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Nice to see the great upgrades in a IS350. I stumbled on your thread.
I hope to get a is350 and I am curious with the F sport rear AR bar and lowering springs (swift) it wouldn't be fun and nimble and balanced. How much would you say that these 2 mods transform the car ? How does it compare to other sporty sedans you have driven? Thanks.
Nice to see the great upgrades in a IS350. I stumbled on your thread.
I hope to get a is350 and I am curious with the F sport rear AR bar and lowering springs (swift) it wouldn't be fun and nimble and balanced. How much would you say that these 2 mods transform the car ? How does it compare to other sporty sedans you have driven? Thanks.
edit.
Welcome to the forums. I definitely recommend a 2nd Gen IS350 as there are plenty of articles/videos of this model being a great sleeper car (0-60 in under 5 seconds).
If you do plan on starting off with the F-Sport rear sway bar with swift springs as your initial mods, you'll certainly make the IS350 a more enjoyable car to drive. The F-Sport rear sway bar is the best bang-for-your-buck handling mod to change the cornering personality of the car (essentially changing the behavior from understeer to oversteer). The swift springs will lower your center of gravity and further enhance cornering performance though I would recommend eventually upgrading to performance shocks as well or switching to coilovers in the future.
With those two specific mods, you should certainly enjoy some spirited driving with the IS350. Performance tires would also help keep you from breaking traction too early. I recommend getting a 2007+ IS350 as you can easily disable stability control by long-pressing the button (the 06 model requires you to perform a "pedal dance"). If you are looking to get an earlier model IS350 (i.e. 2006-2008), check the service records to see if the melting dash TSB was done as the dash and door panels were known to get mushy and melt for the earlier models (2009+ fixed this issue).
The 2nd Gen IS350 is certainly a fun car to own as it has a shorter wheelbase and less curb weight than most newer luxury sedans in the market.
I would strongly second redapencer's comments. The basic chassis on the IS350 is well designed. It has good camber curves front and rear which you will not find on a BMW or M-B. It can be tuned for good balance with either slight oversteer or understeer. So tuned, it is an honest handling car that will not surprise you when traction comes to an end. Again more than you can say for the other two. On the other side, it has a number of faults due to insufficient sorting by the factory. Fortunately these faults are easily remedied. Thus the car is fun to work on with improvements that yield great results which are very noticeable.
Thank you both. I plan to get a 2011 in the coming months. I have read lot reviews and like the car a lot and hope to turn up the sportiness and it make more of a driver's car.
Thank you both. I plan to get a 2011 in the coming months. I have read lot reviews and like the car a lot and hope to turn up the sportiness and it make more of a driver's car.
I waited until I could grab a later year 2IS with F-Sport option as I hate fake wood interior, wanted the OEM suspension and steering ECU as well the USB option. With an $18k loan it was mine with 50k miles on it. It is a much better driving car than two others I looked at before it. Glad I waited but it took a year.
I read this whole thread a few months ago but now im trying to recall, did you do any weight saving or strip anything out of the car that made a significant difference in performance?
I read this whole thread a few months ago but now im trying to recall, did you do any weight saving or strip anything out of the car that made a significant difference in performance?
Nope, my IS350 is, for the most part, still fully-loaded with a Mark Levinson system, navigation, adjustable leather seats, etc. for daily driver use and to haul the kids around. In fact, when I'm on the track, I still keep the kid seats secured in the back as it's not worth the effort to remove them in order to drop the added 10 lbs. I will however remove the spare tire and kit before going on the track which will help save 40ish pounds.
The biggest and most important weight savings I've done to the IS350 are the lightweight wheels. Each wheel reduces approx. 10 lbs of unsprung weight per corner (total of 40 lbs) which will help with acceleration, braking, and cornering performance. I believe the headers and exhaust saved a few pounds of sprung weight but it wouldn't be anything substantial.
As an update to this thread, the month of May has been crazy busy for me so I haven't had much time to do spirited driving or even install the new Figs poly bushings for my front and rear sway bars. It's also love bug season here in Central Florida which means I need to drive extra cautious or else my front bumper will be littered with dead bugs (which will eventually eat away at the clear coat/paint).
Besides the Figs sway bar bushings, I do have another new upcoming mod that I'm waiting to install once the part is delivered. More to come when I receive it.
On another note, a recently released new product from Monkey Wrench Racing (MWR) caught my interest. It looks like we may finally have an option for upgraded camshafts for the 2GR-FSE!
Set of 4 upgraded camshafts; includes necessary upgraded shims and lash caps. Fits all 2GR-FSE engines.
These cams add significant power at higher RPM with no loss of midrange torque thanks to the dual VVT system. MWR recommends upgrading the valve springs if you will exceed 7000 RPM.
Though these upgraded camshafts are worthless without the proper tuning, the thought of maxing out the tachometer at 8,000 RPMs with a high-strung 2GR-FSE would be divine.
I did speak with RR Racing about this latest development and while its predicted that we'd see a ~20ish rwhp gain from this mod, a special tune for this mod would likely only be offered if there was enough demand for this upgrade.
The biggest and most important weight savings I've done to the IS350 are the lightweight wheels. Each wheel reduces approx. 10 lbs of unsprung weight per corner (total of 40 lbs) which will help with acceleration, braking, and cornering performance.
The suspension should be working better as well with the better sprung/unsprung weight ratio
Originally Posted by redspencer
It's also love bug season here in Central Florida which means I need to drive extra cautious or else my front bumper will be littered with dead bugs (which will eventually eat away at the clear coat/paint).
Wax/sealant/coating? In my case bugs still stick, but removal is far easier.
I have one question as my IS350 is about to hit the 150k run, Im about to do the transmission fluid change but Im curios about the filter as I plan to change it every 40k miles. Do aftermarket transmission filter work the same or better than OEM? For what I have seen its just a baffle but the oem cost 3 or 4 times the aftermarket ones.
What do you guys recommend? And what oil for the stock differential.
Thanks in advance and sorry for hijacking the post. Very good info in one place.
No worries. Feel free to post performance-related questions on this thread for others to answer as that was one of the original intents of this build thread that I started nearly five years ago (gee....has it really been that long? ).
When I had the transmission fluid fully flushed at the dealership two years ago (at the 80k mark), I don't believe the filter was changed. I'd have to check my service records to see what it states. When I sent a sample of the fluid to Blackstone for analysis, they did note the presence of some metal but it's possible that the metal was from the wear-in process of the transmission: https://www.clublexus.com/forums/bui...ml#post9796605
Well, the new part that I previously mentioned has finally arrived. It took longer than anticipated as this part was made-to-order from the factory before being shipped to me. I was very impressed with the attention to detail with how well they wrapped this part as it literally took over 20 minutes for me to carefully remove all of the plastic wraps before I was left with this solid piece 2-point Front Tower Brace (FTB):
I decided to go with the Ultra Racing FTB as it is one of the very few companies that produce a solid one-piece steel bar for our platform (I think Tom's also makes a solid FTB but they appear to be unavailable and would also be priced at a premium).
I had contemplated for quite a while on whether or not to purchase a tower brace as 1) The Lexus IS utilizes a double wishbone suspension up front instead of struts and 2) it is difficult to take advantage of the benefits of a strut bar unless a car is heavily modified. As I'm running wider-than-stock front and rear tires with fairly sticky summer tires (Michelin PS4S) along with an OS Giken LSD to add even more lateral g-force, I figured I'd give this mod a shot. Plus I've been very impressed with some of the previous chassis brace mods that I've done in the past (particularly the F-Sport rear chassis brace and the front lower four-point brace) that there's probably more room to increase the rigidity of this chassis for track use. After also doing some research on other Lexus vehicles such as the IS-F CCS-R and the RC-F (both also utilize bracing in the engine bay albeit connected to the firewall), there appears to be a potential benefit even for a double-wishbone setup.
As it is currently raining outside, I have not yet had a chance to see if there is any noticeable difference with the responsiveness of the steering, chassis, or suspension from this FTB (though I suspect it would be minimal on the street and likely more apparent on a track day). I did weigh this solid steel bar and it weighs a hefty 4.8 pounds so it hopefully will have some sort of performance improvement and not just be a dead weight. Time will tell I guess!
In the meantime, here is how the new FTB looks in the engine bay.
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.
Hey I don't want to clutter your build thread but on the topic of Torque Pro and MAF, AFR, Load and Ignition advance, here is what a stock ECU is doing.
On the highway at cruise, assuming 6th and nail it, its first shift just hammers on the ignition dropping it way down. I really didnt expect to see that. Let me know if you have any questions... Throttle is PID "Throttle Pedal D" which neither scales to zero at idle or 100% at WOT so keep that in mind. Also notice AFR from cruise goes lean for moment. I need more data but there is such lag using this method we really don't see the play by play happenings when logging every 0.25 seconds. Def don't try and tune your car w this app....
Also, not shown but the built in PID for Transmission Temperature is crap as it simply mirrors the engine coolant temp. Trans fluid temp will never rise as fast as the engine coolant so that is useless and misleading.
Looks like your inquiry regarding the PID for transmission temperatures was finally answered today thanks to CL member mbski on a recent Transmission Cooler thread:
Originally Posted by mbski
Yes, OBD Fusion can read the pan temp...It's listed as 'A/T Oil Temperature 1' under 'Electronic Controlled Transmission' in Toyota, Lexus, Scion add on PIDs. Mine reached 210F just on the drive to work this morning.
I also confirmed that the sensor reading for "A/T Oil Temperature" on OBD Fusion does vary enough from the Engine Coolant Temperature readings to lead me to believe that it is coming from a different sensor.
Initially, I was on OBD Fusion comparing the readings from the "Engine Coolant Temperature" to the readings found under the "Electronic Controlled Transmission (ECT) Coolant Temperature". Unfortunately, it looked like the app was reading the data from the same sensor as I found the two readings to be either exactly the same or slightly off by 2-5 degrees before matching once again (which is probably also what occurs when trying to obtain the A/T coolant temp reading using Torque Pro as you saw).
Once I applied the "A/T Oil Temperature" display (bottom left), I noticed that the reading for the transmission temperature was rising slower than the engine coolant temperature (which falls in line with your assessment in bold above) and varied differently to the other two temperature displays (top left and right).
Now that it seems possible to read the A/T temperature via an OBD app (OBD Fusion), I'm curious to read what my temps will show on my next autox or HPDE (and whether or not a transmission cooler is necessary for the IS350 when used under constant heavy loads).
EDIT: I did another cold start observation this afternoon and verified that the engine coolant temp reading reached operational temperature several minutes before the A/T oil temp display did which indicates that the app is indeed displaying the transmission temperature.
As the majority of my existing chassis braces are in a F-Sport blue color, I went ahead and changed the color of this tunnel brace from black to blue. I didn't do as good of a paint job as I would have liked but I guess it doesn't matter as it will reside underneath the car. I also weighed this brace and it was a total of 1.4 pounds.
05-15-19, 05:26 PM
I definitely recommend a 2nd Gen IS350 as there are plenty of articles/videos of this model being a great sleeper car (0-60 in under 5 seconds). 
I will however remove the spare tire and kit before going on the track which will help save 40ish pounds.
