NZ951

Curious to know guys, as I do more and more development of the race car...



I am left wondering about aero, front splitters, underbody trays, rear diffusers, front canards, side skirts etc...

Now with things like power, suspension (to a degree) and braking etc you can pretty much muddle your way through, but with aero, its much more difficult because I dont have a wind tunnel, nor have a way to assess with accuracy its impact (but for the *** dyno).

For the amateur racer, do people just go forth based on products companies have made, or is there some science principles to follow that can be applied "in the home".

lart951

A pleasure to help a friend with some awesome ideas

NZ951

All incredibly slippery designs, thank you Lart for the inspiration.

333pg333

All Larts aside (and I did chuckle...), as you say, Aero is a black art. A little bit I've learned from quite a few emails back and forth with an authority on the matter has given me some insight...(despite calls that my rear wing is going to have the drag co-efficient of the Queen Mary), there are so many things that you can do to help and hurt your aero. Most of the 'stuff' we apply to our cars is probably useless at best and counter productive at worst. To be frank, your Widebody kit looks like it was designed in the 80's. Very angular and blunt. However it will allow you to gain some mechanical grip with the wider track/rubber so it might be a bit of a trade off. Things like splitters and flat bottom panels need to be built with an attention to detail and have quite fine tolerances underbody.

Ultimately, as you mention, not many of us have access to a wind tunnel and F1 aero team so it's always a bit of a struggle. Things as basic as wool tufts and a camera aren't so silly by the way.

NZ951

My TRD kit was designed in the 80's Interesting comment about the angular shapes, as thats exactly what Nissan did with the new GTR build, proved that designing a car with a ruler can work.

But as you say, its to run 10" wide rims and wider slicks.

333pg333

Geez, you'd have almost thought I was there...

Not sure that the latest GTR is quite so angular but I get your reference.
I'd wonder if you are going to get 10" of rubber up to heat...unless you're going the f/a route? Or did I miss something?

Fluidplay

Wow, I was just thinking about this very topic this morning....

My question however is in regards to the 968 wing vs the standard rubber tail on the 944/951. Do these two variants offer the same rear down force? Is there any real data on these different rear wing/tail configurations?

pontifex4

This is pretty unscientific, but it feels to me as though my comparably set-up 968 has less rear downforce than my 951 did on the same track. Obviously, there could be a lot of other variables there.

jimmerp

I have seen some great articles on home aero testing in autospeed.com They have a series devoted to it using a magnahelic guage or manometer to measure pressure differential at locations along the body....And the wool tufts/camera get some attention as well..good stuff in my book

NZ951

The GTR reference was from a documentary on the build and the designer referred to the angular lines being effective...

The N2 AE86 race cars have wheels and tires that wide and seem to do ok. I do plan on going turbo down the track

ritzblitz

This.

I was about to say some of the same stuff.

A gopro and some yarn tufts taped on to the body can give you great insight as to airflow around your car.

Jack Olsen did some of this backyard aero testing on his 911 when he developed an aero package.

lart951

Not trying to be a jackass here, but honestly how fast do those toyotits go?

NZ951

The N2 cars are pretty quick, 240HP from a 1.6, some weigh around 750kg, makes for a pretty well balanced race car, they are a bit of a giant killer.

rlm328

You may want to sensor your suspension to see what the various changes you make do to your grip and when.

NZ951

I never thought of doing that, I am swapping out the live axle to IRS after I finish painting the widebody, what do the sensors measure?