DuPuis Family Cobra Build

3393RP said:
Actually a modern production blown or turbocharged EFI engine with VVT or cam phasing can be very streetable and still produce upwards of 800 HP.

But what are you gonna do with it?
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Depends on your definition of streetable I suppose. Blower surge, turbo lag, heavy/stiff clutches, loud exhausts, stiff/lowered suspensions, etc all take their toll on how enjoyable a car is to drive on the street. I agree though, that it doesn’t do you much good to have a ton of power which sits unusable until you are well into the triple digit speeds which should be kept to a race track.

We had a ‘95 twin turbo 300ZX that had around 400 crank HP with nothing more than a tune, exhaust, and boost turned up a bit. Drove just like the 300HP stock engine did. Once you started upgrading fuel injectors to 600cc and above, larger turbos/intercoolers, dual air intakes, etc., it would push 700+ easily on stock internals. However, those little upgrades start to become more troublesome for a streetable car, especially if it’s anything driven weekly.

There’s always nitrous oxide, but it’s an expensive way to only have temporary power increases.


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Also, don’t get me wrong. There are plenty of vehicles that come stock with power levels well above 700HP and drive just fine. FIL has a Challenger Hellcat that does just fine on runs around town. I was mainly referring to modding engines to double their original rated power or higher, which generally becomes problematic at a certain point.


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And I was talking about engines in production cars, like the Hellcat, as you mentioned. Some of the cars available from Mercedes-Benz are also a good example.

The twin turbo giant intercooler 250 lb/hr injectors razor edge stuff in magazines is kinda silly.

I wonder what the average income is for a Hot Rod reader. I think articles about LS swaps, suspension upgrades, and the like is much more interesting to them than the '55 Chevy they featured on the cover last month that had a 780 HP nitrous added LS and cost over a half million to build.

It would be like Kitplanes featuring a Cirrus SF-50.

But here I am talking about car magazines on an aviation forum. I doubt anyone is interested in that either.

:confused:
 
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Last night I spent some time looking through the manual, a combination of looking at the first steps that I'll be working on and figuring out what I need to source. For the most part it's just some minor shop supplies. Drill bits, silicone, Sharpies, threadlocker. Need a pop rivet gun, deburring/countersinking bits, things like that. One other question I'm trying to work out is what to do with the aluminum panels. Just leaving them bare will have them looking terrible in no time.

Powdercoating is considered the most popular option for durability. As I've said before I'm not a huge fan of powdercoating, but I ended up having the frame powdercoated anyway because cost wise it became essentially free.

I've talked to some of my friends who painted their planes and they've mostly done a primer + paint option of some sort. That seems to hold up well in airplanes, but that environment is fundamentally different from the roadgoing environment that this car will see. I'm also going to be putting some Dynamat on the inside pieces to reduce tin can noises from the aluminum.

If anyone has thoughts on what to do on those aluminum panels I'm interested in opinions. Durability is really the goal as this isn't a show car, but I do want the exposed areas to look decent and last. This isn't exactly going to be driving on bad salty roads but since it's on the road there will be rock chips, etc.
 
Ted DuPuis said:
If anyone has thoughts on what to do on those aluminum panels I'm interested in opinions. Durability is really the goal as this isn't a show car, but I do want the exposed areas to look decent and last. This isn't exactly going to be driving on bad salty roads but since it's on the road there will be rock chips, etc.
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Don't know what it weighs, but Rhino coat or Line-X truck bed protector matrial? It would both protect the sheets, look decent, and cut down on the tin can noise in one shot.
 
Bill Jennings said:
Don't know what it weighs, but Rhino coat or Line-X truck bed protector matrial? It would both protect the sheets, look decent, and cut down on the tin can noise in one shot.
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It would help some, but not perform as well per lb as dynomat or its competitor products, it's also a messy job, even if spraying it unless you have a 3rd party do it. Dynomat/Hushmat have several product lines to choose from depending on the area you are covering and what type of sound/vibration dampening is needed.
 
Bill, the standard bedliner options are considerations, but aside from being messy I've heard that they don't ultimately work that well when not applied by a professional shop.

What people tend to like about Lizard Skin is they have products for both sound and heat insulation in one.

Another option I've read some folks do is a standard spray-on undercoating on one side, and then Dynamat or the like on the other side. There are plenty of folks who leave the panels alone and don't care how they look, but I think I want to do something. For the all black build plan I think that leaving the shiny aluminum would look wrong and incomplete.
 
Ted DuPuis said:
Another option I've read some folks do is a standard spray-on undercoating on one side, and then Dynamat or the like on the other side. There are plenty of folks who leave the panels alone and don't care how they look, but I think I want to do something. For the all black build plan I think that leaving the shiny aluminum would look wrong and incomplete.
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I think that would be your best bet.
 
1RTK1 said:
I think that would be your best bet.
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I'm largely thinking that direction might make the most sense. Right combination.
 
I just sold the T-56 transmission that I traded for the rest of the Mustang parts car I bought. That parts car now cost me -$50 and I still have the Edelbrock heads I wanted.

Now I’m looking at another parts car... :)
 
Matthew said:
You and your parts cars reminds me of the Woot Bag o' Crap.

You pays your money, then get to look inside and see what you got.
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It’s all in how you buy them.

I paid $1800 for that blue car that had $1600 heads. I figured it’d be hard for me to lose money. At this point I’ve been paid $50 to take the heads off the guy’s hands, and gotten some other useful bits. So even if they’re totally worthless I broke even.

The one I’ve got my eye on is similar. A few things I want that make up the value of the car, and I can probably part the rest out enough to make it free.
 
You are the Dodson of crappy cars. But I think you are correct, buy them right and you'll be fine.
 
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ja_user said:
You are the Dodson of crappy cars. But I think you are correct, buy them right and you'll be fine.
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I've bought something north of 50 vehicles in my life (this includes trailers), and participated in the purchase of many more. Note that I've been doing it for about 18 years, so that makes for a pretty decent number per year on average. Out of those a good percentage of them have been cars that needed work in some way, shape, or form. Some I've done well on, some I've lost a lot of money on. After doing it for a while I've gotten a good handle on what to look for.

With these parts cars, it's worth noting that I'm buying them specifically for one (or more) key parts that I'll be able to use, making sure those parts make up a large percentage of the purchase cost and then whatever I sell ends up being gravy. Parts cars are generally ugly, which is fine because they don't need to be attractive. The body normally gets scrapped or sold off to someone who can use the final bits for some bigger project that I won't do. Buying something that's rust-free (or close to it) helps a lot in this regard, and being willing to trade for something that's easier to sell. For example, the blue '88 Mustang parts car probably would've fetched around $1,000 at best as a "roller". Trading it for a T-56 transmission netted me $1,400 at the end of the day. After selling other parts I didn't want, I've made $50 off that car, and I still have the $1600 heads.

I'm heading to check out another parts car in a bit. For this one, it has a rear axle set up how I want, and then I'll keep the car itself for a lot of the vehicle donor parts I'll need. I don't expect I'll keep the engine or transmission, and I should be able to sell those off for about the price of what I pay for the car itself. This should get me some more "free" parts. I'm hoping I can find another Cobra builder who will want to buy the drivetrain as it would be a good candidate, complete with wiring harness.
 
Let me know if you run across the hood ornament on a 1978 Ford Thunderbird.
 
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ja_user said:
Let me know if you run across the hood ornament on a 1978 Ford Thunderbird.
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Think you can flip a '78 T-bird with "39,000 miles" and no hood ornament for more than 1500 bucks?

https://sandiego.craigslist.org/ssd/cto/d/1978-ford-thunderbird/6703187764.html

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I neglected to get a picture of it on my trailer, but I present Rustang 2: Return of the Rust

43771624_521076228365191_4196793401699467264_n.jpg


(brought to you by UConnect 8.4 in my Ram)

This one is a '94 Mustang GT, SN95 body style. The main reason I bought it was for the 3.73 limited slip rear end, which is what I want for the Cobra. It has a very short throw shifter for the transmission (which should be a T-5). The engine has been warmed over but ultimately is still a 302 and not what I want, so I'll plan to sell it. May or may not sell the transmission. I expect I'll keep the base car around until I get the Cobra together since it has the rest of the parts I expect I'll need (well, most of them), but I'll start parting it out in the meantime.
 
Ahhh, you missed your chance.

Next time you trailer it, tie down a tarp over the windows and wrap crime scene tape around it. Makes a great conversation starter.
 
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Ted DuPuis said:
This was more fun:
Got a lot of smiles and people taking pictures with their phones.
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You missed a perfect opportunity to slap a "NATIONAL SHRINK RAY LABORATORY TEST BED" magnetic sign -- official looking logo included -- on the doors of the truck.
 
DaleB said:
You missed a perfect opportunity to slap a "NATIONAL SHRINK RAY LABORATORY TEST BED" magnetic sign -- official looking logo included -- on the doors of the truck.
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It was sort of a last minute thing.
 
Here's a better shot of Rustang 2:

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MIFlyer said:
I have to be honest, I kind of want to ride that electric quad.
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We now have two, one for each of the girls. They love the things, and sometimes we have them use them to help move stuff around the property.

Can't find it now, but there's a picture of one of the girls giving me a ride one night. :)
 
Ted DuPuis said:
This was more fun:

41382347_900317509623_1117047300640735232_n.jpg


Got a lot of smiles and people taking pictures with their phones.
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I passed a full size low-boy trailer on an expressway that had a Tonka front end loader strapped down in the middle of it. Made me laugh out loud and I wished I could get a picture, but I was driving solo.
 
I think this weekend I'll get the Mustang off the trailer and might try to get it started. The starter is grinding the flywheel and the clutch doesn't feel right, but it still is going into gear and the clutch does engage and disengage. So I'll see if I can dump the clutch in reverse while rolling it off the trailer and get it started.

One thing I've been thinking about is the transmission. This thing should have a World Class T-5 in it. I'm thinking about doing one of the gearing upgrade kits on it that will give me the horsepower/torque capability I need (equal to a TKO) in a lighter weight unit and a significant cost savings. First I've got to pull it out and figure out what it's got in it. My hope is to find someone who will buy the engine complete.
 
Between this being a 45-hour flying month and having the plague, I didn't get anything done after getting the Cobra in the garage - didn't even get parts car #2 off the trailer... until today.

I still haven't gotten much done, but I've officially started drilling the first holes. The first panels that it has you start with are two "F"-shaped panels that go right behind the front wheels. So I got the holes drilled in the panels. Using a center punch to mark the holes makes that easy, and they include a template so you get the spacing correct. Also got the frame on jacks, which I hadn't done previously.

I also got parts car #2 off the trailer. I turned the engine a bit by hand and sure enough, then the stater would engage. However the battery on the thing was completely dead. The guy wired up the air/fuel ratio gauge such that it's always powered on... that's special. I've got the battery on a charger to see if I can get it to come back to life enough to crank it over and make it fire. Oil looks good, on it, coolant looks acceptable. So I'm hopeful that this can run with a good battery. The transmission goes into all gears, but the clutch will not disengage, so I won't be able to drive it.
 
I'm also trying to figure out what to do for treatment of the aluminum panels to make them black. I'm leaning towards just painting them rattle can flat black for a few reasons.

1) You won't see most of them in the first place, they'll either be covered up with Dynamat, under the car, etc.

2) If you follow the instructions in order, the panels get put on a couple at a time here and there. So if I were to do powder coating, I'd end up having to make a bunch of trips to the powder coater or else do things out of order. I don't particularly like that idea, especially given that I've never built one of these before and would rather more or less follow the instructions in order.

3) Easy touch-up

4) My son has an interest in working with spray paint, so this would give him something that he could do

All in all, makes sense I think.

I got the donor car #2 running this morning. Overnight on the charger gave it enough juice to get it starting. It cranked fine once I got it off of the bad tooth on the flywheel, so it sounds like it's only got 1 or 2 teeth stripped off. Once it got running, the engine sounds fine, but the clutch sounds really bad, lots of chattering. It makes me think that it might've blown the throwout bearing or otherwise have a problem there. When I push the clutch in it obviously changes some sort of geometry (even though the clutch doesn't disengage fully) which would support that theory. It's somewhat irrelevant given that I'm not planning on using the engine in the car, but obviously if it works it makes it easier to sell since that's the plan for it.

Per the instructions, once I get these first aluminum parts on, then I do the front suspension and after that I put the rear end on.
 
It sounds like a typical project where the first 80% goes quickly and it starts to look like something, then the last 20% detail work seems to take an exceedingly long time. But once you get a rolling frame, at least the kids can push it around for you.
 
Greg Bockelman said:
Aww man, I miss Quick Trip.
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I love how much expansion they've been doing the past decade. Now if I could just get them to move into the OKC metro area, lol. One of the first FB groups I saw among the Univ of Oklahoma kids (back in '01-'04) was "I Miss QuikTrip" for all of the Tulsa and DFW folks who had moved to OKC for college.
 
Matthew said:
It sounds like a typical project where the first 80% goes quickly and it starts to look like something, then the last 20% detail work seems to take an exceedingly long time. But once you get a rolling frame, at least the kids can push it around for you.
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That's more or less right. I like the fact that it turns into a roller fairly quickly per the build. Realistically with all my other projects this will take a while, I figured a couple years.
 
FormerHangie said:
Maybe I'm taking this the wrong way, but that doesn't sound like much of a recommendation of the state.
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You fail to understand just how good QuikTrip is. :D

You're correct, though, I should've worded it differently. We are very happy here.
 
Ted DuPuis said:
You fail to understand just how good QuikTrip is. :D

You're correct, though, I should've worded it differently. We are very happy here.
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We have QuikTrips here, also RaceTracs, they're pretty similar. As you go up the Atlantic seaboard, you start seeing Sheetz and Wawa. IMO, they're all interchangeable. Some of them have soft serve FroYo, some have beer caves, some serve fresh food, some don't.

There's a QuikTrip at Clemson, SC along I-85 that sells so much gasoline I think they must have their own pipeline spur.

Edit: I've only ever been through Kansas once, and that was on the way back on a long motorcycle trip. The part I was in just seemed flat and featureless, plus very hot. I started the day in Las Animas, CO, and ended it in Blackwell, OK.
 
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And all the new QT's around here sell Corn free fuel.
 
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Ted DuPuis said:
the clutch sounds really bad, lots of chattering. It makes me think that it might've blown the throwout bearing or otherwise have a problem there. When I push the clutch in it obviously changes some sort of geometry (even though the clutch doesn't disengage fully) which would support that theory
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Clutch plate in backwards....or the center of the plate spun out..?? Or could be a broken pressure plate.

Clutches are simple. Throw everything away and put in new stuff with better pressure.

I had a hot rod 283 that around 6800 RPM the stock pressure plate would just quit. It would lose pressure and just smoke the clutch plate. It would look like the engine blew until the RPMs came down and the clutch would slam together again chirping the rear tires....:lol::lol:
 
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