Gordo takes over the Peter Mac Build.

[redrbzed]

Like your work, PM sent

[d3c0y]

Interested to see how well the fender vents work. What about cutting the back out of the flare?

[Gordo]

Cutting the back out of the flare is the obvious and most logical thing. I've lined the inside of guards. 30mm clearance . Like there tubed.also the front forms part of the structural support for the flat bottom. That's why I've gone to the top of the guard. That's where the most pressure is. Have to get the air going over the car. More down force.

[TomC18]

Haha, hear are some pics. The G nose add on is Top Secret. Lol.

That's because it might scare small children. Keep it hidden!

[Gordo]

So after last weekends sprints at PI I've drawn a few conclusions . The flat bottom doesn't seem to make any noticeable difference with the setup I'm running with. The added G nose give me a little more top end speed . But on the slower Curcuits I would not use it. The Canards on the front gards give a little better turn in. ( down force). And the rear defuser I've been running for a while now gives the back of the car stability as dose the wing. In conclusion . The main two things that make the biggest difference are the Rear Wing, and the front Splitter. After that your just trimming the car small amounts!

[260DET]

It sounds like the wing mods you did were effective too Gordo.

[Gordo]

It sounds like the wing mods you did were effective too Gordo.

Yep. They made the most noticeable changes to how the car handled. Same on the red Zed I used to Track

[Gordo]

Some pics of the G-nose extension I made. When you look at the two cars Side by side there's not a lot of difference .

[Cozza]

Looks great Gordo. Did you do that yourself?

Hey what wheel and tyre setup do you run? They look pretty wide.

 

Mick

[260DET]

I'm going to get in trouble here but my preference goes for the way it was. Lap times will be the decider and certainly I hope it works Gordo. Let us know. Hope to see you at Challenge Bathurst 2017.

[Gordo]

Looks great Gordo. Did you do that yourself?

Hey what wheel and tyre setup do you run? They look pretty wide.

Mick

Yes Mick, I made this g-nose as seen in the step buy step pictures above. The wheel and tire combo. Front 17x11" rear 17x12" with 300mm slicks, the car is over tired as in to big, but it looks good.

[Gordo]

I'm going to get in trouble here but my preference goes for the way it was. Lap times will be the decider and certainly I hope it works Gordo. Let us know. Hope to see you at Challenge Bathurst 2017.

 

Hi Richard. I made the add on nose because the others guys I was playing with at the track had the G-Nose. Some say its worth 5 to 10kph down the straight. And as always I wasn't going to die wondering what difference it makes. It did work to the effect I was 2 to 300 rpm more at the end of the straight. So tracks with long straights it would be worth fitting. PI and Bathurst , Eastern Creek. Other than that I won't fit it. Could be worth 0.3 seconds. I won't be using it at Winton or Sandown.

 

PS I would like to do the Bathurst challenge , this year looks unlikely but maybe 2018.

As for regularity or sprints. Regularity looks better value for money. Cheers.

[Riceburner]

Nice to hear it made the difference mate. 200-300rpm is a good amount and it looks really light weight.

 

How's it been with then new car, was much of the data and tricks from the 240's setup transferable or was it a case of starting all over again?

 

What happens when you have too much tyre? I thought it would mean more grip.

[Gordo]

Nice to hear it made the difference mate. 200-300rpm is a good amount and it looks really light weight.

How's it been with then new car, was much of the data and tricks from the 240's setup transferable or was it a case of starting all over again?

What happens when you have too much tyre? I thought it would mean more grip.

Gareth . The two cars are very similar . Without going into to much detail. The race car is about 60kg lighter but 180mm wider, so more drag. Top end speed is 10to15kph slower down the straight due to drag.

The bigger wheels and tires are good. But very hard to get good temp into them and make them work at an operating temp.at least 20deg cooler than the 245s on the red car. These are 300mm wide and the softest compound I can get in this size.

[Cozza]

Yes Mick, I made this g-nose as seen in the step buy step pictures above. The wheel and tire combo. Front 17x11" rear 17x12" with 300mm slicks, the car is over tired as in to big, but it looks good.

Wow, that is fat!!

With such good grip have you done anything with your struts/hubs to prevent bending. I've seen some have welded stiffening plates between the hub and strut. Also, have heard of using spacers between the wheel bearings to strengthen the spindle.

Also how do the slicks go with heat cycling, any issues? What brand tyre are you using or prefer?

I am toying with the idea of going to 225/600/15 slicks for my next track tyres but wondering if there's other upgrades I should do at the same time.

Finally what do you use for wets?

 

Cheers

Mick

[Gordo]

Ha Mick, so many Questions. If you read through the thread most of your questions will be answered. I have welded in stiffening plats on the front struts. And yes the bearing spaces are a good idea and I should have them , but I don't. As far as wets go I just us R spec tires on other wheels. And to be honest im not happy with the slicks, they work good for two track days and then your back to the grip levels an R-speck tire will give you. im giving the slicks the ass. Cheers.

[Gordo]

Had a great day at PI on Saturday. On this run Greg Keene who runs in the touring car masters passed me on the straight on our fist flying lap. I tried to stay with him. But once his slicks warmed up he disappeared into the distance. He was telling me he ordered his Kaymen GT4 brand new from the Porsche factory. The car was made for an American race class. LHD. Was telling me he thinks its the most well balanced Porsche he has driven.

 

[ilbert]

Gordo, that sounds sweet!

[260DET]

Nice one Gordo, it looks like if you had his tyres and a bit more power you'd give him a run for his money.

[Gordo]

Was out at Sandown in November and was thinking I don't need the big rear wing. So I made this rear spoiler extension which is a common modification . I was pulling a few more revs up the front and back straights and managed a PB.

So I will defanantly give this a run at the Island next year.

[260DET]

That's interesting Gordo, S30 looks better without a wing too if that matters. So obviously less drag sans wing and the car must still be balanced if you did a PB.

[CBR Jeff]

Im with Richard Gordo I like the look without the wing........Like my opionion matters :-)

 

Jeff

[260DET]

What may be happening with the enhanced spoiler is that it may be driving the rear diffuser ie it is helping the diffuser speed up the exit of underbody air so adding some downforce. To explain, the bottom of a F1 wing is quite close to the rear diffuser and, according to the experts, that helps as above. So that the wings on our cars work they have to be mounted fairly high which means the above does not happen, too far away. For the project I'm thinking that both a wing and a spoiler would be the go but with your limited power Gordo that may not be helpful. It sounds like yours is pretty right as is. I've done a fair bit of research on rear 'boot lid' spoilers but there is not a lot around on the tech, probably because they are not used much by modern cars. You could try fitting a vertical Gurney flap though Gordo if a bit more rear high speed grip would help, say 30 - 40mm high.

[Gordo]

Yes Richard. I understand what you mean. I think this may not be the first version of this spoiler. I could be tempted to extend the spoiler even more if the top speed is not effected.

[d3c0y]

I think increasing the angle of the extension will have a better effect than extending it further. I hypothesise that the making it much taller than it is will only increase drag. I also think extending your diffuser strakes down at the back so they are lower if possible and putting L shapes on the bottom (vortex generators) will help increase it's efficiency and intern make it generate more downforce.

 

L shaped strakes:

 

 

 

First off usual disclaimer, I am no aero expert, but I enjoy talking about this stuff and when i get the chance will be playing around with it in a similar fashion on a few different cars.

I agree with the theory of changing the airflow with the new spoiler could be helping/interacting with the diffuser. I disagree that it's the same effect that's happening on an F1 car though. On the F1 car, I believe that the acceleration of air over the low pressure side (bottom) of the aerofoil is causing a "sucking" effect if you position it close enough to the diffuser exit (low down and rearward as possible) it multiplies its effect.

 

In this case, I think it's more to do with cleaning up the way the air comes off the back of the car. The original Z-G/432 wing reduces drag, just like the tiny "track" wing on the back of a 350Z which in return reduces rear lift (and in turn a better CD number). As we aren't dealing with an aerofoil, I think that a gurney flap is not really what you want when you can just angle the extension right up.

 

 

My guess is that without the rear spoiler, the air coming off the back of the car is blocking the diffuser exit which would have obvious knock on effect. Obviously an optimum height for this spoiler, which I think is very close to the height of the factory type 2 kit, 3 piece spoiler, which with Gordo's extension, i'm guessing is pretty close. If you look at the pic of Gordo's car, his spoiler is a different to the factory type-2 3 piece spoiler which has a lot more rake on it, which effects it's overall height too.

 

 

 

Of all the old pics I have of race cars with decent aero, I only have one of a car running any extension on the aforementioned spoiler (Central 20 car) and there are other pictures of it without the extension too. 

By the mid 70s Nissan clearly cared about aero and was developing the zed shape as much as possible within whatever rules they had and were operating (from what I have read) at a similar HP level to Gordo's car. My point here is they probably had it developed to good standard.

 

 

This car is obviously a US spec car that has to replicate the standard Z-G/BRE wing made and has added end fences and i'm guessing a little higher than a factory 3 piece but is obviously a different design.

 

Of course I could be totally wrong too.

 

Sorry for the hijack Gordo

Edited December 19, 2017 by d3c0y