Originally Posted by Invertalon

I am not "hating" on his theories at all. His logic DOES make sense and I do agree with his points, HOWEVER, I still feel that the engineers and designers KNOW what they are doing, and there is a reason that the design allows for the way the air is circulated through the engine compartment.

That's just my opinion. I respect his and what he is doing, but im just voicing my opinion, thats all!

Originally Posted by zio

Hey everyone, I bought my XB back at christmas time, since then I have been smelling very hot rubber everytime I turn her off.

I took her to the dealer and they told me it was not a problem, however the smells continued those hoses were getting way too hot so that means the solid-state sensors and wiring insulation was cooking too, Note: rubber gets brittle on the outside and fails or melts and expands under high heat conditions.

THE FRONT BUMPER:
I thought about it for a while and realized that the engine compartment is sealed off from airflow really quite well. looking at the front bumper and examining the dirt pattern on the radiator I saw that 65% of the radiator fresh air-flow was being blocked by the front bumper and this most likely was the culprit, after examining the fresh air intake on the "Factory" grill I saw that this design DEFLECTED most of the incoming air at speed. Now this may not cause a problem until the radiator down below which is allowed cool air becomes very dirty and blocked by road oils and dirts bugs etc. After this happens the radiator loses it's cooling efficiency and becomes much less effective and that's when REAL problems would occur not just funny smells.

I applied a mod to my front bumper to Uncover my radiator and allow for proper airflow as per the rated BTU of the radiator which requires 80% airflow to work to specs. I will replace the factory grill as well when I can find one that won't block the air as much as the super tight billet grills.

Aluminum is a complex metal, and the motor and tranny are made from it, when aluminum gets really hot it super-expands which could lead to failures in the bearing races in the motor and the tranny if the tolerances are too far off due to high heat warpage. Of course this wouldn't happen for a while (I'd estimate just over 100K miles.) depending upon road oil exposure, and dirt accumulation and would appear as a high-mileage engine or tranny failure not a design flaw caused by radiator blockage. Many of the XB's are Automatic or auto-shift designs which puts a high heat load on the tranny and has to be dissapated through the radiator, these high heat pulses can damage the tranny by causing premature failures in the disk material of the automatic transmission if not dissapated immediately this blocks the tranny pump or blocks fluid cooling channels with little chuncks of the disk material. The tranny filter is not replaced in most cases for up to 50K miles, oops it may be too late by then.

The heat generated in the transmission friction disks can be very high, far exceeding the "normal" less than boilng temps of the radiator, if not removed quickly and effectively, the transmission could fail.

I plan on louvering my hood soon too to get rid of the "sealed" engine compartment effect besides it will look cool too.

I'd guess most of you have never worked with finite analysis software for thermal design, I have, and I see a problem and a simple solution- cut some vent holes in your front bumper and louver your hood. See my profile for a pic on what it "should" look like when you are done with the front bumper.

This radiator air-flow blockage problem exists on most "NEW" cars on the road today- but the XB 08 is one of the worst I've seen and I bought one, so naturally i'd have to fix it. Fix yours today!

I love my XB and will do anything to save her from a bad thermal design engineer, wouldn't you?

Note to scion: Radiators need fresh air, not air deflection plates mounted in front of them. duh.

Zio

Originally Posted by zio

BTW- I built turbo-charged, custom control system import race cars (Honda, Nissan) for fun and profit with my friends for many years, I know what "burnt" smells like and this wasn't it, as for all you other people's negative comments about me or this thread- lol.


Zio

Originally Posted by lvbitwiz

And in true fashion, sooner or later the OP will post their "resume" (as we've seen in several threads from diffrent posters) to somehow make them sound like they are the leading authority on any given topic. Fact of the matter is, you're still only masking your problem, I run 50/50 hwy and city every day, with a header, no heat shields. Several of us do, others have turbos with a fancy intercoolder sitting at the bottom grill. Both with no hot rubber, cooking insulation, burnt toast, searing flesh or farting passengers. Ok, so you cut some holes in your bumper, and it looks like a quality job, you have more air flow, yet you really haven't shown any real data to back up your claims both before and after your mod. Before you post that something is a problem, and getting the 'sky is falling' crowd riled up. Back up your claims with solid facts and quantifiable data (temperatures, air flow rates, not swag) show us some numbers dude!

Originally Posted by zio

The smells are gone, and that is good, it used to be noticable and I worried about my XB, now there is no strange hot rubber smell and I KNOW the engine interior stays cooler. At 55mph my bumper vents put an average of aprox. 1,000,000 cubic centimeters of additional cooling air through the holes every second. (That's 1 million Cm3/sec or 38 Ft3/sec ) each bumper vent has a forward edge profile of 28cm x 8cm times the flow of air per second at 55Mph. So this is a very effective place to put a couple of vents to bring engine compartment temperatures down.

BTW- I built turbo-charged, custom control system import race cars (Honda, Nissan) for fun and profit with my friends for many years, I know what "burnt" smells like and this wasn't it, as for all you other people's negative comments about me or this thread- lol.


Zio

Originally Posted by zio

That is real data, you just obviously can't do advanced math or understand how i got those numbers, if you want the "exact" numbers then I can post them. when I say 1 million Cm3, it's a round down from 1,101,005.8752 Cm3/sec, if you could do math at this level you would have easily figured this out, from an given hole size that is exposed to air moving at 55mph that measures the total size of the forward facing profile of "both" vent holes in my bumper. the 38 Ft3/sec is a round down from 38.88 so a conversion was used from Cm3 to Ft3, when I wrote "each" vent so take the total area of the one vent measurement given and times it by two... lol I feel like I'm teaching class.

Zio

Originally Posted by zio

Wow...you try to talk down to your co-workers like that? Believe it or not Zio, most of us on here aren't the knuckle dragging gear head types that you would sooner spit on than have a conversation with. Consider your audience carefully before looking down your nose.

And your "Improvement" is still based on assumptions. Somehow I doubt you took the time to take real measurements and chose to work in the theoretical world. Yes, I'm sure it looks good on paper, but that dosen't make it real. You should still ferret around under your hood to see just what was cooking. If something was indeed 'hot' then you may want to replace it.

Originally Posted by zio

That is real data, you just obviously can't do advanced math or understand how i got those numbers, if you want the "exact" numbers then I can post them. when I say 1 million Cm3, it's a round down from 1,101,005.8752 Cm3/sec, if you could do math at this level you would have easily figured this out, from an given hole size that is exposed to air moving at 55mph that measures the total size of the forward facing profile of "both" vent holes in my bumper. the 38 Ft3/sec is a round down from 38.88 so a conversion was used from Cm3 to Ft3, when I wrote "each" vent so take the total area of the one vent measurement given and times it by two... lol I feel like I'm teaching class.

As for the tuning comment- not my resume (That's muuch bigger), but thanks for the burn, tuning was just something to keep me busy with automation control systems and help out my friends, just like I was trying to do here before you squashed me.

As for the hot smell testing, GOOD job! But unfortunately no smelly results, think about how lucky you must be, maybe my XB had much better (or worse, lol) engine compartment sealing done than yours, therefore it had a hotter engine compartment, who knows? I do know that the smell is gone and I am happier with my box.

To further detail the hot rubber smell, after stopping and popping the hood the entire engine compartment area would smell strongly of hot rubber and plastics, after a few minutes (about 5) the smell would fade away, you could smell it the moment you got out of the car (with the hood closed) and my friends could smell it too and commented upon it.

In the past when working with multi-million dollar automation control systems I had found that smelly, hot wiring in a control box was an indication of an airflow problem and had work crews install fans to cool the automation control box, which usually cured the problem by actually cooling the air, it cooled off everything in the box! Wow what a relief to think that something so simple as cooling air can be used to fix hot wiring and sensors, Right? But if the control box did not have adequate air supply the fresh cool air would be piped to the location, in locations where fresh cool air was not available and piping was to expensive an option, actual air conditioners were installed on the automation control boxes to increase the longevity of the electrical based systems which were designed to last 20 years. in the case of my XB, fresh air is available and simple vent holes were needed to bring the temp down.

A simple question for you god-like admins- if you block most of the air vents on an "air-cooled computer" with plastic air-blocking plates, seal up the case with rubber gasket material and run it as usual, will that make it last longer? I don't think it will, but, do you? If so please tell us all about it.

Let's be more exact- if you block over half the radiator for the cooling of a water-cooled computer, can you run it like normal without a failure, or will it fail in less time than if you didn't block the air-transfer portion of the radiator?

It WILL fail sooner than later, blocking airflow on a cooling system is a VERY bad idea.

I would much rather vent my bumper than have my car die sooner than later, besides 100K miles is never enough out of a car- I drive a lot more than that.

Besides- it's a simple mod that I was able to do at home with simple hand tools and careful cutting.

Zio

Originally Posted by Nzaw4

i acutally smell that also Zio!

im with ya on this one! but would u mind takin pics of the bumper mod so i can show my dealer when i go in for my next oil change.
Everytime i drive my car for more than 30 mins, and after i park it and get out i do smell it. Ive always thought it was maybe cabling from my HIDs, but i have rechecked all the wiring 10+ times, after and never noticed any burn marks on the cabling, but the smell still persists.


really annoying.,

Originally Posted by zio

So you're saying toyota used the same bumper on a different car? So the same or similar design department is making this blunt nose, air-blocking design a toyota corporate standard? Since this is a "new" look I expect there isn't much long-term data surrounding a car that just came out, say 10+ years? No chance.

You're also saying that there are many newer, different, toyota cars with similar airflow design problems? oops. That's too bad.

It's funny, you can shoehorn in a HUGE motor into a smaller car as long as you have adaquate cooling, i've seen it done many times.

Zio

Originally Posted by nvrmnd05

There has to be a more appealing less intrusive way to cool it.

Originally Posted by jimmbomb

well. ya got me convinced....... Now will I do something about it.. If I can find a good "MOD SHOP" that can cut out me some vents & make a grill for them at a decent price, then I'll do it.......... thanks for your input, zio........ jh