SCCA EMod MGB GT V12 Build

Amazing project! It's crazy how tiny that 302 looks in your engine bay.

mguar wrote:

loosecannon wrote:

Curmudgeon wrote: Nice! What program did you get?

I am using Speed-Wiz and some freeware I found online.

nocones wrote: Are you going to mount the watts pivot to the diff so RC stays fixed relative to the ground or to the chassis so it stays fixed relative the CG?

No, the pivot will be attached to a crossmember so I am not adding all the unsprung weight. The front RC will move up and down with the chassis, too so having the back RC move up and down isn't such a big deal, especially with the small travel amounts in E-Mod

Tell me about speed wiz. Is it simply make measurements and enter data or more complex than that? How adaptable is it? Is it set up to work with IRS? what sort of front springs? Will it work with Torsion Bars? . How about tire data? For example I can run NASCAR sized tires or tall rims with low profile tires.. I'm not even sure how tire/rim choices will affect grip..

It's more complex than that and can work with IRS and torsion bars. It's only $30.00 so even if it doesn't have everything you want, it's still worth it.

This build just gets better and better.... Thank you for posting ALL of it!

CAN

NOT

WAIT!!!!

For this thing to see some action, and for us to see it posted on Youtube. I saw the vids of it running on the gokart track, , but damn I cant wait to see it on asphalt!

I'm surprised no one has suggested this yet, but with the new found space from ditching the V12 there's got to be room now for a turbo. It'd be a lot of work but you could really make that 5.0 scream and for relatively cheap.

arvoss wrote: I'm surprised no one has suggested this yet, but with the new found space from ditching the V12 there's got to be room now for a turbo. It'd be a lot of work but you could really make that 5.0 scream and for relatively cheap.

I intensely dislike turbo lag on an autocross course but have given serious thought to a supercharger. I keep looking at the cost of getting 350 hp out of a 5.0 naturally aspirated vs supercharged and I'm starting to lean towards supercharging.

loosecannon wrote: I intensely dislike turbo lag on an autocross course but have given serious thought to a supercharger. I keep looking at the cost of getting 350 hp out of a 5.0 naturally aspirated vs supercharged and I'm starting to lean towards supercharging.

I'm more of a supercharger guy too but I figured that a turbo would be more cost effective. Also you tend to get shunned here if you speak ill of turbos. I'm sure there's a ton of literature on supercharging that engine which is a big bonus.

I would also lean more towards supercharging a V8 on a budget. Especially given the tight engine bay of an MGB. The exhaust plumbing would be tedious at best.

I approve of this build. And this topic. And this man's skill. Amazing work. Stick with NA, turbos and supers sound nice but keep in mind that they all add a not inconsequential amount of weight. You can make all of the power you'll need with a NA 302. The best part is that short blocks are cheap, so if you want more power, you can build another motor and then swap them. Get any Hot Rod or Car Craft from any month of any year ad you'll find people getting 5,6,7 hundred hp out of those engines without turbos or supercharging.

tuna55 wrote: I approve of this build. And this topic. And this man's skill. Amazing work. Stick with NA, turbos and supers sound nice but keep in mind that they all add a not inconsequential amount of weight. You can make all of the power you'll need with a NA 302. The best part is that short blocks are cheap, so if you want more power, you can build another motor and then swap them. Get any Hot Rod or Car Craft from any month of any year ad you'll find people getting 5,6,7 hundred hp out of those engines without turbos or supercharging.

Thank you very much :) The general opinion of drivers in DMod and EMod is that you don't want an engine with it's power all down low because it is hard to control. They say that getting a broad power band with good top end punch is better. In the case of the 5.0, this would mean building an engine that revs to 8000 rpm with solid cam, billet crank and good rods. I like the idea of this because I used to have a built 302 with 3x2 bbl carbs and it revved to the moon and was awesome, but not sure how it can be done cost effectively. There are plenty of engines for sale for decent prices but I've heard so many horror stories of people buying used performance engines that had problems. Whatever, I have lots of car development work to do and I don't need huge hp for that.

If you want a screamer, a 289 is just a 302 with an even shorter stroke.

That said, if you are after crazy power, I'm not sure you want a small block Ford. The stock blocks start to do this at about 500 whp.

Aftermarket blocks are cheap!

hey, just a question about your brakes? what are they? and did they easily fit on jaguar xj suspension? how well do they work?

Yeah, a lot of bottom end bark in an E Mod car will hurt you because of the possible power/weight ratio. 1600/1700 pounds + 350 low RPM HP = very touchy. That's why I like rotaries: they are more controllable at low RPM and will rev till nearby frogs are rendered sterile and blood squirts out of your nose. Unfortunately, that makes the car not as good at hillclimbing.

mguar wrote: In reply to arvoss: Actually the Ford small block is wider than the V12 (it's only 60 degrees not 90) It's just that the V12 is soooooooo long..

yeah so he could fit at least one turbo in there, and probably 2 small ones to all but eliminate lag and get the power he needs. But he can probably get enough power/weight NA.

mguar wrote: In reply to tuna55: Getting 5,6,7 hundred horsepower is possible but at what cost? Ain't gonna happen with many stock parts..

Even with all aftermarket, it's probably cheaper than a mild rebuild on the V12 or a decent set of turbos and either a guy to tig it all up for you or some kit you can bastardize. You can turbo stuff for cheap, but I am betting a cobbled together cheapy system ain't gonna cut it for this guy, and then the costs rise quickly.

V8 stuff is cheap.

calvindoesntknow wrote: hey, just a question about your brakes? what are they? and did they easily fit on jaguar xj suspension? how well do they work?

I did lots of careful measuring and found Wilwood 4 piston aluminum calipers that bolted right on with no mods. I bought newer XJ6 ventilated rotors and had them machined narrower to fit the calipers. They work great on an autocross course but I haven't really tested them on a road course or anything. The rear brakes are Strange Engineering 4 piston aluminum.

It turns out that a Watts link will only get my rear roll center down to 6" or 7" and I want to at least match my front roll center which is 3". There is a suspension system called a Mumford link but it's overly complicated so I decided to go with a Woblink. I built a Woblink and it's not complete yet but here's a sneak peak at it. I know it's weird looking with the two links going off to one side but it works.

Very Mallock of you, going with the Woblink.

Having the roll centers exactly in line is not really all that important. If there is any slope to the roll axis, it's best to have the roll axis slope down toward the front of the car. The steeper the roll axis the more unpredictable the handling, if there is only a 3" difference in height f/r the chances of it causing a problem are pretty small. That's why I went with a Panhard on the Jensenator. I just didn't see a real need for all the extra fab etc for a Watts, Woblink etc. Less weight, less to break.

Curmudgeon wrote: Having the roll centers exactly in line is not really all that important. If there is any slope to the roll axis, it's best to have the roll axis slope down toward the front of the car. The steeper the roll axis the more unpredictable the handling, if there is only a 3" difference in height f/r the chances of it causing a problem are pretty small. That's why I went with a Panhard on the Jensenator. I just didn't see a real need for all the extra fab etc for a Watts, Woblink etc. Less weight, less to break.

Yeh, you are probably right about the complexity of the Woblink being unneccessary but I want to give it a shot. The general opinion of other Mod competitors is that the rear roll center should be higher than the front. I will have the lowest setting of the rear roll center to match the front and adjust from there. I am also going to try eliminating the sway bars and adjust roll and balance using the suspension frequency and roll centers only.

I spent all of Christmas Day working on the bracket to hold the Woblink in place, and here it is. I also included a video which helps make sense of how the Woblink works. The bracket is made from 3/16" steel and has some stiffening done to it but because it has to take the entire side to side force of the rear suspension, I added braces that go under the diff and tie into the suspension mounts

http://www.youtube.com/watch?v=OW_ofdjHfSc

Have you run the diff through its range of motion with the drive shaft connected?

It looks like it might make contact on the left/driver side looking forward.

Hmmm, you know, there's nothing preventing a Watt's link from being mounted horizontally.
Center link (bellcrank?) pivots horizontally on the bottom of the diff housing, forward and aft links parallel to the axle, each connected to opposite sides of the chassis.
That would allow you to bring your roll center down to a couple of inches, using a straight bellcrank. . A 'bent' U shaped bellcrank allows you to place the roll center a bit higher if you want, depending on the amount of the bend, as long as it clears the diff snout.
Simple, lightweight, effective.

erohslc wrote: Hmmm, you know, there's nothing preventing a Watt's link from being mounted *horizontally*. Center link (bellcrank?) pivots horizontally on the bottom of the diff housing, forward and aft links parallel to the axle, each connected to opposite sides of the chassis. That would allow you to bring your roll center down to a couple of inches, using a straight bellcrank. . A 'bent' U shaped bellcrank allows you to place the roll center a bit higher if you want, depending on the amount of the bend, as long as it clears the diff snout. Simple, lightweight, effective.

True, but it doesn't give you the range of adjustability of the Woblink