Hood/Bonnet scoop/vents...

Post by **FireTruck** » Thu Jan 15, 2004 10:07 am

Yea - found that thread yesterday as well... very full on, but great info. Talk about a month of research for a 15 minute install.

Love to see quantitative results like this though rather than "I think it is better". I also like it when people go to the trouble to dyno for before and after engine mods.

There is also a write up on Ausjeep on an install on a Cherokee.

Post by **Drafty** » Thu Jan 15, 2004 12:55 pm

Home made job. (not by me)

Post by **CRUSHU** » Thu Jan 15, 2004 4:00 pm

wanna wrote:Just remember a rear opening scoop will get you a instant deffect notice the reason being if something in the engine bay blows you end up with oil all over the winscreen ive been deffected before

is that why young guys is slr torana look-a-likes and xc cobra's get defects?? and eb gt mock ups? all factory rear facing scoops.

Post by **spazbot** » Thu Jan 15, 2004 4:03 pm

Rear facing bonnet scoups are allowed, i think you may have just got a asshole cop looking for and excuse,

Post by **LEXX** » Thu Jan 15, 2004 5:17 pm

wanna wrote:Just remember a rear opening scoop will get you a instant deffect notice the reason being if something in the engine bay blows you end up with oil all over the winscreen ive been deffected before

Ummm can I have some of what your on, I hear it's pretty good in Thailand.

A rear facing scoop is not a defective item, what ever coppa got you for that was putting one over on you.

If you check the WRX and new gold hwy pursuit vechiles (in VIC) you will notice they both have a small rear facing bonnet scoops.

FT can you let us know what you decide on, very interested in doing the same to my TJ.

Post by **wanna** » Thu Jan 15, 2004 11:43 pm

The copper new the codes for the id on toranas and the factorys get aways with heaps of stuff that if you do it to other cars will land you a instant deffect and my car at the time was a origanal so i got away with it the other 2 cars i was with got defected i hate it when you geta smart cop that no,s the rules

Post by **MKPatrolGuy** » Fri Jan 16, 2004 9:39 am

Just went down to Halls, they have only had one GU scoop so far and when they get more they will be $85. Looking better to go brand new.

Post by **FireTruck** » Fri Jan 16, 2004 10:04 am

...I wandered into Repco (looking for something else) and in the 'Perfromance' section they had a bunch of different bonnet/hood vents in all shapes and sizes... $18 for a pair.

Some of them have no holes cut in them (??) and some do. Might be a nice little wrenching project for the weekend (along with the 5 other projects that are on the go...).

S.

Post by **Wooders** » Fri Jan 16, 2004 11:10 am

Shane,

As you prob know I've been looking to do this for ages....I thought I had a good line a a set from my local Auto store (auto1) ....when I eventually got there before they closed (I missed 'em 3 times :bad-words:

), the vent had, as you described no openings and said not to locate near heat :?:

So I've just put it onto the back burner until I can find a good one I like at a reasonable price - besides other wrenching is calling right now - but it's still gonna happen....

As for defecting...hmmm I've never heard that one before and considering the number of standard vehicles that have 'em ....... but then again the bastards will ping you for scratching your arse whilst driving if they really want to.....

Post by **FireTruck** » Fri Jan 16, 2004 11:24 am

Wooders - I wish I had the package with me... the instructions are priceless. I'll have a go at them anyway (from memory):

---------------------------
1. super airflow device will convective heat when placed bonnet or bumper
2. do not severe exposure of heat to super airflow or it will damage sticking effect
3. do not exposure to rain or water for 24 hours after sticking is taking place
----------------------------

Hmmmm... either written by a 3 year old or by someone who is 'not from around here'... Anyway, you can open up the holes yourself, or a couple of the models did have holes in them with some mesh covering them. I think the heat comment is more about extreme heat, and should be fine for our purposes.

If not I will be the proud owner of a TJ hood with 2 massive holes cut in it

Oh, and accordning to the instructions these things may be ideal to cool down that hot bumper ????

Post by **bogged** » Fri Jan 16, 2004 1:28 pm

Thor wrote:i had actually seen a bonnet vent write up somewhere and have now found a copy of it on an oman website http://www.oman4x4.com/installs.htm

I think that looks very sweet and professional!

Post by **greg** » Fri Jan 16, 2004 2:13 pm

GaryInOz wrote:A problem with venting air out the rear of the bonnet by packing or by a scoop will be that you will run a greater possibility of getting a bonnet load of water through any deep water crossings. The bonnet lid effectively seals in the underbonnet air bubble keeping everything dry. You will quickly lose any advantage a bow wave may have given you, and end up driving a "catamaran" (two wheelarch areas with water flowing between them) instead of a "monohull" (wheelarch areas linked by air bubble).

I'm guessing you haven't seen Firetruck's car Gary - I'd have to wonder if there are going to be any bog holes in victoria that would come up into his engine bay at all (it's pretty big) :cool:

Firetruck - if this was a big issue for you - you could always carry some racing tape / plastic sheeting with you to put over the inside of these bonnet vents when doing deep water crossings. That would ensure that this "bubble effect" continues to exist when required.

Post by **mike** » Fri Jan 16, 2004 3:19 pm

GaryInOz wrote:A problem with venting air out the rear of the bonnet by packing or by a scoop will be that you will run a greater possibility of getting a bonnet load of water through any deep water crossings. The bonnet lid effectively seals in the underbonnet air bubble keeping everything dry. You will quickly lose any advantage a bow wave may have given you, and end up driving a "catamaran" (two wheelarch areas with water flowing between them) instead of a "monohull" (wheelarch areas linked by air bubble).

Gary do you have any first hand experience of this?
Just curious as I would have thought few bonnets seal well enough to create this effect. It also means that this would be an endemic problem with any vehicle fitted with even a factory turbo scoop, which I'm guessing would have precipitated a solve.

Post by **FireTruck** » Fri Jan 16, 2004 3:38 pm

yea, it's not one of my major concerns... if it becomes a problem then I can tape up the vents when I put the tarp on the front for the deep crossing... would have to be seriously deep for that though...

Post by **MUSS** » Fri Jan 16, 2004 3:47 pm

just make up a tarp for deep water crossings ... i have and it works great only cost 30 bucks from a good upholsterer :armsup:

and a couple of bungy cords

Post by **FireTruck** » Fri Jan 16, 2004 4:27 pm

Tarp is not a problem, I am only talking about taping up the vents on the top of the hood in addition to the tarp covering the grill.

Post by **MUSS** » Sat Jan 17, 2004 12:31 am

FireTruck wrote:Tarp is not a problem, I am only talking about taping up the vents on the top of the hood in addition to the tarp covering the grill.

yeah but to save ya time and effort tapin the grills up every time you cross a deep creek etc make the tarp longer so that it covers the grills to

Post by **mike** » Sat Jan 17, 2004 10:19 pm

JAKE wrote:
FireTruck wrote:Tarp is not a problem, I am only talking about taping up the vents on the top of the hood in addition to the tarp covering the grill.

yeah but to save ya time and effort tapin the grills up every time you cross a deep creek etc make the tarp longer so that it covers the grills to

That was the point of my earlier question Jake, putting a tarp over will not change the effect that Gary described, but I don't think it's a biggy. I'd still like to hear from anyone who has first hand knowledge or seen a detrimental effect of having this ventilation. I am looking to do this soon on my spook and creek crossings are a way of life here!

Post by **Pal** » Sun Jan 18, 2004 10:22 am

Bubble effect. ?? . Ya ' all dreaming again
Have a look at under your bonnet. A rubber seal along the back edge, and a flimsy seal along the front if ya lucky.
Down the sides next to BOTH guards nothing Zilch the bubble has burst big time.
Adding vents for bling bling or to let hot air escape will make no difference to water crossings.
Its the bow wave effect that keeps the water at bay!

Post by **MKPatrolGuy** » Sun Jan 18, 2004 4:03 pm

Timmy wrote:i run a patrol scoop on my tj...but facing fowards....the only thing u have to watch with the patrol ones are that that arnt actually square....the front edge is on a slight angle to the back one....only because they r normally mounted on the side of the bonnet of a patrol, so i guess they want it to follow the curved edge of the grill...but u dont notice it unless u really look hard

How do the Patrol scoops actually mount to the bonnet? Screws from underneath?

Post by **ORSM45** » Sun Jan 18, 2004 8:15 pm

bogged wrote:
383FJ45 wrote:Lift the rear of ya bonnet. just pack it up with washers. flows well, its cheap. and low profile.

Not good in a big front ender accident, it will come thru screen and use your headrest for a stop...

i doubt it. you only lift it half an inch. if its gonna come through the windscreen, half an inch isnt going to stop it.

Post by **Oman4x4** » Mon Jan 19, 2004 6:06 am

Thor wrote:i had actually seen a bonnet vent write up somewhere and have now found a copy of it on an oman website http://www.oman4x4.com/installs.htm

Hey Thor, thanks, that is my website

That write up is essentially Frank's (Daless2's) post from Jeepsunlimited edited lightly and published on my site with his permission.

He's a great guy and certainly put a lot of effort in that!

I was about to do something similar - but a new product has just come out which has made me reconsider.

Frank's method is certainly cheap and effective and looks pretty good (he says you can see the heatwave coming out the vents lol) but this is something I just can't resist. I'll be ordering one of these this summer hopefully, and may add the vents to it also, but I'm not sure if it would weaken the hood too much.

I'll put it on my website when I've got it.

If you read the write up on my page it's the third spot that has low pressure and high temperature overlapping from Frank's testing.

They also had an insert that was all mesh but for some reason they've pulled the pictures off their website. When I last spoke to AEV, they were hoping to sell the thing for $600.

Hope this helps guys.

Post by **LEXX** » Mon Jan 19, 2004 7:30 am

Welcome Oman, been a long time follower of your CAD designs on JU, great to see you here.

One question with that hood "Vent" you posted, how the hell would it go with water? Looks like the first time you go into anything decent that it will come over the bonnett and straight through the vent. Love the design but not practical I think.
I like the "bubbles" on either side just not a fan of that vent at the front, not very suitable for Aussie conditions I think.

Time you got on the CAD and designed something to suit us Aussies!!!!

Post by **FireTruck** » Mon Jan 19, 2004 8:48 am

Well, after looking at all the options I put vents at the rear side of the bonnet... rectangular ones. When I get pics from my dino-camera and scan them I will post some.

Haven't given it a good test yet, but I can feel the air (hot air) coming out of the vents with the JP sitting and idling.

While I was on the cooling bus I installed a tranny cooler on my power steering system... again, will post some pics sometime soon.

Post by **MKPatrolGuy** » Mon Jan 19, 2004 11:55 am

FireTruck wrote:Well, after looking at all the options I put vents at the rear side of the bonnet... rectangular ones. When I get pics from my dino-camera and scan them I will post some.

Haven't given it a good test yet, but I can feel the air (hot air) coming out of the vents with the JP sitting and idling.

While I was on the cooling bus I installed a tranny cooler on my power steering system... again, will post some pics sometime soon.

Were these the Repco vents you ended up using?

Post by **FireTruck** » Mon Jan 19, 2004 12:50 pm

Yep - from Repco, $18.

Post by **Oman4x4** » Mon Jan 19, 2004 2:06 pm

LEXX wrote:Welcome Oman, been a long time follower of your CAD designs on JU, great to see you here.

One question with that hood "Vent" you posted, how the hell would it go with water? Looks like the first time you go into anything decent that it will come over the bonnett and straight through the vent. Love the design but not practical I think.
I like the "bubbles" on either side just not a fan of that vent at the front, not very suitable for Aussie conditions I think.

Time you got on the CAD and designed something to suit us Aussies!!!!

So you guys are based in Australia then? I just traced back one of the hits from my site out of curiosity

Water issues? This will be an easy one.

Just get a flat sheet with the right size holes drilled in it and cut to shape. When you're going out to play in the water, swap the mesh for the solid piece.

Or for a quicker approach, just lay a few strips of duct tape over the holes in the mesh...

And the full mesh is still available, just AEV are having some trouble with their Website.

Post by **LEXX** » Mon Jan 19, 2004 4:00 pm

Thanx for the tip m8, I presume the price tag you gave was US?

When it's converted it comes to about AU$783 + postage so over AU$900 is a bloody expensive hood vent

You may want ton check out www.ausjeepoffroad.com as well to see what else the aussie Jeeper are up to.

Post by **Oman4x4** » Mon Jan 19, 2004 4:11 pm

LEXX wrote:Thanx for the tip m8, I presume the price tag you gave was US?

When it's converted it comes to about AU$783 + postage so over AU$900 is a bloody expensive hood vent

You may want ton check out www.ausjeepoffroad.com as well to see what else the aussie Jeeper are up to.

Yeah it's bloody expensive but it's bloody gorgeous. Like your HSV's, I Just Want One.

And you are correct, that was US dollars

The Omani currency is quite strong and comes up at "only" 231 rials for the hood which is a much easier number to swallow... even if it is the same actual value. Funny how mind games like that work

Unfortunately I didn't save any pictures of the AEV full mesh version to show ya... that one really looks awesome. Just imagine it as that center part of the hood in the same shape, but all in mesh. Only problem is the 4.0 will look a bit tame compared to the 5.7L Hemi on their website

Post by **bogged** » Mon Jan 19, 2004 10:37 pm

http://www.xracing.com.au/htm/accessories.html

http://www.performancestylingcentre.com ... scoops.htm

Sierra Cosworth Style -Medium- Recessed
(PSC-BVE-COSM)

Dimensions - 195mm wide, 265mm long and 5mm high
Made From - ABS Plastic
NOTE: These vents are designed to be recessed into the bonnet. ie you have to cut a hole in the bonnet to fit these vents

$130Pr...

Outer Limits 4x4 Board

Hood/Bonnet scoop/vents...

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