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Heavily modded cossie engine with standard 2wd bonnet
General Car Related Discussion.To discuss anything that is related to cars and automotive technology that doesnt naturally fit into another forum catagory.
Lets face it, it might get a bit toasty under the bonnet after a blast and then sitting in traffic for instance but other than that will probably be just fine. (famous last words)
I have a modded 500hp plus sapphire and now have a 2wd standard bonnet as opposed to the 4wd vented bonnet I was running previously.
Do I really need bonnet vents to release the extra heat from a big turbo?
Or will the non vented bonnet be fine?
I will heatshield the underside of the bonnet and was even contemplating jacking up and spacing the rear of the bonnet on the hinges (I quite like that look tbh)
Cheers Paul
when i first bought my saff the previous owner did track days with it even though he told me he never lying dishonest c..t from chingford. before some people start pissing them selfs i dont mean every body from chingford. mines only a stg1 and the heat damage to the paint work bonnet and even the o/s front wing was bad. i would say vents all the way
I used to hammer the fuck out of mine on the road lol yes road conditions but always flat out only time I used it was bored on a weekend looking for bikers. Never had any paint damage on my bonnet never see the water temp or oil temp go high. Each to there own I guess but I think a lot over think things and worry to much
I used to hammer the fuck out of mine on the road lol yes road conditions but always flat out only time I used it was bored on a weekend looking for bikers. Never had any paint damage on my bonnet never see the water temp or oil temp go high. Each to there own I guess but I think a lot over think things and worry to much
That's what I was thinking, am I just over thinking/over worrying about it ha ha
I used to hammer the fuck out of mine on the road lol yes road conditions but always flat out only time I used it was bored on a weekend looking for bikers. Never had any paint damage on my bonnet never see the water temp or oil temp go high. Each to there own I guess but I think a lot over think things and worry to much
how do you get on chasing fast bikes? In recent years superbikes have become very fast indeed. Being a biker myself (currently on a supermoto) I am genuinely interested in your experiences.
how do you get on chasing fast bikes? In recent years superbikes have become very fast indeed. Being a biker myself (currently on a supermoto) I am genuinely interested in your experiences.
I have had a bit of fun with bikes with 469bhp in a light car. Bikes need a good rider who is brave to give it all the beans.
I had a 500cc commuter bike in front of me and when I overtook it and he dropped some gears and went for it but my car easily out dragged him on a dual carriage way.
how do you get on chasing fast bikes? In recent years superbikes have become very fast indeed. Being a biker myself (currently on a supermoto) I am genuinely interested in your experiences.
Not done it for a while now lol been without an engine. Without doubt my sierra was as fast on the move as my 98 r1 I could easy get bigger numbers on small roads. But that bike only had 130bhp I don't think the sierra as it was would be any faster than my k6 gsxr 1000 but that's 150bhp. Modern 1000's are 180-200 obviously that's a huge leap in performance but comes down to how brave the rider is lol
Cossiedave did a superbike up to and over 140mph...the bloke on the bike pulled up after and asked him what power it was.
I was out in a certain white saff everyone likes to hate on 4 up when it destroyed a 2000 style r1. The rider Ian had a really good go we got off the clock he was amazed and that was back in the days of when it had under 600bhp
Thats a balls out special edition race bike with over 200bhp. The average bike you meat on the road will not have power torque and weight like that
Granted but the cars in the video are pretty special to.
Anyhow when you get your car finished here's to good hunting
There's something really satisfying when you catch a modern fast bike / car in the old cossie.
Vents definitely help cooling, not because they allow hot air to escape, thats nonesense, but it helps increase the pressure differential across the radiator/intercooler as it prevents a pressure build up in the engine bay as speed increases and air has nowhere to flow.
Vents definitely help cooling, not because they allow hot air to escape, thats nonesense, but it helps increase the pressure differential across the radiator/intercooler as it prevents a pressure build up in the engine bay as speed increases and air has nowhere to flow.
Wouldn't you need the (hot) air to be escaping through the vent to create the pressure differential or is it the fast and cold air passing over the vent that does it?
I am keen to add some vents but do not want it to look bad, was thinking of a naca duct orientated to draw air out.???
Wouldn't you need the (hot) air to be escaping through the vent to create the pressure differential or is it the fast and cold air passing over the vent that does it?
I am keen to add some vents but do not want it to look bad, was thinking of a naca duct orientated to draw air out.???
Yes air escapes through the vents, but its not this airflow through the vents that does the cooling, it allows the radiator, intercooler to work harder as it results in more airflow through them due to the increased pressure differential
check out this american lad on youtube sorry no link. max wrist. he`s a soldier based in italy he hunts down supper cars on this mountain road on supper bikes some of the cam footage is really scarey as bike rider my self i allmost found my self peeping arround the back of sofa watching it lol
check out this american lad on youtube sorry no link. max wrist. he`s a soldier based in italy he hunts down supper cars on this mountain road on supper bikes some of the cam footage is really scarey as bike rider my self i allmost found my self peeping arround the back of sofa watching it lol
He won't make "old bones" riding like that, he didn't leave much room for error, overtaking whilst the car overtook other cars etc...I call these riders "organ donors"
Yes air escapes through the vents, but its not this airflow through the vents that does the cooling, it allows the radiator, intercooler to work harder as it results in more airflow through them due to the increased pressure differential
That makes sense.
Utter bull by those suggesting all the heat escapes through them, you only have to look at the position of them to see that ain't true. No ducting or anything either.
He won't make "old bones" riding like that, he didn't leave much room for error, overtaking whilst the car overtook other cars etc...I call these riders "organ donors"
When I see some bikers overtaking on a single road and going really fast there is no room for error, it only takes a vehicle to move over slightly and they would be as I refer to them as "another temporary rider". Bike verses Car, unfortunately there is only ever one winner in a crash, the Car!!
No way would I ever race anyone let alone a biker after what happened in my area a little while back, this guy was racing another guy up the dual carriageway and one crashed and died and the other guy got done for In and is currently serving many years in prison and a massive driving ban. Just let them go on I say it's not worth it
No way would I ever race anyone let alone a biker after what happened in my area a little while back, this guy was racing another guy up the dual carriageway and one crashed and died and the other guy got done for In and is currently serving many years in prison and a massive driving ban. Just let them go on I say it's not worth it
Very true. I think there is a spirited squirt on a dual carriage way etc and racing, I know the law won't see it that way but there is a big difference in a bit of traffic light action and flat out winner takes all over a few miles.
i apologize to interrupt the discussion about bikers...
just an input if you wanna a bit more air under the hood...
made these spacers a while ago... (sorry, bad quality pics)
not such pedestrian friendly...
not a good looking cossie, just a welded diff...
here the measurements...
the car you see fits the highest ones (50mm).
you can either diy them, with some 5mm metal and washers, or send this .jpg to a laser-cut shop and have them done for cheap.
Yes air escapes through the vents, but its not this airflow through the vents that does the cooling, it allows the radiator, intercooler to work harder as it results in more airflow through them due to the increased pressure differential
Yes, that's exactly how it works. This picture shows it nicely.
Yes no matter what way you word it hot air does escape through the vents, obviously it needs to be pushed through which will be done by air coming in from the grill and through the radiator ect.
Yes no matter what way you word it hot air does escape through the vents, obviously it needs to be pushed through which will be done by air coming in from the grill and through the radiator ect.
Yes warm air does escape, but it's not this that has the effect on cooling.....
so does the hot air that we have agreed that escapes not come from the engine or rad? I know you are saying that it is pressure difference but if the vents lead to pressure difference which somehow lets hot air out through the vents (or anywhere) then can we agree that having vents may lead to some heat loss? I,e. In the pic the vents look to be doing something so if hot air air is escaping it Must (by the laws of physics) be taking some energy away with it? If warm air is escaping then it is escaping.
If allowing some warm air to escape somehow allows the inter cooler and rad to be more efficient then air vents must be beneficial? Did ford add them just to sell more cars and then release pics of warm air escaping just to sell more cars for us to argue that warm air does escape but make no difference? I am confused?
It was just before he mapped to 701 bhp (which I saw) but he dropped 40 lbft torque on that run to previous. He said it was a super bike so assumed 1000 as dont know of any 600cc super bikes,. It was a story told at a rolling road so could have been a 125cc but I do know that it is a very fast car as any 4wd 700 bhp car at 1400 kg will be, it is in Veyron worrying territory power to weight and a whole lot of sticky contact patch compared to a bike tyre.
To me there are things that can be done to help cooling. High flow larger aluminium radiator, RS500 size or larger intercooler, pre-turbo cooler, new fans wiring loom and fans thermostatic controller. My cone filter is inside an aluminium group A airbox which shields it from excess heat and has a bottom cool air opening.I have the bonnet vents as well and so far have never had any overheating issues. The standard set up is not good enough once you start going for more power, remember it was designed to cope with about 204BHP not 4, 5 or 600+ bhp !!
Yes, that's exactly how it works. This picture shows it nicely.
So going on that pic cold air enters the front of the car passing the rad and cooler then it combines with the hot air under the bonnet then escapes through the vents being pushed out by pressure under the bonnet?
If that's correct would raising the back of the bonnet not do the same?
I will possibly also be losing all the plastic surround that runs around the heater motor and by the battery tray etc
Agreed with Paul, either pushed out by hot air or pulled out by cool air passing over and will raising the bonnet do similar?
I am tempted to add some air sensors for what it is worth, closed and then vented. Measure air under bonnet constant and air at back of raised bonnet and air at vent. If air at vent or back of bonnet is higher than under bonnet the surely heat energy is escaping somehow for the benefit of heat loss and if under bonnet temps do not alter then all is a waste of time?
Measure water and oil temps throughout
Does that cover all option?
Last edited by Caddyshack; 16-08-2017 at 09:46 PM.
06-08-2017, 04:26 PM
