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Widening the front track on a MGB

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V8MGBV8 Avatar
V8MGBV8 Carl Floyd
Kinggsport, TN, USA   USA
In reply to # 3733869 by fast-MG.com My approach to this would be to step cut the X-member on each side , widen and weld back together with appropriate reinforcements.smoking smiley

I like it! thumbs up

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Peter-Sherman Avatar
Peter-Sherman Peter Sherman
Melbourne, Australia   AUS
Am I missing something? (polite answers only please) why not get some zero offset wheels?

fast-MG.com Avatar
fast-MG.com Gold Member Dave Headley
Cortez, 4 corners, Colorado, USA   USA
Increases scrub radius with negative effects on steering effort and high G braking stability.


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Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
Ergo, EPS.

Jim

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rodgersmg Rodger Grantham
Springfield, MO, USA   USA
1973 MG MGB Racecar "# 74"
I have no idea why there would need to be any other suggestion here other than to just adjust the wheel offset, Dang, just put a 1" spacer on it and be done with it. I use a 0 offset wheel on the SCCA race car, and the track ends up being almost 1" wider each side with that.

mgb281 Philip Waterman
Taunton, Somerset, UK   GBR
Peter
You are missing the point, zero offset wheels have the same effects as wheel spacers, they are a very crude way of widening the track, amongst the downsides in no particular order, much higher loading on the wheel bearings, harder to get the wheels balanced and heavier steering the only upside is its cheap. Many people on this forum using a rubber bumper cross member use dropped spindles (Dave Headley) to achieve better handling, others change to coil over conversions of one make or another. If you only drive the car slowly then none of any improvements are needed, but if like me you like to drive quickly on twisty country roads then you would like something better than the standard offering. I also like to have stabilility under hard braking hard braking, and not having any slight out of balance or the slightest bearing wear amplified by the outward position of the wheel.
From the other perspective if it is not done correctly it will be worse than before, I will not rush it but I do intend to persevere with this and although I have no backround in the subject there are many pieces of suspension design software out there to help. 0ne of which is http://vsusp.com
Philip

Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
The bearings are the exact same ones used in the contemporary Mach-I Mustang, a 3500 lb car. I don't see how you could overload those, so I think you can safely dismiss bearing loads from your concerns.

You might want to try the easy way before going with the drastic action. Yes, it will make the car harder to steer but the EPS is a great solution for not only that but just making the car more fun to drive overall. Particularly when parking. And to get rid of the annoying jiggles in the stock steering. I have a good bit of experience with wider wheels and tires and it isn't as bad as you are afraid of. I'm not sure where this comment about the brakes comes from but if you have an issue with twitchiness you can increase the toe-in a bit. As for balance, how is that an issue? Do you normally have problems there? Maybe it's the shop that does it. Though to be fair the MGB is more sensitive to that sort of thing than it should be. Easily corrected though. And be considerate of your wife. She will be very impressed with a steering system that feels more like a modern sporty car and that she can easily point in the direction she wants to go. Much more so than if you do manage to retain the original MGB feel, which for all it's "connectedness" with the road, is far too harsh and requires far too much effort compared with anything being sold today. I have two cars here currently that I can choose to drive. One has EPS and one does not. In terms of the steering there is simply no contest and every single time I drive either one I solidify my plans to put EPS in the other.

Jim

Speedracer Avatar
Speedracer Platinum AdvertiserAdvertiser Hap Waldrop
Greenville, SC, USA   USA
1967 MG MGB Racecar "The Biscuit"
Are you are changing the fenders to do this, if so you could do with wheel offset, like hundreds of SCCA racers have done for years.



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864-370-3000
Website: www.acmespeedshop.com
hapwaldrop@acmespeedshop.com


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mgb281 Philip Waterman
Taunton, Somerset, UK   GBR
Hap
What I am in the process of doing is fitting a Jaguar AJV6 engine with a T5 gearbox into a chrome bumper MGB GT. This week I have tacked together one exhaust header and will not finish the second until more tube has arrived. Why the AJV6? In my mind it has some advantages, firstly in a chrome bumper body nothing needs to be cut apart from the front cross member, it is also very widely available at very low cost, 240bhp out of the box and if you have seen and heard this engine in the Rocketeer it ticks the right boxes in terms of a modern engine for a B.The weight with a T5 is less than 435lbs so lighter than nearly all of the other options.
The downsides are that this is a first one of its kind and all the conversion parts have to be made, otherwise I can think of none, why not use the Rover V8, they are not as cheap as they used to be, the 4.6 matches the bhp but has far more torque, and you still have to buy most of the parts I will need, ECU (off the shelf from the Rocketeer) etc.
So why widen the track? I plan to run wider tyres at both ends and I could use wheel spacers at the rear as well. Now I could just cut a chunk out of the existing crossmember and buy other parts to upgrade what is already there or buy the fast cars front end, which I have already said that I could not financially justify or to what I am attempting to do,design and build a wider track front suspension to match the rear in width. I certainly do not think I know better than anyone else on the forum but do believe with help of various bits of software and a lot of reading that I might achieve my aims. If it fails back to the standard crossmember, modified stock suspension and wheel spacers.

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bills Avatar
bills Bill Spohn
W. Vancouver, , BC, Canada   CAN
I like the use of a 'new' engine for the swap, but I think you could save yourself a lot of work and thought simply by getting rims/spacers to suit whatever track you want and figure that you'll face enough challenges without adding suspension issues that probably won't make much difference to the way the car drives in the end. Just my POV - plunge ahead regardless!

Have you lowered the engine into the car yet just to see how many packaging challenges you face? First thing I did when I swapped a GM V6 into my MGA chassised Jamaican - and I found that the front shocks interfered with various things and solved it by grafting MGB suspension including shocks (the valve bodies project the opposite way, outward instead of inward) onto the MGA frame - not a big deal.



Bill Spohn www.rhodo.citymax.com/carstuff.html
Current: 1958 MGA Twincam (race car (170 bhp)),1962 MGA Deluxe Coupe (98 bhp)
1957 Jamaican MGA (200 bhp)1965 1971 Jensen Interceptor (350 bhp)
2009 Pontiac Solstice GXP Coupe (350 bhp)
2007 BMW Z4M coupe (340 bhp)
Recent: 1969 MGC roadster (175 bhp),Jensen CV8 (375 bhp),
1969 Lamborghini Islero S (350 bhp), 1988 Fiero GT turbo (300 bhp)
North Vancouver BC

Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
I agree, the new engine is challenge enough. I've done a few conversions, these guys know. Every element you add stretches out the timeline. Very easy for a 1 or 2 year swap to become a 10 year project. Much better to get the engine done, THEN think about the suspension. At the very least that way it gets a shakedown.

It seems everyone here is advising you the same way and there are a lot of good reasons for that. At the same time we all heartily adhere to Bill's "Press on Regardless" mantra and want to see it, but the smart thing is to take the advice. Heck, even Hap agrees. If you have him, Bill, me, and a few others all saying the same thing you might want to give it some serious consideration. I know you are a capable man, I've followed some of your work and I really, really want to see this engine swap. But what I'm telling you about the wheels and EPS is the wave of the future. Don't ignore it.

Jim

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mgb281 Philip Waterman
Taunton, Somerset, UK   GBR
Bill, Jim, Hap and others
The problem with me is the more someone says don't do it the more determined I become, despite that I really do appreciate the advice from those on this forum who have been there and actually done it. If you already know the engine spec you will see it offers promise.
I have already lowered an engine into an old body shel l, not the one that I am going to use so I could make any mods that are required, but there are not any. That is if I change the intake from a S Type/LS to an X type and the sump likewise. Once I have finished the headers then I will be in a better position to confirm these details, the T5 gearlever pops up in the middle of the hole as well. The heater remains intact, the only remaining problem to deal with in getting the major components is the alternator. Now just like the 302 engine it needs the cross member modifying. For my initial fitting I have obtained an engine and auto gearbox for less than $75 the engines head gasket is gone so not worth repairing when you can buy low mileage engines with history for $300. I have not modified the cross member but sat the engine minus sum with a 3/4" spacer on it and the gearbox and believe it or not it sat level not fouling on anything. I have now acquired a good many of the parts that I require to start the front suspension so there is no going back! (unless it fails)

details for adaptor plate for Duratec V6/ AJV6 https://www.ebay.co.uk/itm/rx8-gearbox-conversion-plate-AJ25-AJ30-Jaguar-v6-Ford-V6-duratec/302733421176?hash=item467c516a78:g:5vsAAOSw9bday6NW

If you look up http://www.rocketeerltd.com/ you will see that it is a conversion for the MX5 using the same engine but a RX8 gearbox, but the conversion parts are very expensive, however there is an off the shelf ECU with a map and wiring loom. In the USA you are fortunate in having a wide range of RWD engines with gearboxes to fit, over here we have just Jaguar, BMW, Mercedes and Lexus/Toyota and tuning any of them is expensive, even the Rover V8 is going that way very quickly with gearboxes in particular being very expensive these days.
I will post pictures as I make headway and post them
I do hope though that if I need advice you and those others with the knowledge will help me.



Edited 1 time(s). Last edit at 2018-05-18 01:57 PM by mgb281.

Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
Oh we will definitely do that, I'm just sad that you are on the other side of the pond and I won't get to see the car in person. It sounds like a very good swap.

As for the front end, all the best. I personally think you are doing way too much for far too little reward, and that there is a better way forward, but in the worst case you should be able to go back and begin anew so only the time, effort and money is lost, and experience is gained so even then not a total write-off. But keep that EPS in mind. Those conversions will continue to mature.

Jim

tvrgeek Avatar
tvrgeek Silver Member Scott S
Hillsborough, North Carolinia, USA   USA
1965 MG MGB
You can draw it out on paper and figure where you need to bend the arms to. No idea where the Akerman center point is on a B. Neutral? One may want to play with it while playing with caster and toe and with modern sticky tires. Do we want more as the slip angles will be less? I wonder if the increase in scrub radius of just using wider wheels with the same rear offset is really that bad, or the advantage of moving the scrub point back closer to the tire center. Not at, but close I believe. Just longer A-arms may change the spring rate depending on where yo add the width as it will change the lever ration on the bottom. How yo would lengthen the Armstrongs woudl be much harder, which is why the smart guys here are talking about widening the subframe.

THere is a lot to think about in a simple A-arm. Simple they are not. Tradeoffs have changed over the years as tires have changed and the industry practice to prevent morons from spinning out by making cars plow like a pig. ( Sorry Miata folks)

BTW, my 2500M had horrible bump steer due to the TR-6 arms, so I changed them to the, if I remember, TR-4 arms so it reduced bump steer but the Akerman remained the same. On the old Pinto, we just drilled new holes and moved the rack.



Cogito ergo sum periculoso

mster50 Silver Member Mike Sterling/A
Zanesville, OH, USA   USA
1980 MG MGB
If you are going to widen the track with more than just wider wheels get rid of the MG suspension. There are many aftermarket companies that make bolt in crossmembers with modern suspension. It does not have to be a MG geared company either.

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