LocostUSA.com

Here's a picture of a Surtees, '72 I think. I've looked at about 10 of these cars and haven't seen any real frame on them behind the roll bar. It seems they bolted the engine to the rollbar and then everything else bolts to the transmission. You can see a brace from the transmission to the rollbar. I wonder what the class weight was on these?

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Lots of good info on midengine transaxle adaptation here.

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Ford 5.0 into an M3
mikaelvroom.com | @MikaelVroom

SICK!!! if I can build something even close to the cool of that id be happy.... best most aggresive formula car design!

starting playing with the tubing.... I'm going roughly off the Riley DP trackday chassis. I'm stuck until my $310 tube bender die comes

Should I love this thread to the build logs now that i'm "building"?

No idea how I missed this thread over the last few weeks. Anyway, I want to comment on a few of the things I read:

1. You absolutely, no way at all, need power steering. My car weighs 2400 pounds empty and I'm running either 275 or 315 section R compounds on the front. I have a quick ratio manual rack and it works PERFECTLY. When I called the company who made it, the first guy insisted I would never be able to drive the car. I ignored him and couldn't be happier.

2. While some of the steel I used was pretty beefy, the majority of the car is made from 1.5x0.90 wall DOM tubing. The square tubing is 1.5x.120 just as you are suggesting. The only really heavy piece is the bottom rectangular tube. I had to go with .120 wall because the store I was using didn't carry .09 wall in the size I wanted. Had I looked at what was available first, I would have designed with a different size. You will probably save more from being a single seater, than from changing material sizes.

3. As for the auto, I am using paddle shifters now with a custom computer my dad made. The trans is completely manual; it will stay in whatever gear I have it in. You can bounce the engine off the rev limiter all day long if you wish. I also have the torque convertor locked in every gear but first. If you come to a stop in any other gear, the engine stalls. The system works well and minimizes the heat. Heat is your number one problem. Plan on a big cooler with it's own fan. The only other problem is that the trans is slow to shift from second to third. This isn't unique to me; the guys at Mongoose Motorsports had the same problem with a different controller. I believe they solved the problem, but I need to follow up. Also, with your power and weight, you don't need to shift. I can run almost every track I go to with 3rd gear alone and be very competitive.

4. The wide 5 stuff is pretty much bullet proof, but you want to choose your tires and wheels first. Most of the wide 5 stuff is designed for a 15" wheel and bias ply tires. The bias ply tires are dirt cheap, but the downside is they behave completely different from a 17/18" radial race tire. The sidewalls flex a huge amount, and the tires want a lot of slip angle to work correctly. It dictates a pretty hairy driving style compared to a slick. In our current race group, there is my car, a Panoz, and an ex ASA stock car. I use all Corvette stuff and 17" radials. The Panoz uses custom race pieces and also 17" radials. The ASA car is all 5x5 and 15" bias plys. All of the cars behave differently, but I can tell you the ASA car is the hardest to get the most handling from. If you're used the RX7, going to big bias ply tires will be a whole new learning curve.

I'm sure I forgot a bunch, and I will continue to check back in. I'm really interested to follow your build. By the way, where are you located?

Ken

If you look back through my build log, you will see some pictures and references to a Canadian supercar that did this. I tried contacting them directly with no luck. From what I can tell, they put a large adapter plate between the engine and trans. They used that space to manipulate the shift rod coming out of the front of the trans. It looks like it will add about 4-5 inches over the wheelbase I had. For reference, my wheelbase is right at 118-119" and the front of the engine is actually between the two seats. The only two ways I know to get a shorter wheelbase are to angle the halfshafts which will reduce their life, or put your feet in front of the front axle centerline. That has it's own dangers related to the wheelchair someone else mentioned.

Someone else put together a list of T56 parts that should go together to give you a mid engine capable version, but I have never seen one complete.

Ken

Take a look at this link for more ideas on paddle shifters:

http://www.pro-touring.com/showthread.p ... Technology

I'm pretty sure the TCI box is under $1000.

Ken

Hey Ken, I was a few days away from reaching out to you. Your build and the Corv-am NASA racecar are the two closest builds out there to what I'm planning. A few things have changed. I'm not going "Formula Style" at all. More like a can-am car now. Still single seater, trying to save as much weight as possible. I'm still sold on your style trans setup. The paddle shift sounds like a great system. As long as I cool the trans/diff it should be good. Yes I will not run power steering. I ran no power steering in my RX7 race car with 285 front Michelin slicks and a hunk of LS3 right on top of the rack haha. Arms were tired and buring at the end of a 25 min sprint race but it was ok. With the mid engine setup i'm not even worrying about it. Very good point on the Wide 5 hubs. I'm now looking to get corvette spindles/hubs. I'm having a hard time finding them for some reason. Lots of C4 stuff. I"d like C5 or C6 spindles hubs. I plan on running Michelin or Pirelli slicks only. I've had great experiences with them. I've also decided on Penske doubles or Koni doubles for the coilovers. Any help you can give along the way will be great!

Here is the Nasa racers "Corv-am" that I was talking about. This is basically what I'm building. Chassis is different but same idea. He runs an LS2. From personal experience you cannot run an LS2 or LS3 without dry sumping. They will blow.... Mine blew with 3 track days and 1 race since brand new from the crate. LS6 is the only motor that can live in T1 race cars without a dry-sump. I will be dry sumping it anyway so I can mount the motor a few inches lower.

I found the Corv-Am car a few months ago. I had a few short email exchanges with him about his trans. He is using the 6 speed auto.

As for the engine, I am running a 5.3L with a 3 quart Accusump. I have never had problems with oil pressure, but here's the real irony. The turbo exhaust was leaking a bit and ruined the oil pan gasket. The resulting leak led to low oil pressure and I had to put in a new engine. However, the oil pressure stays constant with the Accusump. I plumbed it directly into the oil galley on the front driver's side with no valves or solenoids. Most people who have problems with the Accusump are using the electronic valve which waits to get a low oil pressure reading before opening. By that time, it's too late. By plumbing it directly in, the system is purely mechanical and the extra 3 quarts is always available. The only downside is that sometimes I forget to close the manual ball valve and the system dumps 3 quarts into the sump on shutdown.

For the Vette spindles, your best bet is to buy new ones. I believe they can be had for about $150 each and come with the new ball joint. Replacing ball joints is a bit tricky because they are pressed into aluminum. The factory uses heat and if you don't use heat when pressing the old one out, the bore isn't absolutely ruined, but it's not good. Of course, if you use too much heat, or have it too localized, you run the risk of changing the material properties of the spindle. I'll see if I can dig up some links to good places to buy, but GMpartsdirect is probably a good place to start. Spend some time on Corvetteforum in the Roadracing section and you will find all the info you want on Vette suspension.

Ken

I hear you on the accusump. On an LS1-LS6 you can get away with an accusump. I guess they changed the oil delivery on the new motors.

Crap! i just bought a set of C5 spindles/hubs on Ebay. I checked out GMpartsdirect.... good site. For some reason they dont sell hubs? strange. Maybe i'm just missing them.

I'm surprised to hear that the LS3 has that problem, bummer! I've been planning around a GMPP crate LS3 with the Corvette pan/windage tray and room for an Accusump.
From a ground clearance standpoint, the Quicktime bellhousing is still the low-point with either dry sump or the Corvette pan. I had hoped to avoid the expense and added complexity of a dry sump.
Any more info on LS3 oil starvation problems (and fixes) would be appreciated.

Wow, you're building in steel already! You move fast

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Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."
Ultima Spyder, Northstar 4.0, Porsche G50/52

Yeah I would follow the SCCA t1 racers on the forums and stuff and the ls2/ls3 has major issues. You can get away with street tire track day work for a while. Once you go to Hooseir A6-R6 or Toyo R888 you might get away with one full season. I havent seen one LS2 or LS3 live for more then 1 season even with an Accusump when driven hard. Slicks.... forget it. The T1 guys can use accusumps and they were still blowing up. I think Ken has a good solution running the oil right into the top. Even though the LS6 is known as being a good motor for starvation, i'm still going to dry sump it. With the slicks i'm going to run and with the super low CG, plus aero.... I doubt even the LS6 will live very long without it.

Here is a thread specifically about the LS3:

http://forums.corvetteforum.com/autocro ... track.html

The root of the problem seems to be lack of oil drain back. On sustained high G corners, the oil gets trapped in the valve covers and heads instead of draining back into the pan. That being said, I have been doing track days for about 7-8 years now, and there are always a lot of Vettes. I have friends with LS1, LS6, LS2, and LS3 engines. I haven't seen any of them blow up. I think if you really dig into the problem, you will see a couple of common things: using fresh slicks; shifting at very high RPM's; actual wheel to wheel racing; and people using Accusumps are using the electric solenoids. I know I can't afford fresh slicks so I am constantly running used R-compounds. That will decrease your grip a lot. With a car as light as mine, I don't feel the need to bounce off the rev limiter. I'm not running wheel to wheel trying to win anything, so I just lowered the rev limited a little bit. The problem definitely exists, but I think some common sense will greatly reduce the chances of it happening to you.

Something else to consider is that you can run any of the LS oil pans you want. Vette guys don't have that option. I am using the Camaro oil pan which I believe is a little deeper than the Vette pan. Look on LS1tech and you will find great information on all the different stock oil pans. Look for one that is deeper and that will help.

As for hubs, they are another one of the weak spots for the Vette. Guys report breaking them during racing. Again, this seems to be with full bodied cars running slicks and possibly bouncing off the curbing. The stock hubs are about $180; look at Rock Auto or even your local auto parts store. SKF makes a heavy duty unit that is about $300.

Ken

Interesting Corvette forum/thread. Lots of good info. Thanks BB69, love your build.

Here's a variety of pans if going wet sump http://nookandtranny.com/Info_LSx.php#LSXOilPan Also several aftermarket pans available. But agreed, dry sump required for serious track time, and aftermarket DS system prefered.

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Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."
Ultima Spyder, Northstar 4.0, Porsche G50/52