Results 1 to 18 of 18
  1. #1
    Join Date
    Aug 2007
    Location
    Riyadh, Saudi Arabia
    Age
    45
    Posts
    109
    Thanked: 1

    Default Safari Snorkel and the Torque Surge

    I have recently installed a Safari Snorkel on my 4L V6 Fortuner, and after installing it I noticed an mazing surge in my vehicle's torque at low RPMs! The vehicle gained so much low-end torque that kicks in at take off, I'm absolutely thrilled. Did any one with a V6 and a snorkel notice such a thing? The gain in low-end torque is truely substantial with the snorkel. Here's a picture of my snorkel right after installation:
    Click image for larger version. 

Name:	Image(38).jpg 
Views:	1488 
Size:	31.6 KB 
ID:	24896

    Click image for larger version. 

Name:	Image(35).jpg 
Views:	1046 
Size:	32.7 KB 
ID:	24897
    Toyota Fortuner 4x4 4L V6 A/T LHD

    Mods: Front airlocker, ARB Bullbar, OME suspension, auxiliary battery, 72L auxiliary fuel tank, Safari Snorkel

  2. #2
    Join Date
    Sep 2006
    Location
    Alicedale
    Age
    39
    Posts
    1,627
    Thanked: 61

    Default

    It all depends on how restrictive the air intake is on the vehicle. SOme are better than others. Also some engines require a lot more air than others. I know for a fact the V6 4.0 uses more than the KZ and d4d by quite a large amount. Almost double if I recall correctly.

    THere was a article i read a few years back a 4.0v6 prado was dynoed before snorkel fitment and after. Gains were over 2.5kw!
    Last edited by Bryan Webber; 2008/10/15 at 11:16 PM.
    '21 Hilux 2.8 Auto 4wd
    '19 Fortuner 2.8 Auto 4wd

  3. #3
    Join Date
    Aug 2007
    Location
    Riyadh, Saudi Arabia
    Age
    45
    Posts
    109
    Thanked: 1

    Default

    Great info, thank you so much I really appreciate it. If you can give me a source for that dyno test that would be really helpful.
    Toyota Fortuner 4x4 4L V6 A/T LHD

    Mods: Front airlocker, ARB Bullbar, OME suspension, auxiliary battery, 72L auxiliary fuel tank, Safari Snorkel

  4. #4
    Join Date
    Sep 2006
    Location
    Alicedale
    Age
    39
    Posts
    1,627
    Thanked: 61

    Default

    It was from a aussie website. I cant recall.

    here I found the site. my figures were incorrect in the above. was a few years ago when i read it. lol

    http://www.lcool.org/technical/120_s...rformance.html
    '21 Hilux 2.8 Auto 4wd
    '19 Fortuner 2.8 Auto 4wd

  5. #5
    Join Date
    Aug 2007
    Location
    Riyadh, Saudi Arabia
    Age
    45
    Posts
    109
    Thanked: 1

    Default

    Quote Originally Posted by Bryan Webber View Post
    It was from a aussie website. I cant recall.

    here I found the site. my figures were incorrect in the above. was a few years ago when i read it. lol

    http://www.lcool.org/technical/120_s...rformance.html
    Thank you very much. I'm reading through the article now.
    Toyota Fortuner 4x4 4L V6 A/T LHD

    Mods: Front airlocker, ARB Bullbar, OME suspension, auxiliary battery, 72L auxiliary fuel tank, Safari Snorkel

  6. #6
    Join Date
    Aug 2007
    Location
    West Coast
    Age
    57
    Posts
    7,039
    Thanked: 1230

    Default

    I think your big gain is in the cool air you are picking up from outside compared to normal. When you pull off, it is normally after standing or being at very low speed where an accumulation of hot air under the bonnet is waiting to be sucked into your engine. Hot air cannot expand as much as cooler air does when the fuel ignites in the cylinder. In effect the the cooler air is denser and hence the volume of air you are taking in is a lot more than at higher temps.

    The cooler denser air creates a lot more power than the hot air that can reach up to 65 Degrees Celsius under the bonnet. The effect on diesel engines is normally even greater and hence the move to inter coolers or water injection systems that can add up to 25% power.

    My 2c
    David/Hillbilly - 1997 SFA Nissan Sani 2,7 TD - 5" lift on 33" tires - Dual Transfer with 4.1 gears

    http://www.youtube.com/user/davidabcab



  7. #7
    Join Date
    Nov 2006
    Location
    Cape Town
    Age
    76
    Posts
    2,227
    Thanked: 1

    Default

    Quote Originally Posted by bfreesani View Post
    I think your big gain is in the cool air you are picking up from outside compared to normal. When you pull off, it is normally after standing or being at very low speed where an accumulation of hot air under the bonnet is waiting to be sucked into your engine. Hot air cannot expand as much as cooler air does when the fuel ignites in the cylinder. In effect the the cooler air is denser and hence the volume of air you are taking in is a lot more than at higher temps.

    The cooler denser air creates a lot more power than the hot air that can reach up to 65 Degrees Celsius under the bonnet. The effect on diesel engines is normally even greater and hence the move to inter coolers or water injection systems that can add up to 25% power.

    My 2c
    I think you are correct in ascribing the power gain to air temperature, and hence improved mass flow rather than volume flow. Fact remains that a significant improvement in pull off is reported by Mr Difflock. Perhaps he can report back whether this improvent was not previously experiencedd when repeating the pull off a few times ie to ensure that no stagnant hot air has built up in the engine compartment?
    A fascinating subject. For the record i am very sceptical over claims about improved power due to ram effect , particularly with Turbo Diesels. I believe ram effect will only come into play at speeds above our legal limit - and then only marginally . I have my Safari intake facing backwards - otherwise it acts as an efficient mossie catcher .Anybody out there think this is wrong ?

    Cheers Dave
    Last edited by pretdave; 2008/10/18 at 05:26 PM.

  8. #8
    Join Date
    Aug 2007
    Location
    West Coast
    Age
    57
    Posts
    7,039
    Thanked: 1230

    Default

    The experts can work it out for us, but I think a 3 liter engine is taking in 3 liter per 0.25 second at 1000rpm (just above idle) to get a ram working to keep up with an engine running at 3000rpm at 130KM/h would require a opening of more than half a meter to just keep up with what the engine needs.

    Naw, the guys with these Ram tubes on the street rods bumpers are fooling themselves and I personally think for cool air, yes great, but when this guy tells me that the "ram effect" has upped his power, I just laugh.
    David/Hillbilly - 1997 SFA Nissan Sani 2,7 TD - 5" lift on 33" tires - Dual Transfer with 4.1 gears

    http://www.youtube.com/user/davidabcab



  9. #9
    Join Date
    Sep 2006
    Location
    Alicedale
    Age
    39
    Posts
    1,627
    Thanked: 61

    Default

    I think it also depends from vehicle to vehicle. The prado intake sits inside by the fender, i doubt airflow is restricted but a snorkel is definately going to give cooler air and better flow. I dont think the ram effect makes that much difference if any as said earlier.

    Turning the snorkel around is best in heavy rains and dust.
    '21 Hilux 2.8 Auto 4wd
    '19 Fortuner 2.8 Auto 4wd

  10. #10
    Join Date
    Mar 2008
    Location
    Pretoria
    Age
    36
    Posts
    980
    Thanked: 14

    Default

    I think it is the combination of the mass of air that get's forced into the std aircleaner and @ much cooler temps than under the bonnet. The V6 generates alot of heat under the bonnet.
    Still deciding on fitting a Snorkel/ K&N CAI on the V6 Ranger, just can't get use to the idea of cutting holes in the fender- even when done proffesionally.
    2005 Ford Ranger SuperCab XLT 4000V6 Manual 5 Speed 4x4
    Petri

    1997 Ford Explorer XLT 4.0 L SOHC V6 Auto AWD 4x4
    Pieter

    2013 Audi Q5 2.0 TDi S-Tronic Quattro
    Daily Drive

  11. #11
    Join Date
    Aug 2007
    Location
    West Coast
    Age
    57
    Posts
    7,039
    Thanked: 1230

    Default

    I did an experiment a while back on 2.7TD and hung a temp pickup in various places under the bonnet. The firewall peaked at 68 deg in heavy town traffic. The probe hanging over the intake mouth got up to 62 while idling around town. Get going and once at speed it can take another minute to come down to as low 35 at 60km/h...

    Pop the probe out the edge of the bonnet here at the windscreen and you can get temps as high as just over 30 when standing still, I presume this is from what is escaping from under the bonnet or the bonnet temp itself. But as you start driving the wind effect in just a couple of seconds can bring the temp down to as low as 12 deg.

    The experiment was done in June, and I think the temps could be somewhat different in Summer when the ambient temp outside is already higher as some that I found.
    David/Hillbilly - 1997 SFA Nissan Sani 2,7 TD - 5" lift on 33" tires - Dual Transfer with 4.1 gears

    http://www.youtube.com/user/davidabcab



  12. #12
    Join Date
    Jan 2008
    Location
    Krugersdorp
    Age
    58
    Posts
    32
    Thanked: 0

    Default Hilux V6 torque

    Hi

    Seems the snorkel may have an effect but I also cannot get used to the idea of this thing sitting out there and the hole in the fender.

    I have the manual 4.0 V6 and the torque is given at 343nm (same as diesel). The gearing ratios are however very long and in 5th it is basically idling along at 100 to 110 (the speed I tow my offroad trailer). I have to then use 4th most of the time to keep up the speed.
    The auto model's torque is quoted at around 375nm. What is different to the auto engine's tuning to get that torque and what can i do (or Toyota) to get that torgue for my manual setup?

    It will make the driving experience so much better overall if torque can be close to 400nm.

    Any advice on this??

    Veldrot

  13. #13
    Join Date
    Sep 2008
    Location
    Cape Town
    Age
    50
    Posts
    22
    Thanked: 0

    Default Ram air effect

    Having owned (and currently owning) various superbikes, which these days all utilise the so-called ram effect to great effect...

    As far as I know, you need a specialised airbox designed to take increased air pressure from the ram air intake, which by way of the increased pressure allows a much greater flow of air into the motor. Without an airbox & filter designed for it, I dont think it adds much.
    2011 Prado VX D4D

  14. #14
    Join Date
    Nov 2006
    Location
    Cape Town
    Age
    76
    Posts
    2,227
    Thanked: 1

    Default

    Quote Originally Posted by JdV View Post
    Having owned (and currently owning) various superbikes, which these days all utilise the so-called ram effect to great effect...

    As far as I know, you need a specialised airbox designed to take increased air pressure from the ram air intake, which by way of the increased pressure allows a much greater flow of air into the motor. Without an airbox & filter designed for it, I dont think it adds much.
    Interesting feedback - but we shouldnt lose sight of the fact that where the off roader really needs a power boost is at low speeds - certainly no ram effect at all . At higher speeds , once the turbo is spinning merrily (assuming a TD ..) the waste gate is in any case dumping excess air . I assume that the super bikes are not turboed ? And by definition they are fast ! (above the 120 km/h hurdle)

    Cheers Dave

  15. #15
    Join Date
    Aug 2007
    Location
    JHB
    Age
    59
    Posts
    627
    Thanked: 0

    Default

    The "cooler air and ram effect" rationale for a snorkel has never sat well with me.

    The idea of the air two meters above the ground being cooler is highly dependant on the micro circumstances (ie is it a tar road, then maybe but by how much, gravel road maybe not etc). In any event as your car moves through the air, the air immediately in front of the car can only do one of three things - go under the car, around the sides or over the top. The vast majority goes over the top, air is lifted from close to ground level as the car moves underneath it. So the temperature of air at the height of the snorkel whilst driving, isnt going to be the same as the temperature profile of undisturbed air at that height. Your engine bay is hotter than outside ambient, and for this very reason all air intakes duct the air from a point where there is an inflowing source of cool air, which is different for every car but the purpose is the same, get cold air for outside the engine bay. So for me the cooler air theory is questionable. The same goes for dust.

    Some people report performance improvements when installing a snorkel, this is far more likely to simply be due to the increased diameter of snorkel ducting, compared to their standard ducting. The ram effect needs quite high speed to begin working and in any event even if you can induce slightly higher pressure at the snorkel mouth by forcing the air to a standstill it will probably have dissapated in the long duct with changing cross sectional areas/corners etc before it reaches the air box IMO.

    In superbikes the inlet design and air box are purpose designed to induce high pressure by feeding high speed air down a short intake straight into a chamber where it is slowed right down (thus increasing pressure) where it is feed straight into the engine.

    To me the only real benefit of a snorkel is for wading.

    I also worry about where the water is going when it rains heavily and whats happening to all the debris in the air thats getting sucked straight in (most standard air intakes are concealed to shield them from sucking in debris directly). I would expect the air cleaner to last less long than normal as a consequence.

    PS The change in torque characteristics is actually quite a well established phenomenon. On performance cars where they dispense with the air cleaner all together you will some times see a trumpet shaped tube leading to the carb or injector. The length of this tube has a large effect on the shape of the torque curve and is thus "tuned" to give the characteristics required. Some more sophisticated cars have "variable length intake manifolds" (I remember Audi used this a while a ago) at high revs the manifold path shortened and at low revs it increased to give more low down torque. I have seen this in Yamaha super bikes as well (a moveable trumpet in the air box). IMO the change in torque characteristics is due to the longer intake duct of a snorkel not the RAM effect.

    Another example for those that drove VW beetles, it was popular to replace the standard air cleaner with a "pancake" air cleaner, supposedly for better performance. In my youth I got hold of a book written by some American who was famous for getting Volksie engines to out perform Porsche's! He had quite a big section on the air cleaner and said in most cases the standard air cleaner gave better performance because it had a longish inlet tube which was the correct length for most normal to mild cams/exhaust systems. He even had the formulas for calculating the correct tube lengths for different set ups.

    My 2c's
    Last edited by alanB; 2008/10/25 at 09:50 AM.

  16. #16
    Join Date
    Aug 2007
    Location
    West Coast
    Age
    57
    Posts
    7,039
    Thanked: 1230

    Default

    Alan

    As I mention in one of my posts up here, amongst my tests I did was move a temperature probe around my engine bay and found that in traffic that temp of the air being taken into the air box can get up to 60 degrees. Even standing still in traffic, the temp on your roof (snorkel level) could never get to that temp from the ambient tar road air.

    Air becomes more dense and hence more volume as the temp decreases. This becomes really evident in the cylinder chamber as the fuel ignites and 10Deg lower temp intake makes a profound change in performance. The dyno results prove it by "super cooling" the intake pipes with nitrogen as they are driving, you see the power go up as the cooling happens.

    As far as the dust aspect goes, I suppose it would differ from vehicles to vehicle, but I know a couple of people that have reported that the snorkel prolonged there air cleaner life. I also see that my old donkey I drive, sucks so much dirty air into the engine compartment on trails via the viscous fan and the wheels churning up the dust with the sides of the engine compartment being open to the wheels.

    The worst I saw was with a trip last year to Hennops, mid winter when the dust gets super fine. We were a group of 6 cars and had hardly any wind the day. When we left, I noticed a drop in power, EGT was running higher than I like. I had to nurse the car back to Joburg. When I investigated, I found the filter so badly soiled that it had become a restriction in just over 1000km of use.

    I personally don't believe the ram effect theory being an influence as most report big gains with the snorkel at pull away, or, on a vehicle that probably would struggle to get 140km/h. The snorkel head is too small to act as a ram anyway.

    My2c
    David/Hillbilly - 1997 SFA Nissan Sani 2,7 TD - 5" lift on 33" tires - Dual Transfer with 4.1 gears

    http://www.youtube.com/user/davidabcab



  17. #17
    Join Date
    Aug 2007
    Location
    Riyadh, Saudi Arabia
    Age
    45
    Posts
    109
    Thanked: 1

    Default

    Thank you every body for your participation.

    The difference between me and the most of you is that I've got it installed on a 4 Liter Petrol engine.

    Quote Originally Posted by pretdave View Post
    I think you are correct in ascribing the power gain to air temperature, and hence improved mass flow rather than volume flow. Fact remains that a significant improvement in pull off is reported by Mr Difflock. Perhaps he can report back whether this improvent was not previously experiencedd when repeating the pull off a few times ie to ensure that no stagnant hot air has built up in the engine compartment?
    A fascinating subject. For the record i am very sceptical over claims about improved power due to ram effect , particularly with Turbo Diesels. I believe ram effect will only come into play at speeds above our legal limit - and then only marginally . I have my Safari intake facing backwards - otherwise it acts as an efficient mossie catcher .Anybody out there think this is wrong ?

    Cheers Dave

    I have no doubt now of the torque surge. Normally with all my mods on the car I used to get an acceleration from 0 to 100Km in 10.9 seconds; now I get it in 10 seconds sharp.

    I've tested several times, and I can confirm the increase in torque at pull off.

    Quote Originally Posted by BigBear View Post
    I think it is the combination of the mass of air that get's forced into the std aircleaner and @ much cooler temps than under the bonnet. The V6 generates alot of heat under the bonnet.
    Perfectly agree ... the heat under the bonnet is quite fundamental. Especially in our region in Saudi Arabia, where the temperature reaches 50 degrees in the summer. I'm probably getting the relatively slow acceleration because of the heat in this region. I should try again in the winter when the temperature is around 5 degrees.

    Quote Originally Posted by bfreesani View Post
    Alan

    As I mention in one of my posts up here, amongst my tests I did was move a temperature probe around my engine bay and found that in traffic that temp of the air being taken into the air box can get up to 60 degrees. Even standing still in traffic, the temp on your roof (snorkel level) could never get to that temp from the ambient tar road air.

    Air becomes more dense and hence more volume as the temp decreases. This becomes really evident in the cylinder chamber as the fuel ignites and 10Deg lower temp intake makes a profound change in performance. The dyno results prove it by "super cooling" the intake pipes with nitrogen as they are driving, you see the power go up as the cooling happens.

    As far as the dust aspect goes, I suppose it would differ from vehicles to vehicle, but I know a couple of people that have reported that the snorkel prolonged there air cleaner life. I also see that my old donkey I drive, sucks so much dirty air into the engine compartment on trails via the viscous fan and the wheels churning up the dust with the sides of the engine compartment being open to the wheels.

    The worst I saw was with a trip last year to Hennops, mid winter when the dust gets super fine. We were a group of 6 cars and had hardly any wind the day. When we left, I noticed a drop in power, EGT was running higher than I like. I had to nurse the car back to Joburg. When I investigated, I found the filter so badly soiled that it had become a restriction in just over 1000km of use.

    I personally don't believe the ram effect theory being an influence as most report big gains with the snorkel at pull away, or, on a vehicle that probably would struggle to get 140km/h. The snorkel head is too small to act as a ram anyway.

    My2c
    I absolutely agree with your thesis.
    Last edited by Mr Difflock; 2008/10/27 at 09:16 AM.
    Toyota Fortuner 4x4 4L V6 A/T LHD

    Mods: Front airlocker, ARB Bullbar, OME suspension, auxiliary battery, 72L auxiliary fuel tank, Safari Snorkel

  18. #18
    Join Date
    May 2007
    Location
    Durbanville
    Age
    73
    Posts
    83
    Thanked: 2

    Default

    I think we are fooling ourselves. The Fortuner air intake is not in the engine bay, but under the double walled fender. Air temperature here will be much lower than in the engine bay.
    I would only believe this if it is proven on a dyno with and without the snorkel. At pull off speed there can be no ram effect.
    On my KZTE, I experienced no difference before and after fitting the snorkel.
    Fortuner 4.0 4X4, Conqueror Conquest, ARB Bullbar, OME, 105L Aux Fuel Tank, ARB Spare Wheel Carrier, Bash Plates etc etc

Bookmarks

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may post attachments
  • You may edit your posts
  •