalogs, larger throttle bodies, porting intake manifolds, etc.) that can help the CL community. I may have to comb through the pages one of these days and create a table of contents on the first post of the thread for ease of reference.
I don't have experience with the AWD version of the Lexus IS350 but I would imagine the upgrades that you are considering will make a very fun daily driver that you can also enjoy at HPDE events. Add some high-performance summer tires, front LCA bushings, and minor brake upgrades (high-temp DOT4 brake fluid and pads) and you'll be set. It's been a while since I tracked my car but each drive out of the house and onto the street is always a pleasant and memorable experience. Every daily drive should feel like a stress relief from the chaos around us. If you plan on keeping your car for many years, the upgrades are worth it.
This is a pretty awesome thread! I didn't go through all 53 pages, but I definitely will when I have time. That is quite a build...and a journey! I would love to do what you have done with my IS350, but unfortunately I have most of my money invested in my property. Also if you are married, you must have a very understanding wife, because my wife has other priorities with my money, like remodeling our garage (she has a saying: my money is my money and your money is my money!). Anyway I may do an LSD (RR Racing Cusco RS LSD), but that is probably about it
04-10-20, 03:58 PM
