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MG MGB GT V8 Factory Originals Technical - Anti squat rear suspension.
|I am designing a chassis for a 302 conversion. One thing that has come up in my reserch is the desire for "anti squat geometry" for the front end. This would be to help the car keep weight on the front end during corner exits. I plan on keeping The MGB solid rear axle.(For as long as it last) Not decided on coil or leaf spring. Tube shocks for sure. Anyone want to try and clarify this issue as regards a chassis that will be designed for track days mostly.|
On the other end, let me quess... I probably need anti-dive geometry. I am planing on keeping the stock front crossmember. Anyone know about the antidive design parameters for stock MGB?
I asked for and received several suggestions for chassis design books. My head is full of caster, camber, roll centre, centre of gravity, squat and anti dive, ect ect. Coouple of more months and a lot more postings and this should come together! Does anyone have a line on any computer programs that would aid in this hobby? AS always, thanks one and all.
|AFIK nothing you can do to the front will keep the rear from squatting, that must be handled by the rear end geometry.|
I am aware of that. Its ideas for rear end geometry that I am looking for. I only mention the front end because I assume a track car will require anti-dive at the front. This should keep weight on the back wheels while braking hard. Any suggestions on front or rear geometry are welcome. This is a case where the compromises in geometry can be made from scratch and weighed in favour of cornering, rather than confort or hard launching (such as drag cars). In the rear I have a clean sheet of paper for design. In the front, I hope to work with what I have, and improve what I can. Has anyone tried Moss's coil over conversion? I know there is an RV8 crossmember that will bolt on, (nice piece) but the price is way high!
I have be using a wishbone design program to create my Jaguar Suspension on an MGB front subframe.
I have added a download of the program to me website if you want a copy go to:
By the time you add everything you need to prevent squat and keep the rear located on a live axle car, the unsprung weight will negate most benefits. Look at something like the 240SX IRS. It is mounted on a sub-frame that could be adapted to the MGB and possibly integrated with your roll cage. Anti-squat is built in.
I have considered such. My main concern is to keep it simple and reliable. My first inclination was to follow in Nicks footsteps and do a jag: old jag sedans are worth nothing in Canada. The bodies rust in 10 years and leave the good bits. I've been looking at the Miata I have in the driveway. It looks good but will it handle 250-300 hp (flywheel) of a 302? The 240 sx is a nice handling car, but will it take any torque?
Nick I an at the stage you were at when you decided you needed more education. I have some books and now your program. It is a steep learning curve. Most of the chassis design conceps I am familiar with, its putting them all together and making them work that will be hard. Your project continues to be awesome.
|I have been looking at the Mustang SLA front suspension. By using a tubular K-member, long A-arm on bottom and a short A-arm that is mounted on top at an angle, anti-dive effect and better handling can be had.|
Maybe shorten a Mustang 5.0 K-member for MGB use?
Never heard of a Mustang SLA in Canada. Not a Saleen is it? My intent is to use a mustang as a donor. Can't say as I have given the front suspension a good hard look. When you say to angle the upper A arm, in what plane do you mean? Can you elaborate on the geometry aspect of long lower and short, angled upper arms? Thanx
|You may want to consider getting the book: Competition Car Suspension by Allan Stainforth. I found it helpful on redesiging my front suspension. Sorry I can't give you any information, I just woke up, and my brain isn't in suspension design mode. From what little I can remember, isn't one key item in anti-dive to keep the CoG as low as possible. Might be a bit difficult with a solid rear axle. |
The 240SX rear is used in cars in Australia and Japan with turbo-charged 2 liter engines developing over 250 HP stock. Maybe some Ozzies can give you more more specifics.
I don't know if this will help, but it may be worth a phone call. Unique Motors is a manufacturer of Cobra replica cars that utilize the MGB front suspension and Jag rear suspension in their design. The front suspension incorporates 11 inch vented disks and an exclusive V-8 tube shock conversion. The business is family owned and are avid racers - so I would assume they have greatly improved the ride and handling characteristics of the original MGB design. Their phone number is 256-546-3708. Good luck and keep us posted.
|It's Unique Motorcars for those doing a search. Seems they have taken a few liberties with the MGB front suspension. |
From their website:
Unique Motorcars' choice of the modified MGB front suspension came about due to the following factors: A) Availability and cost. B) Modular yet self-contained construction. C) Ease of installation (4 factory bolt points). D) Original equipment Cobra steering rack and spindles. E) Accepts Unique's 11" vented disc conversion available as standard equipment from Unique. F) Easily accepts Unique's exclusive V-8 tube shock conversion. G) Includes 5/8" sway bar, same as 289 Cobra.
Here's a couple of pictures of their version:
|I'm about 30 miles from Unique...they will sell their entire custom-made front suspension...only thing is you have to weld a plate to the inner fender so you have a place to bolt the upper suspension trunion link...theirs uses coli-overs & doesn't have an upper fulchrum|
|Tony do you know how much it costs? I'm thinking it is probably wider than stock MGB as well. Still it is very nice.|
|First of all- Sorry to Geore who is a better reader than I am a writter; I re-read my original posting and it does indicate a desire for anti-squat in the front. I should not be allowed to type and think at the same time.|
The unique front suspension does look like a quality piece. I can't tell if it retains king pins or uses ball joints. I will give them a call. I am begining to see why Nick put flares on his project; makes lfe a lot simpler!
|Pete, looks like ball joints to me. Please pass along any info you glean from them. Maybe they would consider selling the components as a kit since most of us already have a MGB crossmember. They could forgo the upper cross brace. That surely won't work in an MG application.|
|Carl...never asked the price...asked if it fit under MG same way & when I found I had to weld a plate in place aka MGC, lost interest...initially Unique only used MGB beams but went to their own design when B beams became harder to find....they're nice folks & its worth a trip to tour their Cobra factory...maybe if you're lucky, they'll take you on a test drive...|
|Anyone out there had any direct experience with the RV8 crossmember/front suspension for the MGB sold in the UK (in 1997 it was 1750 pounds!). I'd like to get an idea if it makes $3,000 worth of difference in handling.|
|No it doesn't make that much $3,000 worth of difference! |
I have experience with several RV8's and whilst the front is certainly smoother in operation the characteristics remain MGB based. I would assess it as worth perhaps half to two thirds of the asking price, however i also know that being avery limited run product it is so much more expensive due to that limited production run.
|As I get closer to my V-8 car actually hitting the road, I'm looking at front end symmetry...have purchased a set of vertically modified stub axles that lower front end 1" along with a larger REAR sway bar to go with stock front sway bar....also thinkying about GT front springs.|
This thread was discussed between 20/09/2000 and 25/09/2000
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