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Bonnet guard - Big mistake
Posted: Tue Apr 23, 2013 6:39 pm
by antlo69
So I read over the weekend a older post regarding the use of Bonnet guard and that its a big no go for diesel models.......
Two months ago I upgraded my Lux and one of the items on the shopping list was a clear bonnet guard "Original Toyota product from Toyota", and I thought it look nice and will add extra protection. So I installed it.
The same time I have upgraded to set of Fortuner 17" with 275/65/17 BFG's. My fuel consumption and performance were very bad all of a suden.
I do 8,000km to 12,000km a month, so the consuption was severely impcting my travel budgets.
The past weekend I removed the guard and did a quick 600km on Saturday.....guess what, my old snappy performance was back, fuel consuption bck where it should be.
So a simple piece of plastic caused me to have verry poor performance and fuel consumption.
The point I want to make is, now even more so than before I realize the importance of propper airflow to the intercooler and the effect it will have on performance/consumption.
I thought I'd share this will my fellow Lux'ers.
Re: Bonnet guard - Big mistake
Posted: Tue Apr 23, 2013 7:07 pm
by Gideonvanzyl
Antonie, I will test your theory on my 2.7 when I do my next roadtrip.
Re: Bonnet guard - Big mistake
Posted: Tue Apr 23, 2013 7:11 pm
by louis fourie
Gideonvanzyl wrote:Antonie, I will test your theory on my 2.7 when I do my next roadtrip.
Gideon
Onthou die D4D se intercooler scoop sit bo-op die bonnet. Glo nie dit gaan jou veel help nie.
Re: Bonnet guard - Big mistake
Posted: Tue Apr 23, 2013 7:18 pm
by Sebata
If u want to get rid of that guard, I'm here
Re: Bonnet guard - Big mistake
Posted: Tue Apr 23, 2013 7:23 pm
by JJBotes
Is that becausre of less air to the intercooler ? or is there air going in under the bonnet ?
Re: Bonnet guard - Big mistake
Posted: Tue Apr 23, 2013 9:29 pm
by antlo69
My theory is that with a intercooler, you need a constant supply of cool air into the scoop in order for the intercooler to work as it should. With the bonnet guard and the aerodynamics of the airflow affected, the intercooler does not get the required cool air flow. Nd we know that hot air is not good.
Cooler air = denser = more oxygen for combustion.
Well thata what the clever guys are telling me.
Re: Bonnet guard - Big mistake
Posted: Tue Apr 23, 2013 9:32 pm
by antlo69
So based on the above, any offers for a slightly used clear hilux bonnet guard??? Lol
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 8:06 am
by george
Sebata wrote:If u want to get rid of that guard, I'm here
Speak to da Lion
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 11:02 am
by Kaaskrul
As said above.
I just shake my head when I see a D4D with Intercooler, and a bonnet guard.
Isuzu had a letter sent out to all Dealers, saying that the clients must remove the Bonnet guards on the 300TDI with scoop on bonnet. They had a few Intercoolers that actually cracked.
If you fit a bonnet guard, you can actually just use duct tape and close off the scoop, same thing.
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 11:22 am
by JEEPIE
the bonnet guard is cosmetic
it does however reduce your vehicle performance ( on a inter cooler / diesel)
it projects the air higher over the bonnet
so decreases air flow to inter cooler
less air flow / reduced performance / increased fuel consumption
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 12:04 pm
by subok
I think I will remove mine and test the effect.
Sent from my GT-I9300 using Tapatalk 2
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 1:34 pm
by WayneSchalk
Now for the BIG one
the older D4D has a smaller scoop than the new model..........
I can only think of one obvious reason why, I wonder how big of a mod it is
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 1:41 pm
by Sebata
george wrote:Sebata wrote:If u want to get rid of that guard, I'm here
Speak to da Lion
PM sent
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 2:04 pm
by Quadmyster
One would never think that it would make that big a difference.
When i installed mine i thought about this same dilema, i know the cooler the air the engine takes in the better. And the intercooler will cool the hot air from the turbo and that will be your gain in performance.
Now how can one protect your bonnet without the guard helping out. The guard saved my bonnet and window from some nasty rock in the past.
A proper test would be nice. Someone with a airflow meter out there?
Good topic this, makes me think alot about my guard that on.
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 3:00 pm
by JEEPIE
Quadmyster wrote:One would never think that it would make that big a difference.
When i installed mine i thought about this same dilema, i know the cooler the air the engine takes in the better. And the intercooler will cool the hot air from the turbo and that will be your gain in performance.
Now how can one protect your bonnet without the guard helping out.
easy , its not a quad race , stop driving so close up peoples behind
The guard saved my bonnet and window from some nasty rock in the past.
A proper test would be nice. Someone with a airflow meter out there?
Good topic this, makes me think alot about my guard that on.
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 3:07 pm
by Quadmyster
Jeepie i know where your factory is. Bwhahahaha.
You must see the new skid i built for the quad. should crush rock. ha ha.
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 3:10 pm
by smokintyres
Quadmyster wrote:One would never think that it would make that big a difference.
When i installed mine i thought about this same dilema, i know the cooler the air the engine takes in the better. And the intercooler will cool the hot air from the turbo and that will be your gain in performance.
Now how can one protect your bonnet without the guard helping out. The guard saved my bonnet and window from some nasty rock in the past.
A proper test would be nice. Someone with a airflow meter out there?
Good topic this, makes me think alot about my guard that on.
I have seen a couple of D4D Vigos (specifically the imports) with a gap in the guard to allow airflow into the scoop. Couldn't locate a picture unfortunately...
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 3:17 pm
by Quadmyster
Would be nice to see one and maybe mod the existing one. Mmmmmm
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 3:20 pm
by Ali3n
This is the bonnet guard you guys need.
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Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 3:23 pm
by ThysdJ
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 3:34 pm
by Ali3n
Now now... I would have shared my coffee with you but not anymore...
They didn't ask for a good looking solution, I just gave them a solution...
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 3:42 pm
by ThysdJ
Granted you posted as solution, but only a partial solution... The center part of the bonnet is exposed.
You can always stick clear vinyl over the front edge of the bonnet. It wont prevent the big stone-chips but it will help prevent the sand-blasting effect. Actually it should prevent the paint from being chipped..
Plus it is pretty cheap, you can re-apply when required..
Re: Bonnet guard - Big mistake
Posted: Wed Apr 24, 2013 4:56 pm
by antlo69
This will be my solution, a clear film (3M product I think) to protect the bonnet.
I'm now on day 4 without my bonnet guard and trust me, a HUGE difference.
And to think I almost wanted to get rid of my 17" nd BFG's. They were NOT the culprits here.
Secondly, I do huge mileage a day, if there's someone that will notice a difference its me in my Lux I have done close to 300,000km the last 3 years.
Re: Bonnet guard - Big mistake
Posted: Thu Apr 25, 2013 1:05 am
by Hennie2
You can apply VPS on the front edge of the bonnet, lights and bumper. Provides very good protection even for some of the bigger stones.
Re: Bonnet guard - Big mistake
Posted: Thu Apr 25, 2013 10:20 am
by Tsa
@antlo69: When you say HUGE difference. What are you referring to? More power felt, drop in fuel consumption?
I have been looking for an excuse to remove mine from Tuna, but just knew the minute I remove it something will hit the bonnet! LOL
This experiment will at least justify it! :)
Re: Bonnet guard - Big mistake
Posted: Thu Apr 25, 2013 11:33 am
by antlo69
In my situation I work on milege per tank since I fill up almost every second day.
With bonnet guard I would get between 690km - 720km on a tank and my higher end rev band feels dead, sluggish. Under powered.
Low speed, town driving power were about the same, but 100km/h plus I moticed a drop in performance.
Without my bonnet guard, my consumption went up on my two last tanks since Saturday (790km and last one 810km)
The above re in the same routes, same driving conditions.
In my eyes this is a testament of how big a impact the airflow had on my performance by just looking at my fuel consumption.
Re: Bonnet guard - Big mistake
Posted: Thu Apr 25, 2013 11:52 am
by Tsa
Thanks for that! Wow big difference! I have been noticing the exact same "under powered" feeling in the on my last 2 long drive trips (200 - 300kms).
Everything else seemed fine, except that.
690 - 720km originally is already a lot in my books, I'm lucky if I get 660 and then the fuel light has already gone on.
Re: Bonnet guard - Big mistake
Posted: Sun Apr 28, 2013 4:53 am
by Oubaas
Thanks for the advice guys.
Took my bonnet guard off yesterday and sold it already.
What to do with the extra R100 now?
Oh, too late, spent it already on a Lee reloading kit for my .308
, had to pay in a few bucks on the kit, but oh well...
Re: Bonnet guard - Big mistake
Posted: Mon Apr 29, 2013 11:18 am
by Tsa
Oubaas wrote:Thanks for the advice guys.
Took my bonnet guard off yesterday and sold it already.
What to do with the extra R100 now?
Oh, too late, spent it already on a Lee reloading kit for my .308
, had to pay in a few bucks on the kit, but oh well...
Sounds like a good swop to me! :)
Re: Bonnet guard - Big mistake
Posted: Sat May 04, 2013 3:09 pm
by Quadmyster
So I did some thinking and some work. What you guy's think about this?
Re: Bonnet guard - Big mistake
Posted: Sat May 04, 2013 9:11 pm
by Klong se Pa
That looks quite the bit, Chris. I actually think it looks better now than before!
Re: Bonnet guard - Big mistake
Posted: Sun May 05, 2013 8:07 pm
by Digger
why then does toy sa sell them as accessories??????would like to know if all vehicles fitted with them have the same problem?Is this maybe why the newer models have the bigger air intake
Re: Bonnet guard - Big mistake
Posted: Sun May 05, 2013 9:18 pm
by Klong se Pa
Before the poopoo hit the fan, I bought a brand new d/c 3,0 D-4D 4x2 in '06, which I traded in April '08 for a 4x4. I fitted the carbon fibre-look guard as well as the headlamp shields to the first one, then changed them over when I got the 4x4.
Both had excellent performance and consumption. Never drove either of them without the guard, but can't say that I had any problems with the guard in place. My cruising speed was always over 140, and both had to pull the Exclusive caravan which we had at the time. Never could feel any lack in power, over heating or any difficulties whatsoever.
But yes, the argument makes logical scense, so would like to know what Toyota SA says about an approved accessory sold by their dealers.
Re: Bonnet guard - Big mistake
Posted: Wed May 08, 2013 12:08 pm
by Bacchus
When I bought my D4D in 2008, I've been told by the dealer not to put this guard on again - had it on my previous bakkie (petrol). I was told that it has an influence of about 25% on the air flow.
Re: Bonnet guard - Big mistake
Posted: Sat May 03, 2014 8:21 pm
by michelyn
Hi Guys, I am new to this page and hope I get my first time right. Well I started doing some research on this bonnet shield/protector after spotting one on a Hilux. This specific one really made the Hilux look smart so I thought I would get one for my Fortuner, along with the headlight shields, obviously in carbon fibre look. I will try and get the pic uploaded for viewing. I must add that I became concerned after reading the reports about the negative effects of the bonnet shield. However, the Hilux I spotted was the later model with the larger intercooler scoop, same as my Fortuner. I have asked Toyota SA for some input & recommendations regarding this accessory supplied by them and awaiting a reply. I can inform you that my fuel consumption drops considerably when the temperature is cooler. I would however like to think that the larger "scoop" will be an improvement for the air intake. I would not like to add something that has the potential to cause future detrimental effects so will keep you informed with the comments from Toyota SA. Hopefully we will get some positive feedback soon. Let me know your views on the latest version . . Gen 3 series Fortuner/Hilux . . . Would be great to fit this and protect ones ride. Does anybody know who the manufacturer of this specific set is or is this the genuine Toyota kit ???? Have a great weekend.
Re: Bonnet guard - Big mistake
Posted: Wed May 28, 2014 3:17 pm
by michelyn
Well Guys, just a quick note on this topic.
If you have one of the new models with the bigger intake . . . . as I have on my Fortuner, leave it on. I have just received confirmation from TSA that the bonnet shield will not influence my performance or fuel consumption.
So needles to say . . . I am over the moon and will be getting my shield this week . . .
Took me some time to get te reply from them but luckily no chips to date. Pity for you folks with the smaller "scoop" Probably not too difficult to fit the larger one !!! Will keep you posted if I do notice any issues and TSA will be at the top of the list
Re: Bonnet guard - Big mistake
Posted: Wed May 28, 2014 4:54 pm
by Hangover
TSA se mense is klomp ape... Lees nou maar net wat se die mense hier en luister... Ek het ook dieselfde F-OP met my bonnet guard gehad... Dit werk NIE... Die wind gan nogsteeds meer as helfde bo-oor... Soos die slim mense se: as jy nie wil hoor nie moet jy maar voel...
Re: Bonnet guard - Big mistake
Posted: Wed May 28, 2014 4:59 pm
by Pumba
Ek hou van wat jy gedoen het Chris
Moet se ek ondervind niks van die probleme wat hierbo genoem word nie.
Hier is wat ek gedoen het toe ek van moontlike probleme hehoor het
- 20140528_164158 small.jpg (50.93 KiB) Viewed 26197 times
3 x 6mm gate net om die lugvloei te versteur... ry al 2 of 3 maande so en was al op die langpad ook gewees sonder probleme - hoop dis ok in die lang duur
Re: Bonnet guard - Big mistake
Posted: Wed May 28, 2014 5:05 pm
by Ali3n
I personally would not listen to what TSA have to say in this regard. I would listen to others who have experience as well as think logically about it.
Logic tells me that the guard will deflect most of the cool air away from the scoop and in turn the intercooler.
Why would TSA admit to a problem with the bonnet guard on the D4D which they supply?
Re: Bonnet guard - Big mistake
Posted: Wed May 28, 2014 5:51 pm
by rood
Ek het my bonnet protector afgehaal en n Carbom Fibre sticker laat maak om dit te vervang, dit is n dik vinel sticker. Aangeheg is n foto, sal een in die dag ook neem en oplaai.
Re: Bonnet guard - Big mistake
Posted: Wed May 28, 2014 8:20 pm
by TOYOMOZ
Naanse manne, hier in Moz. het al die ingevoerde Vigos daai scoop met die oop gat, is mos eenvoudig as jy die deflector opsit is dit wat hy doen met die lug na jou Intercooler toe! Nog nie eenhier gesien wat takke,klippe of stof of enige roadkill deur daai gap gesluk het nie...net my opinie!
Re: Bonnet guard - Big mistake
Posted: Thu Jan 21, 2016 10:58 am
by Alex2539
Hi guys
I have a bonnet guard on my 3.0 d4d Legend 40 (small scoop) for 3 months now and i haven't noticed any difference in consumption or perfomance so i have mixed feelings about this
Re: Bonnet guard - Big mistake
Posted: Thu Jan 21, 2016 12:46 pm
by dalkill
eish i bought my suzie with bonnet guard... guess it will have to go
Bonnet guard - Big mistake
Posted: Mon Jan 25, 2016 6:05 am
by Jaws
dalkill wrote:eish i bought my suzie with bonnet guard... guess it will have to go
I read all the comments here smiling. Don't believe everything your read on the Internet . One guy even callings they poor guys working at Toyota a bunch of apes.
TSA did a proper test with the bonnet guards, they did record a slight increase in under bonnet temps but nothing that would cause a drastic reduction in performance .
I'm on my phone but I'm sure I'll find the article with a quick Google search
Re: Bonnet guard - Big mistake
Posted: Mon Jan 25, 2016 7:22 am
by Mars
The Toyota engineers did not design either of the two scoops with that bonnet guard in place. It has to disturb the inflow of air into the scoop. It works with positive pressure i.e. there has to be positive pressure on the scoop for the air to be forced through the intercooler. There is nothing underneath which facilitates the sucking of the air through the scoop. The interference will happen regardless of whether it has the wide or narrow scoop. The mere fact that an increase in under bonnet temperature was measured is enough reason not to fit it already. Heat is the enemy of any engine and anything that contributes to a greater heat load is completely out in my books. It would be interesting to see what impact the scoop has on cylinder head temperatures and Exhaust Gas Temperature. From where I sit I can see you are hit doubly in the sense that the intake air is hotter and less dense with the guard in place, potentially robbing the engine of some horsepower and you have reduced airflow under the bonnet increasing the temperature in there. So as far as I am concerned I would not fit it to my bakkie. Maybe the one with the slot in which case one can stick VPS there as stated above. I was fortunate not to have had any large stones hitting the bonnet in 10 years and 275000 ks. Obviously there was some chipping but when I had to have my right door fixed due to an attempted theft I had the bonnet redone as well.
Re: Bonnet guard - Big mistake
Posted: Fri Jan 29, 2016 10:56 am
by Jaws
Testing shows that the influence of the bonnet guard makes almost no noticeable difference on engine performance.
Re: Bonnet guard - Big mistake
Posted: Thu Apr 20, 2017 12:50 pm
by jgriesel
Jaws wrote: ↑Fri Jan 29, 2016 10:56 am
Testing shows that the influence of the bonnet guard makes almost no noticeable difference on engine performance.
Numbers don't lie - but after seeing the above post where removing guard made such a noticeable difference, I wonder. Was in the market form a bonnet guard until i found this thread.
This also got me thinking, could a aftermarket bullbar with nudge-bar have the same effect. I fitted 265/75/16 BFg's around the same time i did the billbar ( had clearance issues with bigger tyres ). Its definitely more sluggish but I assumed it was the tyres ... or could it be the bullbar ?
Re: Bonnet guard - Big mistake
Posted: Fri Apr 21, 2017 7:23 am
by Nick S
Not the first time that I have heard this
Re: Bonnet guard - Big mistake
Posted: Fri Apr 21, 2017 7:59 am
by lukestoyzx
All the other mods we do to our rigs would have a lot more of an impact on performance than a bonner guard. Doesn't matter to me anyway I have a fan on mine
Sent from my SM-N920I using Tapatalk
Re: Bonnet guard - Big mistake
Posted: Fri Apr 21, 2017 10:07 am
by RiyadhFortuner
interesting stuff. I didnt bother with one cause of performance concerns. Also Glad I dont have one.