racing rear spoiler

[chev z]

After racing the 240 last Sunday I have come to the conclusion that I need extra down force on the rear wheels.

I base my theory on slower lap times as the day goes on.

With a full tank of fuel, theoretically my times at the start of the day should be slower compared to the last session when carrying less weight.

Previously I thought that the increasing track temp. and hotter air temp. had been the factors.

Sunday was very uniform in outside temp. with cloud cover allday.Tremendous racing conditions.

 

Hopefully you other Z RACERS can point me in the right direction of rear wing design , cost and positioning...thanks Steve

[peter mc]

mate they need lots of downforce on the rear  when you have lots of hp there near undrivable with out the rear wing ,i had one come of as i was driving at the island and went 3 sec slower the car would not hold a line in corners was not fun at all 

 

you can try my rear wing i think it will be very good on your car

[Zedman240®]

I remember Steve Newing used a cut down main helicopter rotor blade as a rear wing on his Datsun 1200 coupe sports sedan. I spoke to a helicopter mechanic that came into our store a while ago and for a slab he can give me a whole blade that could make a few wings..just need to make some ends and brackets to mount and make it adjustable. They are made form a composite material or can get aluminium ones.

[peter mc]

topstage  has the best wing iv seen, most up to date  wings in the contry from the sports car seen ask Freddy for help

[chev z]

G'day Pete, very interesting about being uncontrollable around corners, I thought my driving abillity was to blame, especially around Wintons big sweeper.

If we could have a yarn about this on the phone would be great , text me your number ...... to.... 0427641273  and I will ring you if that is convienient.

 

As a point of interest I came home second in the super TT lites behind Terry Wyhoon, pity I lead such a sheltered life as I hadn't heard of him till I googled him and his capri, which was being tested before the 12hr bathurst event.

 

Then on the other hand I bet he hadn't heard of me....lol

[peter mc]

no problem mate i will call tomorrow

[redrbzed]

You know it's funny this topic should crops up at this time as I am looking into fitting a wing on the back of my car also.

I gave contacted a wing manufacturer in the states called APR, still waiting on a reply.

Also spoke to Alfa Fibreglass as they make a copy of a Porsche GT cup wing and the VP Commodore V8 supercar wing.

Not sure which way to go as this time, so any ideas welcome.

 

cheers,

Sinisha

[PZG302]

If you want to use some rear aero on the back of your car, first thing is to check the rules you are racing to.

 

Sprints/timeattack should be anything goes, but using one may put you in another category up against more modified or modern machinery.

 

For racing, there are more limited rules to worry about, if you are going to go racing in the future, the best bet would be to use what is legal in the category you want to race.

 

For historics with a Zed, you are basically stuck with the Nissan motorsports wing, commonly called a BRE type wing.

 

For production or marque sports the rules are a little freer in that you can a little bigger, for a spoiler up to 150mm from the body and to the rear most part of the car, or for a GT type wing, single plain a maximum 250mm tall and some other restiction in terms of placement and maximum width the width of the car, need to check the CAMS manual for actual restrictions.

 

For what works best, I can only go off what I have used as a rear aero device, also remembering that the front needs to be balanced to work as well. The front of my car used a MKII type spoiler without ubdertray, but still keptthe front down. I have also run without the soiler but the way my radiator was set up, the lower rad support and radiator acted as a air dam, albeit 100mm or so higher tahn the spoiler was.

 

I have used two aero devices on the raer of my Z, firstly a Group C RX7 bird bath and secondly a nissan motorsport bob tail (BRE type).

 

The bird bath, which I still have and is for sale, worked very well by creating a low pressure area behind the car sucking the back down, this could be seen by the amount of grime that was deposited on the rear of the car after a track session. This probably cost me 10-20km/h top speed, but allowed me to go through turn 1 at eastern Creek holding the throttle flat at about 6800rpm in 5th using a 4.1:1 diff.

 

The bob tail didn't create as much downforce, as the car could not be driven flat through turn 1 at eastern Creek. The first time I drove the car with the bob tail at the creek I tried to drive through flat and only myself and my dry cleaner know the true colour of adrelanin. having said that I was clocked by radar at 187km/h after the turn in point, but i did need to lift off at the end of the grandstand and then get back on the throttle as the corner opened up.

 

With the shape of the Zed, my personal preference would be for a spoiler over a wing, with the Group C bird bath first choice, and IMSA type spoiler the second choice, and the Nissan motorsport bob tail third choice.

 

Before I binned the race car I was getting an IMSA type made up that would be within the rules I had to work with and keep as much air flowing over the spoiler as possible without falling of the side of the car as it does with the bob tail spoilers.

 

A quick word on using the helicopter blade as a wing element, on other forums, this has been tried is not as succesful as you might think as the element is designed to work completely differently in its primary function of making a helicopter fly rather than keeping the bum of a car on the ground

 

[luvemfast]

A quick word on using the helicopter blade as a wing element, on other forums, this has been tried is not as succesful as you might think as the element is designed to work completely differently in its primary function of making a helicopter fly rather than keeping the bum of a car on the ground

Wouldn't you just mount it upside down (to rotation) then? 

[dat2kman]

Helicopter blade runs almost same chord length each side, may look nice, but no where near as effective as large  unequal length chord.

The bottom length must be longer, to provide downforce.

Think of an upside down aeroplane wing with full flaps extended

A Gurney lip on top edgewill delaminate flow and cause better downforce.

Air enering front lead edge must be undisturbed and withput pripr effects occuring, ie coming off a Z car roof.

Side plates must not allow air to spill over.

Fwiw, i mucked around with winged open wheelers in mid 1980's

[Six_Shooter]

PZG: Do you have pictures of these different spoilers?

 

From using the keywords "Bird Bath rear spoiler" in Google, the closest thing I could come up with was a spoiler/wing that had sides that extend forward along the 1/4 panel.

 

Also in Google images, "IMSA rear spolier" looks like it is similar to the BRE style spoiler/wing, just extended down the side of the 1/4 panel a a few inches.

 

If I don't know what a BRE spoiler looks like by now, I should have my Datsun club privileges taken away. lol

[PZG302]

PZG: Do you have pictures of these different spoilers?

 

From using the keywords "Bird Bath rear spoiler" in Google, the closest thing I could come up with was a spoiler/wing that had sides that extend forward along the 1/4 panel.

 

Also in Google images, "IMSA rear spolier" looks like it is similar to the BRE style spoiler/wing, just extended down the side of the 1/4 panel a a few inches.

 

If I don't know what a BRE spoiler looks like by now, I should have my Datsun club privileges taken away. lol

 

Your on the money for the spoilers, the bird bath is about 250mm high and the sides extend up the rear quarters to about the hub line of the rear wheels, very good design for keeping the air from falling off the hip of the car.

 

http://www.flickr.com/photos/15569455@N07/4452926527/

This is a link to a pictureshowing the bird bath spoiler I used to run, you can see why they are called bird baths with the amount of water they can hold.

 

The IMSA spoiler is as described with the ends dropping down the rear quarters and the edges formed  to try and stop the air falling off the side and from memory were about 150-200mm tall.

[peter mc]

this is what it looks like Chev z i will bring the front spliter as well so we can try and get the balance right

[260DET]

Powerful S30's also should not run a rear ARB which will improve rear grip in corners. As has been said already, aero needs to be balanced front and rear, a good rear wing will work better than a good spoiler so unless rules get in the way a wing is the way to go.

 

Has anyone used the locally available wings that have been mentioned? Pics and experiences would be good.

[chev z]

Thanks everyone for helping me out .

Peter Mac has kindly offered the areo kit off his car ,so a friday test and tune day at Winton is on the cards ,

thanks Pete.

We will keep all those interested informed of the results .

 

PZG302 great point about the different regulations regarding events like MSCA and sprints, as they are the two series that I am trying to participate in this year.

Sounds like I will have to invest in a fiberglass hatch /rear spoiler combo for sprints and keep the rear as it is now for the MSCA event.

Will a front diffuser help handling without a rear spoiler like the one shown by Peter Mac ?

 

I should post some pics of my cars areo [ or lack of ] if I can bribe someone to do the computer work....Lurch and Simon don't say a word, I'm old

[luvemfast]

MSCA should allow the rear wing.

You're already in the modified class anyway.

Oh

And even an old farmer can upload pics here, I'm sure. 

[chev z]

Your correct Simon , the MSCA rule regulators informed me last night, that because I am in the modern marque section then the rear wing is OK.

OLD farmer hey , atleast I get out of second when racing unlike some youngsters....take that youngun, and don't pronounce that young gun

[Scando]

Will a front diffuser help handling without a rear spoiler like the one shown by Peter Mac ?

 

If you were struggling with a lack of front grip a front diffuser would help solve the problem.  But since you're struggling with a lack of rear grip it could potentially unbalance the car further and make it worse.

With Peter Mac's rear wing fitted, I'm sure he will be able to show you how to adjust it to get the car balanced.

 

Are you running a rear swaybar?  If so, what size?

 

I'm watching this thread with interest as I also want to add a splitter and rear wing in the future.  I'm looking forward to hearing how the test day goes.

[260DET]

this is what it looks like Chev z i will bring the front spliter as well so we can try and get the balance right

 

Who makes that wing Peter? Is that a bit of a lip on the back of it? It looks like it would be a high drag/downforce type.

[peter mc]

its a com VP VP wing with a large lip from the alfa its a old design Freddy has better ones now