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Switch your AC off when pulling RPM past the OEM rev limit. Although the engine seems to handle the RPM, the AC compressor may not.
That said and IMO all the dark oil in the photos indicates this compressor had a problem before it grenaded but it won't hurt to cut the AC if pulling past 65....
Thanks for the heads-up as I have been busy the past few days doing multiple WOT pulls in order to collect new data.
From initial review of that thread, it does sound like there were other factors involved which may have caused the AC compressor to self-destruct. The OP also doesn’t specify much details about his custom tune and what the peak RPM limit was set at. It's also not known what the health and condition was with the engine and accessories. So far so good with my 7,200 RPM limit ECU Tune (3.5+ years of use) but I’ll certainly be mindful of any new oddities or noise coming from the engine bay which may be a precursor to a potential component failure.
Though I am not quite ready to publish my results of the datalogs collected comparing MAF g/s and IAT reading between the F-Sport Lower Intake Box and the OEM Enclosed Intake Box, I will say that the results are quite telling.
I recall Lexus’ claim on the F-Sport brochure that the F-Sport Intake System may have a potential power increase of “up to 3%” which is quite a high figure and a bold claim from a car manufacturer.
The consensus on the forums is that aftermarket intake pipes/systems will not provide any performance gains but based on my previous datalogs comparing different intake pipes and my current datalogs testing intake boxes…well, let’s just say the multitude of real world datalogs may show otherwise.
I will post my final findings later this week once I am satisfied with the test results and conclusive outcome.
/backtracking a little. On my old V8 muscle I converted from V belt to serpentine rib belt and while doing the math on the stock pulley drive system I found my new cam, springs, valves, roller everything to bump the redline by 1200 rpm which made belts slip. Back to the math. At 6400 rpm the alternator was now hitting 13,400 RPM. I don't recall the ratios but I put a smaller crank pulley on it after seeing what the Alt and power steering pump were being subjected too. Just sayin....
Well, in an unexpected turn of events, it looks like my planned datalog comparison of the lower intake boxes will have to be put on hold for the time being in order to take care of other priorities.
Though the upcoming hurricane is still projected to come through the Orlando area and has been elevated to a Category 4, I didn't allow Mother Nature to interfere with my datalogging as I was able to complete my final readings earlier today to reach a satisfactory conclusion. Stay tuned for the results which I plan on uploading tomorrow.
Though the upcoming hurricane is still projected to come through the Orlando area and has been elevated to a Category 4, I didn't allow Mother Nature to interfere with my datalogging as I was able to complete my final readings earlier today to reach a satisfactory conclusion. Stay tuned for the results which I plan on uploading tomorrow.
LOL and I took my cat wind scale post down.
I've had the the lower box installed for a few days now. I can see it really helps on the high rpms better. One thing though is when I first installed it. I noticed kinda sounded like a hollow rumble on hard pulls. So I reset the ECU via fuse method, and it was still there once again. Now two days later it's starting to sound more refined for some reason. I guess the ECU is adjusting air flow via throttle body.
This post is intended to consolidate the research I conducted this year to determine if different intake pipes or systems have a potential benefit to improving airflow. There are lots of opinions on the forums on whether or not modifying the OEM intake to an aftermarket one will result in a gain, no gain, or loss in potential horsepower (without any substantial data to back up these claims). While the opinions have been mixed as some have attempted to verify potential gains, no gains or losses via dyno results, as we know, there are multiple variables which can impact the dyno results. In addition, a dyno setup with large fans in front of the radiator does not properly replicate the real world dynamics of air flow as a vehicle is moving at a high rate of speed.
The datalogs I've collected throughout the year are to provide another perspective on how the ECU reads specific metrics (particularly MAF g/s [which is the calculated intake air flow] and Intake Air Temperatures [IATs]) when certain modifications are done. In this particular case, I've done a comparison between different intake pipes as well as different intake boxes to verify if there are any noticeable (and repeatable) changes to the MAF g/s and IAT readings using the Torque Pro App. Performance Mods that will remain constant between these MAF g/s comparisons are the RR Racing ECU Tune (which allows me to obtain MAF g/s readings at approx 7,200 RPMs), PPE Headers, Megan Racing Midpipes, and F-Sport Exhaust.
1) JoeZ Intake Pipe vs 3IS OEM F-Sport Intake Pipe
Earlier this year during the cooler month of January, I collected datalogs on multiple days to test and see which of the two intake pipes (JoeZ Intake Pipe vs 3IS OEM F-Sport Intake Pipe) consistently provided the highest peak MAF g/s (intake air flow) recording. The JoeZ pipe has a pipe diameter of 2.75" and the 3IS F-Sport Intake pipe has a diameter of 3.00". All of the datalogs were recorded at approximately the same time of the day and comparable outside temperature (low-to-mid 60s) to ensure consistency with the data and the results. All WOT pulls were also conducted in 2nd Gear up to 7,200 RPMs. Below is a revised chart of the documented results for each of the intake pipes (sorted from highest to lowest MAF g/s readings).
The end result was the JoeZ intake pipe consistently having higher recorded MAF g/s readings (approx 3-5 g/s higher) compared to the 3IS F-Sport OEM Intake Pipe during similar weather conditions and at a fairly close IAT range. As IATs decrease, there should be a slight increase in air flow due to the availability of denser air. Though the majority of the IAT readings from the 3IS OEM F-Sport Intake Pipe were lower than the readings from the JoeZ Intake Pipe samples, the collection of recorded MAF g/s of the 3IS OEM F-Sport pipe was unable to surpass the average MAF g/s readings of the JoeZ pipe at slightly higher IATs.
Regarding IATs, though the JoeZ pipe is made of aluminum and the 3IS F-Sport Intake pipe is made of plastic, there were no noticeable differences in IATs between the two pipes. IAT recordings were approximately the same whether I was cruising on the road at a consistent speed, sitting at idle at a traffic light, doing WOT pulls, or letting the IS350 sitting in the garage for 30 minutes to measure heat soak.
2) 2IS F-Sport Lower Intake Box (with the additional intake hole in the front) vs 2IS OEM Intake Box (fully enclosed)
For my recent summer analysis (August), I collected a multitude of datalogs to document changes in IATs and MAF g/s readings between the stock OEM intake box (enclosed) and the F-Sport lower intake box (which has an additional intake hole in the front). As with the intake pipe comparison, all of the datalogs were recorded on multiple days during a two-week timespan at approximately the same time of the day in the morning (outside temp of 75 degrees) or at noon (outside temp of 91 degrees) to ensure consistency with the data and the results. All WOT pulls were also conducted in 2nd Gear up to 7,200 RPMs. The JoeZ intake pipe was used for this comparison.
Here is a precursor on why this intake box comparison was done. For the longest time, we've been hearing that the only benefit of the F-Sport intake box was the increase in sound from the additional hole but no increase in performance (with no actual data to back up these claims). It was also of the opinion that the additional intake hole on the box would draw in an excessive amount of hot air from the engine bay which would reduce performance. These opinions contradict what Lexus had published in the F-Sport Accessories Brochure that the F-Sport Intake System may have a potential power increase of “up to 3%” which is quite a high figure and a bold claim from a car manufacturer.
The intent of this datalog comparison was to see if there were actual performance benefits to the F-Sport lower intake box (via the peak MAF g/s readings after a multitude of WOT pulls). Below is the chart of the documented results for both the F-Sport Intake Box and the OEM Enclosed Intake Box (sorted from highest to lowest MAF g/s readings).
The datalogs show the F-Sport Lower Intake Box having a significant advantage with making use of the additional intake hole on the box as the MAF g/s readings are approx 7-10 g/s higher than what the Factory OEM Intake Box and snorkel can produce at the same IAT range (IAT range in the 80s-low 90s were done in the mornings and the IAT range above 95 were done at noon). These results show that the engineers at Lexus/TRD USA knew what they were doing when designing the F-Sport intake system with both the F-Sport lower intake box (with additional intake hole) and TRD/F-Sport intake pipe (2IS F-Sport Intake pipe is the same design as the JoeZ Intake Pipe) providing additional performance benefits as well as an enjoyable intake induction sound. Also note that the MAF g/s recordings for the Factory OEM Intake Box are with the higher performance JoeZ intake pipe and it's quite possible that with a fully stock OEM intake system (factory OEM intake pipe with OEM enclosed intake box), the MAF g/s difference could possibly be higher (my guesstimate that it could be a difference of 10-15 g/s and would match Lexus' 3% performance claim with the F-Sport Intake System).
Regarding IATs, I was extremely surprised to also discover that the additional intake hole on the F-Sport Lower Intake Box has no noticeable difference to the IATs when compared to the fully enclosed OEM intake box. Recorded IATs were essentially the same whether I was cruising on the road at a consistent speed (104-109 degrees), sitting at idle at a traffic light (115-120 degrees), doing WOT pulls, or letting the IS350 sitting in the garage for 30 minutes to measure heat soak (130-140 degrees).
Hopefully, this post will help fellow CL members with their decision on what performance mods to purchase and this post can be referenced for future use when others state that different intake pipes or the F-Sport lower intake box have no benefits to improving performance on their Lexus IS. These potential performance benefits won't apply to all intake products but other members can feel free to conduct similar testing using different intake configurations or products to validate whether or not that system does or does not improve MAF g/s readings (particularly Short Ram Intake systems). I also plan on posting this info on a new thread in the 2IS Performance Section for more visibility.
Oh nooooo!!! I woke up this morning and found my IS350 jacked up and my wheels missing! Who would do such a thing?!!
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Answer: The wheel repair technician, that's who. I mentioned last month that the tire shop technician damaged all four of my wheels around the lug nut area when the shop replaced my TPMS sensors (https://www.clublexus.com/forums/bui...l#post10562171). It took a while but I finally had all four wheels refinished and they look almost as good as new.
@redspencer Quick question I currently have the megan racing strut tower bar since and I seen your post about the ultra racing one piece strut tower bar, I plan on switching since it's a one piece instead of 3 pieces. RR racing does sell one but, it's really pricey I also noticed that ultra racing has a rear strut tower bar also . I was wondering if it will be beneficial to buy both?? I can get the front and rear for under $300.00 dollars . This car will be driven to and from autocross events , do you think it's worth it?? For the rear strut tower bar???
@redspencer Quick question I currently have the megan racing strut tower bar since and I seen your post about the ultra racing one piece strut tower bar, I plan on switching since it's a one piece instead of 3 pieces. RR racing does sell one but, it's really pricey I also noticed that ultra racing has a rear strut tower bar also . I was wondering if it will be beneficial to buy both?? I can get the front and rear for under $300.00 dollars . This car will be driven to and from autocross events , do you think it's worth it?? For the rear strut tower bar???
I unfortunately don't have any information or feedback regarding the solid tower bar for the rear. If you are looking to spend $300 to stiffen up your chassis and do not have any under braces, I would highly recommend you utilize that $300 for the F-Sport Rear Chassis Brace instead. This had the biggest impact to keeping the suspension and tires planted to the ground while also greatly reducing the polar moment of inertia (improving chassis responsiveness) when engaging in a turn.
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On another topic, when I was collecting multiple datalogs to compare the MAF g/s and IAT readings for different intake boxes and intake tubes, I ran into an issue with my car battery having low voltage (10.5V) and needing to be replaced. On average, I'll typically see a KCLV reading anywhere between 22-25 and the KFV at -3 when cruising. When I'm at WOT, My KCLV reading will slightly drop by 1-2 and my KFV will read between -4 to -5. The consensus on the forums is that a KCLV reading above 20 will indicate that optimal ignition timing advance is being utilized as there is little to no indication of knock or detonation.
After I installed a brand new battery over the weekend, the KCLV defaulted to 15.0 and the KFV was at -3.0 which is normal as the ECU has to re-learn the settings and is 'supposed' to reduce ignition timing until the knock sensors confirm that there is no detonation.
Here is the kicker...after swapping batteries and confirming that my KCLV was at 15 (instead of my normal 23~ range), I did several WOT pulls out of curiosity to see what the ignition timing advance would show. Typically, I would see my ignition timing advance at 29-30 degrees with the KCLV at 22-25. After several WOT pulls with the KCLV at 15, there was no change to the ignition timing advance (still showed 29-30). I rechecked the KCLV and saw that it had bumped up to 17 which should technically still be below the optimal range of 20-25 for peak ignition timing advance. It was a very interesting observation...
@redspencer Thanks for your honest opinion, I do have the front and rear f sport sway bars and it makes sense to just complete the f sport suspension set up with the brace. I was honestly on the fence with the brace. I wish I could've gotten the F sport shocks . I know the springs are still available but, My BC coilovers will have to do. The 71mph slalom that the F sport equipped IS completed really caught my eye especially since I'm building my 250 specifically for autocross. I do have a megan strut tower brace and I will use that.
When you track your car do you use any seat restraining device?? CG seatbelt lock or Schroth racing harness ?? I was looking at the Schroth rallyee racing harness since it uses the factory seatbelt bolts and I dont need a cage.
@redspencer Thanks for your honest opinion, I do have the front and rear f sport sway bars and it makes sense to just complete the f sport suspension set up with the brace. I was honestly on the fence with the brace. I wish I could've gotten the F sport shocks . I know the springs are still available but, My BC coilovers will have to do. The 71mph slalom that the F sport equipped IS completed really caught my eye especially since I'm building my 250 specifically for autocross. I do have a megan strut tower brace and I will use that.
When you track your car do you use any seat restraining device?? CG seatbelt lock or Schroth racing harness ?? I was looking at the Schroth rallyee racing harness since it uses the factory seatbelt bolts and I dont need a cage.
I can vouch for the rear under brace! Transforms the car handling even on stock suspension.
When you track your car do you use any seat restraining device?? CG seatbelt lock or Schroth racing harness ?? I was looking at the Schroth rallyee racing harness since it uses the factory seatbelt bolts and I dont need a cage.
I'm actually glad you brought up the CG Lock as I was briefly looking into it a few weeks back and reading about the positive reviews. As the weather slowly cools down and I make plans to get back to doing more AutoX and HPDE events, I will very likely make the plunge and install one of these.
I've made due in the past with being in the proper seating position (close to the steering wheel), pulling my seat belt back to tighten it, and using the dead pedal to maintain stability while in a tight or high speed corner but it's possible that using the CG Lock will reduce driver fatigue and keep me even more situated in my seat. Looks like I'll be doing further research on this and possibly picking one up in the near future (I just need to determine if it has any impact to daily driving usability).
I'm actually glad you brought up the CG Lock as I was briefly looking into it a few weeks back and reading about the positive reviews. As the weather slowly cools down and I make plans to get back to doing more AutoX and HPDE events, I will very likely make the plunge and install one of these.
I've made due in the past with being in the proper seating position (close to the steering wheel), pulling my seat belt back to tighten it, and using the dead pedal to maintain stability while in a tight or high speed corner but it's possible that using the CG Lock will reduce driver fatigue and keep me even more situated in my seat. Looks like I'll be doing further research on this and possibly picking one up in the near future (I just need to determine if it has any impact to daily driving usability).
I actually spoke to one of the guys in the auto x group I'm gonna join once the car is finished, and he said that the CG lock is great alternative then having a harness, and it works well for autocross. And after explaining all the mods I'm going to do to the IS he told me that I will be slotted into the Street Touring Class most likely STX , or STU according to SCCA guidelines. He said a harness is not needed and some of the fastest guys use the OEM seat belts. I may as well look into the CG lock as well it also a lot cheaper then the harness.
I can vouch for the rear under brace! Transforms the car handling even on stock suspension.
I already have the F sport front and rear sway bar I might as well complete the set with the brace. Thanks for helping me make the decision I was definitely on the fence about it. Since a lot of people on here only mention the front and rear sway bars and don't really talk about the chassis brace.
08-26-19, 06:56 AM
I mentioned last month that the tire shop technician damaged all four of my wheels around the lug nut area when the shop replaced my TPMS sensors (https://www.clublexus.com/forums/bui...l#post10562171). It took a while but I finally had all four wheels refinished and they look almost as good as new. 
