MG Sports Cars

engine swaps and other performance upgrades, plus "factory" and Costello V8s

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v8bloke
Mark Rawlins

(75 posts)

Registered:
02/02/2010 02:13PM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: v8bloke
Date: September 04, 2012 05:21PM

Todd
I believe he was using Toyo R888 tyres.
I much prefer not having a passenger.

Very happy with the aero upgrades. Just need to experiment with angles.

Mark


v8bloke
Mark Rawlins

(75 posts)

Registered:
02/02/2010 02:13PM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: v8bloke
Date: October 14, 2012 03:20PM

Hello again all.
Well, it would seem that the rear wing is producing quite a lot of downforce. I know this because my exhaust is grounding at high speed (130mph+) over slight undulations which it never did before.
I have had an idea that almost seems too simple, but I think could work to reduce drag at high speed.
Just to recap the car is a road legal MGB GT V8 4.8 which is modified for trackdays not racing.
I have been experimenting and found the best angle for maximum downforce and the best angle for minimum drag. The virtical
distance between the rear wing mounting hole for both these setting is less than 30mm.
I was wondering if I could use a strong spring for the rear wing mount each side that would compress at high speed/downforce (80mph+) so giving maximum effect at lower speeds but less effect and less drag at high speed.
it would take a bit of trial end error to get the spring rate right and I could use my Gopro camera too see what is going on. Also I could factor in adjustable stops to set maximum and minimum angle.
How stupid is this? as it seems just too simple.

Mark


Preform Resources
Dave Craddock
Redford,Michigan
(359 posts)

Registered:
12/20/2008 05:46PM

Main British Car:
72 MGB V6 3.4

Re: MGB Aerodynamics. Will this work?
Posted by: Preform Resources
Date: October 14, 2012 05:28PM

Mark, the super modifieds like those in the picture do the very thing you're talking about, I've never looked at one up close to see how they manage the up and down movement , but the wings definately flatten out at speed and come back up on deceleration. these cars run big V8 engines and are direct drive ( in/out box),, oh yeah,,,, they ARE roundy round cars.
Dave
supermodifieds.jpg


v8bloke
Mark Rawlins

(75 posts)

Registered:
02/02/2010 02:13PM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: v8bloke
Date: October 15, 2012 06:36AM

Thanks Dave
I like a challenge
Now I have come up with a linkage that will effectiveley soften the spring after the initial 20mm of movement.
It will take a while but I will post up the vid hopefully of the linkage in action.

Mark


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: MGB Aerodynamics. Will this work?
Posted by: BlownMGB-V8
Date: October 15, 2012 12:14PM

They use "wing cylinders" and you can see them in the photo. There is a controller for it in the cockpit so the driver can adjust it, I think it is some sort of brake cylinder. I am considering the use of these on my wing but will be tying it to the suspension so it works like the mechanical linkage I had before the IRS. Common sizes are 8", 10" and12" travel. I have not seen anything shorter. Speedway sells a hydraulic cylinder now but it is not available in the 8" size. Diameter is 1-1/4". Cost about $140 each. If I use these I will need suspension cylinders with about a 3/4" bore and 4-1/2" of travel. This system holds the ride height constant by applying more downforce if the body lifts.

Jim


classic conversions
bill guzman

(294 posts)

Registered:
01/09/2008 01:58AM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: classic conversions
Date: October 15, 2012 12:44PM

It would be nice if it was that easy, just add a wing and be done.

If traction is the game then yes. there is a formula to figure out the down force area needed. Down force is like adding weight, so spring rate changes.
The front may also need down force to compensate for the rear down force. tires also a factor to include in the formula.
Then angle of the wing etc etc.

Wings create drag which means that they use hp/torque, top speed reduces.

It would be more beneficial to reduce drag first and add the needed down force.
I would start by closing every opening in the front, reduce the air intake on the radiator, be surprise how little you need.

Many books in this area. I am doing the same with my GT I want less drag,


Jim Stabe
Jim Stabe
San Diego, Ca
(829 posts)

Registered:
02/28/2009 10:01AM

Main British Car:
1966 MGB Roadster 350 LT1 Chevy

authors avatar
Re: MGB Aerodynamics. Will this work?
Posted by: Jim Stabe
Date: October 15, 2012 02:02PM

Bill

Post up some pictures of what you are doing to the GT, I'm fabbing the front sheetmetal now so would be the ideal time to make changes. Start a new thread so we don't hijack.



Edited 1 time(s). Last edit at 10/15/2012 02:03PM by Jim Stabe.



classic conversions
bill guzman

(294 posts)

Registered:
01/09/2008 01:58AM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: classic conversions
Date: October 15, 2012 03:45PM

Will do.

Minimizing the grill opening, closing all openings in the radiator support, smooth front valance, reduce the front bumper size and recessed in to the body, will see the possibility of minimizing the rain gutter in front of windshield it is a big air brake

May have to add spats to the front fenders, will determine when is done. The radiator does not need a big opening. I am closing the grill from inside the grill. The opening will be about 50% of the radiator at the grill and 100% at the radiator, funnel effect. I ma going back to woirk on it next week.
GT Body Work 017.jpg
Green GT 047.jpg


classic conversions
bill guzman

(294 posts)

Registered:
01/09/2008 01:58AM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: classic conversions
Date: October 15, 2012 03:56PM

Will post when I complete the radiator opening.

One picture
Green GT 046.jpg


classic conversions
bill guzman

(294 posts)

Registered:
01/09/2008 01:58AM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: classic conversions
Date: October 15, 2012 04:05PM

Forgot to mention that the openings you see in the front balance will be close. You can also see the chin on the front balance, that lip will hold a small lip spoiler sticking out forward about 1". Once I get it running will use wool strings to check the flow of air around the fenders, that will tell me what I should do.

chin spoiler is similar to the Z06 Vette
Green GT 102.jpg


Preform Resources
Dave Craddock
Redford,Michigan
(359 posts)

Registered:
12/20/2008 05:46PM

Main British Car:
72 MGB V6 3.4

Re: MGB Aerodynamics. Will this work?
Posted by: Preform Resources
Date: October 15, 2012 08:47PM

From my understanding thru folks I have worked with a typical opening to rad size should be about 1" to 6" ratio, but like what has has been discussed previously you still need the pressure differential back of the rad to work.
Dave


Todd McCreary
Todd McCreary

(207 posts)

Registered:
03/16/2012 10:57PM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: Todd McCreary
Date: October 24, 2012 08:45AM

it would take a bit of trial end error to get the spring rate right and I could use my Gopro camera too see what is going on. Also I could factor in adjustable stops to set maximum and minimum angle.
How stupid is this? as it seems just too simple.



Too simple? Wait til it breaks, we'll see how simple you think it is then. ;-]

you can get little rubber sliders for the shaft of the adjustment piston which will show you exactly how much maximum compression at speed is. Obviously, that won't work for extension.


roverman
Art Gertz
Winchester, CA.
(3188 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: MGB Aerodynamics. Will this work?
Posted by: roverman
Date: October 24, 2012 01:40PM

Mark, "If" you were to attach the rear wing struts to the rear end or uprights,(unsprung weight), you would not need more spring rate.Using rubber blocks to limit suspension compession, prematurely, can lead to rapid slide of the tires, on that end,(spring of near ifinite rate). I'm not suggesting this, but on early days of winged Indy cars, they did this. Problems arose because the verticals were "triangulated". One failed, there was a crash, and USAC banned suspension mounted wings.Its a good concept, the application was flawed. Footnote, so now high downforce cars can use springs fron the railroad/lol. Onward, roverman.



Edited 1 time(s). Last edit at 10/24/2012 01:43PM by roverman.


v8bloke
Mark Rawlins

(75 posts)

Registered:
02/02/2010 02:13PM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: v8bloke
Date: November 28, 2012 12:42PM

Well here is my idea built up and ready for testing.
http://i76.photobucket.com/albums/j30/V8bloke/phone035.jpg

http://i76.photobucket.com/albums/j30/V8bloke/phone034.jpg

http://i76.photobucket.com/albums/j30/V8bloke/phone033.jpg

Now need to do some testing.

Mark


Preform Resources
Dave Craddock
Redford,Michigan
(359 posts)

Registered:
12/20/2008 05:46PM

Main British Car:
72 MGB V6 3.4

Re: MGB Aerodynamics. Will this work?
Posted by: Preform Resources
Date: November 28, 2012 02:23PM

Mark, it looks great, excellent range of adjustment and you could change spring rate or motion ratios for further adjustment
capability, nice fab work by the way.
Dave



BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: MGB Aerodynamics. Will this work?
Posted by: BlownMGB-V8
Date: November 28, 2012 02:25PM

You may have a little rocking from side to side so watch for that. If it does, watch out for a harmonic. I think it is stiff enough that you will be OK. It looks pretty good. Not sure how your mechanism works though.

Jim


v8bloke
Mark Rawlins

(75 posts)

Registered:
02/02/2010 02:13PM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: v8bloke
Date: April 12, 2013 05:58PM

Here is the final design all fabricated and finished.
http://i76.photobucket.com/albums/j30/V8bloke/car013_zps58ba6d57.jpg


v8bloke
Mark Rawlins

(75 posts)

Registered:
02/02/2010 02:13PM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: v8bloke
Date: April 25, 2013 04:23PM

Sister car now has the same DRS system.
http://i76.photobucket.com/albums/j30/V8bloke/car017_zps4a43ba2d.jpg


v8bloke
Mark Rawlins

(75 posts)

Registered:
02/02/2010 02:13PM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: v8bloke
Date: April 25, 2013 04:26PM

http://i76.photobucket.com/albums/j30/V8bloke/car006_zps7f25e275.jpg


v8bloke
Mark Rawlins

(75 posts)

Registered:
02/02/2010 02:13PM

Main British Car:


Re: MGB Aerodynamics. Will this work?
Posted by: v8bloke
Date: April 28, 2013 03:07PM

Stunning performance improvement. The Wing and drag reduction linkage works just great. knocked off 3 seconds from my best time at Castle Combe.

[www.youtube.com]
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