pmatolcsy wrote:
I agree fully with Horizonjob. Thats why I'm interested in the weight of that 4x4 transfer case trans combo. I think it might be going in the wrong direction weight wise. Even with a v-8 trans-axle combo, the frame can be lighter on a midi for the reasons Horizonjob mentioned. I'm using sketchup . Take the online tutorials . An hour spent there will save you days down the road.
When I said significant , what I really meant was significant enough for me to build a whole second car for. I'm talking about a street driven car for occasional track days, not a single seater. And just like a couple of other Yahoo's on this sight(no disrespect intended, HE doublehockeystick's , I'm one of you), I'm partial to v-8's. The only completed v-8 midi on this sight (BB69s) weighs 2441 sans driver, without much bodywork and no windshield. It uses fairly lightweight aluminium corvette spindles and a-arms and a robust aluminium trans-axle able to handle a v-8s torque. I'm fairly certain that car is extremely robust and will live a long time, and I love it. But I want a lighter car than mine. His car is large. I think the frame material and overall dimensions are what make his car so heavy.And its not streetable
My car has proven to be robust(I am Canadian ,but I plead the fifth, suffice it to say I have beat the *#*! out of it and haven't broken it yet). The windshield washers reqularly relieve themselves on the windshield , and it makes me smile everytime . It weighs 2000lb with full bodywork and a windshield and is fully road worthy. The frame is mostly 1.5"x.063" tube with some 1" as diagonals. The roll cage is 1 5/8" x .125". The wheels and tires are HEAVY, the six-speed trans is huge and heavy ( with the available torque a 4 speed would have been fine). The brakes are probably overkill size wise. And the car is quite a bit larger than it needs to be. I figure if I redesigned the car as a midi I could ditch the t-56, driveshaft and hoops, 8.8 IRS and replace with a Audi diesel 2wd box which could maybe handle the torque but certainly not the abuse ,I could save maybe 100lbs, but I might give up some reliability and it would be expensive by the time I got a working adaptor plate clutch starter and LSD. Reducing the dimensions of the car to 96" WB, making the frame from 1" and the cage from 1.5 x .095 might save me another 100lbs. Reducing the size of the wheels , brakes , spindles from v-8 car size to miata size might save me 100lbs but I might give up traction, and robustness . So I might , If I was very careful,be able to get the weight down to 1700lbs as a small v-8 midlana type midi with a lot of expensive components and potentially reduced reliability. Somebody correct me if I'm wrong.
The Midlana (which I feel is a brilliant design and beautifully built) weighs 1461 without gas , a windshield and several other little bits. So it should end up around 1650 by the time he's done with fuel in it(don't get mad at me Kurt , It's just a guess) . It has a 67% rear weight bias because the engine sits almost directly over the rear wheels. Is that ideal? Will the transaxle live at those power levels ? Will the engine live at those power levels ? Is it locost ? It is compact. And he's definitely using light parts( except for wheels and tires ).
But all 3 of these cars are as aerodynamic as bricks. For me to build another car , It has to be better than the one I already did. And that includes weight ,aero and reliability. I still haven't put on my front fenders because 1) they look awful 2 ) they wreck the aero 3) they break 4) they increase unsprung mass.
Sorry again for the thread hijack
Phil
Phil
I always loved your build. Glad to see another V8 car out and running, and running hard.
I just wanted to throw a few things out there. I think it's been mentioned before, but what is a capable transaxle depends on what you are asking your car to do. My car is for the race track, and the race track only. Every time it's driven, it's driven hard. Harder than anything you can do on the street by a fair amount. I'm putting 100% of the available torque and HP through the transaxle probably 50-60% of the time the car is running. The transaxle has to live through that and it has to be heavy to do it. If you are looking for a everyday driving kind of car, a lighter transaxle will suffice.
I also wanted to make sure everyone knows what's included in my 2441 pounds weight.
-turbocharger from a Duramx diesel; probably weighs 60 pounds
-associated turbo plumbing including two wastegates, intercooler, blow off valve, 6 feet of steel intake tubing
-4 electric cooling fans (coolant, trans, intercooler/trans twin)
-diff cooler and diff pump
-rear wing and steel mount
-3 quart Accusump
-two fuel tanks and two fuel pumps
-oil cooler
All that adds up to probably a couple hundred pounds.
Ken