Project Build - Elise GT: Honda Swap / Widebody Conversion

[MacLotus]

I have driven both S1 and S2 well above 135.

I am unclear why you think that the wind tunnel testing showing rear down force [all be it modest] will disappear at 135mph?

Did you watch the video? What part of REAR LIFT described by Lotus engineers don't you get?

Engineers wanted to address the issue head-on but designers wanted a solution that addressed the 'rear lift' safety issues (at freeway speed) with minimal change to body design. Get it? Preservation of artistic design over optimal performance. Engineers finally got their way with the introduction of the Exige... same car but aerodynamically improved with the addition of front aero, extended rear diffuser, hard-top and swept rear clam, and rear wing.

You went so far as to say "I thought the Elise had front lift?" Admit it. You're on the wrong side of the facts here. Move on.

[MacLotus]

Loving your work Mac. Be an epic car when finished

Thank you sir!

[MacLotus]

To answer your question... The rear spoiler compensated for rear pressure under the car at freeway speeds. At 135mph, the pressure under the car continues to grow, but the open top and rear deck design don't allow clean air over the spoiler. Eventually, pressure wins.

[KingK_series]

To answer your question... The rear spoiler compensated for rear pressure under the car at freeway speeds. At 135mph, the pressure under the car continues to grow, but the open top and rear deck design don't allow clean air over the spoiler. Eventually, pressure wins.

Intriguing...

[graeme]

Skilled build! Thanks for taking the time to post updates. Keep 'em coming!

[Scotty C]

epic build

its ok he will go away, if you dont feed him.

[KingK_series]

epic build

its ok he will go away, if you dont feed him.

Re: Project Build - Elise GT: Honda Swap / Widebody Conversi

Postby MacLotus » Fri Aug 24, 2012 12:40 pm
To answer your question... The rear spoiler compensated for rear pressure under the car at freeway speeds. At 135mph, the pressure under the car continues to grow, but the open top and rear deck design don't allow clean air over the spoiler. Eventually, pressure wins.


What I meant was - I thought the purpose of a spoiler [as opposed to a wing which works in a completely different way] was to force the airflow to detach earlier over the car, ie mess up the airflow. That then reduces air velocity which causes a rise in local air pressure and therefore reduces + lift.

or am I wrong?

If in addition you have some rake on the car I struggle to understand how the diffuser "stops" working at any speed?

[MacLotus]

I have my own theories regarding airflow, and I believe my mods will have a net performance gain. That said, I don't feel the need to do the math. Your questions are more appropriate for another thread.

[KingK_series]

I have my own theories regarding airflow, and I believe my mods will have a net performance gain. That said, I don't feel the need to do the math. Your questions are more appropriate for another thread.

[meatball]

There was a way of ignoring/blocking a users posts, can someone remind me how to do that please?

[Daveb]

Click on his Profile then Add Foe I think.

[mckeann]

You can add the very annoying members to your 'foe' list. Click on the person, purely for example, king k series, then click foe.

[MacLotus]

I finally made the decision to put a wing on the Elise GT, so I ordered a 67" GTC-300 from APR on Friday. Carbon fiber construction. I will custom fabricate the upright supports (which will mount to the subframe through the body) and position the wing a little lower and rearward than most wings. Should look a little like this...

[MacLotus]

Started to fill and block for final finish/paint (pearl yellow). Received the new APR 67" carbon fiber wing (body is 72.5" at the fenders). Wing mount brackets will come straight out the back of the car (bolted extensions direct to rear subframe). Custom wing uprights will be 1/4"-5/16" aluminum, bolted to the custom subframe extension brackets, and adjustable height (2 ft. adjustability).

This way, wing can be removed for street use, or installed at minimal height (as shown).... and once at the track raised up to the clean air.

[j2 lot]

Very tidy