Slow Car Fast
THE MG
April 29, 2008 - The mystery of the terrible ride has been solved.
In several ways, actually. I had a suspicion that the shocks might be involved, as they were the most likely candidate for restricting any bump travel. So I lifted the rear of the car up to have a look and whaddya know, one side didn't drop at all. I supported the spring, loosened off the shock and this fell out. It's jammed at full compression. So not only was it preventing the suspension from compressing at all - due to the way it was mounted - but it also was preventing it from moving. So, problem 1 solved.
But there are remaining problems. The shock was fully compressed at ride height, with several inches to go before contacting the bumpstop. Reading the tube shock conversion article in the MG Experience library, I discovered that the lower shock mount was installed upside down. This was probably a good idea given the jacked up ride height originally, but back at normal heights it compressed the shock too much. So, there's a solution then.
Ah, but not so fast. The shocks are a Monroe-Matic Plus 33076, which according to the MG Experience article is the standard Moss shock and is well known for a terrible ride. So I can probably improve on it regardless. The article discussed rooting through parts book and gives a couple of other options. But I can do better! A visit to the Monroe website unearthed a PDF document with all of the mount types, extended lengths, compressed lengths and other good info. A bit of messing around and I turned it into a spreadsheet. So now I can search quickly and easily! I can't tell anything about the damping of the shock, but once I've picked out a few that have more travel than the originals, I'll look up their applications and see what that tells me. Or I'll call Monroe. This is going to be fun.
entry 54 - tags: suspension
April 30, 2008 - The shocks have been selected.
Most of my early selections turned out to be for various one-ton vans, with an expected stiff damping. The Mitsubishi Cordia of the late 80's has some shocks that have been used in the past, and they looked to be a good match. There's also a Corvette application that looks interesting, but the 1986 Corvette wasn't exactly known for ride quality!
So, with the application nailed down, I was able to choose between a KYB, Monroe-Matic or a Monroe Sensa-Trac. I went for the Monroe-Matic, as I'd heard the Sensa-Trac shocks have some ride quality issues that may be related to internal gas pressure. The cheaper -Matics are probably not damped quite as aggressively. And they're only $17 each, so what the heck. The total bill was $40 shipped. If they don't work, I'm willing to accept that and chalk it up to experimentation.
The fronts use the same size of shock and I considered picking up a set of four, but I'll put that off until later.
entry 55 - tags: suspension
May 21, 2008 - The new vs the old shocks.
The new vs the old shocks.
entry 56 - tags: suspension
May 21, 2008 - First step towards installing the shocks - cut down the bushing.
I cut it a bit too far - a touch longer would have worked better with the bolt length. Nothing an extra washer couldn't fix though.
entry 57 - tags: suspension
May 21, 2008 - Step two - drill out the bushings.
They're sized for 12mm metric bolts, but the MG doesn't speak metric. A bit of time with a 1/2" drill, problem solved.
entry 58 - tags: suspension
May 21, 2008 - Either a really stupid idea or a stroke of genius.
The holes in the lower shock mount can get ovaled out and I was seeing the first signs of this. The threads on the bolt were getting damaged as well as doing damage.
So I welded in a clevis pin. It's a nice tight fit in the resized lower bushing so there's no slop, and being welded into place means it's not going to move. Plus it means I can pull out a pin and easily remove the shock. I can hear the purists crying.
entry 59 - tags: suspension
May 21, 2008 - It's about time.
I've been waiting for this manual for over a month. Now I can sort out the weird wiring bugs. British manuals are really good.
entry 60
June 7, 2008 - It's been pointed out that I never actually updated the results of the shock swap.
Well, the car bounces. That's about as far as I've made it. A few other projects got in the way so the GT went to sleep for a while. Until the Targa Newfoundland car is done with the race, the MG will always be a lower priority.
I did spend some time this weekend at an MG event, though. I was a little busy playing rally driver, but I did get the chance to check out a few nicely finished cars. The grille was well chosen, I think, and a well-finished black dash looks great. So we're on track there.
entry 61 - tags: suspension
October 26, 2008 - The Targa Newfoundland is over.
It was a lot of work getting the Targa Miata built, tested and out to Newfoundland and back. But that's done. And while some post-race analysis continues, it's time to turn my attentions back to the MG. This site is about to come back to life, as is the little black coupe.
entry 62
October 31, 2008 - A new plan.
The original intent was to install a Ford 302 into the MG, as it's cheap and readily available. However, that was before I got mixed up with transplanting an LS1 into a Miata. I fell in love with not only the performance, but also the packaging and the (relatively) light weight of the engine. So I've switched plans. It's going to be an LS1.
entry 63 - tags: engine choice, planning
October 31, 2008 - Sharp eyes will notice the giant "LS2" on the last engine.
Okay, so I cheated on the picture. And here's the engine I'm really considering. It's marketed as the "Vortec 5300" and it's found in late model Chevy Silverado trucks. But in the 1500 extended cab 4wd versions, it's a special high output version called the L33. Unlike the usual truck motors, it has an aluminum block so it's a lot lighter.
It's also taller, but the LS1/LS6 intake manifold and oil pan should bolt right on. Hopefully it won't be too big a deal to drop the alternator somewhat as well. It's a 5.3 versus the 5.7 of the LS1, and that's simply due to a smaller bore. With the right parts bolted on, it'll basically end up a slightly smaller version of the LS1, and all the same hop-up parts will fit. LS6 cam, perhaps?
But the big reason is that they're a lot more affordable. LS1s are well known and are expensive. Truck motors are not sought after by most enthusiasts. I've been able - without trying too hard - to find a 16,000 mile example for under $1000 shipped. I'm sure I can do better. I'll still have to buy a few parts to make it work, but it'll come in well under the price for an LS1. And with 335 lb-ft and 310 hp, it's not going to be a slouch.
entry 64 - tags: engine choice, planning
October 31, 2008 - Of course, a power upgrade of this magnitude will have implications that reach throughout the car.
One victim will be the rear axle. I could cut down a rear from a Mustang or something similar - but why not go with an independent setup? Much more my style. And the obvious choice is a Miata one. I have access to cords of Miata parts, I know how well it works and I can use my access to aftermarket parts to tune the handling.
I'll need a different differential, but that engineering has already been done for the LS1 Miata. So all I need to do is fit the subframe to the car.
Luckily, I have a series of photos showing this being done. Perhaps not with the most subtle techniques, but it's a proof-of-concept. The biggest problem is that the MG's body is narrower than the Miata's, so I'm looking at narrowing the suspension by almost 7". Not difficult, really, but I was amazed at just how much.
entry 65 - tags: rear suspension, planning
November 1, 2008 - I measured the maximum fender width of the MG at 58" front and 57.5" rear.
That's a bit approximate, and it assumes the fenders are fully rolled. Measuring a complete Miata subframe with 205-series tires came up with 61" front and 62" rear. So I don't need to narrow things as much as I'd feared, as long as I don't do anything too foolish with wheel and tire choices.
The picture is of a tubular subframe that's made for installing an LS1 in a Miata. I'm not sure if I'm going to cut down a stock Miata part or build a tubular one like this. The latter will be more work - of course - but will offer more room. Remember, I have to narrow the track by about 3".
entry 66 - tags: planning, subframe, suspension
November 2, 2008 - A serious piece.
I found this vintage V8 badge that I believe came off a Nova. I might have to mount it on the car for a little hint as to what's underhood.
entry 67 - tags: badge, aesthetics
November 8, 2008 - After some rough sketches and much thinking, I'm leaning away from narrowing the Miata suspension.
The roll centers won't be as well controlled as I thought - thanks to Jensenman on the GRM forums for making me take another look at this.
Luckily, there's an alternative. The fender flares from a Dodge Omni can be grafted on to the MG bodyshell, adding a bit over 2" per side. That should be almost perfect. Time to start hunting Omnis, or see if I can find another car that would make a good donor.
entry 68 - tags: suspension, body
November 9, 2008 - We have the drivetrain.
While I was in the middle of trying to figure out just what an L33 would need to convert it into something closer to my needs, I spotted an ad for a 1998 Camaro on Craigslist. The whole car was going for about the usual price for an LS1/T56 combination. So there was a change of plans, and now there's one very evil looking black car parked in the driveway. I could have driven it home, but with the forecast of snow in the mountains I decided that it would be better to give it a ride.
These cars are enormous. It's ridiculous.
Not only do I have an engine and transmission, but here's my ECU, my wiring, potentially the guts for my instruments, a flywheel and clutch, a high-pressure and high-flow fuel system and anything else I might need. All sorts of things that had the potential to really nickle-and-dime the project.
Even better, the engine was rebuilt about 30,000 miles ago with an XR259HR Comp cam and a Comp cam "RPM kit". There's also headwork and some sort of aftermarket shifter. Best of all, because it's all in a running car, we could test drive it.
It's a happy engine. Very strong. The transmission likes to pop out of reverse. The seller - a fellow Grassroots Motorsports reader who originally bought the car as an engine for his GTO race car - thinks that it's simply a shifter in need of adjustment, and it does have that feel when you're trying to slot it into place. I'll see if I can fix that up. He also threw in a couple of extra oil pans he didn't need (the GTO uses a different one), a power brake setup from a GTO and a low-mileage oil pump that he doesn't need. Let's just say he was a kindred spirit when it comes to this sort of project.
So it was a bit more than I'd originally intended to spend. But there are a lot of resellable parts. That hood, for example. And the limited slip rear end. And the Borla exhaust. And possibly the stainless header (that I think includes cats) that was included, uninstalled, in the trunk. And of course, almost a complete car's worth of other stuff.
Janel announced that the car was at the bare minimum of loudness for her project with the Borla. I think I'm going to have to install some exhaust cutouts.
entry 69 - tags: engine choice, donor
November 11, 2008 - A lesser-known alternative to the Omni flares is ones from a Mk1 Golf - aka Rabbit.
There's not as much information about them out there, but they have a better shape in my opinion. I'm going to pick up some Rabbit fenders that are in a junkyard locally and see for myself. I like the hood louvers on this car as well, I suspect something like that will be necessary to keep the temperatures under control.
I think the best order of operations is to strip the MG down and start figuring how to mount the suspension. That'll tell me just how wide the fenders need to be. I'm also going to have access to an LS3 engine and T56 trans going into a Miata, and I'll make the measurements I need to determine just what needs to be done to the chassis and where the engine will sit.
In the meantime, the Camaro will be registered and driven to make sure there are no foibles in the drivetrain prior to installation. I think it's going to be difficult to resist stress-testing the tires on a regular basis, it's that kind of car...
entry 70 - tags: body, plans
November 15, 2008 - I stopped by a local scrapyard today and picked up a pair of fenders.
They're from a square-headlight Rabbit - one of the ones made in Pennsylvania. We tried to pull one off a German-built cabrio but it was built with much more enthusiasm and far more seam sealer so we could not remove it without damage. One nice thing about living in western Colorado is that the cars are almost rust-free.
I'll cut out the flare shortly and get an idea how it sits on the car. The rears looked as if they'd really work nicely on the back of the MG, but the yard wants $100 per side to torch them out "due to the cost of oxygen and acetelyne". I know it's a pain in the butt to do something like that, so just tell me it's a PITA factor. Don't make up fictional costs! I'll see if the fronts can also be used on the back before I go back to negotiate. The good thing is that the yard had a half-dozen potential donors so I have a good selection - including a pickup! Most of them are two-door hatchbacks or convertibles which seems to have the best shape.
entry 71 - tags: body
November 15, 2008 - While walking past the Opel GTs parked in the shop at work, I took a closer look at the shape of the fenders.
This might work. They're nice and round without the flattened edge used on the Golf. And there's a good donor in the shop as well - a parts car that is destined to be chopped into pieces.
Hmm..
entry 72 - tags: body
November 15, 2008 - The engine!
This is ridiculous. The nose of the Camaro is about 15 feet long, and the rear four cylinders of the engine are embedded in the firewall. There's no reason for this car to have such a stupendous nose other than overcompensation. Of course, you could say the same about the cowl induction hood on this particular car.
It looks like changing the serpentine belt would involve crawling into the engine bay, and looking at the rear spark plug on the driver's side makes my hands and back hurt just thinking about having to change it.
The good news is that all the fluids look good and fresh, and under that SLP airbox cover (which doesn't fit as well as it could) is a nice K&N. Someone took care of this powerplant. Can't say the same about the body of the car, which has the look of a shoddy body shop reassembly about it, but that's not a concern of mine!
entry 73 - tags: donor, engine