Hey all I believe it is time for sub frame connectors soon. I am sure that this has been reiterated many times before probably just about every time someone doesn't know which pair to buy or whenever someone is fabing their own. Now I have done it again I am not looking for overkill but it is a cars and concepts t-top car with the untouched sub frame so I will be fully welding them in and would like to eliminate the flex that I can see at the corner of my t-top. I have just bought my own Lincoln electric pro mig 140 so I would also like to know what your stand point on flux core wire is, I have used both but have not bought a tank for gas yet so would prefer to use the flux core.

Thanks for reading any input is appreciated!

 

Mine are made from 2" x 2" thin walled square tubing. I think the wall thickness is less than .134" which is roughly what the thickness of a roll bar is.

Throw away the flux core wire and get a bottle.

 

what kind of steel is best?

 

Not sure but I would think just regular steal so you can stich it in the whole length on the floor easily. I saw a set for forth gens out of chromoly but they were only tied in at the fron and rear of the car.

 

everyday, run-of-the-mill, mild steel is what most are made of, the other option would be chromoly, but it welding is more crucial and should be made by someone who knows how to weld chromoly.

but, like i said, mild steel will be just fine.

 

stephen what is your 60' time, I may be incorrect but your best time is 9.5xx and your corrected time is 9.1xx wouldn't that make your response time 0.35x seems like a long time is that normal I have only been to the strip once but have never run a car if you could explain the time slip that would be appreciated

 

.35 is a third of a second, not really a long time

 

The corrected time is calculated from a dyno correction formula. I race at altitude. My best time is what's on the time slip. Corrected is what it should theoretically do at sea level. That just goes to show how much HP I lose racing at altitude.

Best 60' so far is 1.404. I may consider a lower stall converter to get a better 60' time.

Mild steel is fine for SFC.

 

Thanks for explaining that guys, hope I didn't offend anyone. How much hp would you estimate you are actually loosing?

 

Approximately 80hp. HP calculations should always be taken from MPH. ET relies too much on traction.

I need to get the car weighed again but last year's race weight was 3065 pounds. It takes 686 HP at the wheels to move that much weight to 142 MPH in the 1/4 mile. Using a dyno correction formula, the engine would be making 768 HP which would move the car to 148 MPH in the 1/4.

It's all theoretical. Sort of like dyno racing. It's a fictitious number only used for reference. Going to a sea level track like Mission BC or Gainsville FL, the density altitude could be higher or lower than sea level depending on the time of the year. The dyno correction numbers are only good when comparing engines from different locations around the country.

Rough estimate using a 15% powertrain loss, my engine produces about 900HP at the crankshaft.

Racing at altitude always has it's challenges. A 12 second car in Denver is a lot faster than a 12 second car in Florida because it needs to produce a lot more HP to run the same ET.

 

Great info Stephen! not to mention that to convert weight, speed, distance to horsepower you would have to assume you had perfect traction although without friction (to be accurate) which is an oxymoron. Still it is all together quite interesting and I'm sure relatively reliable for comparing cars considering we are all combating the same forces.