Wednesday, March 28, 2007
Pictures of the new turbo and the manifold autopsy
I took a picture of the new GT40 turbo next to the old Mitsubishi turbo today. That's the GT40 on the left and the Mitsu TE04H on the right. The intake diameter on the GT40 is nearly as big as the compressor housing on the itsy-bitsy Mitsubishi. The round thing, which is nearly as big as the TE04H, is a TiAl external wastegate.
I also took some pictures of the cracks in the manifold. Several of the cracks had black soot, indicating the crack went all the way through the manifold. The last picture shows where a small leak (blue arrow) had leaked out enough soot to leave a mark on the flange (red circle).
The guys at AutoFab wanted to see if they could smash the flange off the manifold with a sledgehammer. Of course, I said to go ahead. After all, the manifold was already not something I wanted repaired, and I figured it would tell me a bit about the damage and how well built the manifold was. And, of course, destruction is fun.
With the flange off, I got a good look at the weld area. The sides looked like the welds extended all the way through the metal, but the top and was not quite as solid. Blackened areas in the crack show where exhaust had leaked through the crack. The last picture shows more about the leak shown earlier. There are two holes (red arrows) clearly visible in the photo. It appears that these were defects in the original welding.
The article on slantsix.org claimed the manifold had 15,000 miles put on it since the flange was welded on, and it may have racked up several thousand more since. I know I didn't put more than a thousand on it myself. So it may have lasted about 30,000 miles or less before it started to crack.
Labels: Dodge Dart
Thursday, March 22, 2007
"I think your old turbo could fit inside there!"
Labels: Dodge Dart
Saturday, March 17, 2007
What makes a great starter motorcycle?
A starter bike is one that you'll buy to learn on, and it should be one that's easy to ride and less likely to do something dangerous if you make a mistake. Remember that it's your first bike, not your last; motorcyclists often buy new bikes as often as car drivers buy different cars. Motorcycles come in a lot of differnt types, and you can find a good first bike whether you like sport bikes, cruisers, or several other categories. I have four rules for what makes a good first bike.
1. It should have 50 hp or less. More powerful bikes can easily get out of hand - not only do they have more power, but often they have touchier brakes and handling too. With sport bikes, it's usually best to stay at 500 cc's or less; you can go bigger with cruisers or dual sports (dual sports are basically street legal dirt bikes, although they may be a bit larger).
2. A good starter bike needs to be light enough that you can easily pick it up if it falls over. Beyond the obvious problem that you might have it fall over (more likely in your garage or at a stop sign than while in motion, at least), a lighter bike will be easier to handle and you'll be less likely to need to pick it up.
3. When you sit on the bike's saddle, you should be able to put both feet flat on the ground. This will again help you avoid having to actually put rule #2 to the test.
4. It needs to fit you. You should feel comfortable sitting on it with your hands on the grips and your feet on the pegs. Any discomfort you feel in the couple minutes they'll let you sit on one in the showroom will seriously hurt after an hour of riding. And you'll want to pick one that matches your plans for riding and your sense of style, too. There's plenty of good choices for first bikes out there, so you don't need to settle for one that just seems wrong for you.
Friday, March 16, 2007
I think I need a radiator for my credit card...
But the biggest thing they've talked me into changing is the turbo and manifold - which, by the way, will remove the last trace of the turbo setup I bought from the
SlantSix.Org turbo article. The turbo I have is way undersized and seems to be holding the engine back above 3,000 RPM. I may be erring in the opposite direction this time. While I did cheap out a little bit by staying with journal bearings instead of ball bearings, I'm going with a brand new Garrett GT40 from Advanced Tuning Products. It'll be mounted to a stock exhaust manifold on a J-pipe, and I'm getting a genuine Tial external wastegate (no knock-offs here) for boost control.
Some people have commented that this turbo is a bit over the top. But I did a lot of fiddling around with the Squirrel Performance Group Turbo Calculator and similar estimates before ordering, and I've calculated this one should be one of the most efficient choices even at low boost. And if I decide to explore the limits of my 2.5 bar MAP sensor (21 psi of boost), the GT40 can take me there.
Labels: Dodge Dart
Tuesday, March 13, 2007
Sunday, March 11, 2007
When do you call in professional help?
S0 this week, I towed the Dart to Autofab Motorsports. It's often kind of hard to find a good mechanic as it is, and when you have something that over the top like a slant six turbo, things get even more tricky. In this case, I know these people fairly well. They have a history of Megasquirt projects, have been working on unusual turbo cars, and best of all, they're two doors over from where I work, so they can talk to me if any questions come up.
But what for people with hot rod projects who don't know someone like that? My best advice would be to hang out at hot rod shows and talk to the owners of the show cars - they'll gladly tell you all about the cars in most cases, including who did the work. You'll get a feel for who is building the good performance cars and who specializes in what. In my case, bringing a Dodge Dart to a shop that mostly works on BMWs was a bit of a stretch, but they're more familiar with my electronics than a shop that normally works on carbureted V8s.
The Dart may leave their shop with a few twists that weren't part of the original plan, but I think they're good touches...
Labels: Dodge Dart