t3hw00t Project Impreza MR RWD thread...

i would just put the engine and tranny where they need to drop in, you can shift other things around pretty easily to move the weight bias

 

or make this a setup for weight in the front!!!

 

well the "50/50" that is commonly mentioned is overall, it would be more accurate to have a +/- based from the center of the car, but thats not how they do it.


with that said, i think if you get the powertrain put in where it needs to be (and yeah, as far forward as possible) i think you would have your best starting point. if you have a rear bias at that point, you can move the parts towards the front and center of the car as needed to balance it out.

i think the most interesting part will be getting the suspension correct, i would advise to start reading up on the MR2OC or similar sites that focus on cars that are MR or RR set up. Porsche, MR2s, ect... are going to be the starting point to get strut, spring, and sway rates down initially for a baseline suspension set up. you can adjust those from the baseline and you can effectively overcome any weight bias front to back really IMO.

 

Sweet idea man!

There's a guy on Honda-Tech who did something very similar to what you are talking about. He did a lot of very interesting things to make it all come together, and it's probably the most meticulous builds of this type I've ever seen. Link here. You might get some good ideas from this dude, he really knows what he's doing.

 

I say just put the motor and trans where they fit best, and where it works with the design of your cage. Once you have that all set, you can play with a few things. In all reality, what is left that has a decent amount of mass? Battery and fuel cell?

I don't think (its a hunch) that your weight bias will be that bad. There will still be a fair amount of weight on the front wheels. The driver and passenger(?) will still be in front of the vehicle centerline.

 

I always figured about 7 lb/gal, but thats splitting hairs.

 

even if the engine and tranny isn't hanging out over the rear axle, they won't be in the front anymore. so your CG is going to drastically shift toward the rear.


There's a guy down in georgia that was hardcore into AutoX with his RX and actually calculated weight distribution. it was an EA82 car, but I think they're pretty similar. lighter motor, but the gas tank is further back. IIRC (I'll try to find the thread) it was almost exactly 60/40 to the front.


I bet you'll pretty much flip that. especially with the added weight of the cage back there.


I'd look at putting the fuel cell in the engine compartment....kinda scary concept, but I think it would work.




also, thinking about putting any sort of firewall between the engine and front seats? might get kinda noisy/fumey without some sort of barrier, not to mention that whole safety thing.....you'll already be making some ductwork for the radiator and intercooler (I'm assuming one on each side....). then you could also improve airflow around the motor so it doesn't make the cabin sweltering hot in the summer.




I can't tell you how excited I am by this project. I've wanted to do something like this for years. It's a Lotus Exige....but sexy

If you ever think of selling it. PLEASE let me know. I don't know if I'll ever have the space or equipment to build something like this anytime in the near future.....

 

Dihydrogen Oxide is about 8lbs/gal. According to my boat owner's manual gas is more like 6.5.

 

Weight distribution should also have an effect on your choice of tire width. It you get the weight close to 50/50 and put giant rear wheels on, the thing's just going to understeer all over the place. That's how they get 911's to handle right with all that ass weight. The rear tires are like twice as wide as the front.

 

Off a 99' L wagon AWD 2.2l 5sp, 56% of the weight is on the front wheels. Per the Subaru service manual.

 

You would be correct, but I can't go back far enough to tell you what it is.

 

Wiring a 32-bit ECU to regular 2.0l heads would make it a bit tricker. I'm sure its doable, though. What's the horsepower goal/turbo size for this thing? Can we get away with using a stock ECU? LGT's have that new airbox with the bigger MAF housing.

 

I looked for these trannys on junkyard sites the other day. They were like $1000-$1200 depending on miles.

 

Will any work be done on this bad idea this weekend?

 

I know its been said but you should really look into one of these kits

 

Project RWD had a lot of unneeded weight removed from the front end on Saturday night.

 

When is the next session, I'd be down to swing over after work tomorrow or Wednesday.