redspencer

iTrader: (1)

This thread 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.

The original post for my findings can be found on my Redspencer IS350 Build Thread: https://www.clublexus.com/forums/bui...l#post10600672

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 thread 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).

Peekb24

I’m curious to know what kind of numbers the RR racing tube would generate?

redspencer

iTrader: (1)

I would suspect that the carbon tube would net a similar MAF g/s increase as the JoeZ intake pipe.

2013FSport

iTrader: (2)

From an air flow perspective, the Fsport box makes sense that it provides more flow as it has the path of least resistance beings it's physically shorter to get fresh air to the filter. Think bends and displacement changes hurt flow as the air has to change volume constantly to conform to its ugly path over the two heat exchangers to the airbox....

So the big question now is, will redirecting that silly air duct into the open wheel well provide further reduction in IAT in a shorter time if coupled to Fsport airbox? An added perk maybe some form of ram air effect at speed but maybe not....
Maybe just a shorter path for mice to fill your airbox with winter bounty! lol


C, thanks for data and time spent sharing your results!

MikeFig82

iTrader: (13)

I've been running with the throttle body gasket grill removed. I used tin snips to cut it out. So far I felt less lag on throttle acceleration. Only way to know if it does anything is to data log. If your willing to test? I'd pay for a replacement from Rockauto.com they are the same as OEM, and cheap.

Peekb24

I saw where someone said that it wasn’t a good idea but I’m interested to see the outcome as well

redspencer

iTrader: (1)

You can probably count me out with testing out that mod. With my luck, a small critter will make itself at home inside the F-Sport lower intake box (since it has a convenient hole to crawl through), chew through the paper filter, and the little guy will eventually get sucked through the intake pipe, passed the throttle body, and down into the intake manifold as I do another WOT pull.

MikeFig82

iTrader: (13)

Fair enough. I may just set a mouse trap in mine, and check every day before start up.

PawanM

Thank you for sharing! I have always wondered that and started to log my IAT on the stock setup so I have a base line. I’m sold on the lower intake box and Lexus should give you a kickback

I want to also try heat reflective tape. The underside of the snorkel gets quite hot sitting behind the radiator. The intake tube also gets very warm sitting over the engine! I’ll log IAT and report back once I get around to it. Is anyone aware of heat reflecting/insulating paint that can be applied to plastic?

Ultra4

Cork and neoprene tapes meant for insulating pipes you can find at any home improvement store. My neoprene tape was intended to go between truck beds and bed caps.

The intake tube itself gets hot with the engine off, but with it running--if you attach one of those little thermocouples designed for monitoring PC hardware and log while driving--the tube is generally within a degree of IAT. Is it adding heat to the tract? Sure, but I bet it has zero impact on air quality. My 3" aluminum DIY F-sport tube flows better than the plastic corrugated stocker--according to the MAF, anyway--under every condition, so the ECU is fueling accordingly. Catalyst temps went up by ~200F from as-we-bought-it, to running IATs 8F below ambient. Somewhere around 80F IAT (I suspect a calculated density here), the ECU drastically alters it's behavior, with lower IATs being obviously better. Cam phasing and SCV actuation appear to be affected by IATs, ACIS appears to be purely RPM-driven.

Sure would be great if someone with a bunch of real-world experience with how the ECU behaves would chime in here...if only someone like that existed in this community...

redspencer

iTrader: (1)

I did something similar over the past weekend in order to see how it would impact IATs and peak MAF g/s readings. In my ever going quest to squeeze out more potential power from this engine, I looked at my current intake setup to see if there were ways to obtain even more cold dense air for the intake system to utilize.

Many moons back on my build thread, I mentioned that I had cut off a piece of the plastic panel inside of the front bumper/radiator area in order to create a larger hole for the slipstream of air to enter behind the headlight and in turn, more cool air for the second intake hole from the F-Sport lower intake box to use. To further improve the concept, I tried to visual on how the air flows inside the front bumper and how much of that dense air would make it to the side in order for the second intake hole to take advantage of. After contemplating on different designs for redirecting air from the front bumper grill to the hole behind the headlight (such as using a 90-degree rubber plumbing tube), I decided to use a piece of hard plastic landscape edging that I had in the garage. To my surprise, the flexibility and firmness of the plastic was the solution I've been looking for with redirecting even more cool air into the engine bay via the headlight access. Plus, the plastic edge piece would minimize rain from entering the headlight hole as it would likely drip downwards (unlike the 90-degree rubber plumbing tube which would allow all rain to flow through).

Here's my experimental ram air duct which secures firmly on both the horn and the access hole behind the headlight. From the looks of it, the air would redirect from the front bumper grill into the headlight access hole and finally to the F-Sport lower intake box hole.





The Results....

Before I go into the results of my findings, I need to reference my earlier MAF g/s results from previous experiments (3IS350 F-Sport Intake Pipe w/ Sound Generator vs 2IS JoeZ intake pipe; F-Sport Lower Intake Box vs Enclosed OEM intake box) which can be found on the first post of this thread.

Here were the results of the MAF g/s comparison between the F-Sport Lower Intake Box vs Enclosed OEM intake box which was done during the summertime last year:



Here were the results of the MAF g/s comparison between the 3IS350 F-Sport Intake Pipe w/ Sound Generator vs 2IS JoeZ intake pipe which was done during the wintertime of last year:



With regards to the ram air duct experiment, I did multiple WOT pulls in 3rd gear in various temperature conditions during the past few days which are reflected with the different Intake Air Temperature (IAT) readings. As Florida experienced some of the coldest recorded temperatures within the past two years, I felt it was the perfect opportunity to see what my peak MAF g/s reading would be with near freezing temperatures. Below are my results of the ram air duct experiment:



I recorded my highest MAF g/s reading ever which was 256.32 g/s. Though it was higher than the previous peak MAF g/s reading from my previous experiments, the IAT of 46 degrees was likely the main contributor to such a high number. When comparing the ram air duct MAF g/s readings to my previous setups and datalogs, I did not notice any significant MAF g/s differences that can be attributed to the ram air duct. As such, I believe that the ram air duct I experimented with has no impact to increasing the MAF g/s values.

However, I did observe that the IAT readings were much closer to the outside temperature readings using the ram air duct. With the ram air duct, IATs were typically around 4-7 degrees higher compared to ambient temperatures. Without the ram air duct, my previous IAT was on average 10-14 degrees higher.

Based on my analysis from when the IS350 was heatsoaking while idling at a stoplight and then moving at cruising speeds (45-50mph), the IAT temperatures also dropped significantly quicker using the ram air duct than without.

In conclusion, while a ram air duct (at least the style I built) will not have any noticeable gains to the peak MAF g/s readings, it will greatly help with ensuring an abundant amount of outside air is available for the secondary intake hole to utilize which will keep IATs low and ensure peak performance of the engine and greatly reducing heatsoak. This ram air duct design/concept might also help those with aftermarket short ram air intake systems that include a cone filter design and heat shield.

MikeFig82

iTrader: (13)

Can you post a picture of the piece? I'd like to see how it looks like. The widths, and lengths needed.

Thanks.

redspencer

iTrader: (1)

First thing first, I recommend trimming a small piece of the panel that resides inside the upper grill/radiator area in order to create a larger opening for cool air to enter behind the passenger-side headlight area. I trimmed just enough for the clip to secure the upper portion of the panel:





For this crude version of the ram air duct, I used a piece of landscape plastic edging that I had sitting in the garage.



The curvature of the plastic is perfect for having both ends of the trim piece secure properly on the horn and partially tucked inside the access hole. For the piece that I used, the height is approx 4.75" and the length (when cut) is approximately 11.5". I just checked the ram air duct this morning and after multiple WOT pulls in third gear, the piece is still secured perfectly at the angle I left it. No added NVH or any negative side effects.

MikeFig82

iTrader: (13)

Thank you for the picture. I cut my piece in guidance with your previous post.

While doing this, and bumper removed. I saw that the radiator packing at the bottom of it was in bad shape. I'm assuming from all the rain, and what not here in Houston. I cut a strip of closed cell foam I had laying around. I cut it about just the length of the lower supports spacing. Approximately 19.25" to the edge of the brackets. My thoughts that the upper part of the radiator is exposed. So that got me thinking what if I pack it too. Instead of the air coming in bleeds over it.

Once the air can't bleed it forces through the condenser and radiator.

Will some tumbling air get pushed to the sides. So that some may go lateral, and be forced into the hole on the frame cutout?

Edit: Maybe not

2013FSport

iTrader: (2)

Hey Chris, I haven't had time to download results and make an official post but I was mildly surprised to see my 4 OEM CATs pull a MAF flow rate of 250 g/s. How about them apples???

R&R tune, F-Sport axleback, F-Sport intake & air box w a WIX paper filter. I've seen 250 g/s pretty consistently while the temps here remain in the 40s 50s. And ya the 254 was off the limiter.

I'll try to post some real data at some point.