Whittie

Hi Richard, I take it you saw the vid on viczcar? The car is getting a pretty major rebuild later this year and the rest of those mods will be done. Should be good to see how it all adds up at Bathurst again next year.

Well here I am, another Bathurst event over (wow, that sounds prissy considering the people who have never done it) and as is typical it started raining. Hence, I present to you, Bonnet Vent Aero Mod MkII: The pics were taken at the motel after the last day at the track. Luckily it didn't rain at the event, but after Dad got stuck in the middle of the city when he picked the car up in the rain, I didn't want to take any chances.

Any chance of re-hosting that pic? I need a solutio for my car after tearing the front mount and then snapping the mustache bar!!!

Yeah the FOSC bathurst event is fantastic! Make sure you get to it before they are not allowed to run it anymore (likely, with cams) Anyways, did the track day today. I did about 50 laps over 4 sessions and the only time the car had cooling issues was when the fuse for the thermo fan came unplugged. And then it only overheated when I got to the pits and there was no airflow through the radiator. I would like to say the vents fixed the cooling, but they didn't. It certainly helped, but it still gets hotter than I would like (about 200F, 93C). However, where before the temp would get to 90C, sit for a while and then keep climbing and boil in 5 laps, now it sits at 90 and doesn't move. The vents are also not ideally situated. The panel beater, despite great pains to try and get it right on my behalf, put the vents too far forward ( the front of the vents is right above the radiator) and too far away from the center of the bonnet. So, the vents aren't properly located, the cooling is not totally solved, but subdued, and I'm out of pocket WAY more than I expected. BUT, it looks F'ing AWESOME!!!! (see attachment) Oh, and just quietly, I was only about 0.5s a lap slower than that R35 on the short track with him on street rubber :D I was SOOO happy when he couldn't keep up with me on parts of the track!!! The straights were a different story though

Cheers mate ps. You have mail **EDIT** Some more pics. To say I'm ecstatic would be an understatement!!!!!!!!!

Cheers mate. Not so much a track day, just a shake-down before the trip to bathurst. The car is at the mechanic now getting the new diff mounts (broke front and rear at the drags two weeks ago ) fitted along with a diff change from 4.4 to 3.9. Then it's getting new brake pads, bonnet fitted and new slotted rotors on friday night and then it's bombs away saturday to see how many laps I can do to make sure everything is up to scratch for the long straight. Considering last time, with 10hp and 35Nm less than now through a SHOCKING 3.5 diff we were clocking 235k's+ down conrod, I want to make sure nothing is going to fail. Btw, this will be my first in 4 months....

Well I said I would do it, and this is what I was getting at after how well the big gaping bonnet holes worked. Here are the pics of the conversion: The first test will be this saturday at the local track. Forecast is for mid 30C (~100F) temps, this will be the real test. I'll post back about how it performs. I'll also take some better pics of the bonnet on the car. Tom.

Haha, I have a roof skin sitting in a box waiting for me to put it on the car when I get started, so don't worry about that. It's just easier to have glass windows. Lexan doesn't fit well and won't slide easily and I still want to have working windows that don't leak. It is still a road car so I don't want to go too insane with it. I am unsure of the legality of plastic side windows, I just want working windows is all.

Bingo. Thats what I was thinking, but I asked about fitting a 260 and he said he didn't know if it would work, Hence the question here. Do you have any of his panels NizmOZed? What is the quality and fit like? As far as Fraser could tell me no one in WA has his stuff on their car for me to check out before I order And I'm ordering the works, a total fibreglass car transformation.

I haven't ordered the doors yet but there from a mob here in AUS called Alfa Motorsport Fibreglass. At $330 a pop it's cheaper than repairing the rust in my steel doors, hence the conversion I plan on cutting out the fibreglass "window" and I'll just cut the track out in the fibreglass edging and put in all the trim from the original chrome piece so that the window slides and doesn't get scratched. It shouldn't be too difficult. If it is too difficult then I'll just use the chrome piece from the doors currently on the car.

Well, as the title says, this is what I would like to do. People have been trying to tell me that the window winder is in a different position so this will never work, but the glorious thing about fibreglass is you can do anything you want to it very easily. So what I would like to know is if this is easy/possible/plausible. The car it is going into has a door intrusion bar on the roll cage and currently the bar goes underneath the arm rest and above the door handle. This picture here is a good shot of the current door: You can see the taped up holes where the arm rest and window winder fit. And here is a pic of the fibreglass one I would like to fit. Note the location of the arm rest and window winder holes in the same position as the door above. What I was thinking I would do is put all the window winding mechanism from my current door (Late 260/280 glass and mechanism), adapt the proper striker so it'll close and Bob's your uncle. But these things never work out that easy so I thought it would be a good idea to ask if anyone see's any glaring issues with this or has done this swap before? Any help is appreciated. Tom. PS, glass has to stay, it's still a street car so lexan side windows is a no-no

Went to the drags for the first time last night since some mods, nice time IMO. Whittie------'77 260z--------S14 Silvia 5 speed-------N/A-----14.546 @ 95.54mph

Wow, I thought they were just the factory rims, they are certainly worth NOTHING here in AUS. My car came with a set as spares, so I decided to do this to them: I have since bought a fifth rim in similar condition to the original posters pic at a grand total of $20...

Thanks ktm. I have the Holden Commodore/ Ford XR8 (Aussie) upgrade and they fit under standard 14's so i should be fine. Doing some work on the car later in 2010 and unsure if i'm still going to get these. They look amazing, but i have 3 sets of wheels already...

Silverdirt, is that the Rota wheels or just 225 rubber? I can't quite understand if the wheel is hitting the brake or if the tyre is hitting the suspension.

Saw this thread and just bought the heel and toe and the z shirt... These would be the only 2 good shirts imo tho

Is there any maths behind this 1/3rd argument? If so then I might pursue that as something to do. Cool. I was wondering though if blocking the top or the bottom effects air over the bonnet or around the car? Maybe one is better or worse than the other? It seems to me that people seem to block the upper portion more than the lower. Also, you might want to look into venting the wheel wells like me to achieve air flow out of them. I'm looking to do something like in the following photo, in fact I was thinking of molding these exact vents into some fiberglass front guards:

Well I've done some reading and had some discussions and from what I understand, a good method of reducing drag and lift is to block above the front bumper, insert directors to make all the air go through the radiator and avoid air going under the car, something like this photo here: Now, my dilemma, this is how the front of my car looks: As you can see, below the bumper is blocked, so if I were to block the top of the bumper, there would be no air flow to the radiator. This car is street driven so the number plate must stay! The vents to either side of the bumper are soon to be enclosed and ducted to the front brakes and the front bumpers are going to be vented to allow air to move out from the wheel well down the side of the car. So, if I can't remove the number plate, I can't block the top of the bumper and I will be filling in the gaping holes in the bumper to direct air to the brakes, is there any more I can do to the bumper to increase front aero? I'm also going to, at some stage, seal between the radiator support and the spoiler, stopping air from going below the car in that manner, and also seal all the holes around the radiator, to force all the air into the engine bay through it and not around except for a small amount directed at the carbies.

I will give it a try then. I'm about to go put the original bonnet back on, i'll give closing off above the bumper a shot tonight and see how it goes without vents. Currently trying to source an Aluminium radiator. I tell myself it's to help cooling but really i think i'm just trying to lose the weight... and they look soo pretty

Yeah it is hard to tell where the air is going, other than out with the front vents. I think that has to do with the large opening and nothing directing the air. With the rear vents the gaps are quite small and all the air is neatly directed up and back, with the front vent there are no deflectors. What is the significance of closing off the front of the car? I just went to all this effort to get MORE air into the engine bay... I have read and seen people closing the front end off but still don't understand the logic.

Well I wasn't totally satisfied with that last video, so with both the stock and new vents in the bonnet and before i removed it i figured i would do one more test. This time i used white wool so it is much clearer to see them moving. Here are some static pictures: The video is here: My observations from the two vents are that the front vents start moving air at lower speeds and seem to allow more through by the way the tabs flick around so much. As you can see in the pictures, the rear woolen tabs are actually situated INSIDE the bonnet. If no air was moving, then these tabs would not stick up. The rear, stock 280z, vents do not move air through the front portion of the vent, only the middle back. You can see the front tabs lying flat with the vent. This i suspect is due to the fact that the front vents upset the pressure over the bonnet and thus doesn't suck air through the front of the vent. That, or the vents are just not as efficient, but when i tested them by themselves without the front vents i remember all the tabs sticking up slightly. Sorry, no video I still stand by my conclusion that the vents up the front are the better ones and this time whilst running the car, the temperature gauge didn't move above 75 DegC with the fan disengaged, the thermostat operating temperature. In the new year i will be taking my good bonnet to a panel beater and having him louver the bonnet where the front vents are located and also the passenger side inspection lid to promote air flow past the carbies.

It's a hard angle, but the wool shows a small amount of air entering the engine bay overall but the wool tufts were actually flicking in and out constantly, there was no constant flow of air either in or out. **UPDATES FOR TODAY** I put the bonnet on the car and you can see in the pictures that the vent is immediately behind the radiator. The pictures are all in the same folder that i linked to earlier: http://smg.photobucket.com/albums/v621/Tommo560/Datsun%20260Z/Bonnet%20Venting/ You'll have to excuse all the masking tape, the bonnet is not the best fit and so i sealed all the edges to replicate how my other bonnet properly fits on the car. I went for a test run but didn't have a camera man and by the time i found someone to help the tabs were pretty frayed, so not the best video but you can see on the drivers side (right for you americans) that the tabs stick upwards. The tabs i placed inside the bonnet stick up out of the hole and the tabs situated toward the windscreen from the hole are even sticking up in the air. Very positive results. I reccommend watching the video in HD (uploaded at 128x720) to get the clearest image. Video is here: For some physical testing I sat the car at idle without the thermo fan engaged. The temperature SLOWLY (about 5 or 6 mins) crept up to about 95 DegC. I engaged the thermo fan at this point and whilst the creeping stopped, when i brought the revs up to 2000 the needle kept moving up to about 100 DegC. You could still feel the heat coming out of the vents. With the fan on a surprising amount of air exits from the vents too. I then jumped in the car with the fan going and went for a spin. Within 400m the temperature was back down to about 90. At this point i disengaged the fan again and drove at 40kph at 2000rpm. The temp dropped quickly (500m) to 85. I upped the speed to 70kph at 2000rpm and the temp dropped to around 80. Re-engaging the thermo fan made no difference to temperature. After coming back home and stopping it was interesting to note how hot the bonnet was around the radiator and above the motor, but so much cooler behind the vent, about 15 DegC difference. This says to me that the vents are moving a significant amount of air. I am concluding from this testing that these vents are sufficient for my purposes to keep the car cool on the track which is where I am having issue on hot days. Last weekend it was about 40 DegC (100+ F) and i had to short shift at 6000rpm to keep the coolant inside the radiator, which really just irritates me. These vents should solve this issue. I also plan to louver the front guards behind the front wheels and louver the inspection lid on the passenger side (left) to promote cool air flow past the carbies to avoid the current heat soaking occurring on the 3rd carburetor.

I'm just about to go out and do some more testing, for now, here are some pictures of a bonnet i got for nothing and had a crack at with a jigsaw: http://smg.photobucket.com/albums/v621/Tommo560/Datsun%20260Z/Bonnet%20Venting/ And here is some video i took a while ago of airflow patterns over the bonnet and why opening the latch at the back doesn't let air in or out of the bonnet: I will update this post when I get the butchered bonnet on the car and do some more videos at speed and testing overheating while stationary. Unfortunately there is not an event for a while for me to test these vents on the track, but we'll see how it goes at low speeds and if it looks promising I'm just gonna go ahead and probably louver the bonnet in the position I cut the holes anyways.

In my N/A 2.9L l28 i have raced 3.5, 3.9 and 4.4 Diffs. Honestly, if i were building a turbo, regardless of what gear and rpm i wanted to be in at the end of the quarter mile (honestly, probably 4th at about 6500 or less, no more, not enough torque) I would run the 3.5 For cruising, racing, strip, whateva, it is just a good compromise. The 3.5 will also let you launch at decent rpm, get some small slip (wheel and clutch) and still have good legs when you hit boost so you're not changing gear all the time.

This. I did have 2 hot-dogs resonators but i took one out to make it louder With 2, or one large one, the car is very streetable and doesn't annoy anyone albeit it a little boring for the driver . With 1 it makes a real nice bark. As others have said, make sure you get mufflers and resonators that don't neck down inside. I used to have one like that before my current setup and it melted..... Magnaflow is one down from the best available here in AUS and about half the price of the next up. It's all Stainless Steel with fiberglass packing and can cop a HUGE punch before breaking down. I've had the current zorst for 5000k's at 4000rpm+ on the track and it still sounds and looks like new. WARNING. The glass packing wears in and WILL be louder after settling than when you drive it out of the shop