quad tips paint and remove!
Driver
Joined: May 2006
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From: Ontario, Canada
Yep, mine's parked as well, lots of snow, especially in london (was out there today).
Driver School Candidate
Joined: Jan 2009
Posts: 13
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From: Maine
My sales rep went on a trip that Lexus Canada hosted for the education of the ISF for all the Ontario sales reps (like a workshop). They learned all the little details of the vehicle (that way prepping them for any kind of questions that would arise from an ignorant to a well educated customer interested in a high end sports car). He loaned me a book that he was given, with all this information of why they designed certain things a specific way. One of the highlights was the quad exaust is done in that way (the exaust tips aren't actually attatched to the quad ends) to help reduce "back pressure".
Seeing the rest of those pictures just made me lose respect for those cars..and even maybe the IS-F. I was going to get one.
I wonder if I'll get over it.
Lexus Champion
Joined: Jun 2008
Posts: 2,162
Likes: 10
From: Dallas, Texas
Seriously? There is a design reason behind it, Lambo, Ferrari, Bugati and Lexus don't just throw on tips for the hell of it, there has to be a reason behind it...
Lexus Fanatic
Joined: Aug 2006
Posts: 7,468
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From: Vancouver, BC
Gonna need pix of the finished product.
IS-Fer (not to be confused with 'ISFer'), just because it's not overtly complicated you loose respect for the F? Oh dear, if that's all it takes I suggest you never examine anything terribly closely.
IS-Fer (not to be confused with 'ISFer'), just because it's not overtly complicated you loose respect for the F? Oh dear, if that's all it takes I suggest you never examine anything terribly closely.
Last edited by Faymester; Jan 8, 2009 at 07:31 PM. Reason: Couldn't resist
Driver
Joined: May 2006
Posts: 189
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From: Ontario, Canada
The New Car Features book says:
The other obvious thing is you can't have exhaust pipes going through any body panel without some kind of effective cooling to prevent the plastic from deforming, melting, or burning. Having the diffuser allows them to put the exhaust tips in the bumper cover without worrying about melting it into a heap of charred plastic.
The exhaust pipe diameter is increased to improve engine output.
Four tailpipes are used to allow for the exhaust diffusers integrated with the rear bumper, reducing losses due to pressure.
Four tailpipes are used to allow for the exhaust diffusers integrated with the rear bumper, reducing losses due to pressure.
Driver School Candidate
Joined: Jan 2009
Posts: 13
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From: Maine
Are you kidding?? All those autos are very exspensive, the amount of R&D that goes into developing a car of that nature is huge....they just don't throw things on for cosmetic appearance. There vehicles are built to win. This isn't your moms civic or the McDonalds part time kid down the road who threw rims and a JDM sticker on his sunfire. Get behind an ISF ....then talk
The only reason I could think of why the exhaust isn't directly connected to the tips is so the exhaust doesn't transfer the heat to melt the surrounding plastic.
I'm a little disheartened by this design - and I will get behind an IS-F in the spring time for a test drive hoping the power and the handling will kill my doubts.
Driver School Candidate
Joined: Jan 2009
Posts: 13
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From: Maine
The New Car Features book says:
The other obvious thing is you can't have exhaust pipes going through any body panel without some kind of effective cooling to prevent the plastic from deforming, melting, or burning. Having the diffuser allows them to put the exhaust tips in the bumper cover without worrying about melting it into a heap of charred plastic.
The other obvious thing is you can't have exhaust pipes going through any body panel without some kind of effective cooling to prevent the plastic from deforming, melting, or burning. Having the diffuser allows them to put the exhaust tips in the bumper cover without worrying about melting it into a heap of charred plastic.
So it has nothing to do with back-pressure.
I picked up a Lexus word document on the net awhile ago. It contains the following statement concerning the exhaust:
"Supporting Systems A true high-performance engine relies on outstanding support systems and thoughtful engineering that touches every detail. The Lexus IS F's unique stacked quad diffusers, for example, make more than a visual statement. They play an important role in a high-performance exhaust system by reducing backpressure. The stainless steel exhaust system starts with tubular exhaust manifolds and integrated catalysts. Next come dual 2.4-inch diameter front pipes that are joined before a pre-muffler and 2.7-inch single center pipe, after which the system splits into two 2.1-inch pipes and enters dual 16.8-liter mufflers."
This was one of the factors that motived me to keep the stock mufflers and tips when I converted my exhaust to a dual system and removed the secondary cats.
1. The stock mufflers have a huge capacity
2. Lexus made a point of talking about the tips and their contribution to the performance of the F.
BTW, I converted the entire Lexus document to a PDF, and attached it here if anyone is interested. I think it's a good read.
Lou
"Supporting Systems A true high-performance engine relies on outstanding support systems and thoughtful engineering that touches every detail. The Lexus IS F's unique stacked quad diffusers, for example, make more than a visual statement. They play an important role in a high-performance exhaust system by reducing backpressure. The stainless steel exhaust system starts with tubular exhaust manifolds and integrated catalysts. Next come dual 2.4-inch diameter front pipes that are joined before a pre-muffler and 2.7-inch single center pipe, after which the system splits into two 2.1-inch pipes and enters dual 16.8-liter mufflers."
This was one of the factors that motived me to keep the stock mufflers and tips when I converted my exhaust to a dual system and removed the secondary cats.
1. The stock mufflers have a huge capacity
2. Lexus made a point of talking about the tips and their contribution to the performance of the F.
BTW, I converted the entire Lexus document to a PDF, and attached it here if anyone is interested. I think it's a good read.
Lou
Lexus Test Driver
Joined: Mar 2008
Posts: 987
Likes: 1
From: Illinois
The thing is, I WANT to love these cars. I know it's kind of nit-picking about the exhaust tips..while they look great, it's like finding out your girlfriend's breasts have been implants all along even though you knew they don't move.
The only reason I could think of why the exhaust isn't directly connected to the tips is so the exhaust doesn't transfer the heat to melt the surrounding plastic.
I'm a little disheartened by this design - and I will get behind an IS-F in the spring time for a test drive hoping the power and the handling will kill my doubts.
The only reason I could think of why the exhaust isn't directly connected to the tips is so the exhaust doesn't transfer the heat to melt the surrounding plastic.
I'm a little disheartened by this design - and I will get behind an IS-F in the spring time for a test drive hoping the power and the handling will kill my doubts.
And by the way, fake breasts are still breasts and I'll still love em just as much. MMMMMotorboat
They are used to prevent backflow which caused upforce on the car when driving faster than 100MPH when a dual tip method was being tested. So there is more to it than you think. I love em. I think they really make the car look different. But in the end, they are still just exhaust tips. Everyone loves to jump on the IS-Fake bandwagon but never criticizes the fake side vents and single fake hood vent on the M3. Lets move on folks.
And by the way, fake breasts are still breasts and I'll still love em just as much. MMMMMotorboat
And by the way, fake breasts are still breasts and I'll still love em just as much. MMMMMotorboat
Lexus Fanatic
iTrader: (10)
Joined: Nov 2004
Posts: 13,441
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From: Under an IS F since 2008
Let me throw in my 2 cents with some info and research done on this.. 
I'll even throw in some prior posts about this Topic.
It is a Functional OEM Exhaust Diffuser that works as designed to properly manage Exhaust Flow as it exits the rear of the IS-F.
From a technical stand point, the 2 OEM mufflers have 4 exhaust tips on the actual mufflers.
The bumper holds the Quad Exhaust Diffusers, which both have form and function.
A true high-performance engine relies on outstanding support systems and thoughtful engineering that touches every detail. The Lexus IS F's unique stacked quad diffusers, for example, make more than a visual statement. They play an important role in a high-performance exhaust system by reducing backpressure. The stainless steel exhaust system starts with tubular exhaust manifolds and integrated catalysts. Next come dual 2.4-inch diameter front pipes that are joined before a pre-muffler and 2.7-inch single center pipe, after which the system splits into two 2.1-inch pipes and enters dual 16.8-liter mufflers.
The Stacked Tips back side are shaped into a funnel type design which I would say is another term for "diffusers"...
See here for a more detailed diffuser definition.. (generally speaking)
http://en.wikipedia.org/wiki/Diffuser_%28automotive%29
Bottom: Bottom-view. Top: Side-cut-view, the red circles mark the front and rear diffuser respectively
I'll even throw in some prior posts about this Topic.
It is a Functional OEM Exhaust Diffuser that works as designed to properly manage Exhaust Flow as it exits the rear of the IS-F.
From a technical stand point, the 2 OEM mufflers have 4 exhaust tips on the actual mufflers.
The bumper holds the Quad Exhaust Diffusers, which both have form and function.
Originally Posted by Lexus Tech Info
A true high-performance engine relies on outstanding support systems and thoughtful engineering that touches every detail. The Lexus IS F's unique stacked quad diffusers, for example, make more than a visual statement. They play an important role in a high-performance exhaust system by reducing backpressure. The stainless steel exhaust system starts with tubular exhaust manifolds and integrated catalysts. Next come dual 2.4-inch diameter front pipes that are joined before a pre-muffler and 2.7-inch single center pipe, after which the system splits into two 2.1-inch pipes and enters dual 16.8-liter mufflers.
The Stacked Tips back side are shaped into a funnel type design which I would say is another term for "diffusers"...
See here for a more detailed diffuser definition.. (generally speaking)
http://en.wikipedia.org/wiki/Diffuser_%28automotive%29
Bottom: Bottom-view. Top: Side-cut-view, the red circles mark the front and rear diffuser respectively
The Exhaust diffusers help smooth the exhaust flow, to eliminate lift from the exhaust as it exists the vehicle at high speeds. Lexus found that in high speed testing, that the billowing effect from the exhaust caused rear end lift, and skittishness in the handling.
The diffusers eliminate this effect.
I work for Lexus, and am trained by Lexus. I hope that this clears things up.
The diffusers eliminate this effect.
I work for Lexus, and am trained by Lexus. I hope that this clears things up.
Driver School Candidate
Joined: Jan 2009
Posts: 13
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From: Maine
Driver School Candidate
Joined: Jan 2009
Posts: 13
Likes: 0
From: Maine
I understand the use of a "diffuser" to create downforce by manipulating airflow through the use of the black fins you see as the rear lower valence, or the use of mesh/chicken wire to let the air escape.
But in the form of an exhaust tip? While the visual language tells me it's an exhaust tip, it doesn't tell me it's a diffuser. So maybe that's why I'm confused and don't like the fact of being faked-out by something it's not (conventionally) suppose to be.
But in the form of an exhaust tip? While the visual language tells me it's an exhaust tip, it doesn't tell me it's a diffuser. So maybe that's why I'm confused and don't like the fact of being faked-out by something it's not (conventionally) suppose to be.